USE OF COARSE-PARTICLE POWDERS IN INJECTION MOLDING PROCESS

Abstract

In the production of steel parts using metal injection molding (MIM), powders with a particle size of up to 22 µm are commonly used. The cost of such powders is very high, which inevitably increases the cost of finished parts. To reduce the cost of producing MIM parts, a new composition of the BMSTU 42CrMo4 feedstock with a particle size up to 50 µm is proposed, as in additive processes. For the new feedstock composition, the rheological and mechanical characteristics were determined and compared with those of the BASF Catamold 42CrMo4 feedstock. The viscous flow of the BMSTU 42CrMo4 feedstock, as well as its melt flow index, is similar to the Catamold 42CrMo4 feedstock. The tensile strength was 70% of the value for Catamold 42CrMo4. Surface roughness R_a equals 1.85–2.22 μm and the hardness varies in the range 144–220 HV1, which indicates that powders with an increased particle size can be used in the MIM process.