Tribocorrosion behaviors of Ti-based bulk metallic glass via laser shock peening in 3.5 wt % NaCl solutions

Abstract

A Ti40Zr25Ni3Cu12Be20 bulk metallic glass (BMG) is treated by laser shock peening (LSP) with 1, 2 and 30 times, and then the phase structure, thermal, mechanical and tribocorrosion behaviors of the Ti-based BMG after LSP processing were studied in detail. The results demonstrate that although LSP did not significantly alter the phase structure of the Ti-based BMG, it facilitated rejuvenation and induced residual compressive stress within the BMG, thereby introducing internal structural heterogeneity. This heterogeneity promoted the generation of a substantial amount of free volume in the LSP-processed BMG specimens, leading to a marked improvement in plasticity and resistance to crack propagation. Consequently, the LSP-1 specimen exhibited higher surface microhardness (7.1 GPa) and plasticity, making it both plastic and tough and mitigating fatigue peeling wear caused by brittleness during reciprocating sliding wear. The average tribocorrosion volume loss rate of the LSP-1 specimen decreased by approximately 11 % to 5.73 × 10−4 mm3 N−1 m−1 (400 mV). However, excessive LSP resulted in elevated surface roughness (552.9 nm) and rejuvenation (ΔHrelax = 3.68 J g−1), rendering the surface of LSP-2 specimens more susceptible to pitting and significantly reducing their tribocorrosion resistance.