This lecture covers the mechanical properties of materials, focusing on hardness testing methods such as nano-indentation and Vickers hardness. The instructor discusses the principles behind hardness testing, including the use of different indenters and the significance of hardness in material characterization. The lecture also delves into the concept of creep, where materials deform under constant load over time, and the influence of temperature on material behavior. Additionally, the lecture explores fracture mechanics, including Griffith's criterion and Irwin's approach, to understand how materials resist crack propagation. Practical applications of these concepts, such as toughness measurement and the role of stress intensity factor, are also discussed.