This book provides insight into advanced numerical and experimental investigations of the microstructural aspects of strength and damage of metals and metal-based composites. In particular, atomistic and dislocation models, micromechanical simulations and homogenization techniques, as well as experimental observations in combination with computer simulations, are described. These methods are successfully applied to analyze the mechanical behavior of metals and metal-matrix composites. Examples of the applications of the described methods include the investigation of microstructure/failure-resistance relationships of tool steels, damage in aluminum-based cast alloys as well as deformation, strength and fracture of hard metals. The book addresses scientists, graduate and postgraduate students, as well as engineers, in the fields of materials science and engineering.