Corrosion and Wear Properties of Carburized Layer on TC6 Titanium Alloy in Different Environments

Surface strengthening of TC6 alloy was conducted by using the induction heating double pulse gas carburizing technology. The microstructures of these carburized layer were characterized by using XRD and metallographic microscope. The corrosion and wear properties of carburizing samples were studied in 0. 1% HF solution, 0. 9% NaCl solution and SBF solution by using a home-made corrosion-wear test device. Meanwhile, the open circuit potential and polarization curves under the interaction of corrosion and wear were measured by an electrochemical workstation. The worn surfaces were characterized and analyzed by the white light interferometer. Results show that a TiC layer is formed on TC6 alloy by carburizing at 910 degrees C and the layer has the hardness of 850 HV0.25. Both the friction coefficient and wear rate of the alloy after carburizing are smaller than that of the bare alloy in three different media. The smallest corrosion current density (9. 64x10(-6) A/cm(-2)) of the carburized sample is obtained in the SBF solution by the corrosion-wear test, indicating an excellent resistance to biological corrosion. Noting that the biggest corrosion current density is found in 0. 1%HF solution (1. 34 x10(-4) A/cm(-2)), the wear mechanism of the bare alloy is mainly adhesive wear and the carburized TC6 alloy is mainly abrasive wear in all three environments. Overall, corrosion can enhance the wear of the alloy and such enhancement leads to material loss of TC6 alloy.