Preparation And Properties Of Ta-O/Mg Composite Coating On Magnesium Alloy ZK60 Surface

Magnesium and magnesium alloys have the characteristics of elastic modulus and density close to human bone,degradability in vivo and excellent biocompatibility,and are a promising biodegradable medical implant material.However,the corrosion rate of magnesium and magnesium alloys in human physiological environment is relatively fast.In the case of unhealed bone tissue and unfinished bone repair,performance failure occurs in advance,eventually leading to failure of implantation surgery.How to improve the corrosion resistance of magnesium and magnesium alloys and match the degradation rate with the growth rate of human bone has become a research hotspot of degradable medical implant materials at home and abroad in recent years.In order to improve the corrosion resistance of magnesium alloy,a Ta-O/Mg composite coating was prepared on the surface of magnesium alloy ZK60.The coating was characterized by XRD and SEM.The coating was applied by scratch and electrochemical workstation.The properties were tested.The effects of the intermediate layer and preparation parameters on the corrosion characteristics of the composite coating in the simulated body fluid environment were systematically studied.The Ta-O coating and The Ta-O coating containing Ta,Mg and Zr intermediate layers?represented by TZ,TTZ,TMZ and TZZ,respectively?were prepared on the surface of magnesium alloy ZK60 by RF reaction technique.Surface morphology,phase composition,bond strength and corrosion characteristics of the layer.The results show that:?1?The surface of the four coatings consists of Ta,Ta₆O and Ta₂O₅.The surface of the TMZ sample has uniform grain size,compact structure and best coating quality.?2?Four coating samples The order of coating adhesion from large to small is TMZ?16N?>TTZ?14.5N?>TZ>?12N?>TZZ?8N?;?3?Four coatings can improve the corrosion resistance of magnesium alloy ZK60 The Ta-O coating with intermediate layer has higher protection effect on ZK60 than single-layer Ta-O coating;?4?TMZ sample has the highest corrosion potential and the lowest corrosion current density,showing the best corrosion resistance.performance.The effects of sputtering power and sputtering time of the interlayer Mg film,sputtering power and argon-oxygen ratio of Ta-O film on the corrosion characteristics of TMZ samples were investigated by single factor experiment.The results show that when the sputtering power of Mg film is reduced from 250W to 50W,or the sputtering time of Mg is reduced to 5min in 25min,or the sputtering power of Ta-O film is reduced from300W to 100W;or Ta The argon-oxygen ratio of the-O film was reduced from 7:1 to 1:1,and the corrosion resistance of the TMZ sample showed a trend of increasing first and then decreasing,The corrosion resistance of the sample in which the sputtering power and the sputtering time of Mg,the sputtering power and the argon-oxygen ratio of Ta-O were 100 W,10min,250 W,and 18:12,respectively,were the best.