界面改性对SiCp／Cu复合材料热物理性能的影响

摘要

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% .%采用热压烧结法成功制备SiCp／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S iC颗粒表面包覆连续性、均匀性较好的MoO3涂层，最佳工艺配比为SiC∶MoO3＝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M oO3涂层的沉积生长。M oO3在540℃第一步氢气还原后转变为M oO2，M oO2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SiCp／Cu复合材料微观组织致密均匀，且相比原始SiC颗粒增强的SiCp／Cu ，经溶胶‐凝胶法界面改性处理的SiCp／Cu复合材料热导率明显提高，SiC体积分数约为50％时，SiCp／Cu复合材料热导率达到214．16W · m －1· K －1。