SLM Based Tooling for Injection Molding - Focus on Reduced Effort in Surface Quality Optimization

Additive manufacturing technologies can provide cost and time advantages in mold making, compared to traditional approaches. Nevertheless, their applicability is not yet completely proven, especially in terms of surface finishing. The aim of this research work is to create perfect mold inserts by Selective Laser Melting (SLM) and to optimize surface quality. Therefore a process is developed to reduce the effort of surface quality optimization including a high flexibility in design. The tested process shows that simple and affordable methods can lead to usable molds with only minor restrictions in terms of appearance. Due to the initial reduction of layer thicknesses and distinct settings of laser melting parameters, the surface smoothness is significantly enhanced during the SLM building process. Subsequently blasting, manual grinding, as well as polishing operations, enable a selective smoothening of the surface up to a polished finish. As a result, the built tool parts can be used instantly for injection molding.