MECHANICAL PROPERTIES OF SUPER–HIGH STRENGTH Al ALLOY 7A04 AT TRANSIENT HEATING

Super-hard aluminum alloy 7A04(Al-Zn-Mg-Cu),whose ultimate strength is higher than that of duralumin,belongs to a class of aluminum alloys with highest ultimate strength tested at room temperature.As it can be utilized as structural material of various heating components such as rocket liquid storage tank and missile wing,super-hard aluminum alloy 7A04 has been widely used in the field of aerospace engineering.However,the ultimate strength and other token mechanical parameters of aluminum alloy 7A04 at transient high-temperature heating environment are still unclear to us, as these key mechanical parameters are lacking in existing strength design handbook.Experimental characterization of these critical parameters of aluminum alloy 7A04 is undoubtedly meaningful to the reliability estimation,life prediction and security design of the high-speed flight vehicle.In this paper,by combining transient aerodynamic heating simulation system and material testing machine, the high-temperature ultimate strength,loading time and other mechanical properties of super-hard aluminum alloy 7A04 under different transient heating temperature and loading conditions were investigated Experimental results revealed that the ultimate strength and loading capability of aluminum alloy 7A04 subjected to transient thermal heating were much higher than those tested in a long-time stable high-temperature environment.The results provided substantial basis for the loading capability improvement and optimal design of aerospace materials and structures subject to transient heating.