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Silver/Copper-Phosphorus Brazing Filler Metals Brazing Filler Metals

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Silver/Copper-Phosphorus Brazing Filler Metals Brazing Filler Metals Metal Joining SILVER/COPPER-PHOSPHORUS BRAZING FILLER METALS BRAZING FILLER METALS contents products at a glance Products at a glance 2 Compositions Silver/Copper-Phosphorus Brazing 3 These products have Sil-fosTM Ag Cu P the following Filler Metals TM compositions: Copper-flo Cu P Sn Sb Silver/Copper-Phosphorus Brazing 4 Standard products are supplied to conform to ISO17672. Filler Metals Special products conform to proprietary Johnson Matthey specifications. TM Recommended uses for Sil-Fos 5 TM & Copper-Flo Filler Metals Uses for the Products Filler Metal Selection 6 The Sil-fosTM and Copper-floTM products are most commonly used to form joints on the following Key 7 materials: Copper tubes, pipes and fittings Copper alloys including brass, bronze, nickel silver and aluminium-bronze Electrical engineering applications Conditions for Use The Sil-fosTM and Copper-floTM products are typically used for brazing in air using a hand torch, fixed burner system, high frequency induction or resistance heating. These products are self-fluxing when used on copper. When used to braze copper alloys a compatible brazing flux should be used. This can be applied using a Johnson Matthey flux powder or paste, or a brazing paste with a flux binder system included. 2 Metal Joining products silver/copper-phosphorus brazing filler metals these products are mainly used for brazing copper to copper. they are self-fluxing on copper and therefore do not require a separate flux for this application. Specification Description Properties Product Forms TM TM 10 Sil-fos Plus Ag Cu P Sil-fos Plus is the most free flowing filler metal from the -50 / 150˚C TM Sil-fos range. It is used in niche applications where its low 1 18 75 7 Flow Melting Range 644˚C melting temperature, flow properties and electrical conductivity Low 1 are an advantage. Sil-fosTM Plus is not particularly ductile and EN1044: 1999 CP101 0.025-0.075 mm should not be used in applications where vibration, stress or ISO 17672:2010 CuP 286 deformation of the joint in service are possible. ˚C 650˚C TM TM Sil-fos Ag Cu P Sil-fos is a widely used product being the most ductile of -50 / 150˚C the silver/copper-phosphorus brazing filler metals and the 2 15 80 5 Flow only one available as a foil. It is used extensively in electrical 10 Melting Range 644-800˚C High engineering applications where it is used to make electrically EN1044: 1999 CP102 0.05-0.2 mm conductive joints. It is also used in heating and ventilation and ISO 17672:2010 CuP 284 refrigeration applications to join copper pipes. ˚C 700˚C TM TM Sil-fos 6 Ag Cu P Sil-fos 6 is one of the most free flowing filler metals from -50 / 150˚C TM the Sil-fos range making it popular in heat exchanger, air 1 10 6 86.75 7.25 Flow Melting Range 644-718˚C conditioning and refrigeration (HVAC&R) applications. It is also Low¹ one of the least ductile and should not be used in applications EN1044: 1999 - 0.025-0.075 mm involving exposure to strong vibrations, impact loads or where ISO 17672:2010 CuP 283 some deformation of the joint might be expected in service. ˚C 720˚C TM TM Sil-fos 5 Ag Cu P Sil-fos 5 provides the best combination of flow and ductility of -50 / 150˚C all the silver/copper-phosphorus type brazing filler metals. As a 2 10 5 89 6 Flow result it is extensively used in heat exchanger, air conditioning Melting Range 644-815˚C Medium and refrigeration (HVAC&R) applications for flux-free brazing of EN1044: 1999 CP104 0.05 - 0.2 mm copper pipes and tubes. It is also used for joining copper and ISO 17672:2010 CuP 281 copper alloys in electrical engineering applications. ˚C 710˚C TM TM TM TM Silbralloy Ag Cu P Silbralloy sits between Sil-fos 5 and Copper-flo . It is less -50 / 150˚C TM ductile and free flowing than Sil-fos 5 but more ductile whilst 2 10 2 91.7 6.3 Flow being less free flowing than Copper-floTM. It is used in HVAC&R Melting Range 644-825˚C Medium-Low applications for flux-free brazing of copper pipes, tubes and EN1044: 1999 CP105 0.05-0.2 mm seams where these properties and its cost are acceptable. ISO 17672:2010 CuP 279 It is also used in some electrical engineering and plumbing ˚C 740˚C applications. 