IL34411A - Improvements in alloys - Google Patents

Claims (1)

1. ' CLAIMS 34411/2 1, A method of making an article from a heat-recoverable alloy, which alloy when s itably heat-treated is one shape, and caused to deform at an appropriate temperature into another shape at least partially recovers ite first shape upon sufficiently raising the temperature of the article, comprising the step of applying^., a strain to the alloy in its high temperature phase which produces a stress which induces a desired shape in its low temper ure phas 2. A method according to c a.±n 1 in which said strain is applied by deforming the alloy in its high-temperature pliase partly towards the shape required for the low-temperature phase. β. A method according to claim 2 in which the temperature is ubsequen l lowered so that alloy changes into its lovf-temperature phase and assumes the required shape, , A method aepprcjing to claim, \ in which h° alloy is defprmed^ into a desired shape in its low-temperature phase and said strain is applied by raising t|ie temperature sp that i tfie a¾loy changes iptP its high-temperature phase while restraint is applied, to the alloy to prevent a change in shape, 5, A method pf making a hea -recoverable article from a heat-recoverable alloy, which method, includes the stops of Shaping the alloy at an elevated tem er tu e into a first shape, cooling to a lower temperature, deforming the alloy at the lower temperature intp a second shape, said temperatures being such that if reheated without restraint to an appropriate temperature the alloy would at least partly resume its firs shape, and reheating the alloy tp said appropriate temperature while subjecting it to restraint which prevents a change of 6. A method according to claim 5 in which the alloy is cooled to the lower temperature after said reheating, still retaining the second shape. 7. A method according to any preceding claim in which the alloy is a binary alloy of uranium containing 2 to 7% by weight molybdenum, 3 to 11% by weight niobium or 2. to 7% by weight rhenium. 8. A method according to claim 7 in which the alloy is a binary alloy of uranium containing 3 to 6.5% by weight molybdenum. 9. A method according to claim 7 in which the alloy is a binary alloy of uranium containing 4 to 10% by weight niobium 10. A method according to any of claims 1 to 6 in which the alloy is a manganese-copper binary alloy containing 5 to 50% by weight copper. 11. A method according to claim 10 in which the alloy contains 5 to 30% by weight copper. 12.. A method according to any of claims 1 to 6 in which the alloy is a nickel-titanium binary alloy containing 52 to 56% by weight nickel. 13. A heat-recoverable alloy as defined in any of claims 7 to 11. 14. A method of making a heat-recoverable article from a heat-recoverable alloy according to claim 13, which, method . includes the steps of shaping the alloy at an elevated temperature into a first shape, cooling to a lower temperature, and causing the alloy to deform at the lower temperature into a second shape, said temperatures being such that if reheated to an appropriate temperature the alloy would at least partly regain its first shape. 15. A heat-recoverable article made by a method according to any of claims 1 to 12. and 14. 16. A heat-recoverable article made of a heat-recoverable alloy, which article has, when the alloy is in its high- temperature phase, internal stress which promotes a desired change of shape in the low-temperature phase. 17. Apparatus including a heat-recoverable article according to claim 15 or claim 16, the article performing a function in said apparatus by virtue of its property of changing shape with temperature. 18. A method of making a heat-recoverable article from a heat-recoverable :>alloy2 using restraint on reheating substantially as hereinbefore described in the Examples. ' · · . 19. A method of making a heat-recoverable article from a heat-recoverable alloy using partial initial deformation above the transformation temperature substantially as hereinbefore described in the Examples. 20. A heat-recoverable uranium-molybdenum, uranium-niobium, uranium-rhenium or manganese-copper binary alloy substantially as hereinbefore described in the Examples. 21. A heat-recoverable article made by a method and/or from an alloy according to any Of claims 18 to 20.