Dissertations / Theses on the topic 'Thermal conductivity'
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Tardieu, Giliane. "Thermal conductivity prediction." Thesis, Georgia Institute of Technology, 1987. http://hdl.handle.net/1853/10014.
Full textMartin, Ana Isabel. "Hydrate Bearing Sediments-Thermal Conductivity." Thesis, Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/6844.
Full textMensah-Brown, Henry. "Thermal conductivity of liquid mixtures." Thesis, Imperial College London, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.362870.
Full textPeralta, Martinez Maria Vita. "Thermal conductivity of molten metals." Thesis, Imperial College London, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.391505.
Full textJawad, Shadwan Hamid. "Thermal conductivity of polyatomic gases." Thesis, Imperial College London, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.367922.
Full textValter, Mikael. "Thermal Conductivity of Uranium Mononitride." Thesis, Linköpings universitet, Tunnfilmsfysik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-122337.
Full textVärmeledningsförmåga är en avgörande egenskap för kärnbränslen, eftersom det begränsar den maximala drifttemperaturen i reaktorn för att ha säkerhetsmarginaler. Uranmononitrid (UN) är ett framtida bränsle för snabba reaktorer. Jämfört med det dominerande bränslet i lättvattenreaktorer, urandioxid, har endast begränsade experimentella studier gjorts av UN. Målet med detta arbete är att bestämma värmeledningsförmågan i UN och bestämma dess porositetsberoende. Detta gjordes genom att tillverka kompakta och porösa prover av UN och undersöka dem med laserblixtmetoden, vilket tillsammans med värmekapacitet och värmeutvidgning ger värmeledningsförmågan. För att analysera resultatet gjordes en teoretisk studie av värmeledning såväl som en genomgång av och jämförelse med tidigare undersökningar. Provernas porositet sträckte sig från 0.1% till 31% av teoretisk densitet. Värmediffusivitetsdata från laserblixtmetoden, värmeutvidgningsdata och värmekapacitetsdata samlades in för 25–1400 C. Värdena från laserblixtmätningen hade hög diskrepans vid höga temperaturer p.g.a. termisk instabilitet i anordningen och avvikelser p.g.a. grafitavlagring på proverna, men data för låga temperaturer borde vara tillförlitliga. Eftersom resultaten från värmekapacitetsmätningen var av dålig kvalité, användes litteraturdata istället. Som en konsekvens av bristerna i mätningen av värmediffusivitet är presenterade data för värmeledningsförmåga mest exakta för låga temperaturer. En modifierad version av Ondracek-Schulz porositetsmodell användes för att analysera värmeledningsförmågans porositetsberoende genom att ta hänsyn till olika inverkan av öppen och sluten porositet.
Anderson, Stephen Ashcraft. "The thermal conductivity of intermetallics." Master's thesis, University of Cape Town, 1996. http://hdl.handle.net/11427/18185.
Full textThe thermal conductivity of titanium aluminide and several ruthenium-aluminium alloys has been studied from room temperature up to 500°C. Ruthenium aluminide is a B2-type intermetallic which is unusual and of special interest because of its toughness, specific strength and stiffness, oxidation resistance and low cost. The possible use of ruthenium aluminide in high temperature industrial applications required an investigation of the thermal properties of this compound. Apparatus, capable of measuring thermal conductivity at elevated temperatures has been designed and constructed. This study represents the first experimental results for the thermal conductivity of ruthenium aluminide alloys. The electrical resistivity of the intermetallic compounds has been measured using apparatus based on the Van der Pauw method. The Weidman-Franz ratio of the ruthenium aluminide alloys has been calculated and this indicates that the primary source of heat conduction in these alloys is by electronic movement and that the lattice contribution is minor. The electrical and thermal properties of ruthenium aluminide are shown to be similar to that of platinum and nickel aluminide. This has important implications for the use of these alloys in high temperature applications.
Karayacoubian, Paul. "Effective Thermal Conductivity of Composite Fluidic Thermal Interface Materials." Thesis, University of Waterloo, 2006. http://hdl.handle.net/10012/2881.
Full textThe following study presents the application of two simple theorems for establishing bounds on the effective thermal conductivity of such inhomogeneous media. These theorems are applied to the development of models which are the geometric means of the upper and lower bounds for effective thermal conductivity of base fluids into which are suspended particles of various geometries.
