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27 Nov 2014
Zirconium Silicate Coating |
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Zircon is widely use in the production of coatings,due to its high refractoriness (melting point at 2200 C) and round grain shape. This nearly round grain shape reaches a very good packing density between the particles and so it is possible to reduce the binder content, but at the same time very strong and stable layer is formed. Zircon has and excellent resistance to thermal shocks and a very small thermal expantions, combined with chemical inertness. (One exception: austenetic manganese steel) Often zircon is used for steel and heavy/alloy iron castings. However the other technical benefits of zircon are limited and it is not the filter of choice in many circumstances A dispersion of Zirconium Silicate in Isopropanol for use in as a refractory coating in foundry the coating is suitable for the production of castings in Steel, Gray and Ductile Iron as well as non ferrous alloys.The coating is designed for the application by brush to small areas,flow coating,dipping of the mould or core. Jame Durrans code of this type of coating is RSB 1002A RSB mean solvent base coatingDegit 1. No 1mean main refractory of raw material,it is zirconDegit 2. No 0mean minor refractory of raw material but this type of coating is nonwe,use 100% zirconDegit 3. No 0 mean color,this type use natural colorDegit 4. No 2 mean medium flow properties Application technique of coating to prevent sand burn at hot spot area by Flooding application for carbon steel casting Condition - alkaline resin sand mesh 50 Step 1 Pre coating(penetrated coat) 1. Mix coating completely in original drum before dilute to using Baume. 2. Dilute with methanol alcohol,ethanol alcohol or IPA,to 50-60 Baume 3. Apply by brushing at hot spot area or sand weakness point in order to allow the coating with lower Baume penetrate into sand probably about 6-8 mm(in sand) 4. Without burning the coating(just leave it and wait for flooding)    Step 2 Normal apply by flooding application 1. Mix coating completely in original drum before dilute to using Baume. 2. Dilute the coating Baume with Methanol,ethanol or IPA alcohol to 65-70 Baume by high speed mixer   3. Transfer the coating into flow coating tank device 4. Flood the coating into the sand only 1 layer 5. Use brushing at some area which retaining of coating 6. Gauge check the coating thickness, it must be 250-350 micron 7. Firing the coating right away   Remark : before setting mould for pouring process,use low flame of gas burner of hot air(do not use high flame direct to coating surface,cause of the flame will destroy the coating binder and moiture from alcohol)
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