3 products silver/copper-phosphorus brazing filler metals These products are mainly used for brazing copper to copper. They are self-fluxing on copper and therefore do not require a separate flux for this application. Specification Description Properties Product Forms TM TM Copper-flo Cu P Copper-flo is the most free flowing copper-phosphorus filler -50 / 150˚C 92.2 7.8 metal, however, due to its high phosphorus content it is one Flow 10 - of the least ductile. It is best suited for making copper joints of Melting Range 714-810˚C Medium-Low the true capillary type and should not be used in applications EN1044: 1999 CP201 0.025-0.075 mm involving exposure to strong vibrations, impact loads or where ISO 17672:2010 CuP 182 some deformation of the joint might be expected in service. ˚C 720˚C TM TM Copper-flo No.2 Cu P Sb Copper-flo No.2 is a specialised copper-antimony-phosphorus -50 / 150˚C 92 6 2 filler metal. It was specifically designed for flux-less brazing of - Flow Melting Range 690-825˚C copper cylinders for domestic and industrial heating systems Medium where it is used for seam joints. The antimony in this filler EN1044: 1999 CP301 0.05-0.2 mm metal improves its flow characteristics whilst allowing the ISO 17672:2010 CuP 389 phosphorus level to be kept low hence optimising ductility. ˚C 740˚C TM TM Copper-flo No.3 Cu P Copper-flo No.3 is a low cost, relatively ductile filler metal -50 / 150˚C TM (when compared to Copper-flo ), which is not too fluid when 3 10 93.8 6.2 Flow molten so can be held in the joint area when brazing. These Melting Range 714-890˚C Medium-Low characteristics make Copper-floTM No.3 a popular choice for EN1044: 1999 CP203 0.05-0.2 mm air-conditioning and refrigeration applications. Where greater TM ISO 17672:2010 CuP 179 ductility is required Sil-fos 5 should be used. ˚C 760˚C TM TM 10 Stan-fos Cu P Sn Stan-fos is not self-fluxing on copper and must be used with -50 / 150˚C TM a brazing flux such as Easy-flo Flux Powder. It is free flowing 1 86.2 6.8 7 Flow TM Melting Range 640-680˚C and produces a smooth fillet. Stan-fos is brittle/not ductile Low and should therefore not be used in applications involving EN1044: 1999 CP302 0.025-0.075 mm exposure to strong vibrations or impact loads. It is used ISO 17672:2010 CuP 386 primarily on copper to copper alloy joints. ˚C 700˚C 4 Metal Joining technical recommended uses for sil-fostm & copper-flotm filler metals Copper to Copper Sil-fosTM & Copper-floTM brazing filler metals are most often used to braze copper to copper. The phosphorus within the filler metals gives them a self-fluxing capability. There is therefore no need for a separate brazing flux. Specific Issues for Copper to Copper Recommendations Tough-pitch copper is subject to deterioration if heated to a high This effect is known as hydrogen embrittlement. When brazing this material temperature in reducing conditions. It contains dissolved cuprous oxide, a neutral or slightly oxidising flame is therefore recommended. Phosphorus which may be chemically reduced in a reducing flame or atmosphere to leave de-oxidised or oxygen-free copper should be specified. small cavities in the metal. Copper Alloys Sil-fosTM & Copper-floTM products can be used to join copper alloys such as brass, bronze or gunmetal. Specific Issues for Copper Alloys Recommendations A separate flux is required because the self-fluxing action only occurs Easy-floTM Flux Powder or Easy-floTM 100 Flux Paste. Easy-floTM Low Temperature on copper. Grade Flux Paste also performs well on copper alloys. TenacityTM No.4A Flux Powder may be used where long heating cycles are required. not recommended for Brazing of Parent Materials Containing Iron or Nickel Sil-fosTM & Copper-floTM products should not be used to braze any iron or nickel containing materials including carbon and stainless steel. Specific Issue: Metals Containing Iron or Nickel Recommendations The phosphorus within the filler metal will form brittle, intermetallic, Silver-floTM or Argo-brazeTM products may be suitable for these applications, phosphide compounds at the joint interface. This will cause complete failure consult Johnson Matthey for more information. of the joints. Sulphurous Atmospheres at Elevated Service Temperatures Sil-fosTM & Copper-floTM products are not suitable for use in sulphurous atmospheres at elevated service temperatures. Specific Issue: Sulphurous Atmospheres at Elevated Service Temperatures Recommendations Phosphorus containing filler metals should not be used in cases where they Silver-floTM or Argo-brazeTM products may be suitable for these applications - will be exposed to sulphurised gases at elevated temperatures, for example in consult Johnson Matthey for more information. model engineering boilers. 5 filler metal selection When selecting a brazing filler metal from the Sil-fosTM & Copper-floTM range The higher the phosphorus content the more free flowing but less ductile it is necessary to understand about the flow and ductility of the different the filler metal becomes.
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