Journal articles: 'Submicron grain'

1

Jain, M., and T. Christman. "Processing of submicron grain 304 stainless steel." Journal of Materials Research 11, no. 11 (November 1996): 2677–80. http://dx.doi.org/10.1557/jmr.1996.0336.

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A novel thermomechanical processing technique for the synthesis of bulk submicron grain (grain size ≈200 nm) 304 stainless steel is reported. This ingot-metallurgical technique requires a total deformation of only 95%, and the key steps to this processing technique involve (i) formation of ultrafine dislocation cell structure, and (ii) the conversion of dislocation cells into grains with medium to high misorientation by grain boundary sliding.

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2

Asabe, Takuma, Muhammad Rifai, Motohiro Yuasa, and Hiroyuki Miyamoto. "Effect of Grain Size on the Stress Corrosion Cracking of Ultrafine Grained Cu-10 wt% Zn Alloy in Ammonia." International Journal of Corrosion 2017 (2017): 1–8. http://dx.doi.org/10.1155/2017/2893276.

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The effect of grain size in the micron to submicron range on the stress corrosion cracking (SCC) of Cu-10 wt% Zn alloys was investigated using constant-load tests in ammonia vapor. The grain size was systematically varied from 4 μm to 0.12 μm by either cold-rolling or equal-channel angular pressing (ECAP), followed by annealing. The time to fracture increased with decreasing grain size above 1 μm but then began to decrease with decreasing grain size into the submicron range. This inverse trend in the submicron range is discussed in terms of a severe plastic deformation- (SPD-) induced ultrafine grain microstructure.

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3

Sima, M., L. Ion, S. Antohe, and E. Vasile. "Submicron wires with nanosized grain structure." Superlattices and Microstructures 46, no. 6 (December 2009): 833–39. http://dx.doi.org/10.1016/j.spmi.2009.09.010.

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Samajdar, I., L. Rabet, B. Verlinden, and P. Van Houtte. "An Investigation on Grain Growth in a Commercial Al–Mg Alloy." Textures and Microstructures 30, no. 3-4 (January 1, 1998): 191–206. http://dx.doi.org/10.1155/tsm.30.191.

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Alloy AA5182 contains coarse constituent particles and submicron dispersoids. While the former may cause particle stimulated nucleation (PSN) during primary recrystallization, the fine dispersoids may ‘arrest’ grain growth during subsequent annealing. Abnormal grain growth was observed after dissolution/coarsening of the dispersoids. Mainly S [{123}〈634〉] grains, but also some Brass [{011}〈112〉] and Cu [{112}〈111〉] grains, were observed to grow abnormally. Both the grain size and the grain boundary character distribution (GBCD) possibly played a role in the selection of the grains for abnormal grain growth. A dramatic increase in the number fraction of extremely low angle (1−5°) boundaries was observed with annealing, the increase being more at 470°C (when dispersoids were stable and grain growth was arrested more effectively) than at 500°C/530°C (when inhibition to grain growth was less). The nature of the CSL boundaries did not change significantly with annealing time/temperature.

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Alateyah, A. I., Mohamed M. Z. Ahmed, Yasser Zedan, H. Abd El-Hafez, Majed O. Alawad, and W. H. El-Garaihy. "Experimental and Numerical Investigation of the ECAP Processed Copper: Microstructural Evolution, Crystallographic Texture and Hardness Homogeneity." Metals 11, no. 4 (April 9, 2021): 607. http://dx.doi.org/10.3390/met11040607.

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The current study presents a detailed investigation for the equal channel angular pressing of pure copper through two regimes. The first was equal channel angular pressing (ECAP) processing at room temperature and the second was ECAP processing at 200 °C for up to 4-passes of route Bc. The grain structure and texture was investigated using electron back scattering diffraction (EBSD) across the whole sample cross-section and also the hardness and the tensile properties. The microstructure obtained after 1-pass at room temperature revealed finer equiaxed grains of about 3.89 µm down to submicrons with a high density of twin compared to the starting material. Additionally, a notable increase in the low angle grain boundaries (LAGBs) density was observed. This microstructure was found to be homogenous through the sample cross section. Further straining up to 2-passes showed a significant reduction of the average grain size to 2.97 µm with observable heterogeneous distribution of grains size. On the other hand, increasing the strain up to 4-passes enhanced the homogeneity of grain size distribution. The texture after 4-passes resembled the simple shear texture with about 7 times random. Conducting the ECAP processing at 200 °C resulted in a severely deformed microstructure with the highest fraction of submicron grains and high density of substructures was also observed. ECAP processing through 4-passes at room temperature experienced a significant increase in both hardness and tensile strength up to 180% and 124%, respectively.

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6

Mayes, C. D., G. J. Tatlock, and D. G. McCartney. "Characterization of submicron particles in Al5Ti1B grain refining master alloys." Proceedings, annual meeting, Electron Microscopy Society of America 48, no. 4 (August 1990): 962–63. http://dx.doi.org/10.1017/s0424820100177945.

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Al5%Ti1%B master alloys are frequently used in the grain refinement of aluminium alloys to induce heterogeneous nucleation during solidification and to promote an equiaxed grain structure. Boride particles are often observed in these alloys and could act as nucleation sites. However there are many more particles than nucleated grains in the samples and hence the precise role of the borides and other particles is not clear. We have therefore been undertaking a systematic TEM study of submicron particles extracted from master alloys using carbon extraction replication of fractured samples, with a view to investigating the nucleation mechanisms.Many of the particles analysed adopted a well defined hexagonal prism morphology (Fig.1) and varied in size from 5μm to 100 nm across the hexagonal face. A combination of EDX and EELS analysis plus electron diffraction was used to identify isolated particles as TiB2 containing little if any aluminium or potassium. These other elements are often detected in agglomerations of particles.

