Ag含量对Al-Cu-Mg-Ag合金高温力学性能及耐热性的影响

通过对高温拉伸强度、延伸率、高温持久时间的测试以及SEM、TEM观察表明:Ag含量的增加显著提高合金在高温拉伸时的强度和高温持久强度极限;合金在高温下的断裂仍为塑性穿晶断裂;Ag含量越大,合金中析出的?相的数量越多,经长时间高温之后,其粗化程度不大,仍为主要强化相。

Effect of Ag Content on Evaluated-Temperature Mechanical Properties and Thermal Stability of Al-Cu-Mg-Ag Alloys

Effect of Ag content on the evaluated-temperature mechanical properties of a series of Al-Cu-Mg-Ag alloys was studied by means of tensile tests, endurance tests, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results show that tensile strength and ultimate endurance strength increased dramatically with Ag content increasing. SEM observations suggest a plastic transgranular manner of tensile fractures. TEM results reveal that increasing Ag content promoted the nucleation of the Ω phase, which was the dominant strengthening phase in matrix. Furthermore, Ω precipitates were not coarsened on a large scale after long time endurance at evaluated temperature.