Study on surface state and thermophysical properties of TA15 alloy by laser ablation

Abstract The active titanium alloy is prone to form an oxide layer with poor thermal strength and fluffy during hot working. Native morphological defects also affect subsequent processing. In this study, the laser ablation was used to remove the thermally processing oxide layer and modified the surface morphology. The effect of the newly formed oxide layer on the surface thermal diffusivity was studied. As the average power increased, the native morphological defects were modified to the crater morphology. Finally, the wavy fringe morphology was formed. The thermal oxide layer of the untreated sample was composed of TiO2 (anatase), TiO2 (rutile), and Al2O3. After laser ablation, the content of TiO2 (rutile) increased. Cross-sectional morphology observation shows, above 12 W, the oxide layer appeared agitating morphology. It is proved that 12 W is the boundary between the thermal effect and the thermo-mechanical composite effect. The effectiveness of laser ablation in modulating the thermo-physical properties of the surface was verified by thermal diffusivity measurements.