Electrical contact material and method for making the same

A material for use in electrical contacts comprising a conductive constituent in the amount of about 20% to 50% by weight, nickel in the amount of about 4% to 13% by weight, and the balance including a refractory metallic constituent, and when sintered in electrical contacts characterized by significantly decreased mean temperature rise of the contacts when subjected to 1,000 switching cycles at a rate of 12.85 cycles per minute under a current load of 20 amperes at 120 volts AC at 60 cycles per second with a 75% power factor compared to essentially the same contacts sintered under the same conditions and subjected to the same number of switching cycles at the same rate under the same load conditions and made of essentially the same material except that such material contains less than 2% by weight of nickel.

A material for use in electrical contacts consisting essentially of silver in the amount of about 20% to 50% by weight, nickel in the amount of about 4% to 10% by weight, and the remainder tungsten, and when sintered in electrical contacts characterized by significantly decreased mean temperature rise of the contact when subjected to 1,000 switching cycles at a rate of 12.85 cycles per minute under a current load of 20 amperes at 120 volts AC at 60 cycles per second with a 75% power factor compared to essentially the same contacts sintered under the same conditions and subjected to the same number of switching cycles at the same rate under the same load conditions and made of essentially the same material except that such material contains less than 2% by weight of nickel.

A material for use in electrical contacts consisting essentially of silver in the amount of about 20% to 50% by weight, nickel in the amount of about 2% to 13% by weight, phosphorus in the amount of about 90 to 1000 ppm and the remainder tungsten.

In an electrical circuit breaker, a circuit breaker contact comprising a conductive metallic constituent in the amount of about 20% to 50% by weight, nickel in the amount of about 2% to 13% by weight, phosphorus in the amount of about 90-1000 ppm and the balance including a refractory metallic constituent.

In a liquid phase sintered electrical contact comprising a conductive constituent selected from the group consisting of silver, palladium, platinum and mixtures thereof in the amount of about 20% to 50% by weight, nickel, phosphorus, and the balance including a refractory metallic constituent selected from the group consisting of tungsten, molybdenum, their carbides and mixtures thereof, the improvement wherein said nickel is in the amount of about 2% to 13% by weight, said phosphorus is in the range of about 90-1000 ppm, and particles of said refractory metallic constituent in said sintered contact have an average particle size of at least about 1.0 .mu.m.