Synergistic strengthening mechanism of copper matrix composite reinforced with nano-Al <sub>2</sub> O <sub>3</sub> particles and micro-SiC whiskers
Huanran Lin, Xiuhua Guo, Kexing Song, Jiang Feng, Shaolin Li, Xiangfeng Zhang
Abstract
Abstract Although Cu–Al 2 O 3 composites have good comprehensive performance, higher mechanical properties and arc erosion resistance are still required to meet heavy-duty applications such as electromagnetic railguns. In this work, a novel hybrid SiC w /Cu–Al 2 O 3 composite was successfully prepared by combining powder metallurgy and internal oxidation. The microstructure and mechanical behavior of the SiC w /Cu–Al 2 O 3 composite were studied. The results show that nano-Al 2 O 3 particles and micro-SiC w are introduced into the copper matrix simultaneously. Well-bonded interfaces between copper matrix and Al 2 O 3 particles or SiC w are obtained with improved mechanical and arc erosion resistance of SiC w /Cu–Al 2 O 3 composite. The ultimate tensile strength of the SiC w /Cu–Al 2 O 3 composite is 508.9 MPa, which is 7.9 and 56.1% higher than that of the Cu–Al 2 O 3 composite and SiC w /Cu composite, respectively. The strengthening mechanism calculation shows that Orowan strengthening is the main strengthening mechanism of the SiC w /Cu–Al 2 O 3 composite. Compared with Cu–Al 2 O 3 composite, the hybrid SiC w /Cu–Al 2 O 3 composite has lower arc time and energy and better arc stability.