Effects of annealing treatments on microstructure and mechanical properties of the Zr345Ti35Al33V alloy

The Zr345Ti35Al33V alloy having good mechanical properties is a potential structural material to apply in the aerospace industry. The microstructure and mechanical properties of Zr345Ti35Al33V alloy during annealing heat treatment were investigated. The specimens annealed from 500 to 800 °C are composed of α and β two phases. No compound is detected in specimens annealed in that temperature range. The microstructure of annealed specimens is characterized as a typical basketweave microstructure. Two microstructural parameters, thickness of plate α phase and relative fraction of β phase, were measured in specimens annealed at various temperatures. The thickness of plate α phase and the relative fraction of β phase increase with the increasing annealing temperature while the specimens anneal from 500 to 700 °C. However, a decreased phenomenon of those microstructural parameters occurs while the specimen anneals at 800 °C. The strength of examined alloy increases from 1306 to 1370 MPa for tensile strength and from 1116 to 1277 MPa for yield strength, inversely, the elongation decreases from 9.5% to 5.8% with the increasing thickness of plate α phase and fraction of β phase in specimens annealed in the range from 500 to 800 °C.