Journal articles: 'Microhardness'

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Serebryakova, A. A., D. V. Zaguliaev, V. V. Shlyarov, V. E. Gromov, and K. V. Aksenova. "Study of Microhardness and Plasticity Parameter of Lead in External Magnetic Fields with Induction up to 0.5 T." Izvestiya of Altai State University, no. 4(132) (September 14, 2023): 52–58. http://dx.doi.org/10.14258/izvasu(2023)4-07.

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Microhardness tests of samples of technically pure lead are carried out without and with exposure to external magnetic fields with inductions of 0.3 T, 0.4 T, and 0.5 T. The dependences of the C2-grade lead surface microhardnesses on the exposure times in a magnetic field are obtained, thus reflecting the influence of the magnetic field on the plastic characteristics of lead. The exposure time at which the maximum effect on microhardness occurs is revealed. Additional microhardness tests are carried out for cases with magnetic fields with inductions of up to 0.3, 0.4, and 0.5 T and exposure times of 0.25, 0.5, and 1 hour. Following the obtained microhardness data, the plasticity parameters of lead samples in their initial state and after exposure are calculated. The dependences of the plasticity parameters on the exposure times are shown. The behavior of the plasticity parameter of lead samples during their exposure to external magnetic field with induction up to 0.5 T is revealed. The percent changes in the values of microhardness depending on the magnetic field induction are shown.

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Constantinidis, G., R. D. Tomlinson, and H. Neumann. "Microhardness of CuInSe2." Philosophical Magazine Letters 57, no. 2 (February 1988): 91–97. http://dx.doi.org/10.1080/09500838808229616.

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Milosan, Ioan. "Study and Researches about the Microhardness’s Variation of a Special S.G. Cast Iron." Materials Science Forum 638-642 (January 2010): 1233–36. http://dx.doi.org/10.4028/www.scientific.net/msf.638-642.1233.

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The paper presents some aspects about the influence of the heat treatment’s parameters over the microhardness’s variation of a Bainitic S.G. Cast Iron at the end of an wear process. It was determinate the variation of the rapport () between the microhardness ( H) and the distance of the wear surface (l).

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Kazak, Magrur, Safiye Selin Koymen, and Nazmiye Donmez. "Can different polymerization times affect the surface microhardness, water sorption, and water solubility of flowable composite resins?" Bioscience Journal 39 (April 14, 2023): e39073. http://dx.doi.org/10.14393/bj-v39n0a2023-66895.

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This in vitro study evaluated and compared the effects of different polymerization times on the surface microhardness, water sorption, and water solubility of flowable composite resins. Three flowable composite resins [Es Flow (ESF), IGOS Flow (IGF), Estelite Flow Quick (EFQ)] were tested in this study. Each flowable composite resin (n = 7) was polymerized in a disc-shaped mould (1x10 mm) with an LED light-curing unit (D Light Pro) for two different times (20 and 40 sec.). The top surfaces of all specimens were polished (Sof-Lex). The surface microhardnesses of the flowable composite resins were measured with a Vickers HMV microhardness tester. Water sorption and water solubility were calculated according to the ISO 4049 standard. One-way ANOVA and post hoc Tamhane, Dunnett, and Tukey tests were used in the statistical analyses. Pearson’s and Spearman’s rho correlation tests were used to assess possible correlations between the different variables. The results were evaluated with a significance of p<0.05. In terms of microhardness, a significant difference was found between materials at the same polymerization times (p<0.05). All materials showed water sorption of less than 40 µg/mm3 and water solubility of less than 7.5 µg/mm3 by following ISO 4049. The correlations among surface microhardness, water sorption, and water solubility showed that the differences were determined by the materials and the polymerization times. The physical properties of all flowable composite resin materials were enhanced after polymerization for twice the time recommended by the manufacturers.

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Neumann, H. "Microhardness scaling and bulk modulus-microhardness relationship in AIIBIVC2V chalcopyrite compounds." Crystal Research and Technology 23, no. 1 (January 1988): 97–102. http://dx.doi.org/10.1002/crat.2170230113.

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Wang, Su Ping, Xue Gong Bi, and De Ming Weng. "Study on Sinter Microhardness of WISCO." Advanced Materials Research 900 (February 2014): 725–29. http://dx.doi.org/10.4028/www.scientific.net/amr.900.725.

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Microhardness of various minerals in sinter was tested in order to better production of sinter with high microhardness minerals in WISCO. The results showed that the hematite microhardness was highest and the glass phase microhardness was lowest, the various minerals microhardness from highest to lowest was: hematitecalcium ferritemagnetiteglass phase. So the hematite and calcium ferrite should be development, and the glass phase should be inhabited in sinter on production. Minerals microhardness was connected with component elements and crystalline structure of the minerals besides ferrous content of sinter.

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El Gezawi, M., D. Kaisarly, H. Al-Saleh, A. ArRejaie, F. Al-Harbi, and KH Kunzelmann. "Degradation Potential of Bulk Versus Incrementally Applied and Indirect Composites: Color, Microhardness, and Surface Deterioration." Operative Dentistry 41, no. 6 (November 1, 2016): e195-e208. http://dx.doi.org/10.2341/15-195-l.

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SUMMARY This study investigated the color stability and microhardness of five composites exposed to four beverages with different pH values. Composite discs were produced (n=10); Filtek Z250 (3M ESPE) and Filtek P90 (3M ESPE) were applied in two layers (2 mm, 20 seconds), and Tetric N-Ceram Bulk Fill (TetricBF, Ivoclar Vivadent) and SonicFill (Kerr) were applied in bulk (4 mm) and then light cured (40 seconds, Ortholux-LED, 1600 mW/cm2). Indirect composite Sinfony (3M ESPE) was applied in two layers (2 mm) and cured (Visio system, 3M ESPE). The specimens were polished and tested for color stability; ΔE was calculated using spectrophotometer readings. Vickers microhardness (50 g, dwell time=45 seconds) was assessed on the top and bottom surfaces at baseline, 40 days of storage, subsequent repolishing, and 60 days of immersion in distilled water (pH=7.0), Coca-Cola (pH=2.3), orange juice (pH=3.75), or anise (pH=8.5) using scanning electron microscopy (SEM). The materials had similar ΔE values (40 days, p>0.05), but TetricBF had a significantly greater ΔE than P90 or SF (40 days). The ΔE was less for P90 and TetricBF than for Z250, SonicFill, and Sinfony (60 days). Repolishing and further immersion significantly affected the ΔE (p<0.05) except for P90. All composites had significantly different top vs bottom baseline microhardnesses. This was insignificant for the Z250/water, P90/orange juice (40 days), and Sinfony groups (40 and 60 days). Immersion produced variable time-dependent deterioration of microhardness in all groups. Multivariate repeated measures analysis of variance with post hoc Bonferroni tests were used to compare the results. ΔE and microhardness changes were significantly inversely correlated at 40 days, but this relationship was insignificant at 60 days (Pearson test). SEM showed degradation (40 days) that worsened (60 days). Bulk-fill composites differ regarding color-stability and top-to-bottom microhardness changes compared with those of other composites. P90 showed better surface degradation resistance. In conclusion, bulk-fill composites are not promising alternatives to incremental and indirect composites regarding biodegradation.

