7. Conclusion

Metallic materials are polycrystalline materials, usually composites, with adjustable mechanical properties. These properties are understood in different ways: detailed analysis of microstructure behavior under the action of stress and temperature, characteristic parameters derived from mechanical testing, phenomenological behavior laws.

Semi-finished products (bars, wires, beams, sheets, etc.) are the materials offered to the designer. The progress made in their preparation can be seen in the precision of the specifications for metal alloys, and in the performance achieved today by the materials available: high yield microalloyed steels, dual-phase steels, aluminum alloys with improved toughness (such as "7475": Al-Zn6-Mg2-Cu1.5), high-ductility β III titanium alloys ( A = 25%) in the quenched or quenched-and-tempered condition, special bearing steels (service...