Concurrent Inconel 625 wire and WC powder laser cladding: process stability and microstructural characterisation

Abstract

The microstructure and hardness property of WC powder–Inconel 625 wire single tracks deposited by laser cladding at varying processing parameters were investigated using a combination of scanning electron microscopy, energy dispersive X-ray analysis, X-ray diffraction, image processing software and hardness testing. The results include the generation of process maps that predict the cladding process characteristics at varying processing conditions. High dissolution of WC particles at high energy input resulted in a decrease in retained WC volume fraction with increasing laser power. The negative dependence of the retained WC volume fraction on the transverse speed and wire feedrate showed that the decreasing powder catchment efficiency with increasing the two parameters is primarily significant to the amount of WC contained in a track. The dissolution of WC in the matrix resulted in the formation of W₂C and Fe₃W₃C hard phases, which mainly contributed to high hardness (540–690 HV0·3) of the composite matrix.