Bbc Brown, Boveri & Company, Limited

Joachim Albrecht

Thomas Duerig

Walter Weber

Olivier Mercier

Dag Richter

Gunther Schroeder

A composite material in rod, tube, strip, sheet or plate shape with reversible thermomechanical properties is produced by joining of at least two parts consisting of a total of at least one shape memory alloy having a two-way effect, whereby each part has a memory effect by itself. In the case of at least two shape memory alloys (1, 2) with different transition temperatures but the same mode of movement, the joining of the individual parts can take place prior to the deformation in the low temperature range necessary to inducing the two-way effect. In the case of differing types and degrees of movement of the individual parts (25, 26), their joining can first be accomplished only after the individual deformations of each part for itself in the low temperature range are accomplished regardless of how many shape memory alloys with different transition temperatures are used in the structure of the composite material.

Composite material in rod, tube, strip, sheet or plate shape with

An article in rod, tube, strip, sheet or plate shape with reversible thermomechanical properties is produced by joining of at least two parts consisting of a total of at least one shape memory alloy having a two-way effect, whereby each part has a memory effect by itself. In the case of at least two shape memory alloys (1, 2) with different transition temperatures but the same mode of movement, the joining of the individual parts can take place prior to the deformation in the low temperature range necessary to inducing the two-way effect. In the case of differing types and degrees of movement of the individual parts (25, 26), their joining can first be accomplished only after the individual deformations of each part for itself in the low temperature range are accomplished regardless of how many shape memory alloys with different transition temperatures are used in the structure of the article.

Material, in the form of bars, tubes, profiles, wires, sheets, or bands, which is, at least partially, composed of a constituent showing a one-way shape memory effect, and a further inactive constituent hindering the one-way effect of the first, and which collectively exhibits a significant two-way effect. The one-way shape memory constituent can be a Cu-Al-Ni, Cu-Al, TiV, Ti-Nb, Ni-Ti, or Ni-Ti-Cu alloy. Production of bi- or multi-constituent components by brazing, welding, roll bonding, extruding, powder metallurgical methods, hot isostatic pressing, or gluing, or by the application of metallic coatings (2) onto a core material (1) and subsequent diffusion treatment to produce an inactive surface layer (3).

Material which is at least partially made from a constituent having a

Process to produce a reversible two-way shape memory effect in Cu-Al-Ni and Cu-Al memory alloys by heat treating said alloy while applying an external lead (G) after the martensite formation accomplished by the conventional steps: solution treatment, quench (1,2) and deformation (3). Additional improvements by optional Martensite Stabilization (10) and Two-way Effect Zero-point Stabilization (12) in the form of further heat treatments.

Process to produce and stabilize a reversible two-way shape memory

A process for manufacturing a component from a mechanically unstable .beta.-titanium alloy which exhibits 3 shape-related memory effects which all differ from one another: a one-way effect, a two-way effect (resembling a bi-metal), this effect being virtually hysteresis-free but occurring continuously over a wide phase-transformation temperature range, and an irreversible effect, which is isothermal. Utilization of the effects in thermal triggering elements (electrical switches) as well as in fixed or detachable connecting elements for components.

Process for manufacturing a component from a titanium alloy, as well as

A noticeable two-way effect can be induced in a component consisting of a shape memory alloy exhibiting only a one-way effect by inhomogeneous deformation of the cross-section so that one part of the component cross-section is deformed sufficiently to hinder the free movement of the one-way effect in the lesser deformed part. Component in the form of a tension/compression (6/8), bending (3), or torsion rod.

Process to produce a reversible two-way shape memory effect in a

A notable two-way effect can be induced in components made of a memory alloy exhibiting only a one-way effect by applying an external force which gives rise to an internal stress opposing the one-way effect. Component made of a memory alloy in the form of a tension, compression bending, or torsion rod (helical spring 2). External force by weight or spring (counter-spring 3).

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Mulligen, Switzerland

Joachim Albrecht