What method can be used to improve the toughness of a metal?

Normalizing is a heat treatment process that can significantly improve the toughness of a metal. It involves heating the metal to a temperature that is above its transformation range, followed by air cooling. This process refines the grain structure and leads to a more uniform distribution of microstructure throughout the material. As a result, the overall toughness of the metal is enhanced due to improved ductility and impact resistance.

This method is particularly useful for steels, as it can help eliminate internal stresses that can make the metal more brittle. By normalizing, the metal becomes less prone to cracking or failure under stress, effectively improving its performance in applications where toughness is critical.