Magnesium alloys are mixtures of magnesium and other alloying metal, usually aluminium, zinc, silicon, manganese, copper and zirconium. Since the most outstanding characteristic of magnesium is its density, 1.7 g/cm3, its alloys are used where light weight is an important consideration (e.g., in aircraft components). Magnesium has the lowest melting point (923 K (1,202 °F)) of all the alkaline earth metals. Pure magnesium has an HCP crystal structure, is relatively soft, and has a low elastic modulus: 45 GPa. Magnesium alloys have also a hexagonal lattice structure, which affects the fundamental properties of these alloys. At room temperature, magnesium and its alloys are difficult to perform cold working due to the fact plastic deformation of the hexagonal lattice is more complicated than in cubic latticed metals like aluminium, copper and steel. Therefore, magnesium alloys are typically used as cast alloys. Despite the reactive nature of the pure magnesium powder, magnesium metal and its alloys have good resistance to corrosion.
Aluminium is the most common alloying element. Aluminium, zinc, zirconium, and thorium promote precipitation hardening: manganese improves corrosion resistance; and tin improves castability.
Strength of Magnesium Alloys
In mechanics of materials, the strength of a material is its ability to withstand an applied load without failure or plastic deformation. Strength of materials basically considers the relationship between the external loads applied to a material and the resulting deformation or change in material dimensions. Strength of a material is its ability to withstand this applied load without failure or plastic deformation.
Ultimate Tensile Strength
Ultimate tensile strength of Elektron 21 – UNS M12310 is about 280 MPa.
The ultimate tensile strength is the maximum on the engineering stress-strain curve. This corresponds to the maximum stress that can be sustained by a structure in tension. Ultimate tensile strength is often shortened to “tensile strength” or even to “the ultimate.” If this stress is applied and maintained, fracture will result. Often, this value is significantly more than the yield stress (as much as 50 to 60 percent more than the yield for some types of metals). When a ductile material reaches its ultimate strength, it experiences necking where the cross-sectional area reduces locally. The stress-strain curve contains no higher stress than the ultimate strength. Even though deformations can continue to increase, the stress usually decreases after the ultimate strength has been achieved. It is an intensive property; therefore its value does not depend on the size of the test specimen. However, it is dependent on other factors, such as the preparation of the specimen, the presence or otherwise of surface defects, and the temperature of the test environment and material. Ultimate tensile strengths vary from 50 MPa for an aluminum to as high as 3000 MPa for very high-strength steels.
Yield strength of Elektron 21 – UNS M12310 is about 145 MPa.
The yield point is the point on a stress-strain curve that indicates the limit of elastic behavior and the beginning plastic behavior. Yield strength or yield stress is the material property defined as the stress at which a material begins to deform plastically whereas yield point is the point where nonlinear (elastic + plastic) deformation begins. Prior to the yield point, the material will deform elastically and will return to its original shape when the applied stress is removed. Once the yield point is passed, some fraction of the deformation will be permanent and non-reversible. Some steels and other materials exhibit a behaviour termed a yield point phenomenon. Yield strengths vary from 35 MPa for a low-strength aluminum to greater than 1400 MPa for very high-strength steels.
Young’s Modulus of Elasticity
Young’s modulus of elasticity of Elektron 21 – UNS M12310 is about 45 GPa.
The Young’s modulus of elasticity is the elastic modulus for tensile and compressive stress in the linear elasticity regime of a uniaxial deformation and is usually assessed by tensile tests. Up to a limiting stress, a body will be able to recover its dimensions on removal of the load. The applied stresses cause the atoms in a crystal to move from their equilibrium position. All the atoms are displaced the same amount and still maintain their relative geometry. When the stresses are removed, all the atoms return to their original positions and no permanent deformation occurs. According to the Hooke’s law, the stress is proportional to the strain (in the elastic region), and the slope is Young’s modulus. Young’s modulus is equal to the longitudinal stress divided by the strain.
We hope, this article, Strength of Magnesium Alloys, helps you. If so, give us a like in the sidebar. Main purpose of this website is to help the public to learn some interesting and important information about materials and their properties.