Additive manufacturing of cermet produced by laser powder bed fusion using alternative Ni binder

Abstract

Abstract. Cermets are composite materials made of a ceramic reinforcement and a metal matrix, generally cobalt as binder, with mass content from 6 to 20 wt.%. Cermets are produced by conventional sintering process and are known for their high hardness, low friction coefficient, high wear resistance, and high melting temperature. Laser Powder Bed Fusion (L-PBF) is an additive manufacturing technology widely applied for direct fabrication of functional metallic parts with complex geometry such as internal channels or lattices structures. Considering several studies, production of cermets by L-PBF process is challenging. Recent publications have demonstrated the feasibility to produce WC-Co parts by L-PBF combined with Hot Isostatic Pressure (HIP) heat-treatment. HIP process is sometimes additionally performed as post-treatment to remove defects. HIP is performed at high temperatures and isostatic pressures in a furnace [1]. In this study, following an experimental design a parametric optimization was conducted in order to maximize the mass density of WC-17Ni. Process parameters were compared to those used for WC-17Co parts from recent study [2]. To improve the printed specimen integrity, the as-built samples were heat-treated. As-built and HIP samples were analyzed and compared in terms of mass density, microstructure, crystallographic phases, and macro hardness.