Electrochemical approch to the development of a simulating physiological environment for strength evaluation of hard tissue replacement materials

In this paper, corrosion damage in the modular femoral hip prosthesis which is retrieved from the physiological environment for 58 months after insertion, has been analyzed with the parameter of the square root of projected area of corrosion pit from the view point of fracture mechanics. The effects of the pitting damage on fatigue properties of Ti-6A1-4V alloy was discussed based on the previous experimental result. Accelerated laboratory corrosion testing method which simulates the physiological corrosion environment has been developed on the basis of the results of corrosion test in simulated environment with Ti-6A1-4V alloy. The empirical formula which represents the relationship of applied current, corrosion time and maximum size of corrosion pit (area _max) has been proposed.