WO2007066555A1

WO2007066555A1 - Co BASED ALLOY AND PROCESS FOR PRODUCING THE SAME

Info

Publication number: WO2007066555A1
Application number: PCT/JP2006/323877
Authority: WO
Inventors: Kiyohito Ishida; Ryosuke Kainuma; Katsunari Oikawa; Yuji Sutou; Toshihiro Omori; Keisuke Ando
Original assignee: Japan Science And Technology Agency
Priority date: 2005-12-05
Filing date: 2006-11-22
Publication date: 2007-06-14
Also published as: EP1959024A4; JPWO2007066555A1; US20080289730A1; EP1959024A1

Abstract

A Co based alloy comprising at least one member selected from among 0.01 to 10% Fe, 0.01 to 30% Ni and 0.01 to 25% Mn, which Co based alloy has a metal structure wherein ϵ-phase of h.c.p. structure having been generated by heat-induced or stress-induced transformation is formed in a ratio of 10 vol.% or more. According to necessity, there may be added at least one member selected from among 0.01 to 10% Al, 0.01 to 35% Cr, 0.01 to 20% V, 0.01 to 15% Ti, 0.01 to 30% Mo, 0.01 to 10% Nb, 0.01 to 3% Zr, 0.01 to 30% W, 0.01 to 10% Ta, 0.01 to 5% Hf, 0.01 to 8% Si, 0.001 to 3% C, 0.001 to 3% B, 0.001 to 3% P and 0.001 to 3% misch metal. The Co based alloy exhibits high elastic deformation capability and is good in ductility and workability. The Co based alloy is used as a functional material of, for example, sensor or actuator capable of displacement control by magnetic field application.

Description

明細書 Specification

Co基合金及びその製造方法技術分野 . Co-based alloy and its manufacturing method Technical field.

本発明は、弾性変形能が高く、磁場印加で変位制御できる強磁性 Co基合金及びその製造方法 (こ関する。背景技術 The present invention relates to a ferromagnetic Co-based alloy that has high elastic deformability and whose displacement can be controlled by applying a magnetic field, and a method for producing the same.

低ヤング率で高弾性変形能を示す材料としてチタン合金が注目されており、人ェ歯根，人工骨，眼鏠フレーム等に使用されている。たとえば、文献 1, 2では、 4A族や 5A族元素を含むチタン合金が低ヤング率で高弹性変形能材料になることを紹介している。 Titanium alloys are attracting attention as materials that exhibit low Young's modulus and high elastic deformability, and are used in artificial tooth roots, artificial bones, eyelid frames, etc. For example, References 1 and 2 introduce that titanium alloys containing group 4A and 5A elements can be made into materials with low Young's modulus and high stiffness deformability.

材料の変形をもたらす外部因子には、文献 1, 2で説明されている外部応力の外に温度，磁場等がある。 ' External factors that cause material deformation include temperature, magnetic field, etc., in addition to the external stress explained in References 1 and 2. '

温度による変位制御には形状記憶合金が知られており、数％レベルの寸法変化が得られている。形状記憶効果は、変形した材料を所定温度以上に加熱したときに生じるマルテンサイト逆変態を利用して元の形状が回復する現象である。形状記憶効果を用いると熱駆動型のァクチユエ一夕として利用できるが、温度制御が必要なことに加え、冷却時の形状変化が熱拡散で律速されるため応答性が悪い。強磁性の形状記憶合金もァクチユエ一夕材料として注目されている。強磁性の形状記憶合金では、従来の磁歪材料を超える数％の寸法変化が外部磁場の印加で得られ、熱駆動型形状記憶合金の欠点である低応答性も解消されている。強磁性型形状記憶合金としては、たとえば Ni-Mn-Ga 系があり、磁場印加で形状変化を引き起こすァクチユエ一夕材料が文献 3 に紹介されている。 Co-Ni-Al系も文献 4, 5に、 Co系合金も文献 6に紹介されている。 Shape memory alloys are known for temperature-dependent displacement control, and dimensional changes on the order of a few percent have been achieved. The shape memory effect is a phenomenon in which the original shape is restored by utilizing the reverse martensitic transformation that occurs when a deformed material is heated above a predetermined temperature. Using the shape memory effect, it can be used as a thermally driven actuator, but in addition to the need for temperature control, the response rate is poor because the shape change during cooling is rate-limited by thermal diffusion. Ferromagnetic shape memory alloys are also attracting attention as potential materials. With ferromagnetic shape memory alloys, dimensional changes of a few percent greater than conventional magnetostrictive materials can be achieved by applying an external magnetic field, and the low responsiveness, which is a drawback of thermally driven shape memory alloys, has been overcome. Examples of ferromagnetic shape memory alloys include the Ni-Mn-Ga system, and Ref. 3 introduces a material that changes shape when a magnetic field is applied. Co-Ni-Al alloys are also introduced in References 4 and 5, and Co-based alloys are also introduced in Reference 6.

しかし、 Ni-Mn-Ga系の材料は延性に劣り、機械部品に要求される複雑で精密な形状を付与し難い。 Co-Ni-Al 系合金は、ァ相を第二相として利用して延性を改善しているが、磁化の強さが小さい。また、 Co 系合金は、延性，磁化の強さは比較的優れ、熱駆動型の形状記億効果が得られるものの、磁歪特性が不十分で超弾性特性も得られない。 However, Ni-Mn-Ga materials have poor ductility and are difficult to form into the complex and precise shapes required for mechanical parts. Co-Ni-Al alloys use the a phase as a second phase to improve ductility, but the strength of magnetization is low. Furthermore, although Co-based alloys have relatively good ductility and magnetization strength, and can provide thermally driven shape memory effects, their magnetostrictive properties are insufficient. Superelastic properties cannot be obtained either.

