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采用注射成型方法制备了SiCP封装盒体的预成型坯, 用压力浸渗方法将熔融铝浸渗到SiCP封装盒体的预成型坯中, 制备出含SiCP体积分数为65 %的SiCP / Al 复合材料的封装盒体。SEM 观察表明, 经过压力浸渗后SiCP / Al 复合材料组织均匀且致密化高, 室温热膨胀系数为8. 0 ×10-6 / K, 热导率接近130 W/ (m·K) , 密度为2198 g/ cm3 , 能够很好地满足电子封装的要求。 相似文献
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《Materials Science & Technology》2013,29(12):1518-1520
AbstractThe characterisation of thermal expansion coefficient and thermal conductivity of Al–Si matrix alloy and Al–Si alloy reinforced with fine SiCp (5 and 20 wt-%) composites fabricated by stir casting process are investigated. The results show that with increasing temperature up to 350°C, thermal expansion of composites increases and slowly reduces when the temperature reaches to 500°C. The values of both thermal expansion and conductivity of composites are less than those for Al–Si matrix. Microstructure and particles/matrix interface properties play an important role in the thermal properties of composites. Thermal properties of composites are strongly dependent on the weight percentage of SiCp. 相似文献
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Polymer/Sr2ZnSi2O7 (SZS) ceramic composites suitable for substrate applications have been developed using the polymers polystyrene (PS), high
density polyethylene (HDPE) and Di-Glycidyl Ether of Bisphenol A (DGEBA). The dielectric, thermal and mechanical properties
of the composites are investigated as a function of various concentrations of the ceramic filler. The obtained values of relative
permittivity, dielectric loss tangent, thermal conductivity and coefficient of thermal expansion of the composites are compared
with the corresponding theoretical predictions. The relative permittivity of the polymer/ceramic composites increases with
filler loading. The dielectric loss tangent also shows the same trend except for DGEBA/SZS composites. The major advantages
of the ceramic loading are improvement in thermal conductivity and a decrease in the coefficient of thermal expansion. The
tensile strength of the composites decreases with increase in filler content, whereas an improvement is observed in microhardness.
The variation of relative permittivity (at 1 MHz) of the composites is also studied as a function of temperature. 相似文献
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The thermal conductivity coefficient in the temperature range from 275 to 450 K and the coefficient of thermal expansion in the range from 300 to 900 K are experimentally determined for solid solutions of the CaLa2S4-La2S3 system. The mechanisms of heat transfer in CaLa2S4- La2S3 samples in the investigated temperature range are discussed, as well as the factors which define the complex concentration dependence of thermal conductivity coefficient. The correlation is treated between the value and temperature dependence of the coefficient of thermal expansion and the variation of the interatomic bond force in the case of variation of the concentration of cation vacancies in the investigated crystals. 相似文献
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采用针刺预制体经化学气相沉积与沥青浸渍-高压碳化致密工艺制备C/C复合材料,通过控制沥青浸渍-高压碳化致密次数,获得了密度分别为1.70g/cm~3、1.82g/cm~3、1.89g/cm~3的三种C/C材料,测试材料的力学、热学性能。结果表明材料拉伸强度随密度升高而降低。当密度较低时,纤维/基体界面结合强度相对较低,可以延缓纤维断裂的发生;拉伸断口显示出假塑性断裂特征,有利于材料拉伸强度的提高。材料的压缩强度与剪切性能密切相关,且均随密度升高表现出先升后降的趋势。材料的热膨胀系数随密度升高而增大,材料中微晶之间的空隙在受热过程中可以吸收一部分膨胀量,因此对于C/C材料,降低密度有利于降低热膨胀系数。材料导热系数随密度升高而明显增大,且随密度升高,微晶尺寸增大,有利于晶格振动的传递,从而使得导热系数增大。热应力因子随密度升高而先升后降,作为热结构件使用时,采用密度为1.82g/cm~3的C/C材料可以获得相对较高的抗热震能力。在C/C材料研究开发中,可以综合对材料力学、热学性能的要求来对C/C材料密度指标进行设计。 相似文献
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Fabrication process and thermal properties of SiCp/Al metal matrix composites for electronic packaging applications 总被引:10,自引:0,他引:10
Hyo S. Lee Kyung Y. Jeon Hee Y. Kim Soon H. Hong 《Journal of Materials Science》2000,35(24):6231-6236
The fabrication process and thermal properties of 50–71 vol% SiCp/Al metal matrix composites (MMCs) for electronic packaging applications have been investigated. The preforms consisted with 50–71 vol% SiC particles were fabricated by the ball milling and pressing method. The SiC particles were mixed with SiO2 as an inorganic binder, and cationic starch as a organic binder in distilled water. The mixtures were consolidated in a mold by pressing and dried in two step process, followed by calcination at 1100 °C. The SiCp/Al composites were fabricated by the infiltration of Al melt into SiC preforms using squeeze casting process. The thermal conductivity ranged 120–177 W/mK and coefficient of thermal expansion ranged 6–10 × 10–6/K were obtained in 50–71 vol% SiCp/Al MMCs. The thermal conductivity of SiCp/Al composite decreased with increasing volume fraction of SiCp and with increasing the amount of inorganic binder. The coefficient of thermal expansion of SiCp/Al composite decreased with increasing volume fraction of SiCp, while thermal conductivity was insensitive to the amount of inorganic binder. The experimental values of the coefficient of thermal expansion and thermal conductivity were in good agreement with the calculated coefficient of thermal expansion based on Turner's model and the calculated thermal conductivity based on Maxwell's model. 相似文献
