Investment Casting Brass

ProcessInvestment  Casting,  lost  wax  casting,  precision  casting,  Silicon  sol  casting,Materialbrass,  iron,  ductile  ironMaterial  GradeGB,  ASTM  ,  AISI  ,  DIN  ,  BS, Weight0.01  kg~70kgAccuracyClass  CT4~CT9Surface  RoughnessUp  To  Ra1.6~Ra6.3Applied  Softwareproe,  catia,  ug,  solidworks,  cad,  pdf,  etcProduction  CapacityMore  Than  100T  Per  MonthHeat  TreatmentAnneal,  Quenching,  Normalizing,  Carburizing,  Polishing,  Plating,  Painting,  etcMachining  EquipmentCNC  Center  ,  CNC  Machines,  Turning  Machines,  Drilling  Machines  ,  Milling  Machines,  Grinding  Machines,  etcMeasuring  ToolCMM  ,  Projector,  Vernier  Caliper,  Depth  Caliper,  Micrometer,  Pin  Gauge,  Thread  Gauge  ,  Height  Gauge,  etcQC  System100%  Inspection  Before  ShipmentReport100%  Report  with  shipmentTransportAir  or  SeaFAQ:  Q 1.Why should we send inquiry to you?  We are professional one-stop customized mechnical parts and service provider.We have the word-class foundry equipment and technology processing.We had 5 years of castings experience in exporting.  We can bespoke manufacture of drawing,samples mapping,raw material processing and design manufacture according to your originality.  Q 2.How long can we get the price list?  We are factory direct best price.So our price list will be quoted within 24 hours after we get your inquiry with detailed informations (such as drawings, material,technology specification,surface treatment,quantity, special requirements and etc)  Q 3.How about quality of your castings parts?  After you confirmed the quotation for pattern cost,raw casting cost,machining cost and coating cost.We will send to you the sample for you inspection approval.  Q 4.How about your after market service?  We could confidential of the quality of delivered parts and compensate 100% on defective parts.  Q 5.What`s your Minimun Order Quantity(MOQ)  According to your requirement that only one piece can customized for you.Copper and Copper Alloys Casting Problems  Pure copper is extremely difficult to cast as well as being prone to surface cracking, porosity problems, and to the formation of internal cavities. The casting characteristics of copper can be improved by the addition of small amounts of elements including beryllium, silicon, nickel, tin, zinc, chromium and silver.  Copper alloys in cast form (designated in UNS numbering system as C80000 to C99999) are specified when factors such as tensile and compressive strength, wear qualities when subjected to metal-to-metal contact, machinability, thermal and electrical conductivity, appearance, and corrosion resistance are considerations for maximizing product performance. Cast copper alloys are used for applications such as bearings, bushings, gears, fittings, valve bodies, and miscellaneous components for the chemical processing industry. These alloys are poured into many types of castings such as sand, shell, investment, permanent mold, chemical sand, centrifugal, and die casting.  The copper-base casting alloy family can be subdivided into three groups according to solidification (freezing range). Unlike pure metals, alloys solidify over a range of temperatures. Solidification begins when the temperature drops below the liquidus; it is completed when the temperature reaches the solidus. The liquidus is the temperature at which the metal begins to freeze, and the solidus is the temperature at which the metal is completely frozen.  Group I alloys  Group I alloys are alloys that have a narrow freezing range (about 50oC), that is, a range of 50oC between the liquidus and solidus temperature. Group I alloys includes: copper (UNS No. C81100), chromium copper (C81500), yellow brass (C85200, C85400, C85700, C85800, C87900), manganese bronze (C86200, C86300, C86400, C86500, C86700, C86800), aluminum bronze (C95200, C95300, C95400, C95410, C95500, C95600, C95700, C95800) nickel bronze (C97300, C97600, C97800), white brass (C99700, C99750).  Pure Copper and Chromium Copper. Commercially pure copper and high copper alloys are very difficult to melt and are very susceptible to gassing. In the case of chromium copper, oxidation loss of chromium during melting is a problem. Copper and chromium copper should be melted under a floating flux cover to prevent both oxidation and the pickup of hydrogen from moisture in the atmosphere. In the case of copper, crushed graphite should cover the melt. With chromium copper, the cover should be a proprietary flux made for this alloy. When the molten metal reaches 1260oC, either calcium boride or lithium should be plunged into the molten bath to deoxidize the melt. The metal should then be poured without removing the floating cover.  Yellow Brasses. These alloys flare, or lose zinc, due to vaporization at temperatures relatively close to the melting point. For this reason, aluminum is added to increase fluidity and keep zinc vaporization to a minimum. The proper amount of aluminum to be retained in the brass is 0.15 to 0.35%. Above this amount, shrinkage takes place during freezing, and the use of risers becomes necessary. After the addition of aluminum, the melting of yellow brass is very simple, and no fluxing is necessary. Zinc should be added before pouring to compensate the zinc lost in melting.  Manganese Bronzes. These alloys are carefully compounded yellow brasses with measured quantities of iron, manganese, and aluminum. The metal should be melted and heated to the flare temperature or to the point at which zinc oxide vapor can be detected. At this point, the metal should be removed from the furnace and poured. No fluxing is required with these alloys. The only addition required with these alloys is zinc. The amount required is that which is eeded to bring the zinc content back to the original analysis. This varies from very little, if any, when an all-ingot heat is being poured, to several percent if the heat contains a high percentage of remelt.  Aluminum Bronzes. These alloys must be melted carefully under an oxidizing atmosphere and heated to the proper furnace temperature. If needed, degasifiers can be stirred into the melt as the furnace is being tapped. By pouring a blind sprue before tapping and examining the metal after freezing, it is possible to tell whether it shrank or exuded gas. If the sample purged or overflowed the blind sprue during solidification, degassing is necessary. Degasifiers remove hydrogen and oxygen. Also available are fluxes that convert the molten bath. These are in powder form and are usually fluorides. They aid in the elimination of oxides, which normally form on top of the melt during melting and superheating.  Nickel Bronzes. These alloys, also known as nickel silver, are difficult to melt. They gas readily if not melted properly because the presence of nickel increases the hydrogen solubility. Then, too, the higher pouring temperatures aggravate hydrogen pickup. These alloys must be melted under an oxidizing atmosphere and quickly superheated to the proper furnace temperature to allow for temperature losses during fluxing and handling. Proprietary fluxes are available and should be stirred into the melt after tapping the furnace. These fluxes contain manganese, calcium, silicon, magnesium, and phosphorus and do an excellent job in removing hydrogen and oxygen.  White Manganese Bronze. There are two alloys in this family; both of them are copper-zinc alloys containing a large amount of manganese and, in one case, nickel. They are manganese bronze type alloys; they are simple to melt, and can be poured at low temperatures because they are very fluid. They should not be overheated, as this serves no purpose. If the alloys are unduly superheated, zinc is vaporized and the chemistry of the alloy is changed. Normally, no fluxes are used with these alloys.