高合金铁基材料熔渗工艺研究

Infiltration Process of Iron-base Materials with High Alloying Elements

采用光学显微镜、扫描电镜观察和力学性能测试研究了熔渗处理对高合金铁基材料显微组织和性能的影响。结果表明,熔渗前预烧温度的控制直接影响熔渗的效果。在1160℃预烧,显微组织中有很多大小均匀、连通的孔隙,有利于熔渗的进行;硬质相中Mo、Cr扩散程度较低,熔渗过程中,铜均匀填充孔隙,大小均匀,密度达到7.85 g/cm3,各项性能较好;Mo、Cr的扩散程度明显提高;Cu基本分布在填充孔隙的部分。热处理后,材料的硬度和强度均有提高,但冲击韧度下降。从冲击断口形貌可以看出,熔渗后的材料呈现明显的塑性断裂特征。通过合理控制熔渗过程中的工艺参数,可获取高致密度、高性能的铁基粉末冶金材料。

The effect of infiltration process on the microstructure and properties of iron-base materials with high alloying elements content was studied by metallography, SEM and mechanical property tests. The results show that infiltration performance is related with pre-sintering temperature obviously. Pre-sintering at 1160 ℃, a lot of uniform connected pores exit in the materials, which advance infiltration process. Then the materials obtained high density （7.85 g/cm^3 ） and good properties. After infiltration, molybdenum and chromium diffusion degree increase, a majority of copper fill in pores, nickel and cobalt distribute in the materials evenly. The material shows a feature of ductile fracture. Through heat treatment, material hardness and strength increase, but impact toughness decreases. In this article, a high density and good properties iron-based material is obtained by controlling the carbon content seasonally.