In this paper, some methods for evaluating the properties of metallic biomaterials are proposed and discussed, with special interest in the requirements of biomaterials which strongly relate to corrosive properties. A simple evaluation method for determining metallic elution was proposed, and the results are shown.
The most important mechanical property of a biomaterial is the fatigue life under consideration of actual usage and environment. The methods employed for the artificial joint were used as an example. The appropriate fatigue test for the biomaterial component is a four-point side notch bend specimen and the dimensions of the specimen are given. The notch tip radius of curvature should be the smallest radius of curvature of the implant design. The notch tip surface finishing condition should especially be examined, because not only notch radius (stress concentration) but also notch surface condition (scratch and structure sensitivity) affect the fatigue properties. The corrosion characteristics of biomaterials are also estimated by measuring the difference of the fatigue life in a laboratory air environment to that in a physiological saline solution environment. The details of the results on pure titanium, titanium alloy, and stainless steel are given.