Residual Stress Distribution in Alpha and Beta Phases of Mechanically Surface Treated TIMETAL LCB Determined by Energy Dispersive X Ray Diffraction

Abstract

TIMETAL LCB is a high strength low cost solute lean beta titanium alloy. Good fatigue performance, high specific strength, excellent corrosion resistance and reasonable cost make this alloy most suitable for spring applications in transport. To improve fatigue life and damage tolerance, mechanical surface treatments are used to induce severe plastic deformation and residual compressive stresses in near surface regions. The main aim of this investigation was to study the presence of residual stresses in both hexagonal close packed hcp amp; 945; phase and body centered cubic bcc amp; 946; phase as induced by shot peening SP and ball burnishing BB . To achieve such aim, energy dispersive X ray diffraction EDXRD was used. The evaluation of complete diffraction spectra by EDXRD allows analyzing of amp; 945; and amp; 946; phases independently. Results clearly indicate significant differences in the amount of cold work and compressive residual stress states between amp; 945; and amp; 946; phase