Research Of Composite Modification Technology On Titanium Alloy Surface

Ti6Al4V alloy micro-arc oxide film was prepared in Na2SiO3-(NaPO3)6-NaAlO2solution. The proper MAO power parameter was determined. The influence of forwardvoltage and duty ratio on the poriness，roughness, film thickness, surface morphology,and phase composition were studied. MAO self-lubricating composite membrane wasmade by using PTFE emulsion to seal the holes. MAO film was composite modificationtreated through HCPEB. The hardness, surface morphology, phase composition, frictionand wear property and corrosion of composite modified layer were studied.Experimental results show that, forward voltage and duty ratio are importantfactors affecting the formation of MAO film. With forward voltage and duty ratioincreasing, the thickness increased. Pore number deceased. Pores aperture increased.The MAO film surface roughness increased. Rutile increased, anatase reduced.On the self lubricating surface the PTFE particle has entered into micro-pores. Thefilm got smooth and dense. The higher the concentration of PTFE, the more surfacemicro-porous membrane layer was filled, and smoother. But the concentration of PTFEshould not be too high, or membrane layer surface will accumulate PTFE and getrugged. The friction coefficient of PTFE self-lubricating film was lower than titaniumsubstrate and MAO film, smaller erosion. The wear resistance increased from0.04to0.24. The corrosion potential moved forward, the corrosion resistance increased.The surface micro porosity of composite modified layer with HCPEB disappearedand got smoother. The film surface appeared melt holes and cracks. Observation sectionmorphology, the film got thick after HCPEB treatment, the cracks have extended tomembrane layer inside. The greater the roughness of prefabricated MAO film, the moredifficult electron beam melting, the greater the roughness of composite modified layer.The hardness of composite modified layer is1695HV. The smaller the hardness is asnear to the base film layer. Modification coefficient of friction is smaller than MAOfilm. The wear resistance increased. Corrosion potential reached0.19. The corrosionresistant ability enhanced.