Higher proportional limit of SiC/Al composites with nano-scaled stacking faults

Abstract

Enhancing the proportional limit of Al matrix composites (AMCs) is critical to the reliability of precision electronic instruments. In this paper, SiC/Al composites containing stacking faults (SFs) were successfully fabricated using pressure infiltration method. The proportional limit (σp5 and σp100) of SiC/Al composites with SFs reached 65 MPa and 124 MPa, respectively, which is 8%∼22% higher than theoretical prediction of the Brown-Lukens empirical formula. The nucleation of SFs may be related to the lattice distortion fluctuation in Al matrix. The origin and stress conditions of SF nucleation in SiC/Al composites were deduced from the perspective of effective stacking fault energy (SFE). This paper provides theoretical support for preparing SF-containing AMCs with higher proportional limit.