Technical properties of graphite materials

Graphite materials should have the following technical properties:

First, with the appropriate resistivity: the resistivity of the graphite material should be matched with different heating methods and hot press winding process conditions. The resistivity can characterize the transformation process of the graphite structure of the material, that is, the degree of graphitization of the material. The resistivity of the material is proportional to its thermal conductivity, and the resistivity is low and the thermal conductivity is high. The degree of graphitization also affects the infiltrability, lubricity, strength, coefficient of thermal expansion, elastic modulus, specific heat and a series of properties of the material, which all affect the performance of the mold.

Second, it has excellent oxidation resistance: the oxidation of stone strong materials is the main reason for mold damage. Therefore, the smaller the impurity content of the graphite material, the better. The impurities of the material are mainly various metal elements, and most of the metal elements play a catalytic role in the oxidation of stone materials. The lower the porosity of the material, the better, and the smaller the pore size, the better, especially the porosity of the open hole. This is because the oxidation process of graphite materials is related to the diffusion rate of oxidizing gas, and the oxidation rate is controlled by the diffusion rate of oxidizing gas.

Third, the structure of the graphite material: the structure of the graphite material should be fine and dense to ensure the high bulk density of the material, low porosity, and high surface finish of the processing mold.

Mechanical strength: The mechanical strength is high, especially the tensile and compressive strength of the material is high.

5. Thermal shock resistance: the thermal expansion coefficient is small, the thermal conductivity and tensile strength are high, and the ability of the material to withstand thermal shock can be greatly improved, and the thermal stability of the material is better.