(西北工业大学 凝固技术国家重点实验室，西安 710072)
摘 要: 以体积比为7:3的比例混合粒径分别为75和15 μm两种尺寸的SiC颗粒，将其分别在1 200 ℃高温烧结2、4、6、8和10 h后采用气压浸渗法制备SiC体积分数为70%的SiCp/ZL101基复合材料，研究预制件高温烧结后复合材料的界面，讨论氧化以及界面反应对复合材料抗弯强度和导热性能的影响，并利用实验热导率反算实际界面传热系数。结果表明：双尺寸的SiC颗粒在Al合金基体中分布均匀；SiC预制件的氧化改变了SiC颗粒与Al合金基体之间的结合形式，从而有效提高了界面结合强度，在1 200 ℃氧化4 h，其抗弯强度和热导率均达到最高，分别为422 MPa和195 W/(m?K)。实际界面传热系数与复合材料热导率变化一致。此外，氧化钝化了SiC颗粒，其形貌的变化使得颗粒周围基体中的应力集中现象大大减少，提高了复合材料的抗弯强度，但是氧化时间过长的界面却不利于载荷的传递和基体的形变约束。
关键字: SiCp/ZL101基复合材料；氧化；界面；抗弯强度；导热性能
（State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072, China）
Abstract:The 75 and 15 μm SiC particles were mixed at a 7:3 volume ratio for SiC preforms, which were then oxidized at 1 200 ℃ for 2、4、6、8 and 10 h, respectively. The pressure in?ltration was carried out to fabricate SiCp/ZL101 matrix composites with SiC volume fraction of 70%. The interfaces with different holding times were investigated, and the effects of oxidation and interfacial reaction on flexural strength and thermal conductivity were discussed. The actual interfacial thermal conductance was back-calculated by experimental thermal conductivity. The results show that the distribution of dual-sized particles in Al alloy matrix is uniform. The bonding form changed by oxidation is considered to improve the bonding strength between SiC and Al. When being oxidized at 1 200 ℃ for 4 h, the flexural strength and thermal conductivity reach the maximum, which are 422 MPa and 195 W/(m?K), respectively. The interfacial thermal conductance back-calculated shows the same variation trend with the thermal conductivity of SiCp/ZL101 matrix composites. Besides, oxidation decreases the stress concentration in Al matrix around SiC particles, which improves the flexural strength of SiCp/ZL101 matrix composites. But if the oxidizing time is too long, the interface is detrimental to the transfer of loads and control of matrix deformation.
Key words: SiCp/ZL101 matrix composites; oxidation; interface; flexural strength; thermal conductivity
