- Mean coefficient of linear thermal expansion; the ratio of the change in length to the original length at a reference temperature, To, per degree of temperature change, where To is normally room temperature. If lo is the length at To and alpha, α is the mean coefficient of linear thermal expansion, the length at temperature T, lt is given be this formula:
Lt = lo [1 + α (T – To)]
- Linear thermal expansion; the change in length over a specific temperature range per 30.5 m.
- Modulus of elasticity (E); 1. The measure of rigidity or stiffness of a material; the ratio of stress below the proportional limit to corresponding strain. 2. The slope of a stress strain curve in the range of linear proportionality of stress to strain. This known as Young’s modulus.
- Thermal conductivity; the quantity of heat transmitted, k, due to unit temperature gradient, in unit time under steady conditions in a direction normal to a surface of unit area and when the heat transfer is solely dependent on the temperature gradient.
- Thermal diffusivity; the constant in heat conduction equation describing the rate at which heat is conducted through a material. It is linked to thermal conductivity, k, specific heat, Cp, and density, , through the equation.
Thermal diffusivity = k/Cp.⍴
- Electrical resistivity; a measure of how strongly a material opposed the flow of electric current.
Electrical resistivity = ⍴ = RA/L
- Specific heat: the amount of heat, Cp, measured in calories, required to raise the temperature of one gram of substance by one degree Celsius.
- Density: the mass per unit volume of a solid material
- Specific gravity: the ratio of the density of a substance to the density of water.
- Shear modulus (G): The ratio of shear stress to the corresponding shear strain for shear stresses below the proportional limit of the material. Value of shear modulus are usually determined by torsion testing. Shear modulus is also known as the modulus of rigidity.
- Melting point: melting point is the temperature at which a metal change from solid to liquid; temperature at which the liquid and solid are at equilibrium.
- Poisson’s Ratio: the absolute value of the ratio of transverse (lateral) strain to the corresponding axial strain resulting from uniformly distributed axial stress below the proportional limit of the material.
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| physical properties of carbon steel |
