Tantalum nitride films for corrosion protection of biomedical Mg-Y-RE alloy

Based on their natural degradation in the human body, magnesium-based alloys are attractive for temporary implants such as cardiovascular stents and bone fixation devices. Unfortunately, rapid degradation of magnesium-based alloys in the physiological environment is a major obstacle limiting wider application. Herein, the WE43 Mg alloy deposited with tantalum nitride films by reactive magnetron sputtering shows enhanced corrosion resistance. The modified WE43 exhibits a 95-fold decrease in the corrosion current density and 100-fold initial increase in the charge transfer resistance in simulated body fluids (SBF). The ion concentration and pH of the soaking solution show that corrosion of the modified WE43 is remarkably retarded during a long-term immersion in SBF for 30 days. The corrosion propagation mechanism of the untreated and modified WE43 during long-term immersion in SBF is investigated.