Dynamic behavior of metals and alloys designed for high-temperature applications

In many real applications, metals and alloys could be subjected to dynamic loading conditions while they are operating in high-temperature environments. The mechanical response in such conditions is determined by the material microstructure: the operating high temperature could produce modifications with respect to the original one due to diffusion mechanisms which govern grain size, dislocation density, number, size, strength of the defects, etc. During the dynamic deformation, dislocation motion is the driving mechanism in which temperature and strain rate play a role mainly in relation to the overcome thermal activated barriers. This chapter describes the physical phenomena involved in the high strain rate plastic deformation of metals and alloys at high temperatures. Particular attention is devoted to superalloys and refractory metals, which are suitable in those applications characterized at high operational temperatures. This chapter reports a selection of experimental results and modeling approaches, including both empirical and physical based models, developed by researchers in the last decades.