Supersolidus liquid phase sintering of tool steel for rapid tooling

Three dimensional printing (3DP) is a solid-free form fabrication technique using metal powder as the building material. Green performs made by 3DP consist of less than 60 volume percent of metal powder and about 10 volume percent binder, with the remainder being pore space. Because of high porosity level, a liquid phase must be present in the thermal process to attain high density, either by infiltration or by liquid phase sintering. In this work, supersolidus liquid phase sintering of prealloyed tool steel powder, M4-Co, was investigated. Promising experimental results and successful manufacturing practices have shown that M4-Co can be used for rapid tooling.