SiC含量对铝基复合材料组织与力学性能的影响

Effect of SiC Content on Microstructure and Mechanical Properties of Aluminum-base Composites

采用半固态-液态搅拌铸造法制备了SiC颗粒增强铝基复合材料。研究了SiC颗粒含量(质量分数分别为0、5%、10%、15%和20%)对铝基复合材料组织及力学性能的影响。结果显示:添加少量SiC颗粒时,SiC颗粒在基体中分散均匀;当SiC质量分数达到15%时,SiC颗粒团聚较严重。随着SiC颗粒含量的增加,复合材料的硬度和抗拉强度先升高后降低。原因是SiC颗粒的位错强化作用,使得铝基复合材料的力学性能得到提升。随着SiC颗粒含量的增加,与界面结合良好的含Mg相数量减少,并且SiC颗粒团聚严重,铝基复合材料的力学性能降低。

SiC particle reinforced aluminum base composites were fabricated by the semi-solid liquid stirring casting method.The effect of SiC particle contents(mass fractions were 0,5%,10%,15%and 20%,respectively)on the microstructure and mechanical properties of the aluminum base composites was studied.The results showed that when a small amount of SiC particles were added,the SiC particles were uniformly dispersed in the matrix,and when the SiC content reached 15%by mass,the SiC particles were highly clustered.The hardness and tensile strength of the composites increased first and then decreased with the increase of SiC particle content.The mechanical properties of the aluminum-base composites were improved due to the dislocation strengthening of SiC particles.With the increase in SiC content,the amounts of Mg-bearing phases combining well with the marix decreased and the SiC particles aggregated seriously,which reduced the mechanical properties of the aluminum-base composite.