The microhardness, morphology and tribological property of TC4 subjected to machine hammer peening

Abstract Ti alloy has become an indispensable material in harsh working environments due to its excellent wear resistance, corrosion resistance and impact resistance. These environments place stringent requirements on the fatigue life, friction and wear, and surface strength of materials. Therefore, this study aims to deeply explore the surface mechanical properties of Ti-6Al-4V (TC4) alloy after machine hammer peening (MHP) treatment. By conducting experiments on TC4 alloys treated with different hammering energies, the changes in surface hardness, morphology, roughness, tensile properties, and friction properties were analyzed, and the strengthening mechanism of MHP was discussed. Experimental results show that MHP treatment can effectively improve the surface properties of TC4. With the increase of hammer energy, due to the double-sided hammering of the plate, the microhardness first increases, then decreases, and then rises again. The tensile strength and yield strength of the sample increase slightly, but the elongation at break decreases. The surface roughness of the sample increases first and then decreases. Similarly, after MHP treatment, the wear resistance of the samples increased, the friction coefficient decreased, and the wear amount and surface height difference showed a trend of first increasing and then decreasing. The wear mechanism mainly included adhesive wear, abrasive wear and fatigue wear.