抽拉速率对一种镍基单晶高温合金凝固组织的影响

Effects of Withdrawal Rate on Microstructure of a Nickel-base Single Crysatl Superalloy

研究了抽拉速度对一种镍基高温合金DD98凝固组织的影响。结果发现随着抽拉速率的增加 ,DD98合金由胞状凝固转变为枝状凝固 ,γ′相尺寸变小 ,由不规划形状逐渐变为规则的立方体形状 ,γ/γ′共晶的含量逐渐增加 ,而共晶中的初生γ′相尺寸逐渐减小。

Effects of withdrawal rate on microsturcture of a nickel base single crystal superalloy were investigated. With the increase of the withdrawal rate, the morphology of liquid solid interface transforms from cellular to dendritic, the size of the γ′ precipitates decreases, the shape of γ′ precipitates tends to regular, the amount of γ/γ′ eutectic increases and the size of primary γ′ precipitates of γ/γ′ eutectic decreases. The maximum primary dendritic arm spacing exists in transformation point from cellular to dendritic solidification.