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Atkarskaya, A. B., S. V. Zaitsev, S. Yu Kabanov, and V. G. Shemanin. "Microhardness of Multilayer Composites." Inorganic Materials: Applied Research 10, no. 4 (July 2019): 884–86. http://dx.doi.org/10.1134/s2075113319040038.

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Zewen, Wang, and Jie Wanqi. "Microhardness of Hg1−xMnxTe." Materials Science and Engineering: A 452-453 (April 2007): 508–11. http://dx.doi.org/10.1016/j.msea.2006.10.079.

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Christodoulou, Periklis, Małgorzata Garbiak, and Bogdan Piekarski. "Materials microhardness “finger prints”." Materials Science and Engineering: A 457, no. 1-2 (May 2007): 350–67. http://dx.doi.org/10.1016/j.msea.2006.12.115.

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11

Lysenko, Vladimir. "Different-Oxides Nanoceramics Microhardness." International Journal of Nanoscience 13, no. 04 (August 2014): 1440003. http://dx.doi.org/10.1142/s0219581x14400031.

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With help of the method of the spark plasma sintering (SPS), the fine-grained (of micron approximately) ceramics based on various alumina nanopowders had created. A comparison of microhardness of ceramic samples obtained from 11 alumina nanopowders and 2 their composites was held. Microhardness of the ceramics obtained both by SPS, and by the traditional method (at successive pressing and sintering) is compared. The dependence of ceramics microhardness on the phase composition of the initial nanopowder and the average size of its particles was investigated. Besides alumina nanopowders ( Al 2 O 3), there were compared microhardness of ceramics from other 10 nanopowders of oxides ( SiO 2, ZnO , Fe 3 O 4, Gd 2 O 3, CuO , WO 3, TiO 2, Y 2 O 3, ZrO 2, MgO ) obtained both by SPS, and by the traditional method. It is obtained that the microhardness of the ceramics created on the method of the spark plasma sintering, is significantly higher than a microhardness of the ceramics obtained by the traditional method; at the SPS method the average size of grain in ceramics decreases (to 1 micron and less).

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Salama, S. N., and H. A. El-Batal. "Microhardness of phosphate glasses." Journal of Non-Crystalline Solids 168, no. 1-2 (February 1994): 179–85. http://dx.doi.org/10.1016/0022-3093(94)90134-1.

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13

Revo, S. L., M. M. Melnichenko, T. G. Avramenko, K. O. Ivanenko, and V. O. Andruschenko. "Microhardness of сompacted thermally expanded graphite." Bulletin of Taras Shevchenko National University of Kyiv. Series: Physics and Mathematics, no. 1 (2019): 170–74. http://dx.doi.org/10.17721/1812-5409.2019/1.40.

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Using the method of continuous microindentation with different loading on the indenter, the microhardness of compacted thermo-expanded graphite (TEG) samples of different dispersion was studied. The analysis of the obtained results showed that, with an increase in the average cross-sectional area of TEG particles from 40 to 120 microns, the microhardness of the samples under investigation also increases. An analysis of the influence of the dispersion and morphology of the TEG particles on the distribution of microhardness on the surface of the compacted samples of TEG was also carried out. The microhardness indicatrix for the samples of the original TEG shows that when the radial displacement from the center of the sample, the microhardness of the material decreases. So in the central part of the discoid sample the values of microhardness lie in the range from 0,04 to 0,025 GPa. In the next concentric region, the microhardness decreases by 30% and gains a value of (0.028 ... 0.014) GPA. When the dispersion of TEG particles changes, the distribution of microhardness also changes. The microhardness indicatrix for a compacted Tg sample with an average particle size of 180 μm shows that the microhardness value at the center of the sample ranges from 0.065 to 0.15 GPa.As you approach the edge of the sample, the microhardness of the material decreases from 0.15 to 0.054 GPa. The study of TEG with an average particle size of 50 μm showed that the indentation in the center and in the middle region of the sample gives an isotropic distribution of microhardness values. The microhardness values coincide in the central and middle regions of the sample and correspond to ≈ 0.1 GPa. The proposed method of research and analysis of microhardness on the surface of compacted specimens of TEG gives an opportunity not only to characterize the micromechanical properties of the investigated material but also to optimize the technological regimes for obtaining samples.

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Gu, Lei, Jing Wang, Xiaoyang Li, and Yanjun Zeng. "Measurement and Analysis of Hydrogen Distribution in Stress Environment Using Vickers Microhardness Technique." Advances in Materials Science and Engineering 2018 (September 27, 2018): 1–8. http://dx.doi.org/10.1155/2018/7857932.

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In this paper, the stress distribution field in front of the crack tip was obtained by loading a modified WOL specimen using a bolt. Considering the relationship between microhardness and hydrogen content or internal stress in the metal, a model based on the change of microhardness increment is proposed to describe the trend of hydrogen concentration distribution in the stress environment. The agreement between theoretical model and experimental results is verified by the Vickers microhardness tester. Based on the model, there is a simple additive relationship between the hydrogen-induced microhardness increment and the stress-induced microhardness increment. Therefore, the microhardness tester can be employed to evaluate the hydrogen distribution in metals quantitatively. The experimental results demonstrated that the Vickers microhardness method has accurately revealed the hydrogen concentration behavior accurately in a known equibiaxial stress environment. The hydrogen distribution of specimens in the stress environment was analyzed by taking the change of the microhardness increment along the crack propagation direction of specimens as the indicator.

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Merza, Apriko, Billy Sujatmiko, and Rinda Yulianti. "Perbandingan kekerasan mikro dentin mahkota setelah aplikasi berbagai bahan bleaching intrakoronal." Majalah Kedokteran Gigi Indonesia 2, no. 3 (December 30, 2016): 128. http://dx.doi.org/10.22146/majkedgiind.11261.

