Feedstock development for fused deposition of 316L stainless steel and characterization of final materials properties

摘要

Additive manufacturing of metals using fused deposition of metal-polymer feedstock is gaining increasing interest from research and industry. The composition of the polymeric binder system is of major importance in this process and needs to satisfy complex requirements. In this work, we demonstrate a novel binder which can be extruded into filaments and allows printing on commercial machines with high resolution. Printability is improved by decreasing the viscosity and increasing the stiffness of the binder. We demonstrate this for several 316L stainless steel feedstocks. Sintered specimens exhibit both intra- and inter-layer porosity. Nanoindentation mapping is performed to characterize the hardness and modulus of the material. The observed properties coincide well with literature for bulk material. Interestingly, the indentation experiments reveal hidden porosity. Further study is needed to assess the potential of nanoindentation as a tool for the investigation of porosity.