Al？50%SiC （volume fraction） composites containing different sizesofSiC particles （average sizesof 23, 38 and 75 μm） were prepared by powder metallurgy. The influences of SiC particle sizes and annealing on the p...Al？50%SiC （volume fraction） composites containing different sizesofSiC particles （average sizesof 23, 38 and 75 μm） were prepared by powder metallurgy. The influences of SiC particle sizes and annealing on the propertiesof the compositeswere investigated. The results show that SiC particles are distributed uniformly in the Al matrix. The coarse SiC particles result in higher coefficient of thermal expansion （CTE） and higher thermal conductivity （TC）, while fine SiC particles decrease CTE and improve flexural strength of the composites. The morphology and size of SiC particles in the composite are not influenced by the annealing treatment at 400℃for 6h. However, the CTE and the flexural strength of annealed composites are decreased slightly, and the TCis improved. The TC, CTE and flexural strength of the Al/SiC composite with averageSiC particlesize of75 μm are 156 W/（m·K）, 11.6×10^-6K^-1 and 229 MPa, respectively.展开更多
采用高频感应炉熔炼制备Al-50Si合金,通过金相、热物理性能、SEM和能谱分析仪对不同参数下得到的Al-50Si合金缺陷和热物理性能进行测试分析。结果表明,当熔炼频率为930 Hz,用4 g C_2Cl_6精炼剂精炼一次时铸态宏观样貌较好。随着温度的升...采用高频感应炉熔炼制备Al-50Si合金,通过金相、热物理性能、SEM和能谱分析仪对不同参数下得到的Al-50Si合金缺陷和热物理性能进行测试分析。结果表明,当熔炼频率为930 Hz,用4 g C_2Cl_6精炼剂精炼一次时铸态宏观样貌较好。随着温度的升高,气体的溶解度变小,气体更容易从金属液中逸出所以930 Hz熔炼时效果较好;随着精炼次数和精炼剂单次用量的增加,气孔有逐渐变大的趋势。这是因为精炼时金属液剧烈翻腾不但会卷入新的气体,还可能会使金属液中的气孔逐渐聚集所以气孔会逐渐变大。铸造气孔的存在降低了材料的热导率,同时气孔的增加也使得材料的线膨胀系数变大。展开更多
A hypereutectic Al-50 wt%Si alloy for electronic packaging was prepared by spark plasma sintering(SPS)technology using gas-atomized Al-50 wt%Si powder.The effect of sintering parameters on alloy phase composition,micr...A hypereutectic Al-50 wt%Si alloy for electronic packaging was prepared by spark plasma sintering(SPS)technology using gas-atomized Al-50 wt%Si powder.The effect of sintering parameters on alloy phase composition,microstructure,thermal performance and the tensile strength at different temperatures was investigated.The experimental results show that the alloy can obey the diffraction peaks of silicon and aluminum without other peaks appearing.The primary silicon in the prepared alloy can be evenly distributed in the aluminum matrix.The coefficient of thermal expansion(CTE)and thermal conductivity(TC)of the alloy will improve with the increase of sintering temperature,but they will decrease after sintering for a long time,which is caused by the large difference of coefficient of thermal expansion between silicon and aluminum.The tensile properties of the alloy at room temperature will increase with the increase of sintering temperature,but higher test temperatures will inhibit the tensile properties except the elongation.The morphology and fracture mode of the tensile fracture are also analyzed to determine the good bonding strength of the alloy.展开更多
基金Project support by the 2015 Shandong Province Project for Outstanding Subject Talent Group,China
文摘Al？50%SiC （volume fraction） composites containing different sizesofSiC particles （average sizesof 23, 38 and 75 μm） were prepared by powder metallurgy. The influences of SiC particle sizes and annealing on the propertiesof the compositeswere investigated. The results show that SiC particles are distributed uniformly in the Al matrix. The coarse SiC particles result in higher coefficient of thermal expansion （CTE） and higher thermal conductivity （TC）, while fine SiC particles decrease CTE and improve flexural strength of the composites. The morphology and size of SiC particles in the composite are not influenced by the annealing treatment at 400℃for 6h. However, the CTE and the flexural strength of annealed composites are decreased slightly, and the TCis improved. The TC, CTE and flexural strength of the Al/SiC composite with averageSiC particlesize of75 μm are 156 W/（m·K）, 11.6×10^-6K^-1 and 229 MPa, respectively.
文摘采用高频感应炉熔炼制备Al-50Si合金,通过金相、热物理性能、SEM和能谱分析仪对不同参数下得到的Al-50Si合金缺陷和热物理性能进行测试分析。结果表明,当熔炼频率为930 Hz,用4 g C_2Cl_6精炼剂精炼一次时铸态宏观样貌较好。随着温度的升高,气体的溶解度变小,气体更容易从金属液中逸出所以930 Hz熔炼时效果较好;随着精炼次数和精炼剂单次用量的增加,气孔有逐渐变大的趋势。这是因为精炼时金属液剧烈翻腾不但会卷入新的气体,还可能会使金属液中的气孔逐渐聚集所以气孔会逐渐变大。铸造气孔的存在降低了材料的热导率,同时气孔的增加也使得材料的线膨胀系数变大。
基金the Shanxi Key Laboratory of Nano-materials and Technology,China(Nos.18JS060,17JS075)。
文摘A hypereutectic Al-50 wt%Si alloy for electronic packaging was prepared by spark plasma sintering(SPS)technology using gas-atomized Al-50 wt%Si powder.The effect of sintering parameters on alloy phase composition,microstructure,thermal performance and the tensile strength at different temperatures was investigated.The experimental results show that the alloy can obey the diffraction peaks of silicon and aluminum without other peaks appearing.The primary silicon in the prepared alloy can be evenly distributed in the aluminum matrix.The coefficient of thermal expansion(CTE)and thermal conductivity(TC)of the alloy will improve with the increase of sintering temperature,but they will decrease after sintering for a long time,which is caused by the large difference of coefficient of thermal expansion between silicon and aluminum.The tensile properties of the alloy at room temperature will increase with the increase of sintering temperature,but higher test temperatures will inhibit the tensile properties except the elongation.The morphology and fracture mode of the tensile fracture are also analyzed to determine the good bonding strength of the alloy.
基金Supported by the National Science Foundation of China (50901025, 50771041, 50975060)State Key Lab of Advanced Metals Materials (2009ZD-06)and Program of Excellent Team in Harbin Institute of Technology
基金National Natural Science Foundation of China (51865012)Natural Science Foundation of Jiangxi Province (20202BABL204040)+3 种基金Open Foundation of National Engineering Research Center of Near-Net-Shape Forming for Metallic Materials,China (2016005)Science Foundation of Educational Department of Jiangxi Province,China (GJJ170372)GF Basic Research Project,China (JCKY2016603C003)Research Project of Special Furnishment and Part,China (JPPT125GH038)。
