In the production of steel parts employing metal injection molding (MIM), powders with particles within 22 μm are commonly used. Such powders are very expensive and inevitably increase the cost of finished parts. To reduce the production cost of MIM parts, a new composition of the BMSTU 42CrMo4 feedstock with particles within 50 μm, like in additive processes, is proposed. The rheological and mechanical characteristics of the new feedstock were determined and compared with those of the BASF Catamold 42CrMo4 feedstock. The viscous flow and melt flow index of the BMSTU 42CrMo4 feedstock were similar to those of the Catamold 42CrMo4 feedstock. The tensile strength was 70% of that for Catamold 42CrMo4. Surface roughness R a equaled 1.85–2.22 μm and hardness varied in the range 144–220 HV1, indicating that coarser powders can be used in the MIM process.

中文翻译：

---

粗粉在注塑成型工艺中的应用

在采用金属注射成型 (MIM) 生产钢部件时，通常使用颗粒在 22 μm 以内的粉末。这种粉末非常昂贵，不可避免地会增加成品零件的成本。为了降低 MIM 零件的生产成本，提出了一种新的 BMSTU 42CrMo4 原料组合物，其颗粒在 50 μm 以内，就像在添加剂工艺中一样。确定了新原料的流变学和机械特性，并与巴斯夫 Catamold 42CrMo4 原料进行了比较。BMSTU 42CrMo4 原料的粘性流动和熔体流动指数与 Catamold 42CrMo4 原料的相似。抗拉强度是 Catamold 42CrMo4 的 70%。表面粗糙度 R a 等于 1.85-2.22 μm，硬度在 144-220 HV1 范围内变化，表明在 MIM 工艺中可以使用较粗的粉末。