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Comparing microhardness of dentine crown after application of various intracoronal bleaching agents. The aim of this study is to compare microhardness of dentine crown after treatment with intracoronal bleaching agents. The method of this study was an experimental laboratory. Thirty two extracted human mandibular first premolars without caries, sectioned at 2 mm below Cemento-Enamel Junction were divided into four groups and bleaching agents were sealed into the pulp chambers as follows: group A – 45% carbamide peroxide, group B – 35% hydrogen peroxide, group C – sodium perborate mixed aquadest and group D – aquadest. Access cavities were sealed and then stored in aquadest at 37 °C. Bleaching procedures were performed on days 0, 7, 14 and 21. After 28 days, the teeth were sectioned longitudinally, and planted on acrylyc. Microhardness of dentine crown was measured by vickers microhardness tester. One Way ANOVA and LSD were used to evaluate the effect of intracoronal bleaching agents on microhardness of dentine crown. The results showed that average values of microhardness of dentine crown on group A was 45,04 VHN, group B was 45,42 VHN, group C was 55,22 VHN and group D was 55,63 VHN. In clonclusion, there was si gnificantly different microhardness of dentine crown between group 45% carbamide peroxide and 35% hidrogen peroxide with sodium perborate mixed aquadest, but between group 45% carbamide peroxide with 35% hidrogen peroxide there was no significant difference.ABSTRAKTujuan penelitian ini untuk mengetahui perbandingan kekerasan mikro dentin mahkota setelah aplikasi berbagai bahan bleaching intrakoronal. Jenis penelitian ini merupakan penelitian eksperimental laboratoris. Sebanyak 32 gigi premolar pertama mandibula tanpa karies, telah diekstraksi, dipotong 2 mm di bawah cemento-enamel junction dibagi dalam 4 kelompok dan bahan bleaching dimasukkan ke dalam kamar pulpa, yaitu kelompok A – 45% karbamid peroksida, kelompok B -35% hidrogen peroksida, kelompok C - sodium perborat dikombinasikan dengan aquadest, dan kelompok D – aquadest. Akses kavitas ditutup kemudian disimpan di dalam aquadest dengan suhu 37 °C. Prosedur bleaching dilakukan pada hari ke-0, 7, 14 dan 21. Setelah 28 hari, mahkota gigi dipotong secara longitudinal dan salah satu bagian ditanam di akrilik. Nilai kekerasan mikro dentin mahkota diuji menggunakan Vickers microhardnes tester. One way ANOVA dan uji LSD digunakan untuk mengevaluasi pengaruh berbagai bahan bleaching intrakoronal terhadap kekerasan mikro dentin. Hasil penelitian menunjukkan nilai kekerasan mikro dentin mahkota pada kelompok A sebesar 45,04 VHN, kelompok B sebesar 45,42 VHN, kelompok C sebesar 55,22 VHN dan kelompok D sebesar 55,63 VHN. Kesimpulan dari penelitian ini terdapat perbedaan kekerasan mikro dentin mahkota yang signifikan antara kelompok 45% karbamid peroksida dan 35% hidrogen peroksida dengan sodium perborat dikombinasikan dengan aquadest, sedangkan antara kelompok 45% karbamid peroksida dengan 35% hidrogen peroksida tidak terdapat perbedaan yang signifikan.

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Torsakul, Pannaros, Praphasri Rirattanapong, and Woranun Prapansilp. "The remineralization effect of calcium glycerophosphate in fluoride mouth rinse on demineralized primary enamel: An in vitro study." Journal of International Society of Preventive and Community Dentistry 13, no. 5 (2023): 410–15. http://dx.doi.org/10.4103/jispcd.jispcd_114_23.

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Abstract Aim: To evaluate the remineralization effect of a fluoride mouth rinse containing calcium glycerophosphate in fluoride mouth rinse based on the surface microhardness of demineralized primary enamel. Materials and Methods: 40 sound primary incisors were placed into self-curing acrylic resin and subjected to a demineralizing solution for 5 days, resulting in the formation of artificial caries. The teeth were categorized into four groups (n = 10): group I artificial saliva, group II sodium fluoride, group III sodium fluoride + sodium monofluorophosphate, and group IV sodium monofluorophosphate + calcium glycerophosphate. The specimens received a pH cycling procedure and were submerged twice in their assigned groups for 7 days. The baseline, after demineralization, and after remineralization surface microhardness values were determined. One-way analysis of variance (ANOVA) was used to analyze the mean surface microhardness between groups and one-way repeated measures ANOVA for the mean surface microhardness within each group and Bonferroni’s for multiple comparisons at 95% confidence level. The percentage recovery surface microhardness was determined by calculating the average surface microhardness. Results: After demineralization, the mean surface microhardness in all groups significantly decreased. After remineralization, group I had the lowest surface microhardness values and the percentage recovery surface microhardness (P value < 0.001), and group IV had the highest surface microhardness values and the percentage recovery surface microhardness (P value < 0.001). No significant difference was found between groups II and III (P value = 0.365). Conclusions: Fluoride mouth rinse containing calcium glycerophosphate has a remineralization effect on demineralized primary enamel.

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Liu, Shuang Shuang, Yu Jun Xue, Yang Yang Xu, and Ji Shun Li. "Effect of Pulse Electrodeposition Parameters on Microhardness of Ni-ZrO₂-CeO₂ Nanocomposite Coating." Advanced Materials Research 1049-1050 (October 2014): 31–34. http://dx.doi.org/10.4028/www.scientific.net/amr.1049-1050.31.

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Ni-ZrO2-CeO2 nanocomposite coating was prepared by pulse electrodeposition. The effect of addition of ZrO2 and CeO2 nanoparticles, average current density, duty cycle and pulse current on microhardness of Ni-ZrO2-CeO2 nanocomposites were studied. The results show that microhardness of nanocomposite is increased at first and then decreased with the increasing additive amounts of two kinds of nanoparticles. With increasing reverse the average current density, the microhardness of the composite coating increases. Also, the microhardness of nanocomposite fall with the increasing of pulse frequency. With the positive duty ratio increasing, the microhardness of the composite coating increase at first and then decreased, but with the increasing of the reverse duty ratio, the microhardness of nanocomposite coating is gradually decreased.

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Lee, Kunho, Jongsoo Kim, Jisun Shin, and Miran Han. "Comparison of Microhardness and Compressive Strength of Alkasite and Conventional Restorative Materials." JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY 47, no. 3 (August 31, 2020): 320–26. http://dx.doi.org/10.5933/jkapd.2020.47.3.320.

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The aim of this study was to compare compressive strength and microhardness of recently introduced alkasite restorative materials with glass ionomer cement and flowable composite resin.For each material, 20 samples were prepared respectively for compressive strength and Vickers microhardness test. The compressive strength was measured with universal testing machine at crosshead speed of 1 mm/min. And microhardness was measured using Vickers Micro hardness testing machine under 500 g load and 10 seconds dwelling time at 1 hour, 1 day, 7 days, 14 days, 21 days and 35 days.The compressive strength was highest in composite resin, followed by alkasite, and glass ionomer cement. In microhardness test, composite resin, which had no change throughout experimental periods, showed highest microhardness in 1 hour, 1 day, and 7 days measurement. The glass ionomer cement showed increase in microhardness for 7 days and no difference was found with composite resin after 14 days measurement. For alkasite, maximum microhardness was measured on 14 days, but showed gradual decrease.

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Du, Hao, Huang Chen, Byung Kyu Moon, and Jae Heyg Shin. "Influence of Spraying Power and Distance on Porosity and Microhardness of Plasma Sprayed TiO₂ Coatings." Materials Science Forum 486-487 (June 2005): 89–92. http://dx.doi.org/10.4028/www.scientific.net/msf.486-487.89.

