A study was made on the effect of creep loading on the precipitate radii evolution of the aluminum alloy 2618A. The overageing process of the alloy was investigated under load at a temperature of 190 °C with stresses between 79 and 181 MPa and compared to stress free isothermal ageing. The precipitates responsible for strength were characterized using dark-field transmission electron microscopy (DFTEM). This allows the experimental determination of radii distributions of the rod-shaped Al₂CuMg precipitates and the evaluation regarding their mean precipitate radius. It was found that the mean precipitate radius enables the comparison of the different microstructural conditions of crept and uncrept samples. The mean precipitate radii of the samples experiencing creep are significantly higher than those of undeformed samples. It was shown that the acquired radii distributions are viable to determine averaged particle radii for comparison of the aged samples. A ripening process including pipe diffusion along dislocations describes the data on coarsening very well for the creep samples.

研究了蠕变载荷对铝合金2618A析出半径演变的影响。研究了合金在190°C的负载和79至181 MPa的应力下的过时效过程，并与无应力等温时效进行了比较。使用暗场透射电子显微镜（DFTEM）对负责强度的沉淀物进行表征。这使得可以通过实验确定棒状Al ₂的半径分布CuMg沉淀物及其平均沉淀半径的评估。发现平均沉淀半径能够比较蠕变和未蠕变样品的不同微观结构条件。经历蠕变的样品的平均沉淀半径显着高于未变形样品的平均沉淀半径。结果表明，所获得的半径分布对于确定用于比较老化样品的平均粒子半径是可行的。包括沿位错的管道扩散的成熟过程描述了蠕变样品的粗糙化数据。