Binder Jetting process chain optimization for M3 High-Speed tool steel

The Binder Jetting (BJT) process expands material options and design freedom in powder metallurgy, enabling the processing of diverse materials, including high-speed steels (HSS), tungsten carbides, and ceramics. By producing near-net-shape geometries, it minimizes costly postmachining steps. While extensive research exists on how sintering temperature, holding time, atmosphere, and particle size distribution influence density, tensile strength, and hardness across materials and processes, for powder metallurgical processes and some additive processes, a comprehensive analysis of the entire Binder Jetting process chain and its key parameters for high-speed steel remains lacking. This study examined test specimens produced via Binder Jetting and sintered at different temperatures (1220 °C, 1230 °C, 1250 °C, 1270 °C) and holding times (4 and 8 hours). The resulting density and microstructure formation were then analyzed using metallographic analysis. Additionally, the influence of the sintering atmosphere was investigated, considering the chemical composition (argon, or nitrogen) and atmospheric pressure (1 or 100 bar). This study contributes to the optimization of the HSS-BJT process chain by presenting that, within the investigated range, higher sintering temperatures, atmospheric pressure and nitrogen atmosphere resulted in higher densities. ... mehrThe results also showed that density is influenced more by temperature than by holding time. Microstructure analyses and hardness measurements suggest that the desired properties of tools for metal cutting cannot be achieved through the used sintering routes. Therefore, alternative approaches are discussed.