Effect of relative extrusion ratio on microstructure and properties of different parts in Al-Zn-Mg alloy component

doi:10.13251/j.issn.0254-6051.2021.03.004

Abstract

Abstract: Effect of relative extrusion ratio on the microstructure and properties of different positions in Al-Zn-Mg alloy component before and after heat treatment was investigated by using inductive coupled plasma (ICP), X-ray diffractometry (XRD), tensile tests and microstructure observation by optical microscopy (OM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy disperse spectroscopy (EDS). The results show that Al₃(Zr,Ti) particles exist in both the as-extruded and aged microstructure. The larger the relative extrusion ratio and the higher the content of Al₃(Zr,Ti) particle is, the stronger the degree of recrystallization inhibition during heat treatment is, and large amount of fibrous tissue microstructure remains in the structure after heat treatment as well as the MgZn₂ phase precipitates and aggregates at the grain boundaries. The larger the relative extrusion ratio is, the smaller the average grain size increment after heat treatment is, and the larger the increments of yield strength, tensile strength and elongation are.

Key words: Al-Zn-Mg alloy, relative extrusion ratio, heat treatment, Al₃(Zr,Ti) particles, MgZn₂ phase, microstructure, mechanical properties

CLC Number:

TG146.2

Huang Yuanchun, Zhang Qiang, Nie Changchang, Tan Weiyang. Effect of relative extrusion ratio on microstructure and properties of different parts in Al-Zn-Mg alloy component[J]. Heat Treatment of Metals, 2021, 46(3): 17-23.

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