US3802930A - Alloys - Google Patents

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Publication number
US3802930A
US3802930A US00033299A US3329970A US3802930A US 3802930 A US3802930 A US 3802930A US 00033299 A US00033299 A US 00033299A US 3329970 A US3329970 A US 3329970A US 3802930 A US3802930 A US 3802930A
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alloy
temperature
shape
weight
uranium
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US00033299A
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G Brook
R Iles
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Fulmer Research Institute Ltd
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Fulmer Research Institute Ltd
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    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C19/00—Alloys based on nickel or cobalt
    • C22C19/007—Alloys based on nickel or cobalt with a light metal (alkali metal Li, Na, K, Rb, Cs; earth alkali metal Be, Mg, Ca, Sr, Ba, Al Ga, Ge, Ti) or B, Si, Zr, Hf, Sc, Y, lanthanides, actinides, as the next major constituent
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C28/00—Alloys based on a metal not provided for in groups C22C5/00 - C22C27/00
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C43/00—Alloys containing radioactive materials

Definitions

  • ABSTRACT A method of making a heat-recoverable article from a [52] U.S. C1. 148/115, -/122.7, 75/134 M,- heat-recoverable alloy. which after suitable treatment 75/ 1 70. 148/132 changes its shape when appropriate temperature [51 1 Int.
  • a characteristic of all heat-recoverable alloys appears to be that, on cooling, they undergo a shear transformation to a banded martensite or retain the high temperature form as quenched, but transform by shear on cold working.
  • the key feature is apparently that, on shaping at a low temperature, a shear transformation occurs which may be of the form described above or may be a change in the type of martensite. It seems that the strain accommodated by this shear transformation is recoverable on heating and it is on this recoverable strain that the heat-recoverable properties depend.
  • high-- temperature and low-temperature are comparative and that, depending on the alloy, the high-temperature phase may exist for example at room temperature while the low-temperature phase exists at lower temperatures.
  • the strain to be accommodated at the lower temperature by the shear transformation can be applied at least in part to the high-temperature phase at a temperature above the temperature (the Ms transformation temperature defined hereinafter) at which transformation begins spontaneously and that it is a practical advantage to apply the strain in this way.
  • the essential feature of our invention is therefore that a stress either external or internal, must be present before and during the shear transformation so as to activate, in our belief, martensitic nuclei of the appropriate orientation to give the required shape change.
  • the invention provides a method of making a heatrecoverable article from a heat-recoverable alloy, which method includes the step of applying to the alloy in its high-temperature phase a strain which produces a stress which induces a desired shape for its lowtemperature phase.
  • saidstrain is applied by deforming the alloy in its high-.
  • the temperature phase partly towards the shape required for the low-temperature phase and the temperature is subsequently lowered so that the alloy changes into its low-temperature phase.
  • the change into the lowtemperature phase is accompanied by a continued change of shape into the desired shape without the 'application of an external force.
  • This form of the invention is of great practical value since it provides a means of putting an alloy at a comparatively high temperature into a condition in which it will deform spontaneously at lower temperatures to a new shape which is dictated by the initial high temperature deformation. It is there- 'fore unnecessary to effect working of the alloy at'low temperatures.
  • the metastable high temperature phase of the alloy is cooled to between its Md and Ms transformation temperatures.
  • Md is the temperature of the start of the martensitic transformation under stress and Ms is the temperature of the start of the transformation without'applied stress.
  • Ms is the temperature of the start of the transformation without'applied stress.
  • the temperature should be as close to the Ms transformation temperature as possible, e.g. within 10C, to obtain the desired residual internal stress by said partial deformation. In .other alloys a greater margin of temperature above Ms is possible. A suitable temperature for a given alloy can readily be found by experiment.
  • the alloy is then deformed a small amountv (i.e. less than the final strain it is desired to put intothe low temperature phase). Cooling is continued to below the Ms transformation temperature when the alloy will continue to change in shape in the direction indicated by the prior deformation. On reheating this' change of shape is wholly or partly reversed-and on cooling again the change in shape towards the low temperature'shape 'occurs spontaneously. Continued heatingand cooling is accompanied by continued changes in shape.
  • the alloy is deformed into a desired shape in its lowtemperature phase and said strain is applied by raising the temperature so that the alloy changes into its hightemperature phase while restraint is applied to the alloy to prevent a change in shape.
  • a method of making a heat-recoverable article from a heatrecoverable alloy which method includes the steps of shaping the alloy at an elevated temperature into a first shape,'cooling to a lower temperature, deforming the alloy at the lower temperature into a second shape, said temperatures being such that if reheated without restraint to an appropriate temperature the alloy would at least partly resume its first, shape, and reheating the alloy to said appropriatetemperature while subjecting it to restraint which prevents a-changeof shape.
