Preparation and Characterization of In Situ Carbide Particle Reinforced Fe-Based Gradient Materials by Laser Melt Deposition

Abstract

To obtain the wear-resistant camshaft with surface rigidity and core toughness and improve the service life of camshaft, wear-resistant Fe-based alloy gradient material was prepared by laser melt deposition. The traditional camshaft was forged by 12CrNi2V. In this paper, four types of wear-resistant Fe-based powders were designed by introducing various content of Cr3C2 and V-rich Fe-based alloy (FeV50) into stainless steel powder. The results showed that the gradient materials formed a satisfactory metallurgical bond. The composition of the phases was mainly composed of α-Fe, Cr23C6, and V2C phases. The increasing of Cr3C2 and FeV50 led to transform V2C into the V8C7. The microstructures were mainly cellular dendrite and intergranular structure. Due to the addition of Cr3C2 and FeV50, the average microhardness and wear resistance of gradient materials were significantly better than that of 12CrNi2V. The sample with 8% V had the highest microhardness of 853 ± 18 HV, which was 2.6 times higher than that of 12CrNi2V. The sample with 6% V had the best wear resistance, which was 21 times greater than that of 12CrNi2V.