Simple operation of silicon carbide wear-resistant mastic
Simple operation of silicon carbide wear-resistant mastic With the development of industry and the improvement of people's living standards, the tradition of single characteristics coating It can no longer meet the needs of today's social development. The development of multifunctional coatings has become an urgent problem for industrial coatings and a new direction for the development of industrial coatings. Wear resistance of tortoise shell mesh in our company ceramics In the research of castable related personnel, a product with independent knowledge has been developed to replace the high-tech product - wear-resistant ceramic castable. The product has good integrity, easy construction and maintenance, and is resistant to rapid heat and cold. It can be used for a long time at 1700 ℃.
Silicon carbide wear-resistant mastic is a kind of non Metal glue Condensed material is a kind of powdery ceramic material, which is made of acid and alkali resistant synthetic materials through strict process ratio and inorganic polymerization technology. At the construction site, the liquid inorganic glue is added to this material, which is manually or mechanically applied to the equipment lining or surface. After a series of chemical reactions, the bonding strength and hardness of ceramics are reached after 3 days at room temperature.
Silicon carbide wear-resistant mastic is mainly applicable to cement , electric power, metallurgy, etc The Conduit , flue, dust collector, blanking hopper, blanking chute, powder concentrator and other equipment and conveying pipelines. This product has been applied in more than 400 cement, power and mining enterprises in China. In the cement industry, this product has been supplied to Leisher vertical mill, Smith vertical mill, Ube vertical mill, raw material mill, clinker mill, coal mill outlet air duct, castor cooler to electric dust collector pipe, upper shell of powder concentrator and other transmission pipelines. It is a new generation of wear-resistant materials to replace traditional ceramic chips, wear-resistant steel plates, and cast stone slabs.
In various powder lines (especially non-metallic mineral powder lines), there are many equipment and pipelines that have been washed by materials or high concentration dust laden gases for a long time. For example, mill outlet air duct, powder concentrator, ball mill chute, unloading hopper, various valve cavities, rams and conveying pipes, etc. The wear-resistant ceramic coating has wear-resistant performance and is an ideal material for lining vertical mill, roller press, powder concentrator, powder pipeline valve and powder conveying pipeline.
When designing wear-resistant ceramic materials, raw materials and processing technology are mainly selected according to the following technical directions:
1. Raw materials with high elastic modulus shall be selected for coating to improve hardness and wear resistance of materials.
The elastic modulus E is an important material constant and a sign of the bonding strength between atoms. In fact, it is the slope of any point on the bonding force curve between atoms. The crystals bonded by covalent bond and ionic bond usually have high elastic modulus due to their strong binding force. Therefore, in order to obtain highly wear-resistant materials, ions and covalent compounds should be selected, such as oxides, nitrides, carbides and borides. For example, powder materials such as corundum, silicon carbide, titanium carbide, titanium boride and zirconium boride are used in wear-resistant ceramic coatings.
2. The coating shall form microcrystalline and high-density microstructure.
In order to defect and improve the integrity of crystal, fineness, density, uniformity and purity are an important direction of current ceramic development. In recent years, many microcrystalline, high-density and high-purity ceramic materials have emerged, such as hot pressed silicon nitride ceramics, whose density is close to the theoretical value and almost contains no pores. The mechanical strength and wear resistance of agricultural systems are unmatched by traditional ceramics. Especially in recent years, various fibers and whiskers have complete crystal structure, almost no defects, and the strength can be improved by an order of magnitude.
3. Fine particles are used to enhance the mechanical strength of the lining.
When high particles are added to the ceramic material, the resistance of the material to stress induced crack expansion will be significantly relieved. When the crack grows under the effect of stress and encounters particles, due to particle strength and small expansion coefficient, the crack is "pinned". To continue to grow, more energy is required to penetrate the particles or deflect the crack, increasing the interface area, thus increasing the energy consumption and improving the strength and toughness of the material. After adding particles, the elastic modulus and shear modulus of the material have increased, the strength and wear resistance of the material have been significantly improved, which can increase the service life of the wear resistant material and reduce the cost.
4. Strength and toughness of chemically strengthened materials.
In order to improve the strength of the wear-resistant ceramic castable during the curing period and the hydration process of the bond, it is necessary to coat the surface of the material with curing agent. Curing agent is a kind of chemical coating. It uses ion exchange to make the surface molar volume larger than the internal one. Due to the large expansion of the surface volume and the limitation of the internal material, it will produce two-way compressive stress, thus improving the yield strength and fracture toughness of the material. Chemical strengthening is an important direction in the development of modern materials, which has strong operability.