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Zhao, Zhong Min, Long Zhang, Yi Gang Song, and Wei Guo Wang. "Microstructures, Properties and In Situ Toughening of Rapidly Solidified Al₂O₃/YSZ Composite Ceramics Prepared by Combustion Synthesis." Key Engineering Materials 368-372 (February 2008): 771–74. http://dx.doi.org/10.4028/www.scientific.net/kem.368-372.771.

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The large-scale Al2O3/YSZ ceramic plates were prepared by combustion synthesis under high gravity, the ceramics were mainly composed of random-oriented rod-shaped grains, and within the rod-shaped grain aligned nano-submicron YSZ fibers were embedded. Compared to the high-performance directionally solidified ceramics, the hardness, flexural strength and fracture toughness of the eutectic ceramics obtained in the experiment increased by 40.7~55.1%, 9.6~26.0% and 172.0~240.0%, respectively. The increase in hardness and strength of the ceramics could be attributed to nano-submicron YSZ fibers and inter-phase spacing and the refinement of the eutectic grains; meanwhile, high-energy, large-angle boundaries between rod-shaped grains could introduce strong toughening mechanisms involving crack-bridging and pull-out of rod-shaped eutectics.

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8

Ferry, Michael. "Uniformity of Grain Coarsening in Submicron Grained Al-Sc Alloy Containing Local Variations in Texture." Materials Science Forum 495-497 (September 2005): 609–14. http://dx.doi.org/10.4028/www.scientific.net/msf.495-497.609.

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The effect of fine particles on the uniformity of grain coarsening in a submicron grained Al-Sc alloy containing significant local variations in texture has been investigated using high resolution EBSD. The alloy was processed by severe plastic deformation and low temperature ageing to generate a fine-grained (0.8 µm diameter) microstructure containing either a dispersion of nanosized Al3Sc particles or a particle-free matrix. The initial processing generated a uniform grain size distribution, but the distribution of grain orientations was inhomogeneous with the microstructure containing colonies of grains consisting predominantly of either HAGBs or LAGBs with the latter possessing orientation gradients of up to 10 o/µm. Despite the marked differences in boundary character between these regions, the alloy undergoes slow and uniform grain coarsening during annealing at temperatures up to 500 oC with no marked change in the grain size distribution, boundary distribution and texture. A model of grain coarsening that takes into account the influence of fine particles on the kinetics of grain growth within an orientation gradient is outlined. The model predicts that a large volume fraction of fine particles (large f/r-value) tends to homogenize the overall rate of grain coarsening despite the presence of orientation gradients in the microstructure.

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9

Bohn, R., G. Fanta, T. Klassen, and R. Bormann. "Submicron-grained multiphase TiAlSi alloys: Processing, characterization, and microstructural design." Journal of Materials Research 16, no. 6 (June 2001): 1850–61. http://dx.doi.org/10.1557/jmr.2001.0254.

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Prealloyed powders of the intermetallic γ–TiAl phase and the ceramic Ξ–Ti5Si3 phase were high-energy milled and hot-isostatically pressed (HIP) to produce silicide dispersed composite materials with grain sizes in the submicron and nanometer range. The amorphous state of the as-milled powders crystallizes via a multistep decomposition reaction during degassing at 440 °C and HIP. At a pressure of 200 Mpa HIP-temperatures as low as 750 °C are sufficient for a complete densification of the milled powder. The microstructure of the compacts is very homogeneous and consists of equiaxed γ–TiAl crystals and Ξ–Ti5(Si,Al)3 particles. Depending on the silicon content, these particles are interspersed within the grain boundary network of the γ–TiAl phase or dispersed inside the γ grains. With respect to technical applications, submicron-grained composites are regarded as promising precursor materials that should allow for easy hot working in the as-prepared state as well as for high-temperature structural applications after a suitable transformation of the microstructure.

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10

PIRGAZI, HADI, and ABBAS AKBARZADEH. "CHARACTERIZATION OF NANOSTRUCTURED ALUMINUM SHEETS PROCESSED BY ACCUMULATIVE ROLL BONDING." International Journal of Modern Physics B 22, no. 18n19 (July 30, 2008): 2840–47. http://dx.doi.org/10.1142/s0217979208047663.

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An ultrafine grained (UFG) aluminum sheet was produced using severe plastic deformation (SPD) by a process known as accumulative roll bonding (ARB). Electron Back Scattered Diffraction (EBSD) method and Transmission Electron Microscopy (TEM) were utilized for characterization of the subgrain and grain structures of the processed sheets. The results indicate that different mechanisms at different levels of strain lead to the gradual evolution of ultrafine or nanocrystalline grains. Grain fragmentation as well as the development of subgrains are the major mechanisms at the early stages of ARB. Strain induced transformation of low angle to high angle grain boundaries and formation of a thin lamellar structure occur at the medium level of strain. Finally, the progressive fragmentation of these thin lamellar structures into more equi-axed grains is the dominant mechanism at relatively high strains which results in grain size reduction to submicron scale.

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11

Ferry, Michael. "Spatial Uniformity of the Rate of Grain Coarsening in a Submicron Al-Sc Alloy Produced by Severe Plastic Deformation." Materials Science Forum 503-504 (January 2006): 251–58. http://dx.doi.org/10.4028/www.scientific.net/msf.503-504.251.

