Structure, processing, property correlation of metastable β titanium Ti-5Al-5Mo-5V-3Cr alloy

This work reports the evolution of "Structure, Processing, Property Correlation of Metastable beta Titanium Ti-5Al-5Mo-5V-3Cr alloy" as a function of different aging temperatures (625,725 and 775 degrees C) for 4 h subsequent to solution heat treatment. The hot-rolled sheet was heat treated in beta phase field and then water quenched. The solution heat treated in beta phase field and then water quenched samples were aged at 625, 725 and 775 degrees C for 4 h. The hot-rolled sample shows the presence of alpha and beta phases. The beta-solution heat treated in beta phase field and then water quenched sample of the alloy exhibits single beta phase. The intensities of X-ray peaks are varying and beta (211) peak shows the maximum intensity. The maximum intensity can be ascribed to beta (211) texture. The solution heat treated in beta phase field and then water quenched sample aged at 625 degrees C for 4 h shows the very fine hexagonal alpha phase precipitates as compared to the samples aged at 725 and 775 degrees C for 4 h. The samples aged at 725 and 775 degrees C for 4 h has resulted in precipitate-free zones as a result of the rejection of Mo, V, and Cr (beta stabilizing elements) during nucleation and growth of alpha precipitates along the beta grain boundaries. The Vickers hardness values of the alloy increase from solution heat treated in beta phase field and then water quenched to all aging temperatures. The sample aged at 625 degrees C for 4 h shows the maximum hardness which is due to the presence of fine alpha phase precipitates. This can be ascribed to typical precipitation hardening.