Читать книгу Materials for Biomedical Engineering - Mohamed N. Rahaman - Страница 140

A common requirement in the design of some biomaterials is that their shape and dimensions should remain constant. For ductile metals and alloys, this means that while plastic deformation might occur locally at a few specific points, such as the vicinity of a microvoid, it should not spread throughout the entire material. Consequently, the highest stress that the metal is subjected to should be less than its measured yield stress. As the fracture of ductile metals is considerably less sensitive to the presence of microstructural flaws such as pores and microcracks when compared to brittle ceramics, the average value of their measured yield stress is a useful design property.