Numerical work indicates that the models show generally good agreement for the various geometric dispersions, in particular for particles with low to moderate aspect ratios. The numerical results approach the lower bound as the conductivity ratio is increased. An important observation is that orienting the particles in the direction of heat flow leads to substantial enhancment in the thermal conductivity of the base fluid. Clustering leads to a small enhancement in effective thermal conductivity beyond that which is predicted for systems composed of regular arrays of particles. Although significant enhancement is possible if the clusters are large, in reality, clustering to the extent that solid agglomerates span large distances is unlikely since such clusters would settle out of the fluid.
In addition, experimental work available in the literature indicates that the agreement between the selected experimental data and the geometric mean of the upper and lower bounds for a sphere in a unit cell are in excellent agreement, even for particles which are irregular in shape.
Mutnuri, Bhyrav. "Thermal conductivity characterization of composite materials." Morgantown, W. Va. : [West Virginia University Libraries], 2006. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=4468.
Full textTitle from document title page. Document formatted into pages; contains vii, 62 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 61-62).
Wei, Xiaohao, and 魏晓浩. "Nanofluids: synthesis, characterization and thermal conductivity." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hub.hku.hk/bib/B44765861.
Full textJiang, Wei, and 姜为. "Synthesis and thermal conductivity of nanofluids." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hub.hku.hk/bib/B45518063.
Full textFreeman, J. J. "The thermal conductivity of amorphous polymers." Thesis, University of Leeds, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.355947.
Full textDudnik, S. F., A. I. Kalinichenko, and V. E. Strel’nitskij. "On Thermal Conductivity of Anisotropic Nanodiamond." Thesis, Sumy State University, 2013. http://essuir.sumdu.edu.ua/handle/123456789/35196.
Full textWebber, Christina Marie. "Prosthetic Sockets: Assessment of Thermal Conductivity." University of Akron / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=akron1404224355.
Full textBeck, Michael Peter. "Thermal conductivity of metal oxide nanofluids." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/26488.
Full textCommittee Chair: Teja, Amyn S.; Committee Member: Abdel-Khalik, Said I.; Committee Member: Meredith, Carson; Committee Member: Nair, Sankar; Committee Member: Skandan, Ganesh. Part of the SMARTech Electronic Thesis and Dissertation Collection.
Madrid, Lozano Francesc. "Thermal Conductivity and Specific Heat Measurements for Power Electronics Packaging Materials. Effective Thermal Conductivity Steady State and Transient Thermal Parameter Identification Methods." Doctoral thesis, Universitat Autònoma de Barcelona, 2005. http://hdl.handle.net/10803/5348.
Full textBihari, Kathleen L. "Analysis of Thermal Conductivity in Composite Adhesives." NCSU, 2001. http://www.lib.ncsu.edu/theses/available/etd-20010808-130536.
Full textBIHARI, KATHLEEN LOUISE. Analysis of Thermal Conductivity in Composite Adhesives (Under the direction of H. Thomas Banks). Thermally conductive composite adhesives are desirable in many industrial applications, including computers, microelectronics, machinery and appliances. These composite adhesives are formed when a filler particle of high conductivity is added to a base adhesive. Typically, adhesives are poor thermal conductors. Experimentally only small improvements in the thermal properties of the composite adhesives over the base adhesives have been observed. A thorough understanding of heat transfer through a composite adhesive would aid in the design of a thermally conductive composite adhesive that has the desired thermal properties.In this work, we study design methodologies for thermally conductive composite adhesives. We present a three dimensional model for heat transfer through a composite adhesive based on its composition and on the experimental method for measuring its thermal properties. For proof of concept, we reduce our model to a two dimensional model. We present numerical solutions to our two dimensional model based on a composite silicone and investigate the effect of the particle geometry on the heat flow through this composite. We also present homogenization theory as a tool for computing the ``effective thermal conductivity" of a composite material.We prove existence, uniqueness and continuous dependence theorems for our two dimensional model. We formulate a parameter estimation problem for the two dimensional model and present numerical results. We first estimate the thermal conductivity parameters as constants, and then use a probability based approach to estimate the parameters as realizations of random variables. A theoretical framework for the probability based approach is outlined.Based on the results of the parameter estimation problem, we are led to formally derive sensitivity equations for our system. We investigate the sensitivity of our composite silicone with respect to the thermal conductivity of both the base silicone polymer and the filler particles. Numerical results of this investigation are also presented.
