Al－Li合金的锯齿屈服现象

来源期刊：中南大学学报(自然科学版)1995年第1期

论文作者：郑子樵 刘明桂 尹登峰

关键词：锯齿屈服； 拉伸变形； Al－Li合金

Key words：serrated yielding； teneile test； Al-Li alloys

摘    要：研究了一种8090型Al-Li合金在室温拉伸变形时的锯齿屈服类型、特征以及相关影响因素，实验结果表明：在一定条件下拉伸变形时，可出现A，B，C三类锯齿，其中B型锯齿常叠加在A型锯齿上构成A+B型复合锯齿屈服；时效抑制B，C型锯齿屈服；在4.2×10^-5S^-1低应变速率下主要出现C型锯齿屈服，而在4.2×10^-3S^-1高应变速率下只产生A型锯齿屈服；可根据据吕德斯带中位错的动态应变时效机制解释不同类型的锯齿屈服现象。

Abstract: The serrated yielding phenomena in a 8090 type Al-Li alloy during tensile testingat room temperature have been investigated.Three different types of serrations(termedA, B and C)appeared under the proper conditions。 B type serrations were generallysuperimposed on A type serrations to form combined A+ B type serrations。 At lowstrain rat e=4.2×10^-5s^-1,C type serrations were mainly observed.At high strainrate e=4. 2× 10^-3s^-1, only A type serrations were observed.Aging suppressed the appear-ance of B and C types of serrations。The results are explained in terms of the strain aging ofmoving dislocations in Luders band front during tensile deformations。