Homogenization heat treatment of 6070 aluminum alloy

doi:10.13251/j.issn.0254-6051.2023.03.009

Abstract

Abstract: Homogenization heat treatment process and microstructure evolution of 6070 alloy were studied by means of OM, SEM, EDS, DSC and conductivity measurements. The results show that in the as-cast 6070 alloy, a large amount of Mg₂Si primary phases produced by non-equilibrium solidification are aggregated and distributed along the grain boundary, and disc-shaped Q phase is distributed in the grains. After 535 ℃×12 h homogenization heat treatment, the primary phase in the as-cast alloy is basically redissolved, and the homogenization effect is good. After homogenization, the alloying elements are mainly precipitated in the aluminum matrix in the form of fine dispersed phase, leading to the increase of conductivity. The overburning starting temperature of the alloy is 550 ℃, at which the overburned characteristics including nearly-triangular remelting phase and grain boundary widening by remelting begin to appear in the alloy. With the increase of homogenization temperature and extension of time, the overburning of the alloy increases and the conductivity decreases, the grain size and Mn containing dispersed phase size become larger, and the coarse overburned phase Q is formed concurrently.

Key words: 6070 aluminum alloy, homogenization, microstructure, overburning, conductivity

CLC Number:

TG166.3

Zhao Yu, Wei Wu, Huang Hui, Liu Zhenshan, Ren Simeng, Dong Yang, Wang Yugang, Shi Wei. Homogenization heat treatment of 6070 aluminum alloy[J]. Heat Treatment of Metals, 2023, 48(3): 51-56.

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