Microstructure and wear properties of laser deposited WC–12%Co composites

Laser engineered net shaping (LENS™) has been used to create dense WC–12%Co composite coatings on stainless steel substrates. Low heat input and controlled atmosphere with oxygen content less than 10 ppm resulted in minimum interface dilution, carbide dissolution and uniform carbide distribution. Under present experimental conditions, coatings produced at laser energy input of 365 and 465 J/mm3 showed similar phase constituents, hardness and wear rate. The coating hardness varied between 1171 and 1181 HV with an average dry sliding specific wear rate in the range of 3 × 10−6 mm3/Nm and 6.5 × 10−6 mm3/Nm against Si3N4 ball. Deformation and extrusion of cobalt phase followed by fracture and removal of carbide particles was found to be a predominant material removal mechanism in the present laser deposited WC–Co coatings. The influence of laser energy input on the microstructural and wear properties of WC–12%Co composites coatings are reported in this article.