Investigations of wear resistance of composite coatings (cobalt alloy-WC) produced by the LENS method

Abstract

Metallic coatings strengthened by the reinforcing phase are among the widely used wear-resistant materials. The work attempted to produce composite coatings in the metallic matrix system (cobalt alloy) – reinforcing phase (tungsten carbide) fabricated by the Laser Engineered Net Shaping (LENS) technique. The obtained coatings were assessed by metallurgical quality (microscopic observations), microhardness test in coating-substrate transition zone and tests of abrasive wear resistance under dry friction conditions. For this purpose, two different test methods were used: the ball-on-disc method and the rubber wheel abrasion test method. For each method, the same test parameters were used, such as force and number of disc/ roller rotations. The conducted tests showed that the weight loss of the coatings subjected to wear resistance tests in loose abrasive was much greater compared to the ball-on-disc method.