升温速率和固溶时间对超高强铝合金挤压材组织性能的影响

Effect of Heating Rate and Solid Solution Time on the Microstructure and Properties of Extruded Ultra-high Strength Aluminum Alloy

采用金相组织分析、EBSD分析、维氏硬度测试、电导率测试、室温拉伸性能等,将Al-10.78Zn-2.78Mg-2.59Cu-0.221Zr-0.047Sr合金分别以3.6℃/h和180℃/h的升温速率升温至470℃,保温2 h和24 h,研究了升温速率和固溶时间对组织和性能的影响。结果表明,快速升温短保温时间的热处理工艺更佳,合金的硬度为218.1 HV,电导率为25.9%IACS,抗拉强度为735.6 MPa,屈服强度为691.7 MPa,伸长率为6.1%。为保证合金性能,应在快速升温时选择低固溶时间,在慢速升温时选择长固溶保温时间。

The effects of heating rate and solution time on the microstructure and properties were studied by means of metallographic analysis, EBSD analysis, vickers hardness test, conductivity test and room temperature tensile test of Al-10, 78Zn-2.78Mg-2.59Cu -0.221Zr-0.047Sr alloy, it was heating to 470 ℃with rate of 3.6 ℃/h and 180 ℃, respectively, and holding 2 h and 24 h. The results show that the short holding time with the rapid increase in heat treatment process, the hardness, conductivity, ultimate tensile strength, yield strength and elongation of alloy are 218.1 HV, 25.9% IACS, 735~6 MPa, 691.7 MPa and 6.1%, respectively, In order to ensure the performance of the alloy, the low solid solution time should be selected the fast heating rate, and the long solid solution holding time should be selected the slow heating rate.