界面改性对SiC_p/Cu复合材料热物理性能的影响

采用热压烧结法成功制备SiC_p/Cu复合材料。采用溶胶-凝胶工艺在SiC颗粒表面制备Mo涂层,研究Mo界面阻挡层对复合材料热物理性能的影响。结果表明:过氧钼酸溶胶-凝胶体系能够在SiC颗粒表面包覆连续性、均匀性较好的MoO_3涂层,最佳工艺配比为SiC∶MoO_3=5∶1(质量比)、过氧化氢∶乙醇=1∶1(体积比),SiC表面丙酮和氢氟酸预清洗处理有利于MoO_3涂层的沉积生长。MoO_3在540℃第一步氢气还原后转变为MoO_2,MoO_2在940℃第二步氢气还原后完全转变为Mo,Mo涂层包覆致密完整。热压烧结SiC_p/Cu复合材料微观组织致密均匀,且相比原始SiC颗粒增强的SiC_p/Cu,经溶胶-凝胶法界面改性处理的SiC_p/Cu复合材料热导率明显提高,SiC体积分数约为50%时,SiC_p/Cu复合材料热导率达到214.16W·m~(-1)·K~(-1)。

Effect of Interfacial M odifying on T hermo-physical Properties of SiCp/Cu Composites

SiCp/Cu composites were successfully fabricated by vacuum hot‐pressing method .Molybde‐num coating w as deposited on the surface of silicon carbide by sol‐gel method .T he effects of the inter‐facial design on thermo‐physical properties of SiCp/Cu composites were studied .The results indicate that :continuous and uniform MoO3 coating can be deposited on the surface of silicon carbide by per‐oxomolybdic acid sol‐gel system ,and the best processing parameters are as follows :SiC∶ MoO3 =5∶1(mass ratio) ,H2 O2 ∶C2 H5 OH=1∶1(volume ratio) ,and surface pretreatment with acetone and hydrofluoric acid is good to the deposition and growth of MoO3 coating .After hydrogen reduction at 540℃ for 90min the MoO3 is changed into MoO2 ,and then hydrogen reduction at 940℃ for 90min the MoO2 is changed into Mo absolutely ,and the Mo coating is continuous and uniform .SiCp/Cu compos‐ites prepared by vacuum hot‐pressing method show a compact and uniform microstructure ,and the thermal conductivity of the composites is increased obviously after the Mo coating interfacial modifica‐tion ,w hich can reach 214 .16W · m -1 · K -1 w hen the volume of silicon carbide is about 50% .