Generally speaking, the mechanical properties of metals can be divided into ten types:
1. Brittleness refers to the property that a material will not undergo plastic deformation before it is damaged. It is the opposite of toughness and plasticity. Brittle materials have no yield point, but they have breaking strength and ultimate strength, and they are almost the same. Cast iron, ceramics, concrete and stone are all brittle materials. Compared with many other engineering materials, the tensile properties of brittle materials are weak, so compression tests are usually used to evaluate brittle materials.
2. Strength: the ability of metal materials to resist permanent deformation or fracture under static load. It can also be defined as proportional limit, yield strength, fracture strength or ultimate strength. There is no exact single parameter that can accurately define this characteristic. Because the behavior of metal changes with the change of stress and its application form. Power is a very common term.
3. Plasticity: the ability of metal materials to permanently deform under load without being destroyed. When the stress of metal material exceeds the elastic limit and the load is removed, plastic deformation will occur, and the material will retain part or all of the load at this time.
4. Hardness: the ability of the surface of a metal material to resist the invasion of harder objects.
5. Toughness: the ability of metal materials to resist impact load without being destroyed. Toughness refers to the characteristic that metal materials have certain plastic deformation before fracture under the action of tensile stress. Gold, aluminum and copper are tough materials, and they are easily drawn into wires.
6. Fatigue strength: the ability of material parts and structural parts to resist fatigue damage.
7. Elasticity refers to the characteristic that a metal material can recover its original size when the external force disappears. Steel is elastic before it reaches the elastic limit.
8. Ductility Ductility refers to the characteristic that a material bears certain plastic deformation before fracture under the action of tensile stress or compressive stress. Plastic materials generally adopt rolling and forging processes. Steel has both plasticity and ductility.
9. Stiffness is the characteristic that metal materials bear high stress without large strain. The stiffness is evaluated by measuring the elastic modulus e of the material.
10. yield point or yield stress yield point or yield stress is the stress level of metal, in MPa. Above the yield point, when the external load is removed, the metal deformation still exists and the metal material is plastically deformed.