BEIJING NORTH REFRACTORIES CO., LTD.  

Product Name: Ceramic Stalk for Aluminum Low Pressure Casting Model NO.: NRSA801 Material: Si3n4 Shape: Tube Type: Refractory Material Feature: Long Time Materials Refractoriness (?): 1400 Trademark: NORTH REFRACTORIES Transport Package: Wooden Box Specification: length: 1300mm max, dia: 40-180mm Origin: China HS Code: 69039000 Product Description Ourlow pressuresilicon nitride riser stalks provide performance cost advantages for low pressure die casting machines.Because of unique properties to withstand thermal shock, erosion, and corrosive attack, coupled with its impervious and non wetting advantages, silicon nitride riser stalks are long lasting and mainly maintenance free.Silicon Nitride riser stalks are available with plain ends, grooved ends for assembly with metal flanges, or with integral collars for the optimum in strength and reliability.This new isostatically pressed class ofadvanced ceramics shows a major improvement with regards to the impact fracture toughnessof Si3N4 .Our riser stalks or riser tubes have excellent non-wetting properties and a smooth surface are also important new features.Sialonceramicscan now be manufactured in nearly all shapes.Silicon Nitride riser tube or riser stalks arean alloy of silicon nitride and aluminum oxide. The combined properties of silicon nitride(high strength, hardness, fracture toughness, and low thermal expansion) and aluminum oxide (corrosion resistance, chemically inert, high temperature capabilities, and oxidation resistance).Low Pressure Die CastingA low-pressure die casting (LPDC) holding furnace isdesigned to maintain pressures required for the casting process. The furnace contains a reservoir of molten metal, which is connected to the casting die by a stalk/riser tube (filling system). Critical issues for low-pressure die casters include melt cleanliness, hydrogen content, furnace pressure, casting temperature, casting cycle timing and mould coating and maintenance.Features:Considerably stronger than Syalon or Silicon Nitride.Excellent non-wetting properties.12 months warranty against chemical attack.Standard tolerance of +/- 0,5 mm(1) High strength: High bending strength of 780MPa without deterioration up to 800deg. C.(2) High density: High dense material with porous ratio of less than 0.3%(3) High toughness: The highest fracture toughness(KIC) of 7.2MPa x m1/2 among ceramic materials(4) High performance: Almost no erosion in molten aluminum and low wettabilityTypical applications:Low pressure diecasting machines.Remarks :North refractories provides various shape of flangeStandard shape is metal Flange Type and One Body stalk tube Type. Special type of heater being equipped at flange position is possible.Surface coatingIn the conditions aluminum and oxidized aluminum are harmful, surface coating is recommended.As standard coating material, series of SiO-ZrO being adjusted to the same thermal expansion as mother ceramics is used in order to protect stripping.MaintenanceAdhered aluminum on tube surface after long period usage is removed by acid cleaning at Kubota with charge upon request.