Enhancing the Mechanical Properties of Titanium Grade 5 by Equal Channel Angular Processing and Rotary Swaging

Titanium Grade 5 (Ti64) is used extensively in many airframe applications and engine components, including bolts, seat rails, fan blades and fan cases. This is directly attributed to its good balance of strength, ductility, fracture toughness, corrosion resistance and overall workability. Nevertheless, an improvement in mechanical properties can further enhance the use of this alloy in aerospace applications and subsequently reduce aircraft weight and fuel consumption.

In this research, equal channel angular processing (ECAP) and rotary swaging (RS) were carried out on as-received Ti64 rods to investigate the effect on microstructure and mechanical properties. The results of mechanical testing demonstrated an increase in yield stress from 877 MPa to 1086 MPa after ECAP and a further increase to 1441 MPa after ECAP and RS. Moreover, ECAP plus RS resulted in an ultimate tensile strength of 1460 MPa, while maintaining good elongation of 8%. These results were attributed to a significant reduction in grain size after each processing stage. Such results demonstrate the potential of ECAP and RS as a means of improving mechanical properties of Ti64 and enhancing overall use of this alloy in aerospace applications.