Property Modification

Many structural metals undergo some special treatment to modify their properties so that they will perform better for their intended use. This treatment can include mechanical working, such as rolling or forging, alloying and/or thermal treatments. Consider aluminum as an example. Commercially pure aluminum (1100) has a tensile strength of around 13,000 psi, which limits its usefulness in structural applications. However, by cold-working aluminum, its strength can be approximately doubled. Also, strength increases are obtained by adding alloying metals such as manganese, silicon, copper, magnesium and zinc. Further, many aluminum alloys are strengthened by heat treatment. Some heat-treatable aluminum alloys obtain tensile strengths that can exceed 100,000 psi.