This course is designed for sophomores. The purpose is to enable students who intend to study mechanical engineering, robotics, aerospace engineering, materials science and engineering, microelectronics, or biomedical engineering to master the basic scientific principles, processing techniques and design methods of engineering materials. This course will focus on the basic scientific principles of engineering materials such as crystallography, defects, diffusion, phase transformation, etc., and then introduce different engineering materials and their characteristics. The purpose is to make students understand the basis for regulating the mechanical, electrical, thermal and magnetic properties of alloys, polymers, ceramics and composites, and to be familiar with the design criteria and selection methods for different engineering materials.