Nano TiC particles modulate wear resistance and impact toughness of 40Cr alloy steel gradient-reinforced layer fabricated by laser melting deposition

Abstract

Alloy steel components can be subjected to serious damage from a variety of conditions during the industrial production procedures, such as wear and fracture failure. Therefore, the preparation of gradient-reinforced layers on the surface of the alloy steel was considered an effective technique to improve the performance. Along these lines, a 40Cr alloy steel, which was commonly used in industry, was systematically investigated in this work. The nano TiC ceramic material was selected in the hard phase. In this work, continuous-wave laser was used to fabricate gradient reinforced layers, which provided a technical reference for the development of protective reinforcement layers for alloy steels with excellent mechanical properties. A dense structure was formed inside the nano TiC gradient reinforced layer, which has a lower friction coefficient (0.25) and wear loss weight (23 mg). The height of the surface material loss under a heavy load wear environment (187 μm) was lower than that of a bare 40Cr alloy steel sample (1116 μm). The impact energy of the nano TiC gradient reinforced layer (75.27 J/cm2) was higher than that of a bare 40Cr alloy steel sample (15.25 J/cm2). Both the wear behavior and impact toughness strengthening mechanism of the nano TiC gradient reinforced layer were revealed.