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The uniformity of grain coarsening throughout the microstructure of a submicron grained particle-containing aluminium alloy has been investigated using high resolution EBSD. The alloy was processed by equal channel angular pressing (ECAP) and low temperature ageing to generate ~0.8 􀁐m diameter grain structure containing a relatively uniform dispersion of nanosized Al3Sc particles. While the initial processing route generated a uniform grain size distribution, the distribution of grain orientations was rather inhomogeneous with certain regions of microstructure containing colonies of grains consisting predominantly of either HAGBs or LAGBs. It was found that, despite the difference in grain boundary character between these regions, the fine particles produced by pre-ageing promote uniform coarsening throughout the microstructure despite the marked differences in boundary character between these regions. An analytical model is outlined which predicts the uniformity of grain coarsening in particle-containing alloys despite the presence of orientation gradients in the microstructure.

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12

Krell, Andreas, Eckhard Pippel, Jörg Woltersdorf, and Wolfgang Burger. "Subcritical crack growth in Al2O3 with submicron grain size." Journal of the European Ceramic Society 23, no. 1 (January 2003): 81–89. http://dx.doi.org/10.1016/s0955-2219(02)00072-9.

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13

Mulyukov, Kh Ya, S. B. Khaphizov, and R. Z. Valiev. "Grain Boundaries and Saturation Magnetization in Submicron Grained Nickel." Physica Status Solidi (a) 133, no. 2 (October 16, 1992): 447–54. http://dx.doi.org/10.1002/pssa.2211330228.

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14

Gunnarsson, R., S. Charlebois, T. Liljenfors, Z. Ivanov, and E. Olsson. "Fabrication and characterisation of La0.67Sr0.33MnO3 submicron grain boundary junctions." Annalen der Physik 13, no. 12 (January 29, 2004): 101–2. http://dx.doi.org/10.1002/andp.200310065.

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15

SAIBE, Kazushi, Yoshihisa KANEKO, Makoto UCHIDA, and Alexei VINOGRADV. "Tensile Deformation Properties of Nickel having Submicron Grain Size." Proceedings of Conference of Kansai Branch 2018.93 (2018): P014. http://dx.doi.org/10.1299/jsmekansai.2018.93.p014.

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16

Galakhov, A. V., E. V. Tsibailo, M. I. Yanovskaya, N. V. Golubko, and I. A. Litvinov. "Grain growth during the sintering of compacted submicron powders." Refractories and Industrial Ceramics 38, no. 3-4 (April 1997): 147–51. http://dx.doi.org/10.1007/bf02767926.

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17

Finsel, Maik, Maria Hemme, Sebastian Döring, Jil S. V. Rüter, Gregor T. Dahl, Tobias Krekeler, Andreas Kornowski, Martin Ritter, Horst Weller, and Tobias Vossmeyer. "Synthesis and thermal stability of ZrO2@SiO2 core–shell submicron particles." RSC Advances 9, no. 46 (2019): 26902–14. http://dx.doi.org/10.1039/c9ra05078g.

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18

Etter, Anne Laure, Denis Solas, Thierry Baudin, and Richard Penelle. "Evolution of Microstructure and Texture during Annealing of a Copper Processed by ECAE." Materials Science Forum 495-497 (September 2005): 845–50. http://dx.doi.org/10.4028/www.scientific.net/msf.495-497.845.

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A submicron-grained (SMG) microstructure, with an average grain size of ~0.4 µm was produced by equal channel angular extrusion (ECAE). The SMG microstructure was composed of large dynamic recrystallized grains within a matrix of deformed elongated cells. Samples were annealed for various times at 473 K and then examined using transmission electron microscopy (TEM) and electron back scattered diffraction (EBSD). The results specify that a large recovery takes place during the first annealing times. Moreover, MET investigations show nucleation of grains which orientations are found in the recrystallized texture. The EBSD measurements established that, after 7min30s at 473 K, the microstructure is equiaxed and stable with an average grain size of about 2 µm.

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19

Vilane, V. N., R. D. Knutsen, and J. E. Westraadt. "Submicron Grain Size Formation in Thermohydrogenated and Deformed Ti-6Al-4V: The Effect of Processing Route on the Degree of Grain Refinement." Advanced Materials Research 1019 (October 2014): 266–72. http://dx.doi.org/10.4028/www.scientific.net/amr.1019.266.

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The aim of this work was to refine the as-cast Ti-6Al-4V grain size and its Widmanstätten morphology to optimise the mechanical performance of Ti-6Al-4V castings. Hydrogenation and deformation were used as variables in processing routes aimed at assessing the degree of refinement in the as-cast Ti-6Al-4V microstructure. Thermohydrogen processing (THP) refined the Widmanstätten morphology and not the prior beta grain boundary network. Therefore, the degree of refinement in THP processing is limited to morphology refinement within pre-existing prior beta grains. Deformation processing and recrystallisation is necessary to eliminate the indelible influence of the prior beta grain boundary network on the extent of THP refinement. In this context, a substantial degree of refinement is achieved from thermohydrogen and deformation processing (THDP). The as-cast Ti-6Al-4V grain boundary network was refined from an average diameter of 2000μm to 20μm. In addition, the Widmanstätten morphology was refined to submicron equiaxed alpha and beta grains.

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Wright, S. I., D. J. Dingley, and P. R. Mainwaring. "New Capabilities for the TEM: Automatic Orientation Measurement and Nanocrystal Grain Maps." Microscopy Today 7, no. 6 (August 1999): 12–15. http://dx.doi.org/10.1017/s1551929500064592.

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Orientation Imaging Microscopy (OIM) is a rapid and spatially specific technique for automatically measuring individual crystallographic orientations in a polycrystalline sample. The technique is based on electron backscatter diffraction in the scanning electron microscope (SEM). While the OIM technique has seen many applications to the investigation of structure/ property relationships in polycrystalline materials, with grain sizes ranging from millimeters to submicron, it is not easily applied to the characterization of microstructures at the nanometer scale due to the inherent resolution limitations of the SEM. Thus, a complementary technique for the transmission electron microscope (TEM) would be advantageous for the study of local orientation in submicron structures such as those that exist in nanocrystalline materials and deformed materials.

