为满足1050℃使用的等温锻模具材料的需求,在IC6合金成分的基础上研制了一种新型的高W,Mo强化的Ni3Al基等轴晶合金,尝试在合金中添加了不同含量的铝改善合金的抗氧化性能,并研究了铝对合金微观组织和1050℃拉伸性能和1100℃持久性能的影响。采用带能谱的扫描电镜分析了合金微观组织以及氧化膜形貌,采用X射线衍射分析了合金氧化膜的相组成。研究结果显示,随铝含量从7wt%增加到8wt%,合金的氧化增重速率明显降低,氧化皮脱落量减少,合金的抗氧化性能明显提高。力学性能测试结果表明,铝含量为7.5wt%的合金具有较好的综合高温性能,当铝含量提高到8wt%时,合金中的初生γ'相大量增加,合金高温强度明显降低。

Based on a cast Ni3Al base superalloy IC6,a new conventional cast Ni3Al base alloy containing high amount of refractory elements,Mo,W,for strengthening has been developed as high temperature die material.Various contents of aluminum were added into the alloy to improve the oxidation resistance,and its effects on microstructure and mechanical property have also been studied.Microstructure of the alloy and morphology of oxide layers were analyzed by the scanning electron microscope(SEM)with the energy dispersive spectrometry(EDS)and phases of oxide layers were identified by the X-ray diffraction analysis(XRD).The results showed that with increment of aluminum content from 7wt% to 8wt%,the rate of mass gain became slower and spallation of oxides decreased,therefore the oxidation resistance of the alloy is improved.The results also showed that the alloy with 7.5wt%Al has the best comprehensive properties,while when the content of aluminum reached to 8wt%,high temperature mechanical strength decreased obviously due to excessive amount of primary γ'phases.