High temperature resistant graphite crucibleIt is a high-temperature resistant container made mainly of natural flake graphite and refractory materials such as clay and silica. It is widely used in metallurgy, casting, machinery, chemical industry and other fields, especially in metal melting, alloy preparation and high-temperature experiments. Its core advantage lies in its high temperature resistance and chemical stability, which can withstand temperatures above 3000 ℃, has a low coefficient of thermal expansion, and has good strain resistance to rapid cooling and heating, ensuring that it is not easily broken under extreme temperature changes.
The main raw material of graphite crucible is crystalline natural graphite, accounting for 45% -55%, with flake or needle shaped graphite being preferred to ensure thermal conductivity and structural strength. Clay as a binder endows the crucible with plasticity, while auxiliary materials such as silica enhance its fire resistance. The production process includes hand molding, rotary molding, and compression molding. The compression molding method is formed by high-pressure equipment and has the advantages of short production cycle, high yield, and high density, significantly reducing porosity and improving mechanical strength. Some high-end products adopt cold isostatic pressing technology to further enhance thermal conductivity and cost-effectiveness.
High temperature resistant graphite cruciblePreparation before use:
1. Check the integrity of the crucible
Appearance inspection: Observe whether there are cracks, gaps or severe wear on the inner and outer walls of the crucible, especially in the bottom and edge areas. If cracks are found, they should be replaced immediately to avoid safety accidents caused by rupture at high temperatures.
Size matching: Ensure that the size of the crucible matches the heating equipment (such as induction furnaces, resistance furnaces) to avoid uneven heating or tilting of the crucible due to large gaps.
2. Preprocessing
Cleaning the crucible: Use a soft bristled brush or compressed air to remove surface dust and impurities, avoiding impurities from reacting with the crucible at high temperatures and shortening its service life.
Coating treatment: Based on the characteristics of the melted material, a protective coating (such as alumina or zirconia coating) is applied to the inner wall of the crucible to reduce the erosion of the crucible by the molten metal. For example, when melting aluminum alloys, coatings can effectively prevent aluminum liquid from infiltrating the graphite lattice.