Ford, Theodore Robert. "Thermal conductivity of bonded hollow-sphere monoliths." Thesis, Georgia Institute of Technology, 1991. http://hdl.handle.net/1853/20045.
Full textRussell, Carissa Don. "INTERFACIAL THERMAL CONDUCTIVITY USING MULTIWALL CARBON NANOTUBES." UKnowledge, 2010. http://uknowledge.uky.edu/gradschool_theses/30.
Full textRegan, Simon Edmund. "The low temperature thermal conductivity of polymers." Thesis, University of Leeds, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.277153.
Full textZalaf, M. "The thermal conductivity of electrically-conducting liquids." Thesis, Imperial College London, 1988. http://hdl.handle.net/10044/1/47321.
Full textBilek, Jaromir. "Sensors for thermal conductivity at high temperatures." Thesis, University of Southampton, 2006. https://eprints.soton.ac.uk/47126/.
Full textKashfipour, Marjan Alsadat. "Thermal Conductivity Enhancement Of Polymer Based Materials." University of Akron / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=akron156415885613422.
Full textDougherty, Brian P. "An automated probe for thermal conductivity measurements." Thesis, Virginia Polytechnic Institute and State University, 1987. http://hdl.handle.net/10919/101183.
Full textM.S.
Natchimuthu, Chinnaraj Anand. "THERMAL CONDUCTIVITY ENHANCEMENT IN NANOFLUIDS -MATHEMATICAL MODEL." OpenSIUC, 2011. https://opensiuc.lib.siu.edu/theses/758.
Full textJensen, Colby. "TRISO Fuel Thermal Conductivity Measurement Instrument Development." DigitalCommons@USU, 2010. https://digitalcommons.usu.edu/etd/838.
Full textLiang, L. H., and Y. G. Wei. "Ultralow Thermal Conductivity and Thermal Stress of Ceramics with Surface Nanowire-structures." Thesis, Sumy State University, 2012. http://essuir.sumdu.edu.ua/handle/123456789/34880.
Full textGanvir, Ashish. "Microstructure and Thermal Conductivity of Liquid Feedstock Plasma Sprayed Thermal Barrier Coatings." Licentiate thesis, Högskolan Väst, Avd för tillverkningsprocesser, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:hv:diva-9061.
Full textMathis, Nancy Elaine. "Measurements of thermal conductivity anisotropy in polymer materials." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1996. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/NQ62173.pdf.
Full textDelap, Martin Richard. "Thermal conductivity studies of YBa₂Cu₃O₇₋δ." Thesis, Durham University, 1990. http://etheses.dur.ac.uk/9301/.
Full textRees, Mary Frances. "Thermal conductivity measurements on high Tâ†c superconductors." Thesis, University of Liverpool, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.317234.
Full textLow, Jasmine. "Thermal conductivity of soils for energy foundation applications." Thesis, University of Southampton, 2016. https://eprints.soton.ac.uk/389737/.
Full textAndersson, Robin. "Modeling Radiation Induced Degradation of Lattice Thermal Conductivity." Thesis, KTH, Materialvetenskap, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-277885.
Full textKärnkraftsteknologin genomgår just nu en revolutionerande utvecklingspro- cess och dess användning debatteras över hela världen där hållbarhet är en av de viktigaste ståndpunkterna i materialvetenskapsområdet. Vissa komponenter i ett kärnkraftverk blir utsatta för en bestrålande miljö vilket orsakat stor skada på materialet över tid. Det är därför av högsta vikt att dessa material är desig- nade för att motstå sådana miljöer på grund av kärnkraftverkens långa livstid. De högenergetiska partiklarna som är förekommande vid kärnreaktioner gene- rerar punktdefekter i materialets mikrostruktur vilka ändrar de makroskopiska egenskaperna hos materialet. Värmehantering är kritiskt i ett kärnkraftverk och därför är detta arbete de- dikerat till att modellera effekten av försämring av värmeledningsförmågan i kristallgittret, som resultat av punktdefekterna, och att definiera sambandet. Detta uträttas genom ab initio simuleringar av superceller där de kvantmekaniska krafterna beräknas med täthetsfunktionalsteori med en generaliserad approximation av täthetsgradienten för den tillhörande utbytes- och korrela- tionstermen. Boltzmann ekvationen löses med hjälp av linjärisering och med en approximation av relaxationstiden vilket används för att beräkna värmeledningen i gittret för modellen. Fononernas band-moder och tillståndstäthet undersöks därtill. För närvarande finns det inga rapporter bland litteraturen där detta ämne behandlas med samma metoder.
