Effect of Ultrasonic Impact Treatment on Microstructure and Mechanical Properties of Commercial Purity Titanium

Abstract

The paper presents a study of the ultrasonic impact treatment effect on the microstructure and mechanical properties of commercial purity titanium (CP-Ti). The texture, residual stresses, the size of coherent scattering region, the thickness of plastic deformation layer and the microhardness of CP-Ti specimens subjected to ultrasonic impact treatment were studied. It was found that ultrasonic impact treatment of CP-Ti specimens resulted in severe plastic deformation of their surface layer. The plastic deformation caused twin and low angle boundary formation in the surface layer. The last-named led to a crystallographic texture change, a decrease in the size of coherent scattering region, an increase in compressive residual stresses and a growth of microhardness of the surface layer of titanium specimens.