Development of magnetic/non-magnetic stainless steel parts produced by two-component metal injection molding

The paper describes results that were achieved by joining the ferritic stainless steel AISI 430 and the austenitic stainless steel AISI 314 by two-component metal injection molding. Sinterdilatometry was used to compare the sintering response of the materials. To compensate discrepancies in shrinkage during co-sintering, several gas-atomized powder fractions were combined. Using this approach, feedstock combinations which did not exceed a shrinkage mismatch of 5% were processed into micro tensile test specimens by sequential or simultaneous co-injection molding. The ferritic/austenitic interfaces were characterized with a focus on interdiffusion of alloying elements and mechanical properties. Defect-free and well-connected bi-material specimens with magnetic/non-magnetic properties were obtained. Results showed that the interdiffusion between the utilized steels resulted in a local strengthening effect that increased the hardness and mechanical properties of the interface. The tensile strength was comparable to the strength of the base material and all specimens failed outside the interface. It demonstrates that the investigated material combination is suitable to produce magnetic/non-magnetic parts by two-component metal injection molding.