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The influence of the two deposition parameters on microstructure, and microhardness of plasma sprayed TiO2 coatings were investigated. It was found that a higher spraying power and a shorter distance resulted in a lower porosity and a higher microhardness for the coatings. The anisotropy on the microstructure and microhardness of TiO2 coatings was also found. The denser microstructure is attributed to the higher degree of melting and higher velocity of the TiO2 powders during spraying. The improvement of microhardness is associated with the lower porosity. The difference of porosity and microhardness between surface and cross section resulted from their different microstructures.

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Al-Saud, Loulwa M., Lina M. Alolyet, and Dhayah S. Alenezi. "The Effects of Selected Mouthwashes on the Surface Microhardness of a Single-shade Universal Resin Composite: In Vitro Study." Journal of Advanced Oral Research 13, no. 2 (October 18, 2022): 234–44. http://dx.doi.org/10.1177/23202068221129020.

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Aim: To investigate the effects of selected alcohol-free mouthwashes with different formulations (zinc-hydroxyapatite, hydrogen peroxide, and sodium fluoride) on the surface microhardness of a single-shade universal resin composite. Materials and Methods: Forty disc-shaped specimens (8 × 2 mm) from the universal resin composite (Omnichroma®), and a nano-hybrid composite (Tetric® N-Ceram) were prepared. After polymerization, baseline surface microhardness values were recorded using Vickers microhardness tester. The samples from each material were randomly assigned to 4 groups ( n = 10) and immersed in 20 ml of the mouthwashes: Biorepair®, Listerine®, Colgate® Optic White, and distilled water (control). The samples were kept in the immersion solutions for 24 hours, and post-immersion microhardness values were recorded. Data were analyzed with one-way ANOVA and paired sample t-tests at p < .05. Results: Significant reduction in microhardness was observed in all resin composite groups after immersion in the mouthwashes compared to baseline values ( p < .0001). The highest microhardness reduction in Omnichroma® group was observed after immersion in Colgate® Optic White; and Tetric® N-Ceram group after immersion in Listerine® mouthwash. For both materials, the least reduction in microhardness was observed after immersion in Biorepair®. Microhardness values for Omnichroma were significantly higher than Tetric® N-Ceram ( p < .0001). However, Omnichroma exhibited a significantly greater reduction in microhardness after immersion in the tested mouthwashes. Conclusion: In vitro simulated use of the investigated mouthwashes negatively affected the surface microhardness of both tested resin composites. The observed effects were both mouthwash and material dependent.

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Astanin, V. V., D. V. Gunderov, and V. V. Titov. "Microhardness distribution over the surface of Zr-based metallic glass exposed to high-pressure torsion." Frontier materials & technologies, no. 3 (2022): 33–40. http://dx.doi.org/10.18323/2782-4039-2022-3-1-33-40.

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Identifying the peculiarities of the transformation of the structure and properties of bulk metallic glass (BMG) under high-pressure torsion (HPT) is of great interest. It is known that under HPT, the degree of deformation differs from the center to the edge of a disk which leads to the non-uniformity of the structure of obtained specimens. The change in microhardness value indicates the direction of change in BMG structure under the HPT, and the microhardness distribution indicates the HPT-specimen non-uniformity. The aim of the study is to identify the HPT influence on the microhardness value and microhardness distribution over the surface of specimens of amorphous alloys using an example of Vit105Zr-based BMG (Zr52.5Cu17.9Ni14.6Al10Ti5). The authors studied the distribution of microhardness over the surface of Vit105 Zr-based bulk metallic glass (BMG) in the initial state, in the state after HPT at n=1 and n=5 rotations, and after relaxing annealing. The study shows that the initial Vit105 BMG is characterized by a small spread in microhardness values, which indicates the material's high homogeneity. By reducing the excessive free volume, relaxing annealing increases microhardness without a significant increase in the spread of its values. HPT leads to a decrease in the zirconium BMG microhardness, which indicates an increase in the excessive free volume, but, at the same time, increases the uneven microhardness distribution over the specimen, while the microhardness values in one half of the HPT sample (n=1) are higher than in the other one. It demonstrates that BMG specimen deformation during HPT is related to the specific loading mechanisms.

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Araújo, Fernanda Santos, Wilton Mitsunari Takeshita, Regiane Cristina do Amaral, and Adriano Augusto Melo de Mendonça. "Assessment of bulk-fill of resins microhardness longitudinal." Brazilian Journal of Oral Sciences 23 (May 2, 2024): e240398. http://dx.doi.org/10.20396/bjos.v23i00.8670398.

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Aim: This study aimed to assess the polymerization effectiveness of bulk-fill composite resins in longitudinal microhardness. Methods: Blocks of bulk-fill composite resin with thicknesses of 6 mm were analyzed with Vickers microhardness. The resin blocks were divided into two groups (n=6): resin AURA and OPUS. The microhardness test was performed before (base and top) and after (longitudinal microhardness) sectioning the blocks at distances of 2 mm, 4 mm, and 6 mm from the top of the block. The mean microhardness values were tabulated and subjected to ANOVA followed by Tukey’s test (p<0.05). Results: The OPUS bulk-fill resin samples presented microhardness means of 55.9 kgf/mm2, 53.7 kgf/mm2, and 49.3 kgf/mm2, the AURA bulk-fill resin samples presented microhardness means of 57,02 kgf/mm2, 55,86 kgf/mm2 e 51,77 kgf/mm2 for the distances of 2 mm, 4 mm, and 6 mm, respectively. Tukey’s statistical test showed a significant difference in microhardness values at different distances of 2 mm, 4 mm, and 6 mm (p<0.001) for each resin. Although there was a statistically significant difference within and between the groups assessed, all samples showed polymerization effectiveness when comparing the top and base of the block. Conclusion: Polymerization was effective in different thicknesses (2 mm, 4 mm, and 6 mm) in both resins studied. The microhardness ratio was adequate when comparing the base and top.

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Yaqubov, Nağı, Aytәn Sultanova, and İmir Әliyev. "Ga-SrSe SİSTEMİNDӘ KİMYӘVİ QARŞILIQLI TӘSİRİN TӘDQİQİ." Elmi Əsərlər, no. 2 (2023): 78–82. http://dx.doi.org/10.61413/pfhg7389.

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Using methods of physicochemical analysis: differential thermal analysis (DTA), X-ray phase analysis (XPA), microstructural analysis (MSA), as well as determination of microhardness and density, the chemical interaction in the Ga-SrSe system was studied and a T-x phase diagram was constructed. It has been established that the Ga-SrSe system is quasi-binary and degenerate of the eutectic type. It has been established that at room temperature in the system Ga-SrSe a solid solution based on SrSe up to 5 mol % Ga. One of the methods for physicochemical analysis of semiconductor compounds is to determine their microhardness depending on the composition. In the Ga-SrSe system, two different microhardness values are defined. One of them is the microhardness of SrSe (1240-1250) MPa, the value of which corresponds to the microhardness of an α-solid solution based on the SrSe compound, and the microhardness value (700- 730) MPa corresponds to the microhardness of gallium.. The densities obtained in the system increase monotonically depending on the composition.

