Technology overview: Related to SRBSN (Sintered Reaction Bonded Silicon Nitride), as the silicon nitride ceramics is excellent in high- strength, high-toughness, anti-abrasion properties compared with other materials, and shows stable performance in extreme surroundings, such as high temperature, high load, etc., it is in the limelight as a promising material capable of replacing the existing materials, such as metal, sintered carbides, etc. As the silicon nitride ceramics were manufactured using the high-price and high-purity overseas silicon nitride powder until now, its application to industry has been limited. In order to solve this problem, we have developed the silicon nitride material based on SRBSN technology using low-cost silicon powder which can be mass-produced with low cost. Due to its eco-friendliness and reduction of the manufacturing cost, we expect that our product will be briskly applied to the overall application industry. Next, related to CDC (Carbide Derived Carbon), mechanical seal parts are mainly used in the severe surroundings both mechanically and chemically, and until now sintered carbon, sintered carbides, etc. were mainly used as the raw material of the parts, but there is a drift that the demand on the structural ceramics is increasing day by day, such as silicon carbide which is outstanding in high hardness, chemical resistance and heat resistance, or alumina. However, the performance of structural ceramics gets lowered at the unlubricated state caused by high frictional coefficient and brittleness via-a-vis general solid lubricant material, and in order to solve this problem, coating of solid lubricant is tried on the surface of ceramics. Among them, CDC is the method of extracting only metal atom from carbide ceramics like silicon carbide and forming the carbon layer on the surface, and its property is very excellent compared with the thin film, such as DLC, MoS2. etc., already used as coating for lubrication. It is expected that application of the developed CDC product to the mechanical seal parts will contribute to strengthening the technology of domestic enterprises and market competitiveness pursuant to increase of the product’s lifespan.
Industrialization: Related to SRBSN, the existing SUS material has been used as the material of bush bearing for zinc galvanizing and sputter roller for LCD, it is being replaced to silicon nitride material due to its weakness in anti-abrasion, and Wonik QnC Corporation has the record of having delivered some silicon nitride products engrafted with low-price SRBSN technology. Also, we plan to carry forward sales increase by entering the market of insulation-bushing silicon nitride product for grinding pad and solar CVD of the semiconductor CMP process. Next, related to CDC, we have secured the reliability test of the CDC product for the mechanical seal used in general pump and high-speed pump, and now we are proceeding with the customer certification test for replacing the existing mechanical seal product. We expect to have a considerable ripple effect when entering the market through already secured customers.
Problem-solving in industrialization: When developing the SRBSN material, we could solve the problem caused by the hydration reaction in the mixture pursuant to use of Si, the starting raw material, through optimization of the mixture time. Although the problem of the product’s unit cost increase was anticipated as a long-time nitriding process was required for reverting to the silicon nitride, we could produce the product with low cost vis-a-vis the existing silicon nitride through optimization of the equipment for nitriding process and the jig structure design.
Technology developer: Wonik QnC Corporation / +82-54-479-9800 / www.wonikqnc.com
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