Hot Compression Deformation Behavior and Microstructural Evolution of Al-7.5Zn-1.5Mg-0.2Cu-0.2Zr Alloy

• Published in: Materials science forum Vol. 913; pp. 43 - 48
• Main Authors: Zhang, Wen, He, Jian Liang, Qiu, Cheng, Zhang, Da Tong
• Format: Journal Article
• Language: English
• Published: Pfaffikon Trans Tech Publications Ltd 01.02.2018
• Subjects: Aluminum base alloys; Compression tests; Computer simulation; Deformation; Edge dislocations; Flow mapping; Flow stability; Heat treating; Hot pressing; Microstructure; Power efficiency; Process mapping; Shear bands; Steady flow; Strain rate; Thermal simulation; Yield strength; Hot Deformation; Processing Map; Microstructure; Al-7.5Zn-1.5Mg-0.2Cu-0.2Zr Alloy
• ISSN: 0255-5476; 1662-9752; 1662-9752
• DOI: 10.4028/www.scientific.net/MSF.913.43

Hot compression tests of as-homogenized Al-7.5Zn-1.5Mg-0.2Cu-0.2Zr alloy were carried out on Gleeble-3500 thermal simulation machine at the temperature ranging from 350°C to 550°C and strain rate ranging from 0.001s-1 to 10s-1. Processing maps were established on the basis of dynamic material model, and the microstructure was studied using electron back scattered diffraction (EBSD) technique. The results showed that the peak stress and steady flow stress decrease with decreasing strain rate or increasing deformation temperature. There are one peak efficiency domain and one flow instability domain in the processing maps. The flow instability domain which exists in high-strain-rate region becomes larger with increasing strain. Shear bands occur at 45° toward the compression axis at grain interiors and meanwhile flow localization occurs. The optimum deformation temperature and strain rate ranges from 450°C to 500°C and 0.003s-1 to 0.1s-1, respectively, with high power dissipation efficiency of 34-39%.