Mechanical Properties of Materials: Toughness and Hardness

This lecture covers the concepts of toughness and hardness in materials. It explains the relationship between toughness, strength, and fracture toughness, emphasizing the critical crack length and the ductile-to-brittle transition. The instructor discusses the mechanical properties of ceramics, polymers, metals, and composites, highlighting their behavior under different loading conditions. Additionally, the lecture delves into hardness testing methods such as Vickers and Brinell hardness, and their significance in material characterization. The comparison of hardness scales and the relationship between hardness, yield strength, and stiffness are also explored, providing insights into material performance and failure mechanisms.