The Microstructure Evolution of AA7050 in the Process of Homogenization

This paper used the metallographic analysis, X-ray diffraction analysis (XRD), differential scanning thermal analysis (DSC), scanning electron microscope (SEM) and electron probe analysis (EPMA) system to research the evolution law of the microstructure and properties of AA7050 under different homogenization system. And analyzes the cause of this evolution combined with the test results put forward. The research shows that high melting point eutectic phase S (Al2CuMg) can be fully re-dissolution through two-stage homogenization, at the same time avoid the overburning of low melting eutectic phase. We optimized the AA7050 homogenization heat treatment system and the optimal homogenization scheme is 430°C/18h+467°C/12h.