Mechanical properties of metals call their ability to resistance to action of the loadings attached to them. Unlike nonmetals, metals have such characteristic properties as good electro- and heat conductivity, gloss, an excellent svarivayemost and malleability, a certain temperature of melting and crystallization and also high durability and the crystal building. What else mechanical characteristics do metals have?
Main mechanical properties
The main mechanical properties of metals are presented by durability, hardness, plasticity, impact strength, an iznosoustochivost and creep. Durability of metals represents their resistance to deformation and destruction as a result of extension, tightening, twisting, bending and cutting. Loadings at the same time are divided into external and internal and also on static and dynamic.
External loadings are presented by the weight, pressure, etc. whereas internal loadings are presented by heating, cooling, change of structure of metal, etc.
Hardness of metals call coefficient of their resistance to penetration into them of more solid body. Elasticity – ability to restoration of an initial form after the end of action of any external loading. Plasticity – ability to change of a form without destruction and under the influence of a certain loading and also preservation of a form after removal of loading. Impact strength represents resistance of metals to influence of the impact loads measured in Joules on square meter. Creep – slow and continuous plastic deformation under the influence of constant loads (especially at the increased temperature). Fatigue – gradual destructions at a large number of repeated and variable loading, whereas endurance – property to keeping of this loading.
Additional mechanical properties
The main mechanical properties of metals are: temporary resistance (strength at a conditional tension), the true resistance to a gap (strength at the valid tension), a physical limit of fluidity (deformation at the minimum tension) and a conditional limit of fluidity (tension in the conditions of which residual lengthening of the site of a sample is 0.2%).
Mechanical properties of metals define in the course of static, dynamic and repeated and variable tests.
Also refer to mechanical properties of metals: a conditional limit of proportionality (tension in the conditions of which the deviation from linear dependence reaches 50% increase in size), an elasticity limit (tension corresponding to residual deformation), relative lengthening after a gap (increment of length of a sample to initial rated length) and relative narrowing after a gap.