# What is Thermal conductivity: Definition and 185 Discussions

The thermal conductivity of a material is a measure of its ability to conduct heat. It is commonly denoted by

k

{\displaystyle k}
,

λ

{\displaystyle \lambda }
, or

κ

{\displaystyle \kappa }
.
Heat transfer occurs at a lower rate in materials of low thermal conductivity than in materials of high thermal conductivity. For instance, metals typically have high thermal conductivity and are very efficient at conducting heat, while the opposite is true for insulating materials like Styrofoam. Correspondingly, materials of high thermal conductivity are widely used in heat sink applications, and materials of low thermal conductivity are used as thermal insulation. The reciprocal of thermal conductivity is called thermal resistivity.
The defining equation for thermal conductivity is

q

=

k

T

{\displaystyle \mathbf {q} =-k\nabla T}
, where

q

{\displaystyle \mathbf {q} }
is the heat flux,

k

{\displaystyle k}
is the thermal conductivity, and

T

{\displaystyle \nabla T}
is the temperature gradient. This is known as Fourier's Law for heat conduction. Although commonly expressed as a scalar, the most general form of thermal conductivity is a second-rank tensor. However, the tensorial description only becomes necessary in materials which are anisotropic.

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5. ### Calculating Effective Coefficient of Thermal Conductivity

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7. ### Physical meaning of thermal conductivity tensor

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9. ### Coefficient of Thermal conductivity

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17. ### I Solution of the 1D heat equation

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18. ### Thermal Conductivity Problem-- Two Reservoirs

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29. R

### Magnetic conductive material but thermally non conductive

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37. ### Thermal conductivity of a thin film

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38. ### B Your Opinion On This Solar Cooker

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39. ### Thermal conductivity of SiC and the mechanisms

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46. ### How Thick Should My Thermal Barrier Be to Protect Against Heat?

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47. ### Thermal Conductivity of Springs

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50. ### Calculating heat flux (Q) without thermal conductivity (K)

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