  • the alloy may be cooled to the lower temperature after reheating, still retaining the second shape. Then'if the alloy is reheated without restraint it will change wholly or partly to its first shape but on cooling will revert wholly or partly to its second shape.
  • Reheating under restraint is particularly useful since it enables the upper temperature to which the alloy is heated to be so far above the transformation temperature that continued reversibility of shape would be lost in the absence of restraint. Nevertheless, the upper temperature must not be sufficient for relaxation of stress to occur by plastic deformation, e.g. creep, or reversibility will be lost.
  • the temperature to which the alloy is heated should be too low for ageing or tempering of the alloy to take place. If precipitation occurs, the alloy assumes its high temperature shape permanently.
  • Reheating under restraint may also be used to change the positions between which change of shape occurs (but not the amount of change) in alloys which have a low yield stress and deform plastically, such as a binary alloy of manganese containing 20 percent copper and a binary alloy of uranium containing percent molybdenum as hereinafter described.
  • the restraint need not always be applied by external mechanical means such as a jig.
  • an oxide skin, a metal coating or the like can provide the necessary restraint.
  • alloys which possess the above properties and are heat-recoverable. These alloys are uranium-molybdenum binary alloys containing 2 to 7% (preferably 3 to 6.5%, e.g. about 4%) by weight molybdenum, uranium-niobium binary alloys containing 3 to 11% (preferably 4 to e.g. about 6%) by weight niobium, uranium-rhenium binary alloys containing 2 to 7% (preferably about 4%) by weight rhenium and manganese-copper binary alloys containing 5 to 50% (preferably, for most uses 5 to by weight copper.
  • a binary alloy an alloy consisting essentially of the two metals specified with or without impurities and/or incidental constituents which do not effect the crystal structure or metallurgical properties so as to prevent the heat-recovery effect from existing.
  • uranium and manganese binary alloys can be readily fabricated from cast ingots without difficulty, e.g. by rolling, forging or extrusion as desired,
  • Uranium binary alloys were treated in the form of strip, 1 mm thick, where the application required that the material bend or flex on recovery, and in the form of rod or tube where the application required that the material change shape longitudinally (rod) or laterally (tube).
  • the material was heated in a protective atmosphere or in a vacuum at a temperature within the y phase field (e.g. 800 C) for a short time depending on its thickness. It was then cooled rapidly e.g. in water or oil or a jet of cold gas or by radiation if the section was small, so as to prevent precipitation of the a phase or eutectoid.
  • the material was cooled to a temperature below the Ms transformation temperature, at which the transformation to banded martensite occurs. At this temperature, the material was deformed from its original shape e.g. by bending strip, or stretching or compressing the rod or expanding the tube or by deforming it as desired. On reheating above a critical temperature, the original shape was at least partly restored.
  • uranium-molybdenum binary alloys at least 2%Mo by weight was needed. However, in an alloy with as little as 2%Mo, the amount of strain which could be applied at ambient temperature was very small and the temperature to which the alloy must be reheated to reverse the shape change was approximately 500 C at which rapid precipitation of a phase occurs. An alloy containing 3%Mo could be deformed at ambient temperature and started to recover its original shape at 350 C and completed the recovery at 450 500 C. However, exposure to 500 C for more than l0-30 minutes cumulatively caused a phase and eutectoid to form after which the heat-recoverable property was lost.
  • Alloys with more than 3% and less than 5%Mo are most useful in practice.
  • An alloy containing 4%Mo could be deformed at ambient temperature and started to recover its shape on heating to 200 C.
  • a straight 1mm thick strip of this alloy was bent through an angle of 100 at ambient temperature.
  • the strip partially straightened to 30 and on cooling to ambient temperature, the movement was reversed to In this example, it was noticed that restraint was applied by a thick oxide skin formed by heating at 800 C in inadequate vacuum.
  • An alloy containing 4.5%Mo was also examined.
  • a strip was bent at ambient temperature and started to straighten at C. On heating to 250 C, almost complete recovery of the original shape was obtained and little reversal took place on cooling to RT. For example, a straight strip bent through,l20 at ambient temperature recovered to 30 after 3 minutes at 100 C. On cooling ambient temperature, reversal to 45 occurred. If the recovery temperature was raised to 250 C, more complete recovery was obtained and the amount of reversal was less e.g. a straight strip bent through 90 at ambient temperature recovered to 5 at 250 C and reversed to 10 on cooling to ambient temperature.
  • An alloy with 5%Mo started to recover'on heating to 50 C and almost complete recovery occurred at 250 C e.g. a straight strip was bent to a specific angle at room temperature (R.T.) and then heated to a temperature T and then cooled to room temperature and the following table shows the amount of recovery.
