Isothermal Aging Precipitate of TB17 Titanium Alloy

Abstract

Transmission Electron Microscope (TEM), X-Ray Diffraction(XRD) and Optical Microscope(OM)were employed to investigate the aging precipitation behavior of a new type of ultra-high strength TB17 titanium alloy. The results show that during heat solution treated in the β phase field followed by aging the secondary α phase is nucleated, precipitated and grew on the β phase matrix,and the precipitated phase is lamellar structure which has burgers relation with the matrix. The secondary α phase content is increased rapidly and finally reach a steady-state as aging time increased and the final product of aging consists of α phase and β phase. there is a good linearity relationship between the content of secondary α phase and the hardness of age hardening. The TB17 titanium alloy isothermal phase transformation kinetics can be described by JMAK equation.

Keywords

• TB17 titanium alloy
• isothermal aging
• secondary α phase
• precipitation