Testing of graphitized blanks and machined products:

(1) The detection of mechanical processing quality mainly involves the detection of dimensional accuracy and surface roughness.

(2) Detection of chemical composition analysis, analysis of components and their elements, and analysis of sulfur, phosphorus, barium, nickel, titanium, and other trace elements based on different products.

(3) General physical performance measurement, including measurement of bulk density, true density, porosity, pore size distribution, and pore size distribution.

(4) The detection of structural analysis mainly includes metallographic microscopy, X-ray diffraction, electron microscopy, and graphitization degree measurement.

(5) Mechanical performance testing includes the determination of compressive strength, bending resistance, tensile strength, elastic modulus, and hardness. In addition, there are measurements of friction coefficient and wear amount.

(6) Electromagnetic performance testing mainly includes the measurement of resistivity, magnetic susceptibility, Hall coefficient, magnetic resistance, etc.

(7) Thermal performance testing mainly includes the measurement of heat capacity, thermal conductivity, coefficient of linear expansion, degree of oxidation, thermal creep, and thermal shock resistance.

(8) Nuclear radiation performance testing includes detection of neutron capture cross-sectional area, nuclear radiation damage, etc.

In addition, there are chemical reactivity testing, brush braid detachment force testing, and other tests depending on the product.

Determination of physical properties of carbon graphite materials

Determination of density and porosity

Carbon graphite material is a porous structural material with a density divided into bulk density and true density. The so-called bulk density refers to the ratio of the mass of carbon graphite materials to their volume. True density is the ratio of the mass of carbon graphite material to its true volume.

The pores of carbon graphite materials include internal pores and surface open pores. The apparent porosity is the ratio of the volume of open pores in a sample to the total volume of the sample, and is measured by vacuum method and boiling method. True porosity is the ratio of the difference between true density and bulk density to true density.