Effect of re-melting on the cladding coating of Fe-based composite powder

• Influences of laser re-melting on the geometry and overlapping pores are analyzed.
• A 3D finite element model has been built to provide a thermal field analysis.
• The surface smoothness of the cladding layer is improved remarkably.
• The overlapping pores could be removed easily.

The aim of this paper is to investigate the influence of laser re-melting on the geometry and overlapping pores of cladding coating. In this study, Fe-based alloy mixed with 5 wt.% Cr3C2 powder was used as cladding material to obtain high hardness and strength coating. However, this coating has overlapping pores and a rough surface. Therefore, re-melting process is explored systematically. The geometry, microhardness and microstructure of the coatings have been analyzed and compared subsequently. Besides, a 3D finite element model has been built to provide a thermal field analysis for laser re-melting. Finally, it is found that re-melting process is an effective method to improve the surface smoothness of cladding layer, which could reduce the process cycle and cost of secondary operations. More importantly, it could remove the overlapping pores easily.