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Yang, Jian Ming, and Di Zhu. "Experimental Study of Mechanical Properties of Electroformed Nanocrystalline Ni-Mn Alloys." Key Engineering Materials 375-376 (March 2008): 148–52. http://dx.doi.org/10.4028/www.scientific.net/kem.375-376.148.

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In this paper, the measurements of microhardness and tensile properties are performed to the electroformed Ni-Mn alloys which the mean grain size is near to or less than 100nm. It is studied that the effect of average deposition current density on microhardness and tensile properties of the alloys and the effect of post-electroforming annealing on microhardness of the alloys. The results show that with the increment of average current density, microhardness and strength of the alloys increase and elongation decreases because of the increment of Mn content and the decrement of grain size of the alloys. Microhardness of the alloys are slightly improved after annealing.

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Vasiliu, Roxana-Diana, Sorin-Daniel Porojan, Mihaela-Ionela Bîrdeanu, Ion-Dragoș Uțu, and Liliana Porojan. "The Effect of Thermocycling and Surface Treatments on the Surface Roughness and Microhardness of Three Heat-Pressed Ceramics Systems." Crystals 10, no. 3 (March 1, 2020): 160. http://dx.doi.org/10.3390/cryst10030160.

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Dental ceramic restorations are widely used in restorative dentistry. However, these restorations can be affected once cemented in the oral cavity by several factors. How can conventional surface treatments, such as glazing and mechanical polishing, diminish the effects of aging? The purpose of this in vitro study was to evaluate the effect of thermocycling and conventional surface treatments on the surface roughness and microhardness of three types of glass-ceramics by using a profilometer, scanning electron microscopy (SEM), atomic force microscopy (AFM), and a microhardness tester. Three types of ceramic systems (zirconia reinforced lithium silicate glass-ceramic, lithium disilicate glass-ceramic, and feldspathic glass-ceramic) (n = 48) were prepared. The samples were subjected to thermocycling for 10,000 cycles. Surface roughness was evaluated numerically using a profilometer and visually by using SEM and AFM. Microhardness was performed using a microhardness tester. The data were interpreted using the ANOVA test, and the results were correlated using Pearson’s correlation formula (r). Significant differences were found before and after thermocycling for the Ra (p < 0.01) and Rz (p < 0.05) parameters. As well, differences between glazed and polished surfaces were significant before and after thermocycling for surface roughness and microhardness (p < 0.05). A correlation was made between average surface roughness and microhardness (r = −460) and for the maximum surface roughness and microhardness (r = −606). Aging increases the roughness and decreases in time the microhardness. The tested ceramic systems behaved differently to the aging and surface treatments. Surface treatments had a significant impact on the microhardness and surface characteristics. The glazed groups were reported with higher surface roughness and lower microhardness when compared to the polished groups before and after thermocycling. The measuring roughness techniques determine the scale-dependent values for the Ra (Sa) and Rz (Sq) parameters. Thermocycling almost doubled the surface roughness for all the tested samples. Microhardness decreased only for the Celtra glazed samples. Nano-roughness increased the values for Vita and slightly for Emax. Thermocycling had little effect on Emax ceramic and a more significant impact on Celtra Press ceramic.

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Oliveira, Marcia Regina Cabral, Pedro Henrique Cabral Oliveira, Luiz Henrique Cabral Oliveira, Ravana Angelini Sfalcin, Renato Araujo Prates, Ricardo Scarparo Navarro, Paulo Francisco Cesar, et al. "Influence of Ultrapulsed CO2 Laser, before Application of Different Types of Fluoride, on the Increase of Microhardness of Enamel In Vitro." BioMed Research International 2018 (August 6, 2018): 1–7. http://dx.doi.org/10.1155/2018/5852948.

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Objective. To evaluate the influence of ultrapulsed CO2 laser in combination with commercial fluoride products in order to verify the increase of microhardness of artificial enamel caries lesions. Materials and Methods. Bovine enamel specimens were prepared, and artificial enamel caries lesions were created. Teeth were randomly divided into 5 groups (n=10): treated with laser (L), laser + neutral fluoride gel 2% (LNF), laser + acidulated phosphate fluoride gel 1.23% (LAFG), laser + acidulated fluoride mousse 1.23% (LAFM), and laser + fluoride varnish 5% (LFV). Microhardness was evaluated at baseline, after caries induction, after CO2 laser irradiation + fluoride treatment in the 1st week, and after fluoride treatment at 3rd and 5th week. Results. There was a decrease in microhardness in all groups after artificial enamel caries lesion formation; no increase in microhardness was found in the first and third weeks in all groups (p > 0.05). In the fifth week, an increase in microhardness occurred in all groups (p < 0.05). Conclusion. Although CO2 laser irradiation in combination with different commercial fluoride products was capable of increasing microhardness on enamel caries lesions in bovine tooth enamel it is necessary to confirm these results by testing the isolated effect of fluoride on enamel surface microhardness. Also, although microhardness was higher in the fluoride varnish group than in the other groups in the fifth week it is not possible to discard the best effect of fluoride varnish treatment on absence of artifacts that may occur with the other fluoride treatments. Clinical Relevance. In order to prove that CO2 laser may contribute to an increase in microhardness when applied to enamel lesions in combination with different commercial fluoride products it is necessary to conduct additional studies. Also, higher microhardness of fluoride varnish group should be carefully considered.

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Shorinov, O., A. Dolmatov, K. Balushok, and S. Polyviany. "PREDICTION OF MICROHARDNESS OF ASD-1 POWDER COLD SPRAYING COATINGS." New Materials and Technologies in Metallurgy and Mechanical Engineering, no. 3 (October 8, 2023): 14–21. http://dx.doi.org/10.15588/1607-6885-2023-3-2.

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Purpose. To develop a mathematical model for describing the dependence of the microhardness of ASD-1 aluminum powder coatings on the three main factors of the cold gas-dynamic spraying process using statistical methods of experiment planning. Research methods. Methods of statistical planning of multifactorial experiments and regression analysis were used to conduct experimental research. The analysis of microhardness was performed according to the standard methodology given in GOST 9450-76. Preparation of transverse microsections for microhardness studies was carried out according to standard methods for preparing samples for metallographic analysis of microstructure. The specialized computer program Stat-Ease 360 was used to process statistical data. Results. The complex effect of cold gas spraying process parameters on the microhardness of ASD-1 powder coatings in a wide range of values was investigated. According to the results of experimental studies, it was established that in the investigated ranges of the deposition modes, it is possible to obtain microhardness of coatings in range from 49 to 66 HV0.15. The dispertion analysis results showed that the gas temperature and the stand-off distance have the greatest effect on the microhardness of the coatings, while the powder feed rate has no significant effect on the microhardness. The obtained regression equation can be used to predict the microhardness of coatings from the ASD-1 powder, and the error between the calculated and actual values does not exceed 5%. Scientific novelty. Empirical dependences of the microhardness of ASD-1 powder coatings, deposited by cold spraying, on the gas temperature at the nozzle inlet, stand-off distance, and powder feed rate in the specified ranges of values were obtained. Practical value. The obtained dependences of the coating microhardness on the process parameters can be used to select modes of cold spraying of protective and restorative coatings, in particular on aircraft engine parts.