Stolk, Jonathan Douglas. "Development of low thermal expansion, high conductivity nanocomposites /." Digital version accessible at:, 1999. http://wwwlib.umi.com/cr/utexas/main.
Full textHua, Zilong. "Hybrid Photothermal Technique for Microscale Thermal Conductivity Measurement." DigitalCommons@USU, 2013. https://digitalcommons.usu.edu/etd/1491.
Full textGhai, Ramandeep Singh. "Modelling Thermal Conductivity of Porous Thermal Barrier Coatings for High-Temperature Aero Engines." Thesis, Université d'Ottawa / University of Ottawa, 2017. http://hdl.handle.net/10393/37035.
Full textKalkundri, Kaustubh. "Development and verification of an apparatus for thermal resistance and thermal conductivity measurements." Diss., Online access via UMI:, 2006.
Find full textTran, Sam, Niklas Lindborg, Souza Vivedes Danilo De, Johanna Sjölund, Veronica Enblom, and Mattias Sjödin. "Theoretical models of thermal conductivity and the relationship with electrical conductivity for compressed metal powder." Thesis, Uppsala universitet, Institutionen för teknikvetenskaper, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-387636.
Full textBelyaeva, A. I., A. A. Galuza, P. A. Khaimovich, I. V. Kolenov, Alla Aleksandrovna Savchenko, I. V. Ryzhkov, A. F. Shtan’, S. I. Solodovchenko, and N. A. Shulgin. "Effect of the grain size on the precipitate distribution of the dispersion-strengthened СuСrZr alloy." Thesis, Національний науковий центр "Харківський фізико-технічний інститут", 2014. http://repository.kpi.kharkov.ua/handle/KhPI-Press/48167.
Full textLin, Wen-chin, and 林文進. "Thermal Conductivity Measurement of Thermal Interface Materials." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/40127527963600451177.
Full text國立臺灣科技大學
機械工程系
96
Applying a Thermal Interface Material (TIM), which has an excellent heat conductivity value, into the interface between the heat source surface and the heat-spreading module could greatly reduce the temperature drop across the interface between the heat source and the heat-spreading module. In order to obtain the optimal choice of TIM, the thermal conductivity of TIM should be determined precisely. The materials used in this study were thermal pad and thermal grease, and two thermal conductivity measuring methods were compared, including measuring the thermal conductivity value using a steady-state heat transfer equation and a transient state heat transfer equation, respectively. The steady state heat transfer equation is based on a one-dimensional heat conduction principle, wherein the temperature difference across a material becomes constant and the thermal conductivity of this material can be determined using a formula. The measurement of thermal conductivity value using transient-state heat conduction employs a line heat source, whose heat dissipates laterally to the material to be tested. The variation of temperature with time in the heat source was used to derive the thermal conductivity value of the tested material. The results showed that measuring the thermal conductivity value by the steady-state heat conduction method obviously needed a longer measuring time, but it could obtain more precise results. On the other hand, the precision of the transient-state heat conduction method was less precise because of the possible existence of air bubble next to the thermocouple and the utilization of a simplified equation for fitting the measured data.
Wang, Shize. "Thermal Conductivity of Nanocrystalline Nickel." Thesis, 2011. http://hdl.handle.net/1807/31628.
Full textAbbasy, Farzaan. "Thermal conductivity of mine backfill." Thesis, 2009. http://spectrum.library.concordia.ca/976499/1/MR63157.pdf.
Full text童資芸. "Thermal Conductivity of Magnetic Nanowires." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/37380308712321489520.
Full text周正三. "= Thermal-conductivity micro pressure sensor." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/00892565758379687449.
Full text周暄苹. "Thermal conductivity, thermal expansion and electrical conductivity in AlxCoCrFeNi ((0 ≤ x ≤ 2) high-entropy alloys." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/16057731030636336468.
