[ad_1]
Thermal expansion is when matter changes in volume due to temperature changes. The coefficient of thermal expansion describes this concept. Solid materials like metals and plastics are used in construction to avoid distortion. Negative thermal expansion causes materials to contract. Anisotropic expansion means that the solid will not expand the same way in each direction.
As a result of temperature changes, matter changes in volume. This concept is known as thermal expansion. When a substance heats up, the particles within the matter move, becoming more active as the temperature increases. This activity causes the particles to need additional space between them, increasing the size of a material. The equation to describe this concept is known as the coefficient of thermal expansion and can be defined by the fact that the degree of expansion is divided by the change in temperature in a material.
The use of certain solid materials in construction and engineering is a direct result of this thermal expansion. The need for objects to hold their shape without major distortion results in the common practice of using metals and plastics. For example, a hammer must hold its shape as the temperature rises to avoid damage. While this principle is generally true based on the type of material used, some structures, such as crystals, may possess different coefficients of thermal expansion depending on the shape.
Likewise with the concept of negative thermal expansion, conditions such as extreme cold cause materials to contract for exactly the opposite reason to normal thermal expansion. Other materials with different coefficients are often needed in combination with these solids. An example would be a window, which needs rubber fittings to prevent the metal frame from expanding and contracting.
The harder the material, the lower the thermal expansion. Liquids will expand more easily than solids. This is caused by the fact that as the energy bond between the particles increases, the thermal expansion of these substances decreases. Additionally, some materials change size due to the absorption or desorption of water or solvents.
A type of expansion known as anisotropic expansion can occur within some types of materials. This means that the solid will not expand exactly the same way in each direction. Any material with a number of layers, such as graphite, usually expands more easily perpendicular with the layers than vertically against the layers. This can be beneficial to designers when attempting to make a fitting that is only expected to expand in one direction when exposed to temperature changes.
[ad_2]