Regulating effect of pre-stretching degree on the creep aging process of Al-Cu-Li alloy

Publication date: Available online 14 July 2019Source: Materials Science and Engineering: AAuthor(s): Jin Zhang, Zhide Li, Fushun Xu, Cheng HuangAbstractRegulating the deformation and property synchronously is a key point of creep aging process. And pre-deformation has been considered to be a good regulating method. In this paper, the laws of the influence of pre-stretching degree on creep strain, strength property, precipitate during creep aging process of Al–Cu–Li alloy were studied, and the pre-stretching design methods suitable for creep aging process were explored. The results indicate that the introduction of different pre-stretching degrees can have various influences on the creep strain of Al–Cu–Li alloy and the nucleation, growth and composition of the precipitates, so as to possess the capacity to regulate deformation and property. The introduction of proper pre-stretching can significantly prolong the duration of the initial creep stage, therefore, the total creep strain in 24 h are 2 times greater than that of the un-pre-stretched specimen. Besides, appropriate pre-stretching can effectively inhibit the orientation precipitation effect of T1 phase and promote a large deal of nucleation and dense distribution. However, when the pre-stretching degree is too large, the composition of the precipitates will be changed, so that the number of θ′ precipitates increases and T1 precipitates decreases, and the alloy strengthening effect is obviously reduced.
Source: Materials Science and Engineering: A - Category: Materials Science Source Type: research