Explain the how temperature affects the atomic scale structures of crystalline materials and use this explanation to further explain the effect of temperature on two different material properties (other than creep). Solution A crystal or crystalline solid is a solid material whose constituents, such as atoms, molecules or ions, are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions. In addition, macroscopic single crystals are usually identifiable by their geometrical shape, consisting of flat faces with specific, characteristic orientations. Crystallization is the process of forming a crystalline structure from a fluid or from materials dissolved in a fluid.The final form of the solid is determined by the conditions under which the fluid is being solidified, such as the chemistry of the fluid, the ambient pressure, the temperature, and the speed with which all these parameters are changing. After crystallisation the solid tends to reduce the boundary area, and hence the internal energy, by grain growth. This can only happen by a process of atomic diffusion within the solid. Such diffusion is more rapid at a higher temperature since it is thermally activated .The reason for this involves entropy: at all finite temperatures, there will be some disorder in the crystal. The temperature increase can cause motion in the atoms, this increase in kinetic energy and movility of the atoms will cause the atomic structure change Materials working outside room temperatures are exposed to thermal loads that may arise from different sources: • Hot sources: from hot gasses, fire, proximity to heat sources such as boilers, incinerators and engines, hot process fluids, or belonging to heat generating equipment such as heat engines. • Cold sources: from low temperature process fluids, cold storage, or cold winter temperatures. Thermoelasticity is an extension of elasticity that includes thermal effects, i.e. the study of the stress field originated by thermal strains in a constrained solid (if the stress overpass the elastic limit, it is thermoplasticity). A material particle can be displaced to other position by an overall motion or by a relative motion to the rest of the material, forced by mechanical, thermal, hygroscopic, or chemical forces. Overall motion maintains the shape but relative motion causes a shape deformation.

1. Explain the how temperature affects the atomic scale structures of crystalline materials and use
this explanation to further explain the effect of temperature on two different material properties
(other than creep).
Solution
A crystal or crystalline solid is a solid material whose constituents, such as atoms, molecules or
ions, are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends
in all directions. In addition, macroscopic single crystals are usually identifiable by their
geometrical shape, consisting of flat faces with specific, characteristic orientations.
Crystallization is the process of forming a crystalline structure from a fluid or from materials
dissolved in a fluid.The final form of the solid is determined by the conditions under which the
fluid is being solidified, such as the chemistry of the fluid, the ambient pressure, the temperature,
and the speed with which all these parameters are changing.
After crystallisation the solid tends to reduce the boundary area, and hence the internal energy,
by grain growth. This can only happen by a process of atomic diffusion within the solid. Such
diffusion is more rapid at a higher temperature since it is thermally activated .The reason for this
involves entropy: at all finite temperatures, there will be some disorder in the crystal.
The temperature increase can cause motion in the atoms, this increase in kinetic energy and
movility of the atoms will cause the atomic structure change
Materials working outside room temperatures are exposed to thermal loads that may arise from
different sources: • Hot sources: from hot gasses, fire, proximity to heat sources such as boilers,
incinerators and engines, hot process fluids, or belonging to heat generating equipment such as
heat engines. • Cold sources: from low temperature process fluids, cold storage, or cold winter
temperatures.
Thermoelasticity is an extension of elasticity that includes thermal effects, i.e. the study of the
stress field originated by thermal strains in a constrained solid (if the stress overpass the elastic
limit, it is thermoplasticity).
A material particle can be displaced to other position by an overall motion or by a relative
motion to the rest of the material, forced by mechanical, thermal, hygroscopic, or chemical
forces. Overall motion maintains the shape but relative motion causes a shape deformation