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Crifo, J. F. "Equilibrium Temperatures of H2O, Co2 and NH3 Ice Grains in the Solar System." International Astronomical Union Colloquium 85 (1985): 261–66. http://dx.doi.org/10.1017/s025292110008475x.

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AbstractThe equilibrium temperatures of spherical grains of pure H2O, CO2 and NH3 ice in the solar system are computed at heliocentric distances ranging from 1 AU out to (> 1500 AU) where solar illumination becomes negligible compared to galactic and extra-galactic light; the grain size range is from submicron to tens of meter in diameter. These results are based on recently published optical constants and on the use of the “complex angular momentum” (CAM) theory for computing the interaction of the grains with light.

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Khoroshko, Ekaterina, Andrey Filippov, Sergei Tarasov, Nikolay Shamarin, Evgeny Moskvichev, Sergei Fortuna, Dmitry V. Lychagin, and Evgeny Kolubaev. "Strength and Ductility Improvement through Thermomechanical Treatment of Wire-Feed Electron Beam Additive Manufactured Low Stacking Fault Energy (SFE) Aluminum Bronze." Metals 10, no. 12 (November 24, 2020): 1568. http://dx.doi.org/10.3390/met10121568.

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An as-cast macrostructure of electron beam additively manufactured metallic materials was represented by coarse columnar grains whose axes were inclined at 25° with respect to the substrate’s plane. One part of the as-grown samples was annealed to form a coarse grain microstructure while the other part was pre-deformed by forging and then annealed what allowed obtaining recrystallized microstructures with small grains and multiple annealing twin boundaries. This sample showed both high strength and plasticity during the tensile tests. These tensile tests demonstrated also two-stage stress-strain curves as depended on their strain hardening rates. High and low strain hardening rates corresponded to a twinning-dominated deformation at stage II and dislocation-base deformation at stage III. A submicron size strain-induced grain-subgrain microstructure was formed in the vicinity of a necked zone as a result of combined twinning/dislocation grain refining.

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Ravi, K. R., A. Murugesan, V. Udhayabanu, R. Subramanian, and B. S. Murty. "Microstructure and Mechanical Property of Fe-Al₂O₃ Nanocomposites Synthesized by Reactive Milling Followed by Spark Plasma Sintering." Materials Science Forum 710 (January 2012): 291–96. http://dx.doi.org/10.4028/www.scientific.net/msf.710.291.

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The in-situ Fe based nanocomposite containing Al2O3 particle is synthesized by reactive milling of Fe2O3-Al-Fe powder mixture in toluene medium followed by consolidation of powders using Spark Plasma Sintering process. Transmission electron microscopy investigation of consolidated Fe-Al2O3 nanocomposites has shown heterogenous grain structure of Fe consisting of nano, submicron and micron size grains together with nanometer Al2O3 particles. The hardness of Fe-Al2O3 nanocomposites consolidated at 800°C is 795 MPa.

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MOHANTA, A., S. DASH, and D. BEHERA. "THERMALLY ACTIVATED FLUX CREEP AND CURRENT CONDUCTION IN YBCO + BZO COMPOSITES." International Journal of Modern Physics B 25, no. 03 (January 30, 2011): 387–98. http://dx.doi.org/10.1142/s0217979211057888.

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BaZrO 3 submicron powder obtained from chemical route was added to YBCO for preparation of YBCO + xBZO (x = 0, 1, 2.5, 5, 10 rm wt%) composites samples. The X-ray peak profile analyses and the scanning electron microscopy have indicated that the mean powder size for BZO ranges from 500 to 800 nm. In fact, the presence of BZO brings about a significant modification in the microstructure of the composites. The resistive transition in presence of magnetic field (0–8 T) was investigated. With application of magnetic field, Tc0 decreases significantly, suggesting that grain boundaries (Josephson junctions) are affected more than the grains (Abrikosov junctions). Activation energy is found dependent not only on the particle size, but also on penetration depth and decreases with increasing doping concentration of BZO submicron size particles in contrast to what has been recently observed by M. Safonchik et al. with grain sizes of 40 nm BZO. It has also been observed by H. Shakeripour, M. Akhavan [Supercond. Sci. Technol.14, 234 (2001)] and Gamchi et al. [Phys. Rev. B50, 12950 (1994)] that the activation energy depends not only on the temperature and magnetic field, but also on the doping concentration.

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Zhou, Haiping, Chengcai Zhang, Baokun Han, Jianfeng Qiu, Shengxue Qin, Kuidong Gao, Jie Liu, Shuai Sun, and Hongbin Zhang. "Microstructures and Mechanical Properties of Nanocrystalline AZ31 Magnesium Alloy Powders with Submicron TiB2 Additions Prepared by Mechanical Milling." Crystals 10, no. 6 (June 26, 2020): 550. http://dx.doi.org/10.3390/cryst10060550.

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In this work, nanocrystalline AZ31 magnesium alloy powders, reinforced by submicron TiB2 particles, were prepared via mechanical milling. It was found that TiB2 particles stimulated the fracture and welding of AZ31/TiB2 powders, leading to the acceleration of the milling process. Meanwhile, the TiB2 particles were refined to submicron-scale size during the milling process, and their distribution was uniform in the Mg matrix. In addition, the matrix was significantly refined during the milling process, which was also accelerated by the TiB2 particles. The formation of grain boundary segregation layers also led to the weakened TiB2 peaks in the XRD patterns during the mechanical milling. The grain sizes of AZ31–2.5 wt % TiB2, AZ31–5 wt % TiB2 and AZ31–10 wt % TiB2 powders were refined to 53 nm, 37 nm and 23 nm, respectively, after milling for 110 h. Under the combined effect of the nanocrystalline matrix and the well-dispersed submicron TiB2 particles, the AZ31/TiB2 composites exhibited excellent micro-hardness. For the AZ31–10 wt % TiB2 composite, the micro-hardness was enhanced to 153 HV0.5.