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Dasani, Sarita, Baljeet S. Hora, Rucheeta S. Ajmera, Brijesh Gupta, Yadnesh Dondulkar, and Suparna Kosta. "The effect of 5% NaOCl and 17% EDTA, at 24hrs and 8days, on the microhardness of MTA, Biodentine and Pozzolan cement: An in- vitro study." UNIVERSITY JOURNAL OF DENTAL SCIENCES 6, no. 3 (January 12, 2021): 16–21. http://dx.doi.org/10.21276/ujds.2020.6.3.5.

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Aim & Objectives: The aim of this study was to evaluate the effects, at 24 h and 8 days, of 5% NaOCl and 17% EDTA on the Vicker’s microhardness of Mineral Trioxide Aggregate(MTA Angelus) (MTAA), Biodentine(Septodont, Saint Maur des Fosse’s France) and Pozzolan based endodontic cement named Endocem MTA(Maruchi, Wonju, Korea). Materials and method: Sixty samples of MTAA, Biodentine and Endocem MTA were tested for baseline microhardness at 24 h. They were divided into 12 subgroups (5% NaOCl or 17% EDTA, 24 h and 5% NaOCl or 17% EDTA at 8 days) and microhardness was evaluated at different time points. Results were recorded and analysed statistically via one-way ANOVA and Tukey’s post hoc test. Results: MTAA had a higher baseline microhardness than both biodentine and Endocem MTA. At 24 hrs, the microhardness of all the materials was reduced by NaOCl and EDTA. At 8 days, NaOCl reduced the microhardness of MTA but that of Biodentine and Endocem MTA was increased. EDTA at 8 days, reduced the microhardness of both MTAA and Biodentine but an increase was seen with Endocem MTA. Conclusion: Changes in microhardness of MTAA, Biodentine and Pozzolan cement(Endocem MTA) were associated with the time for which the materials are allowed to set as well as the irrigating agent used,.

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Yu, Li Ping, Han Ning Xiao, and Yin Cheng. "Microhardness and Machinability of Fluorphlogopite-Mullite Glass-Ceramics." Key Engineering Materials 353-358 (September 2007): 1576–79. http://dx.doi.org/10.4028/www.scientific.net/kem.353-358.1576.

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Effects of mullite on the structure, microhardness and machinability of fluorphlogopitemullite glass-ceramics were investigated by X-ray diffractometry (XRD), differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and microhardness tester. Results show that the microhardness and machinability are related closely to its microstructure. The microhardness decreases remarkably with the increase of crystallization and the formation of interlocking structure. The addition of mullite can decrease the size of mica crystals, which results in the spoil of interlocking structure. The microhardness of the glass-ceramics is slightly increased and then decreased with the addition of mullite. When the content of mullite is 15wt%, the glass-ceramics shows good machinability after reheated at 1200°C for 2h.

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Yusuf, Muhammad, M. K. A. M. Ariffin, N. Ismail, and S. Sulaiman. "Effect of Machining Process on Surface Microhardness of Titanium Carbide Reinforced Aluminium LM6 Composite." Applied Mechanics and Materials 564 (June 2014): 495–500. http://dx.doi.org/10.4028/www.scientific.net/amm.564.495.

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Due to the fact that material is being removed from the bulk material, all machining operations have some impact on the resulting surface integrity of the machined components. This paper presents an investigation on surface microhardness on machining of TiC reinforced aluminium LM6 alloy composite using uncoated carbide tool under dry cutting condition. The experiments that were carried out consisted of different cutting parameters based on combination of cutting speed, feed and depth of cut as the parameters of cutting process. The microhardness of machined surface at a range of cutting speed, feed and depth of cut were measured. The results show that the microhardness was generally found to be higher near the machined surface layer than the hardness of the matrix in the bulk material during machining for all cutting condition. Microhardness increases beyond the bulk hardness of material occurred 50 μm below machined surface, and then microhardness starts to decrease and reaches the bulk hardness. The microhardness values increases with increased the feed and depth of cut. The highest microhardness recorded was 68 HV0.5when machining at a lower cutting speed of 100 m min-1, feed of 0.2 mm rev-1and depth of cut of 1.0 mm.

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Naeem, Meshal Muhammad, Huma Sarwar, Aliza Nisar, Shahbaz Ahmed, Juzer Shabbir, Zohaib Khurshid, and Paulo J. Palma. "Effect of Propolis on Root Dentine Microhardness When Used as an Intracanal Medicament: An In Vitro Study." Journal of Functional Biomaterials 14, no. 3 (March 3, 2023): 144. http://dx.doi.org/10.3390/jfb14030144.

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Application of intracanal medicaments may affect the physical properties of root dentine. Calcium hydroxide (CH), a gold standard intracanal medicament, has proven to decrease root dentine microhardness. A natural extract, propolis, has been shown to be superior to CH in eradicating endodontic microbes, but its effect on the microhardness of root dentine is still not known. This investigation aims to evaluate the effect of propolis on root dentine microhardness compared to calcium hydroxide. Ninety root discs were randomly divided into three groups and treated with CH, propolis, and a control. A Vickers hardness indentation machine with a load of 200 g and dwell time of 15 s at 24 h, 3, and 7 days was used for microhardness testing. ANOVA and Tukey’s post hoc test were used for statistical analysis. A progressive decrease in microhardness values was observed in CH (p < 0.01), whereas a progressive increase was observed in the propolis group (p < 0.01). At 7 days, propolis demonstrated the highest microhardness value (64.43 ± 1.69), whereas CH demonstrated the lowest value (48.46 ± 1.60). The root dentine microhardness increased over time when propolis was applied, while it decreased over time after application of CH on root dentine sections.

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Woźny, Piotr, and Józef Błachnio. "The impact of microstructural non-conformities on microhardness of EN AW 5754 aluminium alloy welded joints made with the use of the TIG method." Journal of KONBiN 48, no. 1 (December 1, 2018): 253–62. http://dx.doi.org/10.2478/jok-2018-0055.

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Abstract The article presents the impact of welding non-conformities on microhardness of EN AW 5754 aluminium alloy welded joints made with the use of the TIG method. The results of microhardness tests of welded samples made with various process parameters. The impact of the welding non-conformities disclosed with the use of a tomographic method on the welded joint microhardness were analysed. The studies showed a strong link between the participation of welding non-conformities, welding process parameters and microhardness of welds.

