How do impurities typically affect the properties of metals?

Impurities generally introduce flaws and discontinuities within the metal's crystalline structure, which can lead to a range of undesirable characteristics. For instance, they often affect the metal's tensile strength, ductility, toughness, and resistance to corrosion. Depending on the type and amount of impurity present, these alterations can make the material less suitable for specific applications, resulting in brittleness, increased susceptibility to cracking, or lower overall performance in various environments.

This intrinsic impact of impurities is historically reflected in metallurgical studies, showing that while some alloying elements can serve to strengthen metals (often in specific contexts and concentrations), most impurities detract from desirable mechanical and physical properties. Understanding this relationship is crucial for materials engineering and quality control in metal processing.