Effect of magnetic field waveform on microstructure and properties of laser cladding

Abstract

Ni60 coating-45 steel substrate was prepared by magnetic field assisted laser cladding with four waveforms:steady magnetic field (SMF), alternating magnetic field (AMF), pulsed magnetic field (PMF). The effects of four kinds of magnetic fields on the morphology, microstructure, phase composition and microhardness of the coating were studied, and the magnetic field mechanism on the coating was briefly analyzed. Results revealed that the addition of magnetic field can significantly reduce the number of cracks, facilitate grain refinement and improve the coating hardness. The improvement degree of four kinds of magnetic fields on the coating performance is: PMF > APMF > AMF > SMF. Among them, the coating performance is prominently improved by PMF, but there is a serious segregation of hard phase; The segregation of hard phase and the slender of the structure occur in the APMF.

Keywords

• Microstructure
• Magnetic materials
• Laser processing