A kind of sialon bonded fused silica preform for aluminum water flow tank and its manufacturing method

Abstract

The invention relates to a sialon combined fused silica preform for an aluminum water flow tank and a manufacturing method thereof. 45-55% fused silica, 8-15% metal silicon powder, 18-30% aluminum nitride fine powder, 8-15% alumina fine powder and 3-8% pure calcium aluminate cement, nitrided Aluminum powder is composed of metal aluminum powder, diluent and nitriding accelerator NH 4 Cl synthesis, vibrating molding, and then demoulding, curing, drying, nitriding and firing according to the temperature system of sub-stage heating, more heating and less heat preservation to produce sialon phase, and finally the finished product is obtained; Long-bonded fused silica preform material has a spatial network structure inside, which has high chemical stability, resistance to aluminum water reduction, resistance to aluminum water erosion, volume stability, thermal shock resistance, not easy to be wetted by aluminum water and low expansion Features, good use effect, long life, more suitable for use in aluminum water flow trough.

Description

Technical field [0001] The present invention relates to a prefabricated piece of aluminum water bonded, a molten stone-based preform and a manufacturing method thereof, belonging to the technical field of refractory materials for aluminum processing industries. Background technique [0002] The refractory materials used in the aluminum water flow tank apply prefabricated parts, as there is a series of physical and chemical properties, which interacts with the partial interaction of the refractory preform with the refractory preform in the stream tank, resulting in the life of the groove Shorten and damaged, which requires the cooling material preform for the aluminum water tank to meet the following requirements: (1) Good chemical stability: high aluminum chemical activity, the temperature of the refractory stream, about 750 ° C , A reducing agent, SiO2, TiO2, Feo in the material should be reduced by aluminum, the resulting impurities cause the product to be affected, so the pref...

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Problems solved by technology

[0007] Because this type of aluminum gutter prefabricated part is mainly composed of high-alumina bauxite raw materials, it has high density, high hardness, good strength, and aluminum water erosion resistance is also better than that of fused silica aluminum gutter prefabricated parts, but at the same time higher The expansion coefficient of this kind of launder also makes the volume stability of this type of launder worse, and the use of bauxite raw materials makes the impurity composition complicated, the chance of being subjected to chemical erosion increases, and being able to be infiltrated by aluminum water is also a big flaw

[0008] In summary, although the two types of refractory materials for aluminum water flow tanks can also meet the needs of use to varying degrees and each has certain advantages, they have common defects such as chemical stability and wetability by aluminum water, and also have their own shortcomings in performance. , due to the nature of the material itself, it is difficult to improve within the material range of the launder prefabricated part itself

[0009] Although some composite fused silica refractory materials are disclosed in the prior art, such as patent CN105541311A, a method for preparing polysilicon ingots with silicon nitride combined with fused silica crucibles is prepared by in-situ solidification molding process and nitriding firing. Silicon-bonded fused silica crucible, use powder with certain particle size and purity as raw material, prepare suspension slurry containing organic monomer, crosslinking agent, water and powder, add appropriate amount of initiator, stir evenly, degas the slurry , poured into a gypsum mold, left to solidify, the green body is dried and cured, and fired in a nitrogen atmosphere to obtain a product, but silicon nitride is added as a quartz composite material, which is poor in density and volume stability. Patent CN105294121A provides A thermal shock-resistant lightweight refractory aggregate, using alumina, fused magnesia, quartz sand, sialon powder, silicon carbide micropowder, α-Al 2 o 3 Raw materials such as fine powder are made by pulping and sintering. However, the composition is complex and it is used as an insulation material, so it cannot be practically applied in the aluminum water flow tank of the aluminum processing industry.

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