Pressureless moulding of 316L and D2 steel powders using a hybrid binder

摘要

A forming process for 316L and D2 steel powders has been studied. It consists of pressureless metal injection moulding of slurries containing, in addition to steel powder, a hybrid inorganic - organic binder. The slurries were prepared at room temperature and poured into polymeric moulds, where the binder polymerised within a few minutes. Rigid and resistant greens have been obtained. A curing process at 80 deg C has been performed in order to complete the crosslinking of the polymer. Different debinding cycles have been studied by thermogravimetric analyses, as a function of experimental parameters, such as heating rates and atmospheres. A number of bulk samples with different shapes have been debinded, using the optimised cycle and sintered under vacuum, reaching high densities (97 percent of theoretical). Microstructural characterisation has been performed on the sintered samples by scanning electron microscopy, along with microhardness measurements.