INFLUENCE OF DEFORMATION ON MICROSTRUCTURE OF TI-15V-3CR-3SN-3AL ALLOY

Titanium and its alloys are widely used in industrial applications due to their attractive properties. Ti-15V-3Cr-3Al-3Sn, a solute-rich, precipitation hardenable, beta titanium alloy shows a unique combination of low density, high strength, ductility, and corrosion resistance. During the production of semi-finished parts, several deformation steps (e. g., rolling or forging) are necessary, leading to different microstructures and properties especially at the rod ends. The aim of the current study is therefore to investigate the microstructure-property relationships of Ti-15V-3Cr-3Al-3Sn exposed to deformation at different strain rates and temperatures. Samples of Ti-15V-3Cr-3Al-3Sn alloy have been deformed in quasi-static and Hopkinson Split Pressure Bar experiments between room temperature and 900 degrees C at strain rates between 10(-3)s(-1) and 10(3)s(-1). The resulting microstructures were investigated by means of optical microscopy, scanning electron microscopy and hard x-ray diffraction. In addition, the hardness of the samples was investigated. The size and shape of grains were determined and compared with the undeformed state. The microstructure and properties strongly depend on the initial experiment temperature and strain rate. The highest increase of lattice parameter has been observed at low strain rates and low temperature, which has been identified by the x-ray diffraction analyses.