GB/T 11108-2017 in English

GB/T 11108—2017 Standard Overview

This standard GB/T 11108—2017 "Determination of thermal diffusivity of cemented carbide" was issued in 2017, replacing the old standard from 1989. This standard specifies the method for determining the thermal diffusivity of cemented carbide using the flash method and is applicable to other isotropic materials.

Background of Standard Formulation

With the continuous advancement of industrial technology, the demand for cemented carbide in the fields of aerospace, automobile manufacturing and electronics is increasing. In order to ensure the consistency of material properties and the accuracy of test results, it has become an urgent need to revise and improve relevant standards. GB/T 11108—2017 combines the latest research results and technological developments and makes many improvements to the old standard.

Technology Evolution Analysis

Compared with the old version, the new version of the standard has been updated in the following aspects:

• Modified Figure 1: Relationship between temperature and time on the back of the specimen.
• Added symbols and definitions.
• Revised the specimen preparation requirements, especially providing more detailed guidance on the selection of thickness.
• Added the handling of the specimen before the start of the test.

Standard Framework Comparison

Test instrument and technical details

Thermophysical property comprehensive tester is the key equipment for measuring thermal diffusivity, and its structure includes:

• Solid-state pulse laser: The laser pulse width is less than 1 ms, and the output energy is adjustable, with a maximum of not less than 50 J.
• Heating furnace: The furnace temperature is adjustable, the maximum temperature is not less than 1300 K, and the accuracy is ±1 K.
• Temperature sensor: Thermocouple or infrared temperature measuring element, with an accuracy of ±1 K.

Implementation suggestions

To ensure the accuracy of the test results, it is recommended to:

1. Choose a suitable specimen size: Adjust the thickness according to the material type and test temperature, usually between 3 mm and 4 mm.
2. Optimize coating treatment: Use a thin and uniform graphite coating to improve energy absorption efficiency.
3. Regularly calibrate the instrument: Ensure the stable performance of the laser system and temperature sensor.