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Gao, Wei, and Cong Chen. "Analysis on Microstructure and Properties of Plasma Welding Joint with Surfaced Cobalt - Based Alloy Layer." Advanced Materials Research 154-155 (October 2010): 480–84. http://dx.doi.org/10.4028/www.scientific.net/amr.154-155.480.

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The microstructure and microhardness of plasma welding (PAW) joint with surfacing welded cobalt-based alloy have been investigated by using Optical microscope (OP) ,X-ray, scanning electron microscope (SEM),and microhardness testing. The results show that the surfacing layer microstructure is made up of the dendrite (γ-Co) and eutectic (γ-Co+M7C3). The microhardness decreases from surfacing layer to substrate. The highest hardness on the surfacing layer obtains with 550HV up. The fusion zone’s and substrate’s microhardness is about 380HVand 280HV respectively.

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Bilanych, V. S., K. V. Skubenych, M. I. Babilya, A. I. Pogodin, and I. P. Studenyak. "The Effect of Isovalent Cation Substitution on Mechanical Properties of (CuxAg1–x)7SiS5I Superionic Mixed Single Crystals." Ukrainian Journal of Physics 65, no. 5 (May 11, 2020): 453. http://dx.doi.org/10.15407/ujpe65.5.453.

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(CuxAg1−x)7SiS5I mixed crystals were grown by the Bridgman–Stockbarger method. The microhardness measurements are carried out at room temperature using a Vickers indenter. The compositional dependence of the microhardness is studied. The dependence of the microhardness on the depth of imprint is analyzed in the model of geometrically necessary dislocations. The indentation size effect is observed. It is established that the microhardness of (CuxAg1−x)7SiS5I mixed crystals decreases at the substitution of Cu atoms by Ag atoms.

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Zhang, Xiao Meng, Li Bin Niu, Xiao Cui Wei, Xiao Gang Wang, and Xiao Hu Hua. "Preparation and Properties of Electroless Ni-P-β-SiC Composition Coating." Materials Science Forum 809-810 (December 2014): 621–26. http://dx.doi.org/10.4028/www.scientific.net/msf.809-810.621.

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Through orthogonal test of Ni-P chemical plating process optimization to determine the optimum process recipe, the Ni-P-β-SiC composite coating were prepared by chemical plating method. The deposition rate, microhardness, composition and organization of Ni-P-β-SiC composite coating are observed and analyzed by scanning electron microscopy (SEM), vivtorinox microhardness tester, X ray diffraction (XRD) and energy spectrum analysis (EDS). The influences of β-SiC particle concentration in bath on the solution of composite coating deposition rate and microhardness. The results show that the influence of composite coating deposition rate and microhardness are NiSO4•6H2O, NaH2PO2•H2O, C3H6O3, and PH. The optimum process conditions: NiSO4•6H2O 25 g/L, NaH2PO2•H2O 27 g/L, C3H6O327 ml/L, PH 5.2. It was found that the Ni-P-β-SiC composite coating with 5g/Lβ-SiC particles exhibited a maximum deposition rate and microhardness, the deposition rate of composite coating is 12.32μm/h, microhardness is 567.93HV0.05.

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Malara, P., Z. Czech, and W. Świderski. "Influence of the Light Source and Curing Parameters on Microhardness of a Silorane-Based Dental Composite Material." Archives of Metallurgy and Materials 61, no. 3 (September 1, 2016): 1331–36. http://dx.doi.org/10.1515/amm-2016-0219.

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Abstract The aim of the study was to determine the influence of the light source and the light-curing parameters (the distance of the material from the light source and time of light-curing) on microhardness of Flitek Silorane dental composite material. Standardized samples of Filtek Silorane material were cured using two types of Light Curing Units (LCUs) – halogen and LED. The distance of the light source and time of curing differed between samples. The Knoop’s microhardness was tested using microhardness tester Micromet 5103. Using LED light curing unit allowed to achieve significantly higher microhardness of silorane-based dental material Filtek Silorane than using halogen light curing unit. Decreasing the distance from the light source to the surface of silorane-based material Filtek Silorane improved its microhardness. A prolonged curing time could compensate the drop in microhardness of Filtek Silorane material resulting from an increased distance from the light source to the surface of the material only in a limited range of intervals.

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Duan, Chun Zheng, Min Jie Wang, and Tao Dou. "Microscopic Examination of Primary Shear Zone in High Speed Machining of Hardened High Strength Steel." Advanced Materials Research 97-101 (March 2010): 1887–90. http://dx.doi.org/10.4028/www.scientific.net/amr.97-101.1887.

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The microstructure observation and microhardness measurement were performed on the adiabatic shear bands in primary shear zone in the serrated chips formed during high speed machining of two tempering hardness of hardened high strength steel under different cutting speeds by optical microscope, SEM, TEM and microhardness tester. The investigation results show that two types of adiabatic shear bands are formed as cutting speed increases. One is deformed band with heavy elongated microstructures generated under lower cutting speed, another is transformed band with fine grains under higher cutting speed. The increase of the cutting speed little influences on the microhardness in the transformed bands, and the microhardness in deformed band results from strain hardening, whereas transformation hardening leads to very high microhardness in transformed band.

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Valizadeh, Sara, Arezu Mirzaei, Nasim Chiniforush, and Zohreh Moradi. "Effect of conventional and power office bleaching with diode laser and led light on enamel microhardness." Brazilian Journal of Oral Sciences 21 (August 25, 2022): e226630. http://dx.doi.org/10.20396/bjos.v21i00.8666630.

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Aim: The present study aimed to asses enamel microhardness after office bleaching with diode laser and LED light compared to the conventional bleaching procedure. Methods: Thirty-nine human premolar teeth were collected and randomly divided into three groups regarding of the bleaching technique. Group 1: Snow O bleaching gel with LED light-curing unit; Group 2: Snow L bleaching gel with diode laser irradiation; and Group 3: Opalescence Boost bleaching gel with no light source in group 3. Enamel surface changes were evaluated in one tooth in each study group and one intact tooth as a reference under a scanning electron microscope (SEM). In the remaining samples (n=12), enamel microhardness was determined by Vickers microhardness test before and after bleaching. Data were analyzed with repeated-measures ANOVA to compare microhardness changes, followed by post hoc Tukey tests at the 0.05 significance level. Results: Enamel microhardness decreased in all the groups after bleaching, with the maximum decrease in microhardness in the Snow O bleaching group with LED light, which was significantly higher than the other groups (P=0.002). The two other groups did not exhibit any significant difference in microhardness decrease (P>0.05). Conclusion: Based on the limitations of this study, it can be concluded power bleaching with 980nm diode laser was less time-consuming compare to conventional bleaching procedure and yielded better outcomes in terms of enamel surface microhardness compared to the use of an LED light-curing unit.

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Shivanna, Vasundhara, and Rucha Nilegaonkar. "Effect of alcohol containing and alcohol free mouth rinses on microhardness of three esthetic restorative materials." CODS Journal of Dentistry 6, no. 1 (2014): 5–8. http://dx.doi.org/10.5005/cods-6-1-5.

