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影响因子：8.0

DOI码：10.1016/j.msea.2026.149724

发表刊物：Materials Science and Engineering: A

关键字：In-situ TEM; Crack propagation; Aluminum alloy; DispersoidsPrecipitates

摘要：Secondary phases play crucial roles in the strengthening and toughening of aluminum alloys. Compared with the well-known impeding effects of the secondary phases on dislocations, their roles in crack propagation remain obscure. In this work, by using in-situ TEM, we investigated the roles of secondary phases during the crack propagation process in a high-strength Al-Zn-Mg-Cu alloy. It was revealed that crack propagation modes depended on whether leading dislocations near the crack tip bypass or shear through the secondary phases. The secondary phases could pin dislocations and passivate the crack tip; consequently, cracks were deflected by large dispersoids or sheared through fine precipitates like the GPⅡ (Guinier-Preston zone II). Under quasi-static loading, in-situ observations showed that discontinuous cracks preferentially nucleated at the interfaces between the secondary phases and matrix, presumably through segregation of over-saturated vacancies—a phenomenon further explained by density functional theory calculations on the vacancy formation energies. The findings provide insights into the roles of different secondary phases in crack propagation.

合写作者：Xiang Wang, Yuan Ma, Luning Wang

第一作者：Lei Jiang

论文类型：期刊论文

通讯作者：Yang He, Jianxin Xie

学科门类：工学

文献类型：J

页面范围：149724

是否译文：否

发表时间：2026-01-02

收录刊物：SCI

发布期刊链接：https://www.sciencedirect.com/science/article/pii/S0921509326000043