GB1338278A - Heat recoverable alloys - Google Patents

Abstract

1338278 Nickel-base alloy; preparation RAYCHEMCORP 17 June 1971 [2 July 1970] 28456/71 Heading C7A and C7D A nickel base alloy contains, in atomic percent, 49.1 to 50.2% titanium and 2.1 to 4.7% iron, the balance being nickel and impurities. Preferably the iron is present at between 3.2 and 3.6 atomic percent. Impurities present should not exceed 0.1 per cent by weight of carbon, 0.2% of nitrogen and 0.2% oxygen, other metal or non-metal impurities may also be present, the total impurity level not exceeding 0. 5 per cent by weight. The alloy is particularly suitable for use as a coupling for hydraulic circuits in aircraft, the martensitic transition temperature being well below the operating temperature required. The alloys have the property of being heat-recoverable i. e. they may be deformed at below the transition temperature, but revert to an undeformed condition when heated again to above that temperature. Alloy Preparation Strips of each of the constituent metals are assembled in bundles, each strip having the same length and width and the numbers being such as to give the required proportions at any crosssection. The bundles are then melted in an inert atmosphere progressively along their length, the falling droplets being collected in a cold copper mould. The resulting ingot was then subjected to a further heating step in an inert atmosphere, a molten zone passing along the ingot at 0.5 cms/ minute to produce a void-free bar.