【摘要】 用粉末冶金法制备了纳米SiC颗粒增强纯Al基复合材料(AlMMC),对该材料的微观结构和拉伸性能进行了研究。结果表明,纳米SiC颗粒在含量很少时即对Al有明显的强化作用。此时。纳米颗粒在基体中的分散比较均匀,且多位于Al的晶界处;当含量较高时则颗粒易于团聚。颗粒团聚体和晶界处的SiC颗粒会使SiC对Al的弥散增强效果明显低于理论预测值。纳米SiC颗粒含量发生变化,Al MMC的断裂机制也有所改变。更多还原

【Abstract】 The SiC nanoparticles reinforced aluminum matrix composites (Al MMC) were fabricated by a powder metallurgy technique. The microstructure of the Al MMC was observed, and the tensile properties were investigated. When the concentration of SiC nanoparticles is lower, the Al MMC is greatly reinforced, and the SiC nanoparticles are uniformly dispersed in the Al matrix. The SiC nanoparticles are mainly distributed at the Al grain boundaries. However, when the concentration of SiC nanoparticles increases, the SiC nanoparticles are easily agglomerated. The MMC possesses lower strength compared with that predicted by Orowan strengthening theory because of the agglomeration of SiC nanoparticles and SiC nanoparticles on the grain boundaries. The tensile fracture surface shows that the change of the damage mechanism of the Al MMC will take place when the concentration of SiC nanoparticles increases.更多还原