Microstructure, wear, and corrosion resistance of Nb-modified magnetic field-assisted Co-based laser cladding layers

Abstract

Cobalt-based alloys with different Nb content were prepared by alternating magnetic field-assisted laser cladding. The magnetic field has a significant impact on the laser cladding layer performance. An alternating magnetic field can produce negative expansion features of the cobalt-based alloy. The magnetic characteristics of the cobalt-based alloy were investigated, and the magnetic transition was found to be an important reason for the negative expansion characteristics. The microstructure, mechanical properties, wear properties, and corrosion properties of the cladding layer with the effect of different Nb content on the properties of the cladding layer were revealed. The laser cladding layer with thermal negative expansion properties has better wear and corrosion resistance. The elastic modulus of the material decreases abnormally with increasing hardness. Different mass fractions of Nb can regulate and control the generation of negative expansion properties induced by external magnetic fields. This study also presents the possibility that a small external magnetic field can effectively control or achieve negative thermal properties.