The Al-Zn-Mg alloy belongs to the 7xxx series of Al alloys. Al-Zn-Mg alloys have been widely used in structural load-bearing parts of transportation and aerospace due to their great mechanical properties and formability. According to previous research, the major strengthening is due to η’(η)-phase and T’(T) phase. There is much brief research on the η’(η)-phase about the orientation relationship of morphology, lattice parameter, and interface between the Al matrix, but not much information about the T’(T) phase. Now our aim is to research the T’(T) phase morphology, orientation relationship, and interface between the Al matrix. According to previous studies, we know that the interface is very important for mechanical properties. When we have information about the interface, we can change the interface by adding the transition metals. Al-Zn-Mg alloy with a Zn/Mg ratio of 0.71 aged at 200°C for 2000 minutes exhibited the highest hardness, according to the observations. The strengthening precipitates in the investigated alloy were totally T′ (T) phase, according to TEM observation. We observe the lattice parameters T’ (a = 1.435 nm) and T (a = 1.461 nm) and the interface (100)T′ // (111)Al || [010]T′ // [112]Al and (010)T′ // (112)Al || [110]T′ //[001]Al with Al matrix. We observe the shape, lattice parameter, and orientation relationship between the T’(T) with Al matrix by using transmission electron microscopy.
December 28, 2025