Cu-Ni Plasma Alloying On The Surface Of Titanium Alloy

Because of it’s superior properties of low density, high specific strength and anti-corrosion, titanium, as the new kind of industrial metal, has been widely applied in aviation-aerospace, shipbuilding and petrochemical industry. Nowadays, for the special application fields of food processing&transportation and medical health, titanium alloy has been asked to be equipped with antibacterial property.In order to hit the mark, alloying ti-alloy was prepared through double glow plasma chromizing process with TC4(Ti-6Al-4V) as substrate and Cu, Ni as pre-seeding metal in this experiment. X-Ray Diffraction, Scanning Electron Microscope and Energy Dispersive Spectrometer were utilized to observe and check the morphology,composition and phase of the alloyed layers. The antibacterial property to escherichia coli and staphylococcus aureus of samples were tested with plating method. Due to the reciprocating friction&wear experiment, the abrasion resistance of the alloyed layers were detected. The corrosion resistance of substrate and alloying TC4 were examined by adoption of immersion method in0.5mol/L Na-Cl solution. Here are the conclusions:1)With alloying treatment, there’s an alloy coating formed on the surface of TC4. The thickness Of Cu-Ni alloyed layer is7.5μm with Ra=220.3nm. Consists of various sosoloid, interstitial compound, both are composed of Ti、Cu%Ni, and some pure titanium, the surface of Cu-Ni alloyed layer contains40%of Ni and8%of Cu. The thickness Of Ni alloyed layer is20μm with Ra=78.34nm. Consists of Ti2Ni, TiNi and some pure titanium, the surface of Ni alloyed layer contains96%of Ni.2) With alloying treatment, samples have shown some level of antibacterial property to both strains and Cu-Ni alloying TC4is better than Ni alloying TC4which indicates that both Cu and Ni have antibacterial quality, but compare to Ni, Cu is better. Therefor, This paper focused on the antibacterial mechanism of Cu but It’s detailed mechanisms need to be studied by more experiments.3) With alloying treatment, the surface hardness of Cu-Ni alloying TC4is697HV0.1and Ni alloying TC4is1442HV0.1. The reciprocating friction&wear experiment shows that fNi>fCuNi>fs, which means substrate TC4has the best property of anti-attrition, and Ni alloying TC4is the last one. However, Ni alloying TC4has the optimum performance of abrasion resistance for it’s minimum wear volume, followed by Cu-Ni alloying TC4. The reason for the situation is mainly about the solution strengthening functioned by Cu and Ni. The abrasion resistance test has proved that the antibacterial titanium alloy prepared through Cu-Ni plasma alloying has some practicable value.4) With alloying treatment, in0.5mol/L Na-Cl solution, ICuNi>INi> Is which equals to VcuNi> VNi> Vs means that on the premise of using0.5mol/L Na-Cl solution, corrosion resistance of Ni alloying TC4is the best, and substrate TC4is the worst. The infiltration of Cu、Ni have some impact on the corrosion resistance of TC4. Therefor, more experiments will be needed to study the way to improve the corrosion resistance of antibacterial titanium alloy. However, the corrosion resistance of alloying TC4can be improved by keeping corrosion current remain at maintaining passivity current on the premise of passivation in0.5mol/L Na-Cl solution.