  • Uranium-niobium binary alloys behaved in a similar way to U-Mo alloys. 3% Nb was needed to obtain the same effect as 2%Mo but such an alloy was of little practical use as the amount of recoverable deformation was small and the temperature of recovery so high that a and eutectoid formation occurred and no further recovery was possible. With 4%Nb, recovery was possible at 350 C and with 5% Nb, recovery occurred at 250 300 C, after deformation at ambient temperature. 7%Nb alloy recovered at about 100 C and is comparable to a 5%Mo alloy. Alloys with 8 to 10%Nb could be deformed at --80 to l96 C and recover on heating to ambient temperature.
  • 25%Cu alloy was deformed at room temperature and heated to higher temperatures but no recovery occurred. This was as expected because at room temperature the 25%Cu alloy deforms by plastic deformation and not by shear transformation. It was necessary to cool this alloy and deform at l96 C. On deforming at l96 C and heating this alloy, it behaved like the 17.5%Cu alloy except that most deformation was recovered between 196 C and room temperature and less between room temperature and l00 C. Cooling down again caused reversal of the change of shape, and changes of shape continued with repeated heatingand cooling.
  • the- 25% Cu alloy changed in shape over a considerable range of temperature and not sharply over a narrow range.
  • the strip was bent through an angle of 25 at room temperature. On cooling to l96 C the angle changed spontaneously to an angle of 45. On heating again to room temperature the angle changed to 30. On heating and cooling between room temperature and l96 C, the angle of the strip changed from 30 to 45 reversibly.
  • the strip was bent to U-shape at room temperature. It was cooled to 1 96 C when its shape changed spontaneously, the legs of the U moving towards each other and crossing. Heating to room temperature nearly restored the U-shape so that a C-shape was formed. Continued heating to 100 C caused the strip to become flat again. Subsequent cooling to room temperature caused the strip to assume a right angle shape and further cooling to 1 96 C caused it to became C-shaped again. Reheating to room temperature resulted in an angle of 85 between the legs of the strip and further heating to 100 C caused the strip to flatten. Cooling to room temperature resulted in a right angle shape and further cooling to 1 96 C resulted in a C-shape.
  • Articles made by the methods and from the heatrecoverable alloys described herein are useful for many purposes where a change of shape is necessary.
  • they may be used as tubes in couplings, which tubes change shape to grip two elements to be connected together, as temperature-responsive elements in switching devices, and as formers or dies on which a plastics or metal sheet is shaped whereafter the former or die is caused to shrink away, allowing the removal of the shaped sheet and the former or die is then caused to revert to its original shape for the next operation.
  • the accompanying drawing at (5) shows a temperature-responsive switch having three contacts 10, 11 and 12.
  • a bent strip 13 made by a method and of an alloy as hereinbefore described makes an electrical connection between the contacts and 11 at one temperature and between the contacts 10 and 12 at a different temperature.
  • a method of making a heat-recoverable article from a heat-recoverable alloy which article is repeatedly changeable in shape from a first shape towards a second shape by lowering its temperature and from the second shape towards the first shape by raising its temperature, said changes in shape corresponding to changes in phase in the alloy from a high-temperature phase to a low-temperature phase and from the lowtemperature phase to the high-temperature phase respectively, which method comprises the steps of deforming the alloy in its low-temperature phase so as to change its shape from the first shape to the second shape, applying restraint to the alloy in the second shape so formed, raising the temperature so that the alloy changes into its high-temperature phase while said restraint prevents a change in shape, and subsequently repeatedly altering the temperature to cause said changes in shape without applying any further deformation to the alloy.
  • a method according to claim 1 in which the alloy is selected from the group consisting of binary alloys of uranium containing 2 to 7% by weight molybdenum, 3 to l 1% by weight niobium and2 to 7% by weight rhenium.
  • a method of making a heat-recoverable article from a heat-recoverable binary alloy selected from the group consisting of uranium-molybdenum containing 2 to 7% by weight molybdenum, uranium-rhenium containing 2 to 7% by weight rhenium, manganese-copper containing 5 to 50% by weight copper and nickeltitanium containing 52 to 56% by weight nickel which method includes the steps of deforming the alloy in its high-temperature phase partly towards the shape required for the low-temperature phase, thereby applying to the alloy in its high-temperature phase a strain which produces a stress which induces a desired shape for its low-temperature phase, and subsequently lowering the temperature so that the alloy changes into its lowtemperature phase and assumes the required shape.
  • a method of making a heat-recoverable article from a heat-recoverable binary alloy selected from the group consisting of uranium-molybdenum containing 2 to 7% by weight molybdenum, uranium-rhenium containing 2 to 7% by weight rhenium and manganesecopper containing 5 to 50% by weight copper 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 temperature being such that if reheated to an appropriate temperature the alloy would at least partly regain its first shape.
  • the alloy is a binary alloy of uranium containing 3 to 6.5% by weight molybdenum.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Heat Treatment Of Articles (AREA)
  • Bending Of Plates, Rods, And Pipes (AREA)
  • Heat Treatment Of Nonferrous Metals Or Alloys (AREA)
  • Automotive Seat Belt Assembly (AREA)
  • Laminated Bodies (AREA)
US00033299A 1969-05-01 1970-04-30 Alloys Expired - Lifetime US3802930A (en)

