Abstract: The quench transfomation in a Ti-10V-2Fe-3Al near B-titanium alloy was studied by means of X-ray diffraction, transmission electron microscopy, and optical micyoscopy. The quenching temperatures were above and below the β transus temperature. The phase constitutions of specimens quenched from various solution temperatures were identified and the phase morphologies were examined. In addition, the relationship between phase lattice parameters and quenching tempera- tures was given for α, β and α ~(11) phases. This alloy has a tendency of precipitation of athermal ω phase and formation of stress induced α~(11) mar- tensite from β phase during quenching. Quenched from the temperatures above the β transus tem- perature, the alloy mainly consists of β phase, a small amount of α~(11) martensite and athemal ω phase aye also present in the alloy. After quenching from the temperatures below the β transus temperature, the α phase appeays in the alloy in addition to the phases mentioned above.

Key words: β-titanium alloy, phase trasformation, quenching