egg shape electrode paste
Thermal shock resistance of egg shape electrode paste
The egg shape electrode paste is used as a conductive electrode under high and ultra-high temperature conditions. The temperature of the electrode protruding from the copper tile part of the submerged electric furnace often reaches about 2000 degrees, and some of the temperature is even higher [such as the calcium carbide smelting temperature 2000 degrees].
All materials have different thermal shock resistance. Therefore, we Chenguang Carbon believes that it is necessary to discuss the thermal shock resistance of egg shape electrode paste and improve the level of understanding of the use of egg shape electrode paste to ensure normal and reliable production.
One, what is thermal shock resistance. When the material is used at high temperature, the ability to withstand drastic changes in temperature without being damaged is called thermal shock resistance. [Or thermal stability]. Thermal expansion and contraction are a universal principle of physics, that is, when the temperature changes drastically, if the material cannot transfer the heat away in time, the surface and interior of the material will produce a temperature gradient, and their expansion and contraction will produce internal stress. When the stress reaches a very limited strength, the material will be destroyed. Therefore, it is necessary to discuss the thermal shock resistance of egg shape electrode paste.
Second, the factors affecting thermal shock resistance. According to the research results of carbon experts at home and abroad, the main factors affecting thermal shock resistance are tensile strength, linear thermal expansion coefficient, Young’s modulus, bulk density, thermal shock parameters, thermal conductivity, etc. According to the characteristics of the production and use of egg shape electrode paste, under certain production equipment and process conditions, the tensile strength and bulk density of egg shape electrode paste during the sintering process are almost a fixed value, such as after the egg shape electrode paste is sintered The bulk density is 1.4 grams per cubic centimeter, and the tensile strength is 6 MPa per square centimeter, so the discussion can only be conducted from the perspective of production equipment and technology. The Young’s modulus and thermal shock parameters that affect the thermal shock resistance are constants. The discussion of the linear thermal expansion coefficient is more complicated, and Chenguang Metallurgy will do a special discussion. Here we mainly discuss the influence of thermal conductivity on thermal shock resistance.
Third, the role of thermal conductivity in the thermal shock resistance index. In solid materials, there are two ways of heat conduction, one is conduction by free electron flow, and the other is conduction by thermal vibration of lattice atoms. Carbon materials are lattice heat conductors. Due to the structure and characteristics of carbon atoms, carbon materials have very good thermal vibration conductivity of lattice atoms, and this conductivity also increases with the increase of temperature. The higher the temperature, the higher the thermal conductivity. Fourth, due to the high thermal conductivity of carbon materials, low Young’s modulus, and small value of linear thermal expansion coefficient, the thermal stress can be relieved under the condition of a certain volume density, so its thermal shock resistance is strong. The thermal shock resistance of egg shape electrode paste is a very complicated parameter. There are always things we can’t recognize in the discussion under high temperature. We welcome colleagues and colleagues to correct and discuss.