Experimental Study on Isothermal Forging Technology for a Complex-Shaped Titanium Alloy Wing

Abstract

The complex-shaped Ti-6Al-4V alloy is widely used in the aerospace engineering and automobile industry. However, because of its high hardness, easy adhesion, large dimension and high precision, it is a great deal of cost of raw materials, and besides, it is difficult to machine by the traditional manufacturing methods unless it uses special cutting tools. In this study, a closed isothermal forging process was adopted for precision forming of the wing. The rational billet shapes were estimated by flow simulation experiment, and then mechanical property, forming ability, process parameters of the Ti-6Al-4V wing were studied by the isothermal forging tests to meet performance targets. The results show that compared with the titanium wing formed by conventional methods, the wing made by isothermal forging remarkably improves mechanical performances, and material utilization increases from 13% to 50%. During the isothermal forging process of Ti-6Al-4V, the flake α grains at 950 °C are transformed to β grains in the matrix; while the progress of transformation diminishes when the forging temperature decreases to 900 °C.