Full text國立清華大學
材料科學工程學系
96
In order to investigate fundamental properties of high-entropy alloys, this study has selected 5 elements, such as Al, Co, Cr, Fe and Ni, to prepare various AlxCoCrFeNi alloys for 0 �T x �T 2, and to explore the effects of microstructure on the heat conductivity, thermal expansion and electrical conductivity of the alloys in the temperature ranges of 298 – 573 K, 298 – 1073 K, and 298 – 400 K, respectively. Besides, the relation between properties and atomic bonding among elements in the alloys is also explored in this study. Experimental results from XRD and SEM show that the microstructure of these alloys is single FCC, duplex FCC + BCC, and single BCC for as-cast alloys (C-alloys) in the composition ranges of 0 �T xFCC �T 0.375, 0.5 �T xduplex �T 0.75, and xBCC �d 0.875, respectively, while the duplex phase area xduplex extends from 0.375 to 1.25 and xBCC �d 1.25 for the homogenized and quenched alloys (H-alloys). DSC analyses show no evidences of phase transformation in the temperature range of 298 to 773 K, indicating that the high-entropy effect makes the alloys more soluble among components in the alloys. The XRD peak intensities for H-alloys are lower than those of the pure component elements indicates that FCC and BCC structures in H-alloys have larger scattering effect for x-ray diffraction and more electron-phonon scattering and hence H-alloys have lower thermal and electrical conductivity. The ratio of thermal conductivity to electrical conductivity shows the contribution of phonon is comparable to that of electron in thermal conductivity. The anharmonic oscillation for atoms due to lattice distortion is large. As temperature increases the thermal expansion coefficient increases accordingly. This study shows various aspects of microstructural influence on the properties of the alloys. Since the atomic radius of Al is approximately 14.4 % greater than the radii of Co, Cr, Fe and Ni, the increasing amount of Al addition to the alloys decreases the XRD intensities of the alloys. This in turn increases the x-ray scattering in the alloys and influences properties of both single phases and duplex phase of the alloys. The relation of both thermal conductivity and electrical conductivity as a function of the amount of Al addition is seen to divide in three regimes just as that in the case of microstructure, i.e., FCC, FCC + BCC, BCC regimes. In both single-phase regimes, both thermal conductivity and electrical conductivity decrease as the amount of Al, x, increases. In duplex FCC/BCC regime both thermal conductivity and electrical conductivity are smaller than those in single-phase regimes. This is because of the additional scattering effect of FCC-BCC phase boundaries. Hardness increases monotonically with x for both C- and H-alloys, indicating that the atomic bonding strength also increases with x. In both single-phase regimes although the hardness increases slightly with x, the hardness keeps roughly constant in single-phase regimes, while the hardness of alloys in the duplex regime increases linearly with x. In BCC regime the hardness for H-alloys is slightly higher than that for C-alloys. This is attributed to the spinodal decomposition during homogenization of H-alloys at 1100 oC. The thermal expansion coefficient of H-alloys decreases with x is also attributed to the increase in bond strength as x increases. There are two phase-transformation temperatures for H-alloys in both thermal expansion measurements and DTA analyses. One is for ferromagnetic-to-paramagnetic transition (i.e., Curie temperature,) the other is for �耤VNiCoCr precipitation that is characterized by HTXRD and DTA. Curie temperature for single-phase H-alloys increases slightly with x, while there is a lower point for Curie temperature for duplex H-alloys. Since Curie temperature is proportional to molecular field in the Weiss theory of magnetism, the molecular field is also closely related to bond strength and microstructure of the alloys.
Schneider, Donald A. "Thermal contact resistances in a thermal conductivity test system." Thesis, 1998. http://hdl.handle.net/1957/33742.
Full textGraduation date: 1999
Chi, Fu Yao, and 紀富耀. "The Thermal Conductivity of Asphalt ConcreteMeasurement Using Thermal Probe." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/a3k5yd.
