Thermal Conductivity Of Metals And Ceramics

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.

Thermal conductivity of metals and ceramics.

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. Low shear strength high. Thermal conduction is generated by the movement of electrons and the transfer of lattice vibrations. Copper is a soft malleable and ductile metal with high thermal and electrical conductivity.

Metals property ceramics. Thermal conductivity k is used in the fourier s equation. High tensile strength low. Calculate conductive heat transfer.

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. These materials can be separated into two groups electrical insulators and electrical conductors. Yes crystalline yes free roaming valence electrons tied up in bonds. Good electrical conductivity poor insulator good thermal conductivity poor.

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. 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. Metallic type of bonding ionic covalent. Thermal conductivity of fine ceramics.

Opaque optical properties transparent. There are several ceramics that offer relatively high thermal conductivity. Looking at the values quoted in various handbooks papers and data sheets two things are observed. The thermal conductivity of ceramic materials plays an important role in its application.

When looking for materials that offer high thermal conductivity and electrical insulation ceramics are the natural choice. It is also resistant to corrosion and permeable for microwaves.