Cu含量和Sc添加对高锌Al−Zn−Mg−Cu合金淬火敏感性和显微组织的影响

Quench sensitivity and microstructures of high-Zn-content Al−Zn−Mg−Cu alloys with different Cu contents and Sc addition

根据7085合金成分,调整7xxx铝合金中Zn、Cu和Sc的含量;研究Zn、Cu含量及Sc添加对7xxx铝合金显微组织、硬度和淬火敏感性的影响。在距淬火端3 mm处,高Zn和Sc添加合金的硬度值高于7085合金的。在距淬火端120 mm处,η和T相的密度随Zn和Cu含量的增加而增加,Sc添加导致形成Y相和更多的η相。与7085合金相比,高Zn高Cu和Sc添加合金具有更高的淬火敏感性。增加Zn含量并降低Cu含量可在提高7085合金硬度的同时降低其淬火敏感性。

The Zn,Cu,and Sc contents of 7xxx Al alloys were adjusted according to the chemical composition of a 7085 Al alloy,and the effects of Zn and Cu contents and Sc addition on the microstructures,hardness,and quench sensitivity of the 7xxx Al alloys were studied.The alloys with high Zn content and Sc addition exhibited higher hardness than the 7085 alloy at the position 3 mm away from the quenching end.The density ofηand T phases increased with the increase in Zn and Cu contents,and the Sc addition led to the formation of the Y phase and moreηphases at the position 120 mm away from the quenching end.Compared with the 7085 alloy,the high Zn−high Cu and Sc-added alloys exhibited higher quench sensitivity,while the simultaneous increase in Zn content and decrease in Cu content could enhance the hardness and reduce the quench sensitivity of the 7085 alloy.