The effect of heat treatment and exposure on the microstructure and mechanical properties of extruded, burn-resistant beta titanium alloy Ti-25V-15Cr-2Al-0.2C (wt%) has been studied. It has been found that pre-exposure annealing at 600, 700 and 800 degreesC affected the distribution of alpha phase that precipitated following subsequent exposure at temperatures between 450 and 550 degreesC. Samples annealed at 600 degreesC and subsequently exposed at 450 degreesC showed excellent microstructural and property stability. Although the room-temperature ductility of the alloy decreased and the strength increased slightly with increasing exposure time at 500 degreesC, no further drop in ductility was observed after 500 It. However, a gradual degradation of properties with exposure time was observed in samples exposed at 550 degreesC. The significance of the observations is discussed in terms of the effect of pre-exposure annealing and exposure on alpha precipitation and tensile properties. (C) 2001 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved.
- titanium alloys
- mechanical properties