Experimental Study And Characteristic Analysis On Tribo-Electrochemistry Of Titanium And Aluminium Alloy's Oxidation Film

Titanium alloys are used as alternative hard tissue materials because of their good biocompatibility, appropriate mechanical properties and excellent corrosion resistance. Though they are promising biomedical metallic materials in modern biomedicine area, their applications were limited to their poor wear-corrosion behavior. Surface modification can be used to improve wear-corrosion resistance and biocompatibility of titanium alloy implants in body. Similarly, with a high strength and good formability, 7A04 alloy has consumption just less than steel in modern industry, and its performance as anti-wear resistance, heat resistance and corrosion resistance could also be improved by surface modification methods. As one kind of up-to-date surface modification methods, micro-arc oxidation technique has been widely used to form oxide ceramics on light alloy surfaces in-situ., holding an extensive application potential.Tribo-electrochemistry deals with various electro-physics and electro-chemical processes of friction pairs in lubrication systems of both aqueous media and non-aqueous solutions by combining modern electrochemistry theory and technique with tribology. By investigating the relationship between frictional behavior of electrode surfaces and electrode potentials applied with this theory,we can reveal the mechanisms of the influence of applied potential on tribological behavior.For anode oxide films and micro-arc oxidation coatings formed on TC4 alloy and on 7A04 alloy respectively, we measured the micro-hardness of these surface modification layers, observed their surface morphologies through SEM, analyzed phase composition and characteristics of the modification layers by EDAX and XRD spectrum analysis.In this paper, the experiments have been done on the improved pin-on-disc friction tester. For different samples of TC4 alloy, by using the advanced methods of three electrodes electrochemistry, the tribo-electrochemical performance of samples of the modification layer rubbing with different materials in the various solutions were studied. It shows that the corrosion resistance of anode oxidation films is improved in 0.9%NaCl and SBF solutions, but its anti-wear ability is bad,...