AlN覆钨对AlN/W-Cu复合材料组织和性能的影响

Effect of tungsten coated AlN on microstructure and properties of AlN/W-Cu composites

采用溶胶凝胶法对AlN粉体进行表面覆W后,将其与适量W粉混合,经压制、预烧结,制得多孔AlN/W骨架,再熔渗Cu后制备出不同AlN含量(0~8%)的AlN/W-Cu复合材料。考察了AlN含量对于烧结体微观组织、力学性能和热学性能的影响,并与由未覆钨AlN粉体制备的AlN/W-Cu复合材料进行对比。结果表明,采用溶胶凝胶法可在AlN颗粒表面均匀制备覆W层,其界面结合良好。覆钨AlN/W-Cu复合材料的相对密度、硬度、抗拉强度以及热导率均优于未覆钨AlN/W-Cu复合材料的。AlN/W-Cu复合材料的相对密度、抗拉强度及热导率随AlN含量的增加而降低,而硬度随AlN含量的增加而上升。当AlN含量为2%时,覆钨AlN/W-Cu复合材料的综合性能最佳,相对密度达到97.69%,显微硬度达到277HV,热导率达到205.54 W/(m·K)。

AlN powders were coated with tungsten by sol-gel method,and then mixed with tungsten powders.The AlN/W-Cu composites with different AlN contents(0−8%)were prepared by infiltrating the porous AlN/W skeletons which were obtained by pressing and sintering the AlN/W powders mixes with Cu.The effects of the AlN contents on the microstructure and properties of the sintered simples were investigated and compared with those of the AlN/W-Cu composites prepared from uncoated AlN powders.The results show that the W particles are uniformly coated on the surface of AlN particles with good interfacial bonding.The relative density,hardness,tensile strength and thermal conductivity of the AlN/W-Cu composites prepared from tungsten-coated AlN powders are better than those of the AlN/W-Cu composites prepared from uncoated AlN powders.While the relative density,tensile strength and thermal conductivity of the AlN/W-Cu composites decrease with the increase of AlN content,the hardness increases with the increase of AlN content.The relative density of the AlN/W-Cu composites prepared from tungsten-coated AlN powders reaches 97.69%,the hardness reaches 277HV and the thermal conductivity reaches 205.54 W/(m·K)with addition of 2%AlN.