Creep Behavior of Commercially Pure Titanium TA2 After Supersonic Fine Particles Bombardment

In this study, the effect of supersonic fine particles bombardment (SFPB) on the creep behavior of commercially pure titanium TA2 was investigated. Microstructural observations with x-ray diffraction and a transmission electron microscope indicated that the grain size of the TA2 surface layer was refined to nanometer scale in the topmost surface layer after SFPB treatment. Indentation creep tests showed that the SFPB-treated sample had a lower maximum depth and higher hardness than the original sample at the same load, indicating an enhancement of the surface strength with SFPB. With lower creep displacements, the creep resistance was also improved after SFPB treatment. The maximum creep rate under different loading conditions showed obvious loading time and load dependencies. The maximum creep rate of the SFPB-treated sample was lower than the original sample for all test conditions, and the maximum creep strain rate of the SFPB-treated sample was similar to that of the original sample. The indentation stress of the SFPB-treated sample was higher than the original sample, while the creep stress exponent of the original sample was slightly higher than for the SFPB-treated sample, with no obvious variation tendency with different loading times or loads.