动态时效对Al-Cu-Mg-Ag合金组织与力学性能的影响

Effect of Dynamic Aging on Microstructure and Mechanical Properties of Al-Cu-Mg-Ag Alloy

对Al-Cu-Mg-Ag新型耐热铝合金进行预时效+中温轧制变形+终时效的动态时效工艺处理,采用硬度测试、拉伸性能测试,结合金相显微组织分析和透射电子显微分析,探究动态时效对其力学性能与微观组织的影响。结果表明:动态时效能够提高合金的时效硬化速率,随着变形量的增大,合金的峰时效时间逐渐减小,峰值硬度逐渐增大。动态时效能够改变晶粒形貌,随着变形量的增大,晶粒的纵横比增大,位错数量增多,强化相数量增多尺寸减小,使得合金强度随着变形量的增大而逐渐增大,但伸长率逐渐减小。变形量为50%合金的强度最高,抗拉强度和屈服强度最大,分别为527. 4 MPa和467. 0 MPa,伸长率保持在较高值9. 1%。

The dynamic aging process of Al-Cu-Mg-Ag new heat-resistant aluminum alloy was subjected to pre-aging,rolling deformation at intermediate temperature and final aging.The influence of the dynamic aging on the mechanical properties and microstructure were explored by the hardness test,tensile performance test,and combined with metallographic microstructure analysis and transmission electronic microscopy(TEM)analysis.The results show that dynamic aging can increase the age hardening rate of the alloy.As the amount of deformation increases,the peak aging time of the alloy decreases and the peak hardness increases gradually.Dynamic aging can change the morphology of the grains.The aspect ratio of the grains increases with the increase of the deformation amount,more dislocations generate and the number of the strengthening precipitations with finer size increases,leading to the larger strength of the alloy.The sample with a 50%deformation has the largest tensile strength and yield strength of 527.4 MPa and 467.0 respectively,and its elongation remains at a relatively high value of 9.1%.