Influence of Laser Energy Input on the Microstructure Development of Additively Manufactured WC-Co Hardmetal

Abstract

The field of Laser Powder Bed Fusion (LPBF) is constantly growing within the last few years. Since the beginning of LPBF, there were several approaches to manufacture cemented tungsten carbide (WC-Co). Many approaches end in porosity, undesirable phases and inhomogeneous carbide distribution in the WC-Co microstructure. Most promising results regarding high density were achieved by increasing the powder bed preheating temperature combined with decreasing the laser energy input. In this study the effect of a high powder bed preheating (800 °C – 950 °C) on densification of cemented carbides was investigated. For high laser energy input, the powder bed preheating temperature did not influence the densification. However, η-phases were present in the sample