T6热处理对复式连通双连续相SiC/Al复合材料性能的影响

研究了T6热处理(固溶处理 时效)对复式连通双连续相SiC/A1复合材料的组织和压缩性能的影响.结果表明,经T6热处理后,复合材料基体中第二相共晶硅从粗大的针状变成了细小的粒状,增强了弥散强化效果,时效析出相Mg2Si强化了基体;界面附近的基体中残余应力增大,使复合材料的压缩强度显著提高,材料的弹性模量和塑性稍稍降低.随着固溶时间的延长,复合材料的压缩强度先升高后降低.其影响机制是,随着固溶时间的延长共晶硅扩散充分,球化完全,继而粗化长大,从而提高了弥散强化效果.随着时效时间的延长,材料中的残余应力减小,位错密度降低,时效强化相Mg2Si的强化能力减弱,使复合材料的压缩强度降低.

Influence of T6 treatment on microstructure and compressive property of SiC/Al double-interpenetrating composites

Influence of T6 heat treatment (solution treatment+aging) on the microstructure and compressive property of SiC/Al double-interpenetrating composite were investigated.Results showed that the compressive strength of composites treated by T6 treatment increases obviously,but the elastic module and the plasticity decrease because of the morphology change of eutectic silicon in matrix from coarse needle shape to fine particle and the strengthening of the precipitation Mg_2Si phase after T6 treatment.The compressive strength of composites get the peak value when the solution time is 8 hour for eutectic silicon is fining.The compressive strength is decreasing with the augment of aging time for the residual stress, density of dislocation and the strengthening of Mg_2Si on the matrix fall.