Precipitation behaviour of single and duplex aged metastable beta-Ti alloy, Ti-5Al-5Mo-5V-3Cr

This work presents the influence of single-aging and duplex-aging treatments on microstructure evolution and the associated properties of Ti-5553 beta-Ti alloy. We found that single-aged samples with a slow heating rate and duplex-aged samples produced approximately the same microstructures and microhardness at all aging conditions. This can be attributed to the same precipitation mechanism in both cases as observed via in situ electrical resistivity measurements. The slowly heated and duplex-aged samples generally produced higher microhardness in comparison to fast-heated samples; however, the difference in the microhardness tended to decrease with aging time at higher temperatures. A correlation (H-v = 252 + 1790/root d) between the microhardness values and the width of alpha-phase (d) was established for all the aged samples. [GRAPHICS] .