Heat treatment is crucial for enhancing the properties of both ferrous and nonferrous metals. Ferrous metals like steel benefit from treatments such as carburizing and normalizing to improve hardness and strength, while nonferrous metals like aluminum and copper can undergo annealing and precipitation hardening. Surface treatments like phosphating, blackening, and plating methods such as copper, electroless nickel, hard chrome, and zinc (including silver and gold plating) are used to provide corrosion resistance and improve appearance. These processes play a vital role in extending the lifespan and performance of metal components in industries like automotive, aerospace, and electronics.