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GB2237269 1969-05-01

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US (1) US3802930A (de)
JP (1) JPS4815130B1 (de)
AT (1) AT315524B (de)
BE (1) BE749851A (de)
CA (1) CA929084A (de)
CH (2) CH555892A (de)
DE (1) DE2021348C3 (de)
FR (1) FR2044754A1 (de)
GB (1) GB1315652A (de)
IL (1) IL34411A (de)
NL (1) NL172971C (de)
SE (1) SE389688B (de)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2516749A1 (de) * 1974-05-04 1975-11-20 Univ Osaka Metallkoerper mit reversiblem gestaltwechselvermoegen und verfahren zu deren herstellung
US4002954A (en) * 1975-12-11 1977-01-11 The United States Of America As Represented By The Secretary Of The Army Trigger circuit
US4010455A (en) * 1975-07-17 1977-03-01 The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration Cyclical bi-directional rotary actuator
US4036669A (en) * 1975-02-18 1977-07-19 Raychem Corporation Mechanical preconditioning method
US4067752A (en) * 1973-11-19 1978-01-10 Raychem Corporation Austenitic aging of metallic compositions
US4448824A (en) * 1982-01-28 1984-05-15 Raychem Corporation Wraparound protective closure
US4493737A (en) * 1980-05-21 1985-01-15 The United States Of America As Represented By The United States Department Of Energy Method for fabricating uranium alloy articles without shape memory effects
DK156254B (da) * 1975-02-18 1989-07-17 Raychem Corp Fremgangsmaade til fremstilling af en varme-restituerbar genstand af et metalmateriale, der kan undergaa reversibel omdannelse mellem en austenitisk og en martensitisk tilstand
US5019456A (en) * 1987-08-25 1991-05-28 Raychem Corporation Article which can change its shape
US5133721A (en) * 1991-03-19 1992-07-28 The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration Device for removing foreign objects from anatomic organs
US20100107628A1 (en) * 2008-10-31 2010-05-06 Fort Wayne Metals Research Products Corporation Method for imparting improved fatigue strength to wire made of shape memory alloys, and medical devices made from such wire
CN104195484A (zh) * 2014-08-20 2014-12-10 西安钢研功能材料有限责任公司 一种Mn72Ni10Cu18合金带材的制备方法

