2524铝合金在蠕变时效成形工艺影响下的疲劳断裂分析

Fatigue Fracture Analysis on 2524 Aluminum Alloy with the Influence of Creep-Aging Forming Processes.

作者信息

Ma Liyong, Liu Chi, Ma Minglei, Wang Zhanying, Wu Donghao, Liu Lijuan, Song Mingxing

机构信息

School of Mechanical Engineering, Hebei University of Architecture, Zhangjiakou 075031, China.

School of Mechanical and Electrical Engineering, Changsha University, Changsha 410199, China.

出版信息

Materials (Basel). 2022 Apr 30;15(9):3244. doi: 10.3390/ma15093244.

DOI:10.3390/ma15093244

PMID:35591577

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC9104990/

Abstract

The different creep-aging forming processes of 2524 aluminum alloy were taken as the research object, and the effects of creep-aging temperature and creep stress on the fatigue-crack propagation properties of the alloy were studied. The research results showed the following under the same sintering time of 9 h, at creep-aging temperatures of 100 °C, 130 °C, 160 °C, and 180 °C, respectively, with an increase in creep-aging temperature: the fatigue-crack propagation rate was promoted, the spacing of fatigue striations increased, and the sizes of dimples decreased while the number was enlarged; this proves that the fatigue property of the alloy was weakened. Compared with the specimens with creep deformation radii of 1000 mm and 1500 mm, the creep deformation stress was the smallest when the forming radius was 1800 mm, with a higher threshold value of fatigue-crack growth in the near-threshold region of fatigue-crack propagation (Δ ≤ 8 MPa·m). Under the same fatigue cycle, the specimens under the action of larger creep stress endured a longer fatigue stable-propagation time and a faster fracture speed. Comparing the effect of creep-aging temperature and creep stress, the creep-aging temperature plays a dominant role in the fatigue-crack propagation of creep-aged 2524 aluminum alloy.

摘要

以2524铝合金的不同蠕变时效成形工艺为研究对象，研究了蠕变时效温度和蠕变应力对该合金疲劳裂纹扩展性能的影响。研究结果表明：在相同烧结时间9 h下，分别在100℃、130℃、160℃和180℃的蠕变时效温度下，随着蠕变时效温度的升高，疲劳裂纹扩展速率加快，疲劳条纹间距增大，韧窝尺寸减小而数量增多；这证明合金的疲劳性能减弱。与蠕变变形半径为1000 mm和1500 mm的试样相比，成形半径为1800 mm时蠕变变形应力最小，在疲劳裂纹扩展近门槛区（Δ≤8 MPa·m）具有较高的疲劳裂纹扩展门槛值。在相同疲劳循环下，较大蠕变应力作用下的试样疲劳稳定扩展时间更长，断裂速度更快。比较蠕变时效温度和蠕变应力的影响，蠕变时效温度在蠕变时效2524铝合金的疲劳裂纹扩展中起主导作用。