Fe-Cu-Mn-C合金的性能与烧结行为

摘要

Mn element carried by FeMn alloy powder was added into Fe based alloy powder, Fe-Cu-Mn partially pre-alloyed powder was prepared by annealing treatment, and the Fe-Cu-Mn-C alloy was fabricated by die-wall lubricated warm compaction. The compress and sintering behaviors of Fe-Cu-Mn-C alloy and the effect of Mn content on density and mechanical property were studied by density, hardness testing and microstructure observation. The results indicate that Fe-Cu-Mn partially pre-alloyed powders have good compactivity after annealing treatment;densities of the green compact and sintered Fe-2Cu-0.5Mn-0.9C alloy sample are 7.37 g/cm3 and 7.33 g/cm3, respectively. The mechanical properties of the alloy can be effectively improved by adding appropriate amount of Mn. Fe-2Cu-0.5Mn-0.9C has the best tensile strength of 715 MPa. With the increasing of Mn content, the porosity increases and density decreases, which results in the decrease of the strength and hardness. Partially oxidation of the alloy has negative impact on compression and mechanical properties. Mn content has little affect on the microstructure of the alloy which is composed of pearlite, ferrite and small amount of bainite. Evaporation and condensation of Mn is the sintering mechanism of Fe-Cu-Mn-C alloy.%以FeMn合金粉末的形式在铁基合金粉末中添加Mn元素，退火后得到Fe-Cu-Mn部分预合金粉末，采用模壁润滑温压工艺制备 Fe-Cu-Mn-C 合金，通过对合金密度与硬度的测定以及形貌观察，研究 Fe-Cu-Mn-C 粉末的压制与烧结行为，以及Mn含量对合金密度和力学性能的影响。结果表明，通过退火处理实现部分预合金扩散而得到的 Fe-Cu-Mn 粉末具有很好的压制性能，Fe-2Cu-0.5Mn-0.9C 压坯密度达到7.37 g/cm3，烧结密度为7.33 g/cm3；添加适量Mn能有效提升铁基合金的力学性能，其中Fe-2Cu-0.5Mn-0.9C合金的性能最佳，抗拉强度达到715 MPa；随Mn含量增加，合金的孔隙增多、密度下降，导致强度和硬度下降。合金的局部氧化对性能产生一定的负面影响。Mn含量对合金组织影响不大，Fe-2Cu-Mn-0.9C合金呈现混合显微组织，由铁素体、珠光体和少量贝氏体构成。Mn的蒸发与凝聚是Fe-Cu-Mn-C的烧结机制。