Microstructures and performances of Cr13Ni5Si2 based composite coatings deposited by laser cladding and laser-induction hybrid cladding

Abstract

Metal silicide based composite is a promising wear resistant material, and it is an effective way to improve the wear resistance of materials by cladding metal silicide based composite coatings on the surface of conventional materials. Laser cladding (LC) is well-known for its low dilution, precise track and high performance for the coatings, however, the coatings were feasible to crack due to its high temperature gradient when the welding ability of the materials is not well enough, which affects the performance of the coatings seriously. Laser-induction hybrid cladding (LIHC) is a novel technology for depositing wear resistant composite coatings. Compared with conventional laser cladding, LIHC can avoid the cracks in the hard face coatings effectively. In this paper, Cr13Ni5Si2 based composite coatings was firstly deposited by laser-induction hybrid cladding (LIHC). The microstructure, mechanical properties, cracking behaviors and wear resistance of the composite coatings deposited by LIHC were studied comparatively with those prepared by LC. The results reveal that ternary metal silicide (TMS) Cr13Ni5Si2 and Ni-based matrix were the main component phases in the composite coatings deposited by both the two cladding techniques. However, there was a significant difference among the microstructure, mechanical properties, cracking behaviors and wear resistance of the composite coatings deposited by LC and LIHC. Although the composite coatings deposited by LIHC exhibited lower volume fraction of the Cr13Ni5Si2 and lower hardness than that by LC, they have much better fracture toughness, which makes them have much better wear resistance. Besides, almost no macro/microcracks can be observed in the composite coatings deposited by LIHC.