Design engineers are expected to have knowledge of materials science. If you want to gain an in-depth knowledge about the properties and behaviors of various materials, then you should definitely read W. D. Callister and D. G. Rethwisch's Materials Science and Engineering: An Introduction. The book covers all the major materials that are commonly used in machine manufacturing such as ceramics, metals, and polymers. It also discusses about the relationships that exist between the structural elements of materials and their properties.