Preparation And Properties Of Biofunctional Coatings On The Surface Of Biomedical TiNiCu Alloy

In the present paper,Ti49.2Ni43.8Cu7 alloy was used as research object,and the porous structure was constructed and the biological functional composite coating containing hydroxyapatite and antibacterial silver ion were deposited in situ by electrochemical methods.The influence of the preparation processing parameters of the biological functional coating on the surface morphology and surface performance of Ti49.2Ni43.8Cu7 alloy was systematically investigated,which provides theoretical guidance and experimental reference for the design and development of the surface treatment technology for biomedical titanium alloys with both antibacterial function and biological activity,and has a promising clinical application prospect.The results of anodic oxidation showed that the porous structure consisting of micro pits and nano tubular was formed on the surface of biomedical Ti Ni Cu alloy,and the anodizing voltage,NH₄F content in electrolyte and anodizing time had great influence on the morphology of porous structure.When the anodizing voltage was 40 V,NH₄Fcontent was 0.1 wt%,and the anodizing time was 2 h,the diameter of the formed nanotubes was greatest,which was 40.7 nm.After anodizing,the surface phase composition of biomedical Ti Ni Cu alloy did not change significantly,which was composed of B2 phase and Ti₂(Ni,Cu)phase.The surface roughness was about 19 nm,which was at the nanometer level,and the contact angle with water increased from 53.5°to 119.51°,indicating superhydrophobic property.With the increasing anodizing voltage,the contact angle firstly decreasd and then increased.In addition,the anodized Ti Ni Cu alloy showed decreased microhardness,increased friction coefficient,and imporved corrosion resistance and antibacterial property.The results of annealing treatment after anodizing treatment showed that the titanium nanotubes formed by anodizing changed to rutile structure during heat treatment,leading to the increased surface microhardness,decreased friction coefficient and superhydrophobility with the surface contact angle ranging from 69.52°to 119.88°.When the heat treatment temperature was higher than 550?,the surface of titanium dioxide nanotubes collapsed.When heat treated at 450?,the structure of nanotubes was almost invariable.and the obtained surface exhibited superhydrophobic and good antibacterial property.The results of the bioactive coatings deposited by electrochemical methods showed that the electrodeposited pure HA coating exhibited dense needle and block shape,while the Ag/HA composite coating was loose.Compared with the original Ti Ni Cu alloy,anodized Ti Ni Cu alloy with HA and Ag/HA composite coatings showed decreased friction coefficient,increased corrosion resistance and antibacterial property,as well as better biomineralization ability.