With the rapid development of iron and steel industry and the requirement of improving the performance of electronic components, zirconia refractories are more and more applied, among which metallurgical industry uses the most and has the most characteristics in the electronics industry. Zirconia is a very stable refractory oxide, and the relevant research shows that the melting temperature of which is 2680 ℃.
The zirconia refractories used in the electronics industry take advantage of the chemical stability of zirconia and the phase-change toughening mechanism. Zirconia refractory is an important basic material involved in the high-temperature industry such as steel, nonferrous, petrochemical, building materials, machinery, electricity, environmental protection and national defense, as well as an indispensable supporting material for all kinds of high temperature industrial thermal furnace and equipment. The technical progress of refractories plays an irreplaceable key role in the development of the high-temperature industry.
Zirconia metering nozzle
The metering nozzle is one of the refractories for small billet continuous casting, which plays a role in controlling the flow of molten steel. The steady flow of molten steel through the orifice is a necessary condition for continuous casting. As a result, the metering nozzle should have good corrosion resistance and thermal stability, and no blockage, shedding, cracking and diameter expansion is allowed during the operation. The expansion of the metering nozzle will lead to too much-molten steel flowing into the nozzle, and the casting machine is forced to increase the pulling speed, which will result in steel leakage accident.
The advantages of zirconium composite metering nozzle are low production cost and low price, and it is more suitable when the continuous casting time is less than 500min. In the early stage of continuous casting development, the continuous casting time is short, and the ordinary zirconia fixed metering nozzle made by the composite of zirconia can meet the requirements, and the content of zirconia is 72%-85%. When the casting time is greater than 500min, zirconia reacts with some components in the molten steel and decomposes to produce very fine zirconia and poly liquid phases. The reaction products are easy to be washed away by the steel water, resulting in the expansion of the metering nozzle, and the ordinary zirconium metering nozzle has been unable to meet the requirements at that time. The electrocast refractory with β-Al2O3 as the main component is characterized by high strength, high refractoriness, and good corrosion resistance, so it is generally applicable to the upper structure of the masonry glass pool.
Zirconia setter plate
Zirconia setter plate is a kind of refractory material with high strength and excellent thermal shock resistance, which is made from imported high purity stable zirconia and sintered through high temperature with special process formula. It can guarantee the stability and consistency of the performance of electronic ceramic products and improve the qualified rate of the products.
Zirconia setter plate was mainly used in MLCC (multilayer ceramic capacitor) before it was developed into magnetic material. With the development of magnetic properties, the level of zirconia burning plate is also increasing, and higher requirements are put forward for raw material manufacturers, such as the total content of impurities and the level control of certain impurities. It requires no chemical reaction with the burnt product and can be used for a long time under the condition of rapid circulation at room temperature.
Besides that, zirconia special refractories can be made into amorphous refractories for high-temperature electric furnaces, thermal resistance, gas sensor, spray coating and castable.
Copyright © 1994-2019 Stanford Advanced Materials, All Rights Reserved.