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4758285A (en) * 1986-10-14 1988-07-19 Cvi/Beta Ventures, Inc. Shape-memory alloy resetting method
WO1988002787A1 (en) * 1986-10-14 1988-04-21 Cvi/Beta Ventures, Inc. Shape-memory alloy resetting method and apparatus
US6068623A (en) 1997-03-06 2000-05-30 Percusurge, Inc. Hollow medical wires and methods of constructing same

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4067752A (en) * 1973-11-19 1978-01-10 Raychem Corporation Austenitic aging of metallic compositions
DE2516749A1 (de) * 1974-05-04 1975-11-20 Univ Osaka Metallkoerper mit reversiblem gestaltwechselvermoegen und verfahren zu deren herstellung
US4036669A (en) * 1975-02-18 1977-07-19 Raychem Corporation Mechanical preconditioning method
DK156254B (da) * 1975-02-18 1989-07-17 Raychem Corp Fremgangsmaade til fremstilling af en varme-restituerbar genstand af et metalmateriale, der kan undergaa reversibel omdannelse mellem en austenitisk og en martensitisk tilstand
US4010455A (en) * 1975-07-17 1977-03-01 The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration Cyclical bi-directional rotary actuator
US4002954A (en) * 1975-12-11 1977-01-11 The United States Of America As Represented By The Secretary Of The Army Trigger circuit
US4493737A (en) * 1980-05-21 1985-01-15 The United States Of America As Represented By The United States Department Of Energy Method for fabricating uranium alloy articles without shape memory effects
US4448824A (en) * 1982-01-28 1984-05-15 Raychem Corporation Wraparound protective closure
US5019456A (en) * 1987-08-25 1991-05-28 Raychem Corporation Article which can change its shape
US5133721A (en) * 1991-03-19 1992-07-28 The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration Device for removing foreign objects from anatomic organs
US20100107628A1 (en) * 2008-10-31 2010-05-06 Fort Wayne Metals Research Products Corporation Method for imparting improved fatigue strength to wire made of shape memory alloys, and medical devices made from such wire
US8414714B2 (en) 2008-10-31 2013-04-09 Fort Wayne Metals Research Products Corporation Method for imparting improved fatigue strength to wire made of shape memory alloys, and medical devices made from such wire
US9272323B2 (en) 2008-10-31 2016-03-01 W. L. Gore & Associates, Inc. Method for imparting improved fatigue strength to wire made of shape memory alloys, and medical devices made from such wire
US10041151B2 (en) 2008-10-31 2018-08-07 W. L. Gore & Associates, Inc. Method for imparting improved fatigue strength to wire made of shape memory alloys, and medical devices made from such wire
US11001910B2 (en) 2008-10-31 2021-05-11 W. L. Gore & Associates, Inc. Fatigue strength of shape memory alloy tubing and medical devices made therefrom
CN104195484A (zh) * 2014-08-20 2014-12-10 西安钢研功能材料有限责任公司 一种Mn72Ni10Cu18合金带材的制备方法

Also Published As

Publication number Publication date
AT315524B (de) 1974-05-27
NL7006402A (de) 1970-11-03
FR2044754A1 (de) 1971-02-26
IL34411A0 (en) 1970-06-17
BE749851A (fr) 1970-10-30
CH567103A5 (de) 1975-09-30
GB1315652A (en) 1973-05-02
SE389688B (sv) 1976-11-15
CH555892A (de) 1974-11-15
DE2021348C3 (de) 1980-06-04
IL34411A (en) 1976-03-31
NL172971C (nl) 1983-11-16
DE2021348B2 (de) 1979-09-20
JPS4815130B1 (de) 1973-05-12
CA929084A (en) 1973-06-26
DE2021348A1 (de) 1971-01-14

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