Hardening processes are techniques used to increase the strength and durability of materials, particularly metals. These processes involve altering the material's structure through methods such as heating, cooling, or mechanical treatment. Common hardening methods include quenching, tempering, and case hardening, each designed to enhance specific properties like toughness or wear resistance. In addition to metals, hardening processes can also apply to polymers and ceramics. For example, curing is a hardening process for certain plastics, where heat or chemical reactions lead to a more rigid structure. Overall, hardening processes are essential in manufacturing to ensure materials can withstand various stresses and conditions.