CH638924A5 - USING AN ALLOY OF PALLADIUM, COBALT AND COPPER AS MATERIAL FOR ELECTRICAL CONTACTS. - Google Patents

Description

638 924

2

Claims (4)

PATENT CLAIMS 1. Use of an alloy of 30 to 60% by weight palladium, 30 to 60% by weight cobalt and 8 to 25% by weight copper as a material for electrical contacts. 2. Use of an alloy of 40 to 50% by weight palladium, 30 to 50% by weight cobalt and 10 to 20% by weight copper for the purpose mentioned in claim 1. 3. Use of the alloy of 40% by weight of palladium, 50% by weight of cobalt and 10% by weight of copper for the claim 1 mentioned purpose. ok 4. Use of the material according to any one of claims 1 to 3 for sliding contacts. The invention relates to the use of an alloy of palladium, cobalt and copper as a material for electrical contacts, especially sliding contacts. 20 The use of palladium-copper alloys with 10-15% copper for electrical contacts is known from German Patent Specification 947 742. With these alloys, a somewhat higher load occurs, albeit a small and even amount of material removal. 25 A switching contact made of an alloy of 60-85% palladium or platinum, 10-35% silver or copper and 0.5-5% nickel, cobalt or iron is known from US Pat. No. 2,070,271. The object of the invention is to find such an alloy 30 made of palladium, cobalt and copper for use as a material for electrical contacts, which has very good strength properties and can be mechanically heavily stressed. The object is achieved according to the invention by using an alloy of 30 to 60% by weight of palladium, 30 to 60% by weight of cobalt and 8 to 25% by weight of copper. In addition to the electrical properties required for use in the field of electrical contacts and high corrosion resistance, the alloy according to the invention has very good mechanical strength properties, so that it can be used with particular advantage for sliding contacts for transmitting small voltages and small currents. The use of the alloy of 40 to 50% by weight of palladium, 30 to 50% by weight of cobalt and 10 to 20% by weight of copper has proven particularly successful. A very advantageous alloy whose composition falls within this range is that of 40% by weight palladium, 50% by weight cobalt and 10% by weight copper. The alloy according to the invention is produced in a known manner by melting together the metallic components palladium, cobalt and copper in amounts corresponding to the composition of the finished alloy. Due to its excellent ductility, the alloy according to the invention can be processed well, for example by rolling or drawing. The table below shows the density, tensile strength, yield point, hardness and specific resistance of four alloys according to the invention and, for comparison, the corresponding values of known palladium-copper and palladium-cobalt-copper alloys. Compared to the known alloys, the alloys according to the invention are distinguished by higher strength, hardness and yield point values. Table Alloy Density Tensile strength Yield point Elongation Hardness HVI spec. Resistance [g/cm3] [N/mm2] [N/mm2] [%] [kp/mm2] [Q mm2/m] avail.1 avail.2 avail.' 2 available 1 available 2 available 1 available-2 available 1 available 2 Pd40Co50Cul0 9.96 1445 805 1415 550 1 50 445 255 0.23 0.21 Pd50Co30Cu20 10.24 1270 680 1240 375 1 31 410 195 0.36 0.34 Pd50Co40Cul0 10:23 1345 720 1300 385 2 35 430 195 0.26 0.24 Pd60Co30Cul0 10.54 1195 625 1170 265 1 •34 405 160 0.31 0.29 Pd85Cul5 11:42 810 375 800 165 1 42 255 105 0.40 0.40 Pd60Cu40 10.57 870 450 870 175 1 41 310 120 0.35 0.36 Pd84Co6Cul0 11:38 855 430 815 170 1 36 265 115 0.51 0.51 Pd75Co5Cu20 11.06 915 500 885 205 1 38 300 135 0.59 0.60 ' available = deformed !gegl. = soft annealed G