Hf含量对DD6单晶高温合金组织和持久性能的影响

研究了Hf含量对DD6单晶高温合金热处理组织和持久性能的影响。结果表明，在本实验研究范围内，随着Hf含量的增加，热处理后合金残余共晶量增加，枝晶干的γ′相尺度无明显变化，枝晶间的γ′相尺度有所减小。在1100 ℃, 140 MPa条件下，随着Hf含量的增加，合金的持久寿命先升高后降低, 持久延伸率先快速增加, 然后慢速增加。讨论了不同Hf含量合金的显微组织与持久性能的关系

Effect of Hf Content on the Microstructures and Stress Rupture Properties of DD6 Single Crystal Superalloy

The effect of Hf content on the microstructures after heat treatment and stress rupture properties of DD6 single crystal superalloy was investigated. The results show that with increasing of Hf content in the range of current research, the residual γ/γ' eutectic increases apparently, the size of γ' particles in dendritic cores has no obvious change and that in interdendritic decreases after heat treatment. With the increase of Hf content, the stress rupture life increases at first and decreases afterwards, and the elongation displays fast increasing first, and slow rising afterwards at 1100 ℃, 140 MPa. At last the relationship between the microstructures and stress rupture properties of DD6 alloy with different Hf contents was discussed.