The mechanical properties of metals reflect the ability of materials to be resistant to the loads applied to them. These abilities are expressed in quantitative indicators. The mechanical properties of metals and alloys are, first of all, impact strength, hardness, ductility, strength. Products also have creep, wear resistance and other qualities.
The main mechanical characteristics of the materials are determined during testing. Depending on the nature of the impact of the load per unit time, distinguish between alternating, dynamic and static tests. The mechanical properties of metals are also manifested when external loads are applied to products. In particular, tests are carried out by shock bending, torsion, compression, stretching and other influences.
The mechanical properties of metals are also manifested during deformation. Under this process is understood the change in the size and shape of the product under the influence of loads. Deformation in solids is divided into plastic and elastic. In the first case, the product after unloading is not restored to its size and shape, and in the second it comes to its original state before the application of force.
As a rule, the mechanical properties of metals begin to be described with hardness. It is she who is the most important quality of products. Hardness is understood to mean the ability of a metal to be resistant to plastic deformation. A quantitative indicator of this ability is the most common when controlling the quality of products.
The next important property of metal is strength. Under this quality is understood the ability of the product to withstand destruction and deformation. Upon destruction, a cracking process occurs, which provokes the separation of the material into parts. The strength index is determined during tensile tests.
Plasticity of a material characterizes its ability to plastic deformation. In other words, this quality determines the possibility of obtaining residual changes in size and shape without violating the integrity. Plasticity is an important criterion for choosing a product for pressure treatment.
The ability of a part to absorb mechanical energy from an external force through plastic deformation is called viscosity.
Among alloys, a special place is occupied by cast iron (iron-carbon alloy). It contains more than 2.14% carbon and a number of impurities. Iron-carbon alloy is characterized by high casting characteristics.
The most common in industrial production are varieties such as white, gray and ductile iron.
The first, for example, has high hardness, this provides resistance to wear. Along with this, white cast iron is fragile. In addition, the material is poorly machined.
As one of the main in the foundry industry, gray cast iron is used. This material has a tensile strength high enough and lends itself very well to processing.
Accordingly, high-strength cast iron is endowed with good casting and physical qualities.
Among non-ferrous metals and alloys, aluminum should be distinguished. They are endowed with high indicators of corrosion resistance, are easily subjected to cutting and pressure.
Also quite common raw materials in production are copper alloys. These mixtures have good anti-friction, technological and physical qualities.
Titanium alloys are characterized by high corrosion resistance, heat resistance, high strength. They also have a low density.
There are magnesium alloys that are well machined.