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Teng, C. M., T. F. Kelly, J. P. Zhang, H. M. Lin, and Y. W. Kim. "HREM observation of NiO growth on submicron spheres of pure nickel." Proceedings, annual meeting, Electron Microscopy Society of America 47 (August 6, 1989): 548–49. http://dx.doi.org/10.1017/s0424820100154718.

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Spherical submicron particles of materials produced by electrohydrodynamic (EHD) atomization have been used to study a variety of materials processes including nucleation of alternative crystallization phases in iron-nickel and nickel-chromium alloys, amorphous solidification in submicron droplets of pure metals, and quasi-crystal formation in nickel-chromium alloys. Some experiments on pure nickel, nickel oxide single crystals, the nickel/nickel(II) oxide interface, and grain boundaries in nickel monoxide have been performed by STEM. For these latter studies, HREM is the most direct approach to obtain particle crystal structures at the atomic level. Grain boundaries in nickel oxide have also been investigated by HREM. In this paper, we present preliminary results of HREM observations of NiO growth on submicron spheres of pure nickel.Small particles of pure nickel were prepared by EHD atomization. For the study of pure nickel, 0.5 mm diameter pure nickel wire (99.9975%) is sprayed directly in the EHD process. The liquid droplets solidify in free-flight through a vacuum chamber operated at about 10-7 torr.

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Prangnell, Philip B., Yan Huang, M. Berta, and P. J. Apps. "Mechanisms of Formation of Submicron Grain Structures by Severe Deformation." Materials Science Forum 550 (July 2007): 159–68. http://dx.doi.org/10.4028/www.scientific.net/msf.550.159.

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Krell, Andreas, Angelika Teresiak, and Dietrich Schläfer. "Grain size dependent residual microstresses in submicron A12O3 and ZrO2." Journal of the European Ceramic Society 16, no. 8 (January 1996): 803–11. http://dx.doi.org/10.1016/0955-2219(96)00003-9.

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Eichler, Jens, Mark Hoffman, Ulrich Eisele, and Jürgen Rödel. "R-curve behaviour of 2Y-TZP with submicron grain size." Journal of the European Ceramic Society 26, no. 16 (January 2006): 3575–82. http://dx.doi.org/10.1016/j.jeurceramsoc.2005.11.012.

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Testa, G., A. Monaco, E. Sarnelli, A. D Agostino, D.-J. Kang, E. J. Tarte, S. H. Mennema, C. Bell, and M. G. Blamire. "Submicron YBa2Cu3O7 xbicrystal grain boundary junctions by focused ion beam." Superconductor Science and Technology 17, no. 2 (December 22, 2003): 287–90. http://dx.doi.org/10.1088/0953-2048/17/2/009.

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TORBATI-SARRAF, S. A., and R. MAHMUDI. "ULTRA FINE-GRAINED AZ31 MAGNESIUM ALLOY OBTAINED BY A COMBINATION OF GRAIN REFINEMENT AND EQUAL CHANNEL ANGULAR PRESSING." International Journal of Modern Physics: Conference Series 05 (January 2012): 307–15. http://dx.doi.org/10.1142/s2010194512002176.

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Different amounts of Al -5 Ti -1 B master alloy ( TiBAl ) were added to the AZ 31 magnesium alloy ( Mg -3 Al -1 Zn -0.2 Mn ) as grain refiner and the resulting microstructure and grain size distributions were studied after extrusion and equal channel angular pressing (ECAP). Results showed that the addition of 0.6% TiBAl had the strongest grain refinement effect, reducing the grain sizes by 54.5 and 48.5% in the extruded and ECAPed conditions, respectively. The observed grain refinement was partly due to the presence of the thermally-stable micron- and submicron-sized particles in the melt which act as nucleation sites during solidification. During the high-temperature extrusion and ECAP processes, dynamic recrystallization (DRX) and grain growth are likely to occur. However, the mentioned particles will help in reducing the grain size by the particle stimulated nucleation (PSN) mechanism. Furthermore, the pinning effect of these particles can oppose grain growth by reducing the grain boundary migration. These two phenomena together with the partitioning of the grains imposed by the severe plastic deformation in the ECAP process have all contributed to the achieved ultrafine-grained structure in the AZ 31 alloy.

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Bae, Ki Wook, Jeong Yun Hwang, Sang-il Kim, Hyung Mo Jeong, Sunuk Kim, Jae-Hong Lim, Hyun-Sik Kim, and Kyu Hyoung Lee. "Thermoelectric Transport Properties of n-Type Sb-doped (Hf,Zr,Ti)NiSn Half-Heusler Alloys Prepared by Temperature-Regulated Melt Spinning and Spark Plasma Sintering." Applied Sciences 10, no. 14 (July 19, 2020): 4963. http://dx.doi.org/10.3390/app10144963.

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Herein we report a significantly reduced lattice thermal conductivity of Sb-doped Hf0.35Zr0.35Ti0.3NiSn half-Heusler alloys with sub-micron grains (grain size of ~300 nm). Polycrystalline bulks of Hf0.35Zr0.35Ti0.3NiSn1−xSbx (x = 0.01, 0.02, 0.03) with a complete single half-Heusler phase are prepared using temperature-regulated melt spinning and subsequent spark plasma sintering without a long annealing process. In these submicron-grained bulks, a very low lattice thermal conductivity value of ~2.4 W m−1 K−1 is obtained at 300 K due to the intensified phonon scatterings by highly dense grain boundaries and point-defects (Zr and Ti substituted at Hf-sites). A maximum thermoelectric figure of merit, zT, of 0.5 at 800 K is obtained in Hf0.35Zr0.35Ti0.3NiSn0.99Sb0.01.

