Cupro Alloys Corporation

CUPROSIL 72CdF is the eutectic composition of the silver-copper system. It is suitable for use in controlled atmosphere brazing without the use of any flux. When molten, it is very fluid and may flow out over the work surfaces during some furnace brazing applications. The wetting action on ferrous metals is limited, minimizing its use on carbon steel. Improved wetting is observed when furnace brazing of stainless steel with silver-copper filler metals. Where improved corrosion resistance is needed, nickel may be added to the eutectic composition.

‘CUPROSIL 64CdF’ is an intermediate temperature silver brazing filler alloy with a slight tendency to liquate (i.e. separate into low & high melting constituents) if heated slowly through its melting range. When this filler alloy is used for brazing silver base alloys, the remelt temperature is raised by solution of silver in the brazing alloy. Conversely, the remelt temperature of this brazing alloy is lowered by solution of copper when brazing copper base alloys. Flux is generally used with this alloy.

‘CUPROSIL 61CdF’ is an intermediate temperature cadmium free silver brazing filler alloy. It has a short melting range and a relatively low silver content. Flux is generally used with this brazing alloy.

‘CUPROSIL 50CdF’ is widely used for brazing in the electrical industry, as well as in the dairy and food industries where the use of cadmium containing filler alloys is prohibited. It has a broad melting range, making it a good choice for filling wide joint clearances or forming large fillets.

‘CUPROSIL 45Sn’ is a free flowing, low melting alloy, and is an excellent substitute for the cadmium bearing alloys with similar silver content. Its narrow melting range makes it very useful for automatic wire feeding into the braze joint. The alloy is best suited for narrow gap filling in the .001 to .005 joint clearance range. This alloy has found great acceptance in the brass faucet industry.

‘CUPROSIL 45CdF’ is a good general purpose alloy often used where cadmium must be avoided such as in the dairy and food industries.

‘CUPROSIL 43CdF’ is a good general purpose alloy often used where cadmium must be avoided such as in the dairy and food industries. It is a cheaper substitute to ‘CUPROSIL 45CdF’. It is a good general purpose alloy often used when cadmium must be avoided such as in the dairy and food industry. It is also used for brazing in the electrical industry and for brazing brass parts such as ships, piping, band instruments and lamps.

‘CUPROSIL 40Sn’ is a good general purpose, low melting, cadmium-free alloy, often selected for its low temperature, wetting and good flow. It has a lower brazing temperature with a relatively narrower melting range than other cadmium-free classifications with similar silver content. It does not liquidate excessively if heated slowly through its melting range.

‘CUPROSIL 45CdF’ is a good general purpose alloy often used where cadmium must be avoided such as in the dairy and food industries.

The tin content in ‘CUPROSIL 30Sn’ provides good wetting on many difficult to wet metals such as stainless steel and tungsten carbide. This alloy, being free of Pb or Cd is preferred for long heating cycles and is suitable for use in controlled atmosphere brazing without flux. The largest use of this alloy is for furnace brazing although it is also suitable for other brazing.

‘CUPROSIL 30CdF’ does not contain cadmium and is often used as an alternate to cadmium containing alloys when the brazed assembly comes in contact with food or dairy products. Its slightly higher melt temperature provides improved mechanical strengths when exposed to elevated temperatures.

‘CUPROSIL 25Sn’ is an economical filler metal for ferrous and nonferrous joints not requiring high ductility or impact strength. It is similar to ‘CUPROSIL 40Sn’, however flow is less active and temperature range and brazing temperatures are greater. This alloy is not ductile during cooling. After brazing, it must be allowed to cool without being subjected to mechanical or thermal stress.

‘CUPROSIL 25CdF’ does not contain cadmium. Its slightly higher melt temperature provides improved mechanical strength when exposed to elevated temperatures or cyclic loads at elevated temperatures.

‘CUPROSIL 70CdF’ is an intermediate temperature silver brazing filler alloy with a slight tendency to liquate (i.e. separate into low & high melting constituents) if heated slowly through its melting range. When this filler alloy is used for brazing silver base alloys, the remelt temperature is raised by solution of silver in the brazing alloy. Conversely, the remelt temperature of this brazing alloy is lowered by solution of copper when brazing copper base alloys. Flux is generally used with this alloy.