Mechanical Property and Failure Mechanism of Metal Rubber/ZA8 Composite Made by Squeeze Casting Process

Abstract

High‐performance lightweight composites are developed by integrating metal rubber (MR) into a zinc alloy (ZA8) matrix via squeeze casting. MR, comprising 304 stainless steel wires (SSWs) with diameters of 0.15 mm, forms 3D network skeletons with volume fractions of 8.8 vol% (S1), 11.1 vol% (S2), and 13.4 vol% (S3), respectively. The preparation parameters of the composites are optimized, and their microhardness is investigated. Special attention is paid to the ultimate compression and shear performance at 25, 150, and 250 °C. The microstructure and failure analysis are performed via scanning electron microscopy. The results reveal a 48.0% increase in microhardness at composite interfaces relative to ZA8. At 25 °C, S2 possesses an ultimate compressive strength (UCS) of 401.4 MPa, which is 33.7% higher than that of ZA8. At 150 and 250 °C, S3 exhibits UCS values of 180.3 and 74.3 MPa, exceeding those of ZA8 by 61.7% and 110.5%, respectively. Meanwhile, the ultimate shear strength of composites slightly drops below that of the matrix: the corresponding value of S1 specimen (158.4 MPa) at 250 °C is 11.5% below that of ZA8. Therefore, compression and shear failure mechanisms of MR/ZA8 composites are quite intricate, involving SSW separation, necking, and ZA8 fractures.