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Abstract Introduction Daily application of mouth rinses has been recommended for the prevention and control of caries and periodontal disease. Aims & Objectives The aim of this study was to evaluate the effect of alcohol-containing and alcohol-free mouth rinses on the microhardness of three restorative materials – resin composite (Filtek Z350XT), light cure glass ionomer cement (Vitremer) and conventional restorative glass ionomer cement (GC Fuji II). Methods Twenty samples of each restorative material were fabricated and their microhardness values were checked at 100g load and 15 seconds dwell time. Ten samples of each restorative material were stored in alcohol containing mouth rinse (Listerine) and ten samples each were stored in alcohol free mouth rinse (Hiora) for 12 hours. At the end of the test period microhardness was measured with a Vickers microhardness tester. Results Alcohol containing mouth rinses reduced the microhardness values of composite and light cure glass ionomer significantly more than alcohol free mouth rinses. Reduction in the microhardness value of conventional restorative glass ionomer cement was similar for both alcohol containing and alcohol free mouth rinses. Conclusion Both mouth rinses showed reduction in microhardness values of all three restorative materials, with more reduction caused due to alcohol containing mouth rinses in composite and light cure glass ionomer. How to cite this article Vasundhara S, Rucha N. Effect of alcohol containing and alcohol free mouth rinses on microhardness of three esthetic restorative materials. CODS J Dent 2014;6;5-8

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Alfahed, Bashayer, and Abdullah Alayad. "The Effect of Sintering Temperature on Vickers Microhardness and Flexural Strength of Translucent Multi-Layered Zirconia Dental Materials." Coatings 13, no. 4 (March 28, 2023): 688. http://dx.doi.org/10.3390/coatings13040688.

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This study evaluated the effects of the sintering temperature on Vickers microhardness and three-point flexural strength values of two multi-layered zirconia materials. Multi-layered zirconia systems with four distinct layers were selected: DD cube ONE ML (4Y-TZP) and DD cubeX2 ML (5Y-TZP). In total, 96 plate-shaped A2-shade specimens were obtained using individual layers of these two zirconia materials. The individual layers were then divided equally into batches with three different sintering temperatures (1300, 1450, and 1600 °C), and the Vickers microhardness was assessed. Another group of 72 bar-shaped specimens was prepared from the same materials. These were similarly divided into three different sintering temperatures, and the flexural strength was assessed. SEM was used to conduct fractographic analyses. The data were analyzed using SPSS 24.0 software with a p-value < 0.05. The microhardness and flexural strength of 4Y-TZP were higher than those of the 5Y-TZP at all the sintering temperatures. A significant difference was found in the microhardness and flexural strength values between groups sintered at different sintering temperatures (p < 0.05). The highest microhardness and flexural strength values were found at 1450 °C (p < 0.05). The microhardness values of different layers were not significantly different (p > 0.05). The sintering temperature and type of ceramic material significantly affected the microhardness and flexural strength. However, the layers did not significantly affect the microhardness.

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Mason, W., P. F. Johnson, and J. R. Varner. "Data from recording microhardness testers." Journal of Materials Research 7, no. 11 (November 1992): 3112–19. http://dx.doi.org/10.1557/jmr.1992.3112.

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An apparatus was constructed that measured hardness under load. The instrument measured hardness using a strain-gauge load cell and a linear voltage displacement transducer. Loading rates were less than 1 μm/s. Results were similar to the results of other electronic hardness measurement devices, in that the hardness fell with increasing load. Glasses measured have Meyers indexes from 1.6 to 1.75, while polycrystalline materials showed much more complex behaviors. A model was formulated to explain the data for glasses based on expansion of shear planes.

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Tamaki, Regina, Carolina Mayumi Iegami, Priscila Nakasone Uehara, Ricardo Jun Furuyama, and Rafael Yague Ballester. "Transverse microhardness of artificial teeth." Clinical and Laboratorial Research in Dentistry 21, no. 4 (December 31, 2015): 204. http://dx.doi.org/10.11606/issn.2357-8041.clrd.2015.122750.

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Objective: Hardness is an indicator of several mechanical properties of artificial teeth, also related to wear resistance. The purpose of this article is to map the microhardness of artificial teeth as a function of depth and commercial brand. Methods: Knoop microhardness of sectioned artificial second molars was measured every 200 µm starting at a depth of 100 µm up until 4700 µm of the following brands: Premium (Pr), Orthosit (Or), SR Postaris DCL (Po), Biotone (Bi), Artiplus IPN (Ar), VITA MFT (Vi), Natusdent (Na), Trilux (Tr), and Biolux (Bx). Results were analyzed with ANOVA for repeated measures and Tukey test (5%). Results: SR Orthosit PE commercial brand presented higher hardness values (until the depth of 3.1 mm was 30 N/mm2), significantly higher than the other brands analyzed. Conclusion: Knoop hardness did not present differences between layers for eight of the nine brands studied. Different hardness values were found between superficial and cervical areas for the brand SR Orthosit PE.

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Pajares, A., F. Guiberteau, A. Dominguez-Rodriguez, and A. H. Heuer. "Microhardness anisotropy in cubic Zro2." Revue de Physique Appliquée 23, no. 4 (1988): 719. http://dx.doi.org/10.1051/rphysap:01988002304071900.

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Riches, P. E., N. M. Everitt, A. R. Heggie, and D. S. McNally. "Microhardness anisotropy of lamellar bone." Journal of Biomechanics 30, no. 10 (October 1997): 1059–61. http://dx.doi.org/10.1016/s0021-9290(97)00075-4.

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Igarashi, S., A. Bentur, and S. Mindess. "Microhardness testing of cementitious materials." Advanced Cement Based Materials 4, no. 2 (September 1996): 48–57. http://dx.doi.org/10.1016/s1065-7355(96)90051-6.

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Horner, John D. "Jack." "Microhardness testing of plated coatings." Metal Finishing 98, no. 1 (January 2000): 611–15. http://dx.doi.org/10.1016/s0026-0576(00)80369-4.

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Horner, John D. Jack. "Microhardness testing of plated coatings." Metal Finishing 97, no. 1 (January 1999): 611–15. http://dx.doi.org/10.1016/s0026-0576(00)83120-7.

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Horner, John D. “Jack.” "Microhardness testing of plated coatings." Metal Finishing 105, no. 10 (2007): 531–35. http://dx.doi.org/10.1016/s0026-0576(07)80371-0.

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Horner, John D. “Jack.” "Microhardness testing of plated coatings." Metal Finishing 99 (January 2001): 606–10. http://dx.doi.org/10.1016/s0026-0576(01)85320-4.

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Horner, John D. “Jack.” "Microhardness testing of plated coatings." Metal Finishing 100 (January 2002): 601–5. http://dx.doi.org/10.1016/s0026-0576(02)82063-3.

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Journal articles on the topic 'Microhardness'

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