The effect of carbon fiber strengthening on the mechanical properties and wear resistance of 24CrNiMo alloy steel fabricated by laser deposition

Abstract

Carbon fiber (CF) strengthened 24CrNiMo alloy steel was fabricated by laser deposition, and the microstructure, mechanical properties and wear resistance were thoroughly examined. As a microstructural feature of a macroscopic property, 24CrNiMo alloy steels with 0vol%, 4vol%, 8vol% and 12vol% CFs were characterized by differentiated interface bonding and fiber distributions. As indicated by mechanical tests and wear process assessments, the best interface bonding and fiber distribution were found in the 24CrNiMo steel matrix with 8vol% CF, showing high average microhardness and a tensile strength of 752 HV0.3 and 667MPa, which increased by 61.5% and 23.7% respectively compared with those of the 3D-printed no CF variant. Additionally, the wear process of the steel with the addition of 8vol% CF exhibited reduction of wear weight loss by approximately 70%. The excellent performances in these analyses can be mainly attributed to the particle dispersion strengthening, good interfacial bonding between CFs and matrix, the inhibitory effect of CFs on the nucleation and the propagation of microcracks as well as the lubrication effect. The results from this study allow for fabrication of a complex-shaped CF-reinforced alloy steel matrix material with the desired properties suitable for a wide range of practical applications.