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Su, Shitian, Jixue Zhou, Shouqiu Tang, Huan Yu, Qian Su, and Suqing Zhang. "Synthesis of Nanocrystalline AZ91 Magnesium Alloy Dispersed with 15 vol.% Submicron SiC Particles by Mechanical Milling." Materials 12, no. 6 (March 18, 2019): 901. http://dx.doi.org/10.3390/ma12060901.

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The development of a magnesium matrix composite with a high content of dispersions using conventional liquid-phase process is a great challenge, especially for nanometer/submicron particles. In this work, mechanical milling was employed to prepare nanocrystalline AZ91 dispersed with 15 vol.% submicron SiC particles (SiCp/AZ91). AZ91 with no SiCp was applied as a comparative study with the same mechanical milling. In order to investigate the mechanism of dispersing, the morphology evolution of powders and the corresponding SiCp distribution were observed. As the scanning electron microscope (SEM) analysis exhibited, the addition of SiCp accelerated the smashing of AZ91 particles, which promoted the dispersion of SiCp in AZ91. Thus, after mechanical milling, 15 vol.% SiCp, which was smashed from 800 to 255 nm, got uniformly distributed in the Mg matrix. Based on X-ray diffraction (XRD) results, part of the Mg17Al12 precipitate got dissolved, and an Al-supersaturated Mg solid solution was formed. The transmission electron microscopy (TEM) results showed that the ultimate Mg grain (32 nm) of milled SiCp/AZ91 was much smaller than that of milled AZ91 (64 nm), which can be attributed to a pinning effect of submicron SiCp. After mechanical milling, the hardness of SiCp/AZ91 reached 185 HV, which was 185% higher than the original AZ91 and 33% higher than milled AZ91, due to fine Mg grain and submicron dispersions.

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34

Rust, Martin A., and Richard I. Todd. "High Resolution Surface Studies of Superplastic Deformation." Materials Science Forum 551-552 (July 2007): 615–20. http://dx.doi.org/10.4028/www.scientific.net/msf.551-552.615.

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Previous studies of superplasticity using surface markers have tended to use either diamond paste scratches, with which it is difficult to make quantitative measurements, or regular grids with spacing greater than the grain size, which prevents measurements of any deformation occurring within the grains. This paper reports the etching of regular marker grids with submicron line spacings using Focused Ion Beams (FIB), as well as mesoscopic grids with line spacings many grains across. These have enabled us to make quantitative measurements of deformation within the surface grains, and at length scales up to 0.5 millimeters. Further refinements used include the use of Interferometric Surface Profilometry to measure the out-of-surface displacement during deformation. Results on Sn-Pb eutectic alloy tested in tension in Regions I and II showed that there was almost no intragranular deformation anywhere in any of the surface grains. Grain boundary sliding took place, particularly at Sn-Sn grain boundaries, and the accommodation mechanism was separation of interfaces normal to the tensile axis where sliding was blocked, particularly Pb-Pb grain boundaries. It is argued that this is a surface artifact not readily available in the bulk thus the case is made for testing under a different strain condition.

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Nguyen, Ann, Ernst Zinner, and Roy S. Lewis. "Identification of Small Presolar Spinel and Corundum Grains by Isotopic Raster Imaging." Publications of the Astronomical Society of Australia 20, no. 4 (2003): 382–88. http://dx.doi.org/10.1071/as03030.

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AbstractThe oxygen isotopic compositions of densely packed submicron oxide grains in two grain separates of different grain size from the CM2 carbonaceous chondrite Murray were determined by multi-detection raster imaging on the NanoSIMS ion microprobe. This led to the identification of 81 presolar spinel and 3 presolar corundum grains among ∼51 700 grains in the CF residue (mean diameter 0.15 µm) and 171 presolar spinel and 29 presolar corundum grains among ˜21 500 grains in the CG residue (mean diameter 0.45 µm). Previous NanoSIMS analysis of individual grains from the same residues has led to the discovery of 15 presolar spinel and 3 presolar corundum grains among 628 CF grains, and 9 presolar spinels among 753 CG grains. The oxygen isotopic compositions of the presolar oxides found by raster imaging are comparable to those of the presolar oxides measured individually. While the abundance of presolar spinel among the (larger) grains of the CG residue is the same for both techniques, the detection efficiency for presolar spinel by imaging among the (smaller) grains in CF is lower due to the small size of these grains. Nonetheless, it is possible to identify presolar grains of this size range. Though single grain measurements are effective for determining the precise isotopic compositions and abundances of presolar grains, raster ion imaging is the method of choice in searches for rare presolar grain types such as presolar silicates.

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36

Wang, Jian Min, Wen Tao Hou, and Lin Lu. "Preparation and Mechanical Properties of Ultra-Fine Grain Medium-Carbon Steel Based on Equal-Channel Angular Pressing." Key Engineering Materials 645-646 (May 2015): 427–34. http://dx.doi.org/10.4028/www.scientific.net/kem.645-646.427.

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A new technology of preparing submicron medium-carbon steel quickly using martensitic steel by equal-channel angular pressing is developed. The technology combines martensite phase transformation with severe plastic deformation. In this research, martensitic steel is heated to 923K quickly and held for appropriate time, then equal-channel angular pressing is implemented. Supersaturated ferrites of average grain size within 0.5μm are obtained by the interaction of dislocation intersection, dynamic recrystallization and strain-induced phase transformation. At the same time, strain-induced phase transformation leads to dispersive precipitation of supersaturated carbon particles in the form of carbide inside grains or in grain boundaries. The optimal size of ferrite grains and the optimal distribution of carbides are acquired by controlling tempering temperature and time. The results show that ultra-fine grained materials prepared by this technology possess superior thermal stability.

