GB/T 39862-2021Test method for thermal conductivity of high thermal conductivity ceramics (English PDF)

Foreword

This standard was drafted in accordance with the rules given in GB/T 1.1-2009.

1 Scope

This standard specifies the thermal conductivity test method for high thermal conductivity ceramic materials.

This standard applies to homogeneous ceramic materials with room temperature thermal conductivity greater than 20W/(m·K) and apparent porosity less than 0.2%.

2 Normative references

The following documents are indispensable for the application of this document. For dated reference documents, only the dated version applies to this document. For undated reference documents, the latest version (including all amendments) is applicable to this document.

GB/T 6425 Terminology of Thermal Analysis

GB/T 8170 Numerical rounding rules and the expression and determination of limit values

GB/T 22588 flash method to measure thermal diffusivity or thermal conductivity

GB/T 25995 Test method for density and apparent porosity of fine ceramics

JB/T 13176 Differential Scanning Calorimeter

3 Terms and definitions

The terms and definitions defined in GB/T 22588 and GB/T 6425 apply to this document.

4 Principle

When the specific heat capacity, density and thermal diffusivity of the sample are known, the thermal conductivity (lambda) of the sample can be derived according to formula (1). Where.

lambda --- Thermal conductivity, the unit is watts per meter [W/(m·K)];

alpha --- Thermal diffusion coefficient, in square meters per second (m2/s);

Cp --- specific heat capacity, the unit is coke per kilogram open [J/(kg·K)];

rho --- Bulk density, the unit is kilogram per cubic meter (kg/m3).

Note: It is approximated that the density of the sample remains unchanged within the measurement temperature range.

5 Measurement of thermal diffusivity

The thermal diffusivity (alpha) is tested in accordance with the method specified in GB/T 22588.

6 Measurement of specific heat capacity