Research On The Preparation Of Compound Coating Ti(C、N) On The Surface Of Ti-6Al-4V Via Plasma Electrolytic

Ti-6Al-4V is attractive material because of its excellent mechanical adaptability. However, it’s resistance to frictional wear is poor, and its hardness is relative low. Surface engineering techniques are widely used to improve the surface hardness and wear resistance of Ti-6Al-4V.Moreover, plasma electrolytic is verified to be possible for conversion the surface of Ti-6Al-4V. In this dissertation, Ti-6Al-4V was researched by direct voltage and pulse voltage via plasma electrolytic. The element carbon and nitrogen was compound on the surface of Ti-6A1-4V, also calcium and phosphorus was tested to be compound.The surface structure and their corresponding elemental composition of the coating were obtained by SEM, which was equipped with EDS. Coating phases were analyzed via XRD. The hardness was characterized by micro-hardness tester. The friction property and corrosion behavior were detected by specific machines. The main conclusions were drawn as follows:In the condition of direct voltage, the surface modification coating containing carbon and nitrogen was prepared via changing voltage and processing time using the method plasma electrolytic. The harden coating was about 100 μm thick and its hardness was HV 1362 at the loan 0.05N. The modification film possessed a better wear resistance and antifriction due to its high hardness. Also, the surface coating contributed to enhance the corrosion behavior.In the condition of pulse voltage, he surface modification film containing carbon and nitrogen was also prepared via changing electrical parameter and processing time using the method of plasma electrolytic. The harden coating was about 120 μm thick and its hardness was HV 840 at the loan 0.05 N. The modification film possessed a better wear resistance and antifriction due to its high hardness. Also, the surface coating contributed to enhance the corrosion behavior.In the mixed solution, which contains sodium phosphate, calcium nitrate and formamide, a compound coating containing carbon, nitrogen, calcium and phosphorus was prepared using the method plasma electrolytic. The element calcium exists in the form of calcium phosphate and calcium titanate. The element phosphorus exists in the form of calcium phosphate. The element carbon and nitrogen form titanium carbonitride. Surface scan results show the relative uniformly distribute of all elements. Electrochemical test result indicates the corrosion rate of the treated samples is reduced.