时效处理对中高体积分数SiC_(p)/2024Al复合材料力学性能的影响

Effect of aging on mechanical properties of medium and high volume fraction SiC_(p)/2024Al composites

采用热等静压工艺分别制备了SiC_(p)体积分数为35%、45%和55%的SiC_(p)/2024Al复合材料,研究了固溶时效处理对3种复合材料硬度、弯曲强度和冲击性能的影响。结果表明,3种SiC_(p)体积分数的复合材料均由Al、SiC和Al2Cu相组成,致密度均较高,基体与SiC_(p)增强体之间结合紧密。固溶时效处理(T6)可以显著提升复合材料的硬度。SiC_(p)体积分数为35%、45%和55%的复合材料的时效硬化曲线变化规律基本一致,均在时效2 h时达到峰时效状态,硬度分别比制备态复合材料提升了51.56%,41.51%和18.78%。SiC_(p)体积分数为35%的时效态复合材料弯曲强度提升幅度最显著,由622.48 MPa提升至838.11 MPa。随着SiC_(p)体积分数的增加,制备态复合材料的冲击吸收能量由3.43 J逐渐降低至1.00 J,T6处理会进一步降低复合材料的冲击性能。

SiC_(p)/2024Al composites with SiC_(p) volume fractions of 35%,45%and 55%were prepared by hot isostatic pressing(HIP).The effects of solution and aging treatment on the hardness,bending strength and impact property of the composites were studied.The results show that the composites with different SiC_(p) volume fractions are all composed of Al,SiC and Al 2Cu phases and have high density,indicating the good bonding between SiC_(p) reinforcement and matrix alloy.The hardness of the composites can be significantly enhanced by solution and aging treatment(T6).The aging⁃hardness curves of the SiC_(p)/Al composites with SiC_(p) volume fractions of 35%,45%,55%are basically the same,with the peak⁃aging time being 2 h,and the hardness increment of which are 51.56%,41.51%and 18.78%,respectively.The SiC_(p)/2024Al composite with SiC_(p) volume fractions of 35%presents the most significant increase in bending strength,being from 622.48 MPa to 838.11 MPa.As the SiC_(p) volume fraction increases,the impact absorbed energy of the HIP state composite decreases gradually from 3.43 J to 1.00 J,which can be further reduced after T6 treatment.