Ebsd Analysis of Microstructure and Properties of a New High Strength Corrosion Resistant Titanium Alloys Hot-Rolled and Heat-Treated Sheets

Abstract

In this study, a new α titanium alloy Ti-6.0Al-3.0Zr-0.5Sn-1.0Mo-1.5Nb-1.0V (Ti603) with high strength and good corrosion resistance was investigated. The materials were initially hot rolled into sheets and subsequently annealed at 740℃ for 2 hours. Meanwhile, it was subjected to a solution treatment at a temperature of 900℃ for 0.5 hours, followed by an aging treatment at 580℃ for 3 hours. The microstructure and texture of the material were analyzed using electron back-scattered diffraction (EBSD) observation. The study found that the microstructure of the Ti603 alloy changed from lamellar to equiaxed after undergoing annealing and solution plus aging treatments. Additionally, the grain size of the sample that received solution plus aging treatments was larger compared to the annealed sample. Following annealing, low-angle grain boundaries (LAGBs) transformed into high-angle grain boundaries (HAGBs) due to dynamic recrystallization (DRX). This weakened the dislocation accumulation at grain boundaries and resulted in changes in grain orientation, leading to lower texture intensity in the sample. Post solution plus aging treatments, stress concentration at grain boundaries increased, and there was a shift in the preferred orientation of grains, leading to a slight rise in the crystal texture intensity.

Keywords: Titanium alloy, mechanical properties, heat treatment, microstructure evolution, Crystal texture