Microstructural and mechanical properties of Al-Zn alloy 7075 during RRA and triple aging

Abstract

Since aluminum is used in many essential applications, it has become a focus of researchers, mainly aluminum alloy 7075, because of its importance in the aircraft industry. The alloy 7075 incorporates high-strength materials such as Al-Cu-Mg, but with Zn through the primary alloy ingredient, instead of copper. Variations in the properties achieved in heat handling of Al-Zn-Mg ingredient 7075 are caused by solution and hardening process precipitation. The word heat-treatment solution means heat-treatment of a metallic structure to remove precipitated particles in the matrix. This work aims at studying the effect of solution treatment, the aging process, and the retrogression process on the mechanical properties of the Al 7075. Test measurements were taken by heating to 470 °C, intended for 30 min, then water quenching from goods, machines, and solutions. For example, not numerous of these collections were aged at R.T. Across 120 h. Other participants aged 24 h at 120 °C artificially. Then the retrogressed for 35 min at 180 °C; the group of these samplings was typically aged in R.T. across 120 h. Other groups were chemically aged for one day at 120 °C and retrogressed for 8 min at 200 °C, and all these samples were naturally aged at the average temperature for 120 h. Many classes were aged chemically for one day at 120 °C. Materials were evaluated by studying their microstructure, hardness, and tensile strength. It has been concluded that the best heat treatment values are the condition (1), indicating that the triple artificial aging gives the highest values of Hardness 49.4 HB and UTS 690 MPa, which were seen and convinced with the microstructure taken for each specimen.