The Effect of Mechanical Shot Blasting in Producing the Surface Ultrafined Grain Layer on Large-Size Titanium Plate

This paper reported that the mechanical shot blasting was a feasible method for producing ultra-fined grain layer on large-size titanium plate. The MSB effects on producing ultra-fined layer were investigated by optical microscopy, X-ray diffraction, transmission electron microscopy, and micro-hardness tester. The experimental results showed that the thickness of the surface severe plastic deformation layer increased with the improvement in processing speed, but presented stabilization with prolonging the processing durations. The maximum thickness of the ultra-fined grain layer was about 320 mu m, and the minimum grain size in the topmost surface was about 180 nm. The ultra-fined grain presented equiaxed grain morphology with random crystallographic orientation.