低温时效法消除DD8单晶高温合金的拉伸变形不均匀性

摘要

Method and mechanism for eliminating deformetion inhomogeneity of Ni-base single ctystal superalloy DD8 was investigated. It is found that deformation inhomogeneity in DD8 is eliminated by additional 750℃/24h low temperature ageing ,meanwhile yielding strength of the present alloy is raised. It is demonstrated by TEM observation that the inhomogeneous precipitating of fine γ′ particle under induction of applied stress is prevented by low temperature ageing, thus the homogeneity of slip deformation along is attained.%研究了消除DD8单晶合金的变形不均匀性的方法和机理，发现增加750℃/24h的低温时效处理后，可以消除DD8单晶高温合金中的拉伸变形不均匀现象，同时合金的屈服强度得到提高。观察表明，低温时效能阻止基体通道中应力诱导下小γ′粒子的不均匀析出，保证滑移变形沿试样均匀分布。