Thermal Conductivity Of Metals And Ceramics

The thermal conductivity of ceramic materials plays an important role in its application.

Thermal conductivity of metals and ceramics.

Low shear strength high. Thermal conductivity k is the quantity of heat transmitted due to an unit temperature gradient in unit time under steady conditions in a direction normal to a surface of the unit area. Good electrical conductivity poor insulator good thermal conductivity poor. Metals property ceramics.

Calculate overall heat transfer coefficient. Metals with low electrical resistance and crystals in which lattice vibrations are transferred easily for example crystals with atoms or ions of similar masses at lattice points and covalent crystals with. The problem with the thermal conductivity of ceramics is the dependence on the composition grain size and manufacturing process which make it rather difficult to obtain a reliable value from literature only. When looking for materials that offer high thermal conductivity and electrical insulation ceramics are the natural choice.

Looking at the values quoted in various handbooks papers and data sheets two things are observed. Majorly composed of al 2 o 3 aluminum ceramic is a dense ceramic material with excellent thermal and electrical resistance properties. Yes crystalline yes free roaming valence electrons tied up in bonds. Thermal conductivity k is used in the fourier s equation.

Thermal conduction is generated by the movement of electrons and the transfer of lattice vibrations. Thermal conductivity of fine ceramics. A theoretical analysis of the thermal conductivity κ v of metals and ceramics from their young s modulus e atomic weight m and density ρ based on a harmonic oscillator model is presented the κ v value is expressed as a g n 0 3 ρ e m 3 2 2 where a is the maximum displacement of a harmonic oscillator and equals the mean free path of lattice vibration g is the size factor. In a certain range increasing the thermal conductivity of ceramic materials by specific methods will improve its ability of heat conduction heat convection and heat radiation so as to further expand its application field.

Metallic type of bonding ionic covalent. High tensile strength low. There are several ceramics that offer relatively high thermal conductivity. Thermally conductive electrical insulators.

Copper is a soft malleable and ductile metal with high thermal and electrical conductivity. Opaque optical properties transparent.