Full text國立高雄應用科技大學
土木工程與防災科技研究所
102
Global warming primarily caused by modern industrial pollution has been a long-existing issue attracting great concerns. Taiwan is located around the fault where Eurasian Plate and Philippine Sea Plate are merged, resulting in a high reoccurrence of earthquakes. In addition to this, high degrees of temperature and natural hazards such as typhoons frequently occurred during summer season have resulted in a fast deterioration of civil infrastructures. Pavement among many of those is gaining problems such as lowered performance and durability than ever, which will indirectly affect the economy of the entire society. This study mainly focuses on the investigation of thermal conduction characteristics of asphalt concrete (AC) at high temperature. One of the research novelties is to employ by design an economic measuring apparatus. A low-cost thermal probe and self-assembled data acquisition system (both software and hardware) were used in this study. AC specimens were prepared for heating test by drilling two sizes of apertures (Φ5mm and Φ12mm) at the center, filling with thermal cement, and inserting properly the thermal probes. The coefficients of thermal conductivity (CTC) of AC specimens were obtained by observing and analyzing the temperature histories of the heating test. The study results show that CTC of AC materials varies with temperatures. Specifically, CTC is higher at low temperature and lower at higher temperature – there exists an inversely proportional relationship. Furthermore, CTC of AC materials was affected by the heating rates as well. Testing results indicate that CTC varies from 1.207 to 2.047 W/mK for low heating rate test (supplied with 2.5 to 15V), and from 1.326 to 1.718 W/mK for high heating rate test (supplied with 5 to 30V). The obtained CTCs in this study using thermal probe apparatus are shown to be comparable with other literature works. This suggests that thermal probe apparatus to be an economic, feasible and practical approach for extracting CTC of AC materials in fields.
Fu, Yu-Hsiu, and 傅裕修. "Thermal Conductivity and Sensitivity Analysis of Thermal Interface Material." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/63072920902327608273.
Full text國立清華大學
工程與系統科學系
95
At present, all the heat dissipation elements used in computer would be include heat sink, fan or heat pipe etc. Strictly speaking, the Thermal Interface Material (T.I.M.) should be account into too. A good T.I.M. could reduce largely the thermal resistance between heat source and the heat sink. In order to obtain the optimal selection, we need to measure the thermo properties of the T.I.M. very accuracy. The purpose of this paper is to build up a very high sensitivity T.I.M. measuring system which was based on one-dimension heat transfer theory and the precise processing technology. This article includes four parts, the first one is to discuss the effect of the different thickness of the spacer to the sensitivity of the instrument, the second part and the third part was discussing the repeatability and the reproducibility respectively. The fourth part was used dummy heater developed by ECS laboratory to evaluate the thermo resistance value of the grease and double check was that consistence evaluate from T.I.M. instrument. The experiment results showed that the ABS spacer developed by ECS laboratory a very good sensitivity performance. The relative error of the conductivity coefficient from the repeatability experiment was within 5%, while the relative error for the contact resistance was within 10%. The relative error of the reproducibility made by different operator was control within 2%.
Yuan, Mengqi. "Thermal conductivity measurements of polyamide powder." Thesis, 2011. http://hdl.handle.net/2152/ETD-UT-2011-12-4476.
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Chou, Hung-En, and 周弘恩. "Thermal Conductivity of Diamond-containing Grease." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/p76755.
Full text國立臺北科技大學
材料及資源工程系研究所
98
As one thermal interface material (TIM), thermal grease (TG) is widely applied to heat dissipation of electronic devices. Despite the superior thermal conductivity of diamond, reports about diamond-containing TG were rare. In the present study, thermal conductivity of five TGs was measured by hot disk technique. At first, the diamonds of two sizes were used alone or in combination to mix with CH3-terminated polydimethylsiloxane (PDMS). Under the same total filler content, the latter showed a better k(TG), especially at a small diamond content of 20 vol%. If a hybrid OH-terminated PDMS was adopted, 350 cps was a preferred viscosity to break through 3 W/mK. Unlike these single-filler TGs, if large diamonds were retained and small diamonds were replaced by Al2O3 or ZnO, it was found that diamond was not always the best choice of small filler. The highest k(TG), which was 23 times greater than k(PDMS) appeared in a ZnO-containing double-filler grease (=3.52 W/mK). The prediction for the maximum attainable k(TG) proposed by Bigg et al. was preliminarily supported. Scanning electron microscopy (SEM) images revealed that unlike homogeneous distributions of small-sized diamonds, the agglomeration of ZnO powders occupied regions with large area between diamonds and formed continuous thermal paths, which resulted in a better k(TG). Although k(TG) could be further improved to approximately 4 W/mK by replacing either large-sized diamond or ZnO by a small amount (5 vol.%) of h-BN, the so-called tri-filler grease was not available for application due to the hardened structure and poor flowability. From thermogravimetric analysis (TGA), no significant weight-loss was recorded for three double-filler TGs prepared in this study until 200℃, under which an central processing unit (CPU) operated. Their thermal stability was thus roughly suggested.