温度与保温时间对2519A铝合金高温力学性能的影响

Effects of temperature and holding time on elevated-temperature mechanical properties of aluminum alloy 2519A

利用高温拉伸力学性能测试、扫描电镜与透射电镜等分析手段对2519A铝合金在不同温度与保温时间下的高温力学性能进行研究。结果表明:合金在保温10 min后进行拉伸,从室温至400℃,随着温度的升高,抗拉强度从471 MPa下降至55.5 MPa,屈服强度从440.3 MPa降至50.3 MPa,延伸率由11.6%提高至21.3%。300℃时,随保温时间的延长,合金的抗拉强度先由171.6 MPa下降至151.4 MPa,屈服强度由139.4 MPa降至130.5 MPa,1 h后基本上稳定不变。高温条件下,该合金力学性能的下降主要是由于析出相的粗化与转变引起的。

The elevated-temperature mechanical properties of aluminum alloy 2519A annealed at different temperatures and different holding times were investigated by tensile test, scanning electron microscopy （SEM） and transmission electron microscopy （TEM）. The results showed that for the holding time of 10 min, with increasing of temperature from room temperature to 400 ℃, the ultimate tensile strength descended from 471 MPa to 55.5 MPa, the yield strength from 440.3 MPa to 50.3 MPa, and the elongation rised from 11.6% to 21.3%. At 300 ℃, with the prolongation of holding time, the ultimate tensile strength descended from 171.6 MPa to 151.4 MPa and the yield strength from 139.4 MPa to 130.5 MPa, and then they had no remarkable changes after 1 h. At high temperatures, the decrease of the mechanical properties of the studied alloy was due to coarsening and transformation of the precipitates.