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37

Wang, Jingtao, Zenji Horita, Minoru Furukawa, Minoru Nemoto, Nikolai K. Tsenev, Ruslan Z. Valiev, Yan Ma, and Terence G. Langdon. "An investigation of ductility and microstructural evolution in an Al−3% Mg alloy with submicron grain size." Journal of Materials Research 8, no. 11 (November 1993): 2810–18. http://dx.doi.org/10.1557/jmr.1993.2810.

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A submicrometer-grained (SMG) Al−3% Mg solid solution alloy, with an initial grain size of ∼0.2 μm, was produced by intense plastic straining. Experiments show that tensile specimens of the SMG alloy exhibit high elongations to failure at low testing strain rates at the relatively low temperature of 403 K. The stress exponent is high (∼7–8) and calculations show deformation is within the region of power-law breakdown. The initial microstructure of the alloy consists of diffuse boundaries between highly deformed grains. At strain rates of ∼10−4 s−1 and lower, plastic deformation leads to dynamic recrystallization and the formation of highly nonequilibrium grain boundaries that gradually evolve into a more equilibrated configuration.

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Khan, Aamer Nusair, S. K. Mehmood, and K. Mehmood. "Effect of Heat Treatment on Deformation Induced Martensite in Austenitic Stainless Steel." Key Engineering Materials 510-511 (May 2012): 214–20. http://dx.doi.org/10.4028/www.scientific.net/kem.510-511.214.

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Austenitic stainless steel with submicron gain size has been attracted due to fine structural control of mechanical properties. In order to achieve a submicron grain size, meta-stable austenitic steel AISI 304 is severely cold deformed and then annealed to different heat treatment cycles. The heat treated samples were then tested for metallurgical phase change, texture components and hardness. It was observed that at 750°C, all the martensite transformed completely into austenite. Further, at the same temperature, it was observed that the texture component {221}<232> was the dominant texture component.

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Ryu, Ho Jin, Yeon Soo Kim, G. L. Hofman, J. Rest, Jong Man Park, and Chang Kyu Kim. "Radiation-Induced Recrystallization of U-Mo Fuel Particles and Radiation-Induced Amorphization of Interaction Products in U-Mo/Al Dispersion Fuel." Materials Science Forum 558-559 (October 2007): 319–22. http://dx.doi.org/10.4028/www.scientific.net/msf.558-559.319.

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Two kinds of radiation-induced structural changes were observed in U-Mo/Al dispersion fuel: radiation-induced recrystallization of U-Mo fuel particles and radiation-induced amorphization of interaction products. During irradiation, U-Mo fuel showed refined microstructures of submicron-size grains due to dynamic recrystallization, occurring initially from pre-existing grain boundaries. The interaction products formed by interdiffusion between the U-Mo particles and Al matrix in U-Mo/Al dispersion fuel transformed from crystalline to amorphous during irradiation. In this paper we deal with both of the phenomena simultaneously.

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40

Oehring, Michael, Fritz Appel, Th Pfullmann, and Rüdiger Bormann. "Preparation and Mechanical Properties of TiAl Alloys with Submicron Grain Size." Materials Science Forum 179-181 (February 1995): 435–42. http://dx.doi.org/10.4028/www.scientific.net/msf.179-181.435.

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41

Chang, Joon-Yeon, Jong-Seo Yoon, and Gyeung-Ho Kim. "Development of submicron sized grain during cyclic equal channel angular pressing." Scripta Materialia 45, no. 3 (August 2001): 347–54. http://dx.doi.org/10.1016/s1359-6462(01)01040-5.

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42

Gurao, N. P., and Satyam Suwas. "Evolution of crystallographic texture during deformation of submicron grain size titanium." Journal of Materials Research 26, no. 4 (February 11, 2011): 523–32. http://dx.doi.org/10.1557/jmr.2010.70.

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43

Islamgaliev, R. K., N. A. Akhmadeev, R. R. Mulyukov, and R. Z. Valiev. "Grain boundary influence on the electrical resistance of submicron grained copper." physica status solidi (a) 118, no. 1 (March 16, 1990): K27—K29. http://dx.doi.org/10.1002/pssa.2211180146.

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44

Ivanov, V. V., S. N. Shkerin, Al A. Rempel, V. R. Khrustov, A. S. Lipilin, and A. V. Nikonov. "Electrical conductivity of zirconia-based solid electrolyte with submicron grain size." Doklady Physical Chemistry 433, no. 1 (July 2010): 125–27. http://dx.doi.org/10.1134/s0012501610070055.

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45

Ivanov, Z. G., N. Fogel, P. Å. Nilsson, E. A. Stepantsov, and A. Ya Tzalenchuk. "Transport properties of submicron YBaCuO low angle grain boundary weak links." Physica C: Superconductivity 235-240 (December 1994): 3253–54. http://dx.doi.org/10.1016/0921-4534(94)91153-3.

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46

Burhan, N., and Michael Ferry. "Changes in Grain Size Distribution of a Submicron Grained Al-Sc Alloy during High Temperature Annealing." Materials Science Forum 519-521 (July 2006): 1617–22. http://dx.doi.org/10.4028/www.scientific.net/msf.519-521.1617.

