THE REDISTRIBUTION OF ALLOYING ELEMENTS BY RAPID-HEATING SOLUTION TREATMENT OF AN (ALPHA + BETA) TITANIUM-ALLOY

Thin-foil X-ray energy-dispersive chemical analysis of an ( alpha plus beta ) titanium alloy has been used to establish the compositional profiles which develop between the alpha and beta phases as a result of heating into the beta field at a rate of 100 K sec** minus **1. The results show that alpha phase transforms to beta via a diffusional mechanism as it is progressively enriched in beta -stabilizing solutes. Complete diffusional transformation of alpha to beta occurs 160 K above the beta transus but the beta phase remains chemically inhomogeneous. On subsequent quenching at a rate of 400 K sec** minus **1, beta phase containing less than approximately 10 wt% Mo equivalent of beta -stabilizing solutes transforms to martensite.