Regression analysis and optimization of direct energy deposition parameters for functionally graded 316L stainless steel-tungsten carbide coatings

Abstract

In this study, the manufacturing of a two-layered functionally graded 316L stainless steel-tungsten carbide coating using directed energy deposition was investigated. The aim was to determine the optimal deposition parameters to achieve minimum porosity using a thickness of 1mm per layer. The input factors considered were laser scanning power and scanning speed, which were varied at different levels according to a full factorial design of an experimental matrix. To determine the optimum parameters regression analysis using analysis of variance was carried out. The optimum parameters were found at a laser scanning power of 607.4 W and a scanning speed of 8.5 mm/s for the first coated layer, and at a laser scanning power of 700 W and a scanning speed of 11 mm/s for the second coated layer. Minimum porosities of 0.0065 % and 0.0554 % were achieved for each coated layer respectively.