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Ice‐Templated Assembly Strategy to Construct 3D Boron Nitride Nanosheet Networks in Polymer Composites for Thermal Conductivity Improvement 下载免费PDF全文
Xiaoliang Zeng Yimin Yao Zhengyu Gong Fangfang Wang Rong Sun Jianbin Xu Ching‐Ping Wong 《Small (Weinheim an der Bergstrasse, Germany)》2015,11(46):6205-6213
Owing to the growing heat removal issue of modern electronic devices, polymer composites with high thermal conductivity have drawn much attention in the past few years. However, a traditional method to enhance the thermal conductivity of the polymers by addition of inorganic fillers usually creates composite with not only limited thermal conductivity but also other detrimental effects due to large amount of fillers required. Here, novel polymer composites are reported by first constructing 3D boron nitride nanosheets (3D‐BNNS) network using ice‐templated approach and then infiltrating them with epoxy matrix. The obtained polymer composites exhibit a high thermal conductivity (2.85 W m−1 K−1), a low thermal expansion coefficient (24–32 ppm K−1), and an increased glass transition temperature (Tg) at relatively low BNNSs loading (9.29 vol%). These results demonstrate that this approach opens a new avenue for design and preparation of polymer composites with high thermal conductivity. The polymer composites are potentially useful in advanced electronic packaging techniques, namely, thermal interface materials, underfill materials, molding compounds, and organic substrates. 相似文献
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With the rapid development of the electronic information industry, better properties are required for substrate and packaging materials such as high thermal conductivity, low coefficient of thermal expansion, and low dielectric constant. Polymers are ordinarily being used for this purpose due to their high electrical resistivity and low density, but unfortunately they suffer from a disadvantage like low thermal conductivity. To offset this deficiency, adding inorganic conductive particles to polymer is a versatile method. In view of this, the present work aims at developing a class of particulate filled polymer composites with micro-sized aluminum nitride (AlN) particles having an average particle size of 60–80 µm reinforced in epoxy matrix. A set of composites, with filler content ranging from 0 to 25 vol%, have been prepared by the hand-layup technique. Effects of filler percentage on various properties like effective thermal conductivity (keff), coefficient of thermal expansion (CTE), glass transition temperature (Tg), and dielectric constant (εc) are studied. It is found that the incorporation of AlN in resin increases the keff and Tg, whereas CTE of the composite decreases favorably. Though dielectric constant of the matrix increases with filler content yet it remains well within the desirable limit. With modified thermal and dielectric characteristics, these composites can possibly be used for microelectronics applications. 相似文献
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D. V. Shangina J. Gubicza E. Dodony N. R. Bochvar P. B. Straumal N. Yu. Tabachkova S. V. Dobatkin 《Journal of Materials Science》2014,49(19):6674-6681
Quenched and slowly cooled (annealed) Cu–0.7 %Cr, Cu–0.9 %Hf, and Cu–0.7 %Cr–0.9 %Hf alloys were processed by high pressure torsion (HPT). The microstructures of the alloys were studied immediately after HPT and subsequent annealing. It has been shown that the microhardness and the thermal stability of the severely deformed microstructure increase, while the average grain size decreases in the order of Cu–0.7 %Cr, Cu–0.9 %Hf, and Cu–0.7 %Cr–0.9 %Hf alloys. The microhardness in all alloys is higher after quenching and HPT, than after annealing and HPT. The largest dislocation density is achieved by quenching and HPT in Hf-containing samples. Cu5Hf phase precipitations in Hf-containing alloys are more effective in retarding grain growth in comparison with Cr particles and lead to additional hardening during aging. It has been demonstrated that HPT-processing with subsequent heat-treatment might yield the combination of large hardness and high electrical conductivity in Cu alloys. 相似文献
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研究了采用不同放电等离子烧结(SPS)工艺获得的单质金属(Ni、Cu、Ag、Al)电极与Mg-Si-Sn基热电材料结合界面的微观形貌和成分分布特征, 测试了合金(Ni-Al、Cu-Al)、金属/合金复合电极材料的热膨胀系数、电导率和热导率等物性参数。实验结果表明: 通过SPS烧结可以有效实现电极材料与Mg-Si-Sn基材料的连接, 复合电极材料Ni-Al/Al(60:40)和Cu-Al/Cu(45:55)具有高的电导率和热导率, 并且热膨胀系数与Mg-Si-Sn基热电材料相匹配, 有可能成为Mg-Si-Sn基材料的较理想电极材料。 相似文献