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Severe plastic straining is an established method for producing submicron grain (SMG) structures in alloys. However, the development of such a fine grained structure in single-phase alloys is usually futile if they are to be exposed or processed at elevated temperatures. This is a direct consequence of the natural tendency for rapid and substantial grain coarsening which completely removes the benefits obtained by grain refinement. This problem may be avoided by the introduction of nanosized, highly stable particles in the metal matrix. In this work, a SMG structure was generated in an Al-0.3 wt.% Sc alloy by Equal Channel Angular Pressing (ECAP). The alloy was prepared initially to produce a fine grained microstructure exhibiting a large fraction of high angle grain boundaries and a dispersion of nanosized Al3Sc particles. The evolution of microstructure during annealing at temperatures up to 550 °C was examined in detail and grain size distributions generated from the data. It was shown that grain coarsening is rapid at temperatures above 450 °C and the initial log-normal grain size distribution exhibiting low variance and skewness was altered considerably. The statistical information generated from the grain size distributions confirms that discontinuous grain coarsening occurs in this alloy only at temperatures greater than 500 °C.

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47

Liu, Zong De, Bin Li, Zhang Qi Wang, Jing Jing Liu, and W. Ji. "Microstructure and Grain Abrasion Properties of TiC-xNi Coatings Prepared by Electro-Thermal Explosion Ultra-High Speed Spraying." Advanced Materials Research 33-37 (March 2008): 489–94. http://dx.doi.org/10.4028/www.scientific.net/amr.33-37.489.

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In this work, a new method, electro-thermal explosion ultra-high speed spraying (EEUSS), was utilized to synthesize the titanium carbide based and nickel bonded (TiC-xNi) coatings. The nickel content was varied at the weight percents of 5, 10, 15 and 20%. The microstructure and properties of the coatings were studied by means of scanning electron microscope (SEM), X-ray diffraction (XRD) and microhardness tester, respectively. The TiC-xNi coatings had the metallurgical bonding with the substrate, and consisted of submicron grains. The grain abrasion tests results showed that the abrasion resistance of the coatings was affected by the contents of Ni.

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48

Li, Ji Zhong, Hua Ding, Xiao Lin Wu, Wei Xu, and Kenong Xia. "The Influence of Texture and Grain Size on Compressive Deformation Behavior of Pure Mg through Equal-Channel Angular Processing." Materials Science Forum 667-669 (December 2010): 385–90. http://dx.doi.org/10.4028/www.scientific.net/msf.667-669.385.

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Multi-pass of equal channel angular pressing (ECAP) at a single temperature as low as room temperature from 200 °C were measured using electronic back scatter diffraction (EBSD). The effect of texture and grain size on mechanical properties was investigated to realize the strengthening and large plastic deformation mechanism. A room temperature ECAP with multi-pass procedure is effective to product high strength and large plastic Mg, as a result of submicron grain structure and texture strengthening.

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Lau, Lik Nguong, Kean Pah Lim, Amirah Natasha Ishak, Mohd Mustafa Awang Kechik, Soo Kien Chen, Noor Baa’yah Ibrahim, Muralidhar Miryala, Masato Murakami, and Abdul Halim Shaari. "The Physical Properties of Submicron and Nano-Grained La0.7Sr0.3MnO3 and Nd0.7Sr0.3MnO3 Synthesised by Sol–Gel and Solid-State Reaction Methods." Coatings 11, no. 3 (March 22, 2021): 361. http://dx.doi.org/10.3390/coatings11030361.

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La0.7Sr0.3MnO3 (LSMO) and Nd0.7Sr0.3MnO3 (NSMO) possess excellent colossal magnetoresistance (CMR). However, research work on the neodymium-based system is limited to date. A comparative study between LSMO and NSMO prepared by sol–gel and solid-state reaction methods was undertaken to assess their structural, microstructural, magnetic, electrical, and magneto-transport properties. X-ray diffraction and structure refinement showed the formation of a single-phase composition. Sol–gel-synthesised NSMO was revealed to be a sample with single crystallite grains and exhibited intriguing magnetic and electrical transport behaviours. Magnetic characterisation highlighted that Curie temperature (TC) decreases with the grain size. Strong suppression of the metal–insulator transition temperature (TMI) was observed and attributed to the magnetically disordered grain surface and distortion of the MnO6 octahedra. The electrical resistivity in the metallic region was fitted with theoretical models, and the conduction mechanism could be explained by the grain/domain boundary, electron–electron, and electron–magnon scattering process. The increase in the scattering process was ascribed to the morphology changes. Enhancement of low-field magnetoresistance (LFMR) was observed in nano-grained samples. The obtained results show that the grain size and its distribution, as well as the crystallite formation, strongly affect the physical properties of hole-doped manganites.

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Guo, Tingbiao, Junjie Wang, Yibo Wu, Xiaoyang Tai, Zhi Jia, and Yutian Ding. "Fabricate of High-Strength and High-Conductivity Cu–Cr–Si Alloys through ECAP-Bc and Aging Heat Treatment." Materials 13, no. 7 (April 1, 2020): 1603. http://dx.doi.org/10.3390/ma13071603.

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The effect of equal channel angular pressing (ECAP) through the route Bc and aging treatment on the grain structure and properties of the Cu–1Cr–0.2Si alloy was investigated. Microstructure was detected by scanning electron microscopy (SEM), x-ray diffraction (XRD), and electron backscatter diffraction (EBSD) and the mechanical properties and electrical conductivity were tested. Results shown that after ECAP, accompanying the grains refined to nano-and submicron-structure, the Cr particles were gradually spread along the grain boundaries (GBs), aging treatment promoted Cr particles dispersed in the matrix. ECAP greatly increased the ultimate tensile strength (UTS) while having a small effect on the conductivity, and aging treatment increased electrical conductivity. The stable {111}<110> texture after ECAP and the lower dislocation density after aging treatment maybe the main reasons for the high conductivity of the material.

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Journal articles on the topic 'Submicron grain'

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