A
platinum alloy composition is composed of, in weight percent, 0.0 to 5.0 gold, 0.0 to 2.5
cobalt, 0.0 to 3.0
copper, 0.0 to 5.0 iron, 0.0 to 2.75
gallium, 0.0 to 3.0
indium, 0.0 to 5.0
iridium, 0.0 to 5.0
manganese, 0.0 to 5.0
palladium, 0.0 to 5.0
rhenium, 0.0 to 5.5
rhodium, 0.0 to 5.0
ruthenium, 0.0 to 3.0
tin, 0.0 to 5.0 silver, and incidental impurities, where the sum of
platinum and
iridium is 95.0 or more, and wherein the following formula is satisfied, in which the sum of
platinum and
iridium is 95.0 or more. WCo, WCu, WFe, WGa, WIn, WNi, WPd, WSn, WRh, WIr, WAu, WRu, WRe, WAg and WMn are respectively weight percentages of
cobalt,
copper, iron,
gallium,
indium,
nickel,
palladium,
tin,
rhodium, iridium, gold,
ruthenium,
rhenium, silver and
manganese in the
alloy, 60 + WPd * 2.5 + WRh * 3.4 + WIr * 6.455 + WIr * 16.6 + WNi * 16.9 + WMn * 18.48 + WCo * 18.69 + WFe * 21.879 + WIn * 29 + WSn * 28.207 + WGa * 42.379 + WAg * 9.0 > = 130, and wherein the following conditions are satisfied, in which the weight percentages of
cobalt,
copper, iron -0.10406 * WAg-0. 1028 * WCo-0. 1201 * WCu-0. 2113 * WFe-0. 3368 * WGa-0. 1125 * WIn-0. 1639 * WNi-0. 0959 * WSn + 17.276261-0.20 * WMn + 0.0678 * WRu + 0.035 * WIr + 0.045 * WRh-0. 059 * WAu + 0.066 * WRe < = 17.1, and wherein the following formula is satisfied in which WCo, WCu, WFe, WGa, WIn, WNi, WPd, WSn, WMn, WRu, WIr, WRh, WAu, WAg and WRe are respectively aluminum, cobalt, copper, iron,
gallium,
indium,
nickel,
palladium