摘要
研究了镍基单晶高温合金ＤＤ３在五种不同温度下的慢拉伸（拉伸速率为０．０５ｍｍ／ｍｉｎ）的断裂行为。试验结果表明：杨氏模量在室温与８７３Ｋ之间具有反常变化，在８７３Ｋ以上ＤＤ３的弹性模量与温度关系具有正常变化；ＤＤ３单晶高温合金的屈服强度在室温和１０３３Ｋ（极点温度）之间保持不变，在１０３３Ｋ以上，屈服强度随温度升高急剧下降；在极点温度处ＤＤ３的延伸率最差；扫描电镜观察表明：从室温一直到１０３３Ｋ在ＤＤ３的拉伸变形过程中开动的滑移系具有强烈的择优性，从而导致变形的不均匀及断口上断面较平整。ＤＤ３的拉伸断裂在微观上主要呈现韧性断裂特征。
Single Crystal Superalloy DD3 was deformed in tension at slow strain rate at temperatures betweenambient temperature and 1273Kto investigate the mechanical properties.The anomalous temperature de-pendence of Young’s module at temperatures between room temperature and 873K, and the normal rela-tionship above 873K,were found.The results showed a plateau in yield strength between R. T. and 1033K(peak temperature).A significarit drop in strength occured above 1033K. The elongation was lowest atpeak temperature. Observation by SEM showed that tensile deformation for DD3 occured only in some pri-or slip systems. This priority led to the highly slip in homogenous nature. The fracture appearance was seento be ductile feature at all temperature although there were some quasi- cleavages in view of macro-ob-servation under the peak temperature.
出处
《航空材料学报》
CAS
CSCD
1994年第4期8-14,共7页
Journal of Aeronautical Materials
