Nowadays, most surface treatments are realized through vapor deposition techniques as thin hard coatings to guarantee high surface hardness, low friction coefficient, and improve wear resistance. Several experimental investigations have led to the development of multilayer coatings in preference to the traditional TiN coating. In the current chapter, research was conducted on the fretting wear of (TiAlCN/TiAlN/TiAl) and (TiAlZrN/TiAlN/TiAl) multilayer coatings deposited by reactive DC (magnetron sputtering) of Ti-Al and Ti-Al-Zr alloys on AISI4140 steel. Fretting wear tests (20,000 cycles at 5 Hz) were conducted in ambient conditions, where the interaction between normal load and displacement amplitude determined the fretting regime. The influence of the normal load and displacement amplitude on the coefficients of instantaneous coefficient of friction and stabilized coefficient of friction is different in the two multilayer, coated steels. The PVD coating (TiAlZrN/TiAlN/TiAl) reduces the friction. The worn volume of coated AISI4140 steel is sensitive to normal load and displacement amplitude. The relation between worn volume and cumulative dissipated energy was established for the two coated steels. The energetic fretting wear coefficients were also determined. A multilayer (TiAlZrN/TiAlN/TiAl) coating has a low energetic wear coefficient.
Part of the book: Tribology in Materials and Manufacturing
The simulation and theoretical or numerical predictive modeling of the development and growth of biological tissues mainly in the case of bone is a complicated task. As a result, many and various knowledge tools required (experimental, theoretical and numerical) are not yet mastered and even discovered. We will cite here some techniques and methods as well as results specific to the multi-scale numerical modeling methodology, and multiphysics using finite element coupling with neural network computation of biological tissues applied to the predictive behavior of cortical bone based of the microstructure of their local constituents and their reconstruction according to local mechanobiology. It follows that additional work is necessary to give more precision on the different models, the considered approaches show their potential utility to understand this behavior in terms of biological evolutions as well as the subsequent use in medical applications.
Part of the book: Biomechanics and Functional Tissue Engineering