摘要

  Magnesium alloy due to biocompatibility,biodegradability,mechanical compatibility and biological activity which has become the most valuable development and utilization of new materials,bio-medical metal,in high value-added products,especially within the medical device manufacturing plant application prospects very attractive,but its rapid degradation caused a series of problems,but restricts the process of biomedical magnesium alloys,therefore,the development of biodegradable magnesium alloy control technology has important significance.This paper selects AZ91D magnesium alloy as main research object,use bionic passivation as pre-treatment technology,use cathodic deposition method as "sealing hole" and "reinforce" technology,the preparation of bionic passivation-cathode deposition combined treatment on the surface of AZ91D is realized.The result of achromatization experiment and electrochemical test show that,the bionic passivation pre-treatment can improve the effect of cathode deposition modification notably.Compared with the direct cathode deposition treatment,combined treatment can make corrosion resistance of the film increased by 114.95%.The analysis result of XRD show that,the main composition of coating which prepared from cathode deposition in NH4H2PO4/Ca(NO3)2·4H2O combined system is DCPD;The coating prepared from cathode deposition in KH2PO4/CaCl2 combined system is mostly comprised of DCPD with small amount of HA.The analysis result of SEM show that,the coating prepared by combined technology is more uniform and dense,the cathode deposition coating is slate-shape grains.

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