(北京航空材料研究院 先进高温结构材料国防科技重点实验室，北京100095)
摘 要: 对单晶高温合金DD6进行表面吹砂处理，然后在1 100~1 250 ℃加热4 h，研究其铸态与标准热处理状态的表面再结晶行为。结果表明：当加热温度为1 200 ℃时，铸态合金出现等轴再结晶晶粒；而加热温度为1 150 ℃时，热处理态合金出现等轴再结晶晶粒，铸态与热处理态合金的再结晶是由胞状再结晶晶粒和等轴再结晶晶粒组成的；随着加热温度的升高，等轴再结晶晶粒逐渐长大，胞状再结晶晶粒逐渐减少，胞状再结晶内部粗大的g ¢相由长条状向颗粒状转变。由于铸态合金含有一定数量的粗大g ¢相以及g+g ¢共晶组织，在相同的条件下，铸态合金的再结晶倾向小于热处理态合金的。
关键字: 单晶高温合金；DD6合金；等轴再结晶；胞状再结晶；合金状态
single crystal superalloy DD6
（National Key Laboratory of Science and Technology on Advanced High Temperature Structural Materials,
Beijing Institute of Aeronautical Materials, Beijing 100095, China）
Abstract:The samples of single crystal superalloy DD6 were grit blasted and heat treated in the temperature range of 1 100−1 250 ℃ for 4 h in vacuum atmosphere, then the recrystallizations of as-cast and standard heat treatment DD6 alloys were investigated, respectively. The results show that the equiaxed recrystallization grains nucleate in as-cast samples heat treated at 1 200 ℃, while the equiaxed recrystallization grains occur in the standard heat treatment samples heat treated at 1 150 ℃. The recrystallization region consists of cellular recrystallization and equiaxed recrystallization grains at different states. With the improvement of the heating temperature, the size of cellular recrystallization decreases, while the size of equiaxed recrystallization grains increases, and the coarse g ¢ phase in the cellular recrystallization changes from lamellar to equiaxial. By comparing with the as-cast samples, the standard heat treatment samples tend to recrystallization at the same heating temperature due to the absence of coarse g ¢ and g+g ¢ eutectic.
Key words: single crystal superalloy; DD6 alloy; equiaxed recrystallization(ERX); cellular recrystallization(CRX); alloy states