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Rare‐earth aluminate ceramics for thermal‐barrier coatings (TBCs) are synthesized. The Young's modulus and thermal properties decrease with erbium additive increasing. The Y3?xErxAl5O12 ceramics (x = 1, 3) possess a much‐lower thermal conductivity compared with 8YSZ. The lower Young's modulus and thermal‐expansion coefficient are due to the larger atomic weight of the Er substitutional atom. Additional phonon‐scattering effects also contribute to the lower thermal conductivity. The results indicate that Y3?xErxAl5O12 can be explored as a candidate material for TBC systems. A theoretical model that describes the influence of point defects on the thermal conductivity is discussed. 相似文献
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P. Li G.S. Wu S.L. Yan J.L. Zhou K.M. Xue W.C. Shi 《Materialwissenschaft und Werkstofftechnik》2019,50(10):1273-1281
High pressure torsion experiment followed with heat treatment were carried out on as‐cast Al‐Zn‐Mg‐Cu‐Zr alloy at 400 °C under the pressure of 1 GPa. The microstructure, mechanical property and stress corrosion resistance properties for the as‐cast and high pressure torsion processed samples were studied. The results show that high pressure torsion processing can improve the mechanical property by the refinement of grains and grain boundary precipitates, as well as the homogeneous distribution of fine matrix precipitates. On the other side, the grain refinement, broken of coarse grain boundary precipitates and narrowed precipitates free zone caused by the high pressure torsion result in the improvement of stress corrosion cracking resistance. And due to the influence of heterogeneous lamellae structure, the sample after 0.5 high pressure torsion turn shows preferable mechanical property and stress corrosion cracking resistance than the sample after 2 high pressure torsion turns. 相似文献
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Optimization of Strength‐Electrical Conductivity Properties in Al–2Fe Alloy by Severe Plastic Deformation and Heat Treatment 下载免费PDF全文
Andrey E Medvedev Maxim Y Murashkin Nariman A Enikeev Ruslan Z Valiev Peter D Hodgson Rimma Lapovok 《Advanced Engineering Materials》2018,20(3)
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《Materials Science & Technology》2013,29(8):1057-1064
AbstractSiCp/Al composites containing high volume fraction SiC particles were fabricated using a pressure infiltration casting process, and their thermophysical properties, such as thermal conductivity and coefficient of thermal expansion (CTE), were characterised. High volume fraction SiC particulate preforms containing 50–70 vol.-%SiC particles were fabricated by ball milling and a pressing process, controlling the size of SiC particles and contents of an inorganic binder. 50–70 vol.-%SiCp/Al composites were fabricated by high pressure infiltration casting an Al melt into the SiC particulate preforms. Complete infiltration of the Al melt into SiC preform was successfully achieved through the optimisation of process parameters, such as temperature of Al melt, preheat temperature of preform, and infiltration pressure and infiltration time after pouring. Microstructures of 50–70 vol.-%SiCp/Al composites showed that pores resided preferentially at interfaces between the SiC particles and Al matrix with increasing volume fraction of SiC particles. The measured coefficients of thermal expansion of SiCp/Al composites were in good agreement with the estimated values based on Turner's model. The measured thermal conductivity of SiCp/Al composites agreed well with estimated values based on the 'rule of mixture' up to 70 vol.-% of SiC particles, while they were lower than the estimated values above 70 vol.-% of SiC particles, mainly due to the residual pores at SiC/Al interfaces. The high volume fraction SiCp/Al composite is a good candidate material to substitute for conventional thermal management materials in advanced electronic packages due to their tailorable thermophysical properties. 相似文献
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Ge Mu Daobin Mu Borong Wu Chengwei Ma Jiaying Bi Ling Zhang Hao Yang Feng Wu 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(3)
To address the non‐negligible volume expansion and the inherent poor electronic conductivity of silica (SiO2) material, microsphere‐like SiO2/MXene hybrid material is designed and successfully synthesized through the combination of the Stöber method and spray drying. The SiO2 nanoparticles are firmly anchored on the laminated MXene by the bonding effect, which boosts the structural stability during the long‐term cycling process. The MXene matrix not only possesses high elasticity to buffer the volume variation of SiO2 nanoparticles, but also promotes the transfer of electrons and lithium ions. Moreover, the microsphere wrapped with ductile MXene film reduces the specific surface area, relieves the side reactions, and enhances the coulombic efficiency. Therefore, superior electrochemical performance including high reversible capacity, outstanding cycle stability, high coulombic efficiency, especially in the first cycle, excellent rate capability as well as high areal capacity are acquired for SiO2/MXene microspheres anode. 相似文献
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SiC换热器材料热物理性质的研究 总被引:1,自引:0,他引:1
本文采用TLP-18型激光热常数仪和岛津TMA-30热分析仪研究了温度对等静压SiC换热器材料的导热系数和热膨胀系数的影响,并对影响SiC抗热震性能的各因素进行了分析。 相似文献