Development of High Performance Ferrous Sliding Abrasive Wear-Resistant Materials Through MIM Process

Metal injection molding (MIM) is a suitable processing route for the mass production of complex-shaped and high performance components. Therefore, MIM process may be quite useful for improvement of the quality and productivity in the automotive sintered parts. This study has been performed to develop the high performance ferrous sliding abrasive wear-resistant materials through MIM process. A prealloyed powder (SCM440) was used as the matrix and also 3 mass% TiN powder was added to improve the wear-resistance. Those compacts were densified to about 95% of relative by sintering, and the final carbon content was almost exactly controlled to be 0.4 mass% by adjusting the debinding and sintering atmospheres and conditions. Sintered compacts showed the dual homogeneous microstructures consisted of ferrite and fine pearlite, and the pores and TiN powder particles were distributed uniformly, regardless of the injecting direction. Thus, the wear characteristics were not influenced by the injecting direction. Injection molded SCM440 steel showed the same wear-resistance as the wrought SCM440 steel. However, addition of 3 mass% TiN powder caused a remarkable improvement of wear-resistance, which indicates that MIM process has enormous potential to produce high performance ferrous composites for the automotive parts.