献 1：特開 2002- 332531号公報 Reference 1: Japanese Patent Application Publication No. 2002-332531

文献 2：特開 2002-249836号公報 Document 2: Japanese Patent Application Publication No. 2002-249836

文献 3：米国特許 5,958, 154号明細書 Document 3: US Patent No. 5,958, 154

文献 4：特開 2002-129273号公報 Document 4: Japanese Patent Application Publication No. 2002-129273

文献 5：特開 2004-277865号公報 Document 5: Japanese Patent Application Publication No. 2004-277865

' 文献 6 ：特開 2004-238720号公報発明の開示 ' Document 6: Japanese Patent Application Publication No. 2004-238720 Disclosure of the invention

本発明者等は、従来のチタン合金や Ni-Mn-Ga系合金の欠点に鑑み、高弾性変形能を維持しながら強磁性で磁場駆動でき、延性も良好な材料も種々調査'検討した。その結果、 Co をベースとし、合金成分，組成の適切な選択及び h.c.p. 構造を有する ε相の適量生成により、高弾性変形能を有する Co基合金が得られることを見出した。 In view of the shortcomings of conventional titanium alloys and Ni-Mn-Ga alloys, the present inventors have investigated various materials that can be driven in a magnetic field with ferromagnetism and have good ductility while maintaining high elastic deformability. . As a result, we found that a Co-based alloy with high elastic deformability can be obtained by appropriately selecting the alloy components and composition, and by producing an appropriate amount of ε phase with an h.c.p. structure.

本発明は、かかる知見をベースとし、 Fe，. Ni, Mn の一種又は二種以上を添加した成分系において ε相の生成量を制御することにより、高弹性変形能を有し延性，加工性も良好な Co 合金を提供することを目的とする。 The present invention is based on this knowledge, and by controlling the amount of ε phase produced in a component system containing one or more of Fe, Ni, and Mn, the material has high deformability, ductility, and processing properties. The purpose is to provide a Co alloy with good properties.

本発明の Co基会金は、質量比で Fe： 0.01〜： 10%, Ni： 0.01〜30%, Mn： 0.01~25%の一種又は二種以上を含んでいる。 Fe, Ni, Mnの二種又は三種を添加する場合、好ましくは合計含有量を 0.02〜50%の範囲に設定する。以下、質量比を単に％と表記する。 The Co-based metal of the present invention contains one or more of Fe: 0.01 to 10%, Ni: 0.01 to 30%, and Mn: 0.01 to 25% in mass ratio. When adding two or three of Fe, Ni, and Mn, the total content is preferably set in the range of 0.02 to 50%. Hereinafter, the mass ratio will simply be expressed as %.

更に、 Fe, Ni, Mn以外に、 Al： 0·01〜10%, Cr： 0.01~ 35%, V： 0.01〜 20%, Ti： 0.01 ~ 15% , Mo： 0.01 ~ 30%, Nb： 0.01 ~ 10%, Zr： 0.01 ~ 3% , W： 0.01 ~30%, Ta： 0.01〜： 10%， Hf： 0·01〜5%, Si： 0.01〜8%, C： 0·001〜 3%, B : 0.001〜3%, P： 0.001 ~ 3%, ミッシュメタル： 0.001〜3%から選ばれた一種又は二種以上を合計含有量： 0.001~50%の範囲で含むこともできる。提案した Co基合金は少なくとも常温で強磁性であり、熱誘起又は応力誘起で生成した h.c.p.構造の ε相が分布している。 ε相の割合は 10体積％以上とされ、成分調整，製造条件等で制御できる。 h.c.p.構造の ε相が分布した金属組織は、所定組成の Co基合金を 900〜1400°C で溶体化処理することにより形成される。溶体化処理後、加工率： 10%以上で加ェしても良く、更に 300〜800°Cで時効処理しても良い。図面の簡単な説明 Furthermore, in addition to Fe, Ni, and Mn, Al: 0·01 to 10%, Cr: 0.01 to 35%, V: 0.01 to 20%, Ti: 0.01 to 15%, Mo: 0.01 to 30%, Nb: 0.01 ~ 10%, Zr: 0.01 ~ 3%, W: 0.01 ~ 30%, Ta: 0.01 ~: 10%, Hf: 0 01 ~ 5%, Si: 0.01 ~ 8%, C: 0 001 ~ 3% , B: 0.001 to 3%, P: 0.001 to 3%, misch metal: 0.001 to 3%, and one or more selected from 0.001 to 3% may be included in the total content: 0.001 to 50%. The proposed Co-based alloy is ferromagnetic at least at room temperature, and contains a thermally or stress-induced hcp-structured ε phase. The proportion of the ε phase is set to 10% by volume or more, and can be controlled by adjusting the components, manufacturing conditions, etc. A metal structure in which the ε phase of the hcp structure is distributed is formed by solution-treating a Co-based alloy with a predetermined composition at 900 to 1400°C. After solution treatment, processing may be performed at a processing rate of 10% or more, and further aging treatment may be performed at 300 to 800°C. Brief description of the drawing

図 1は、 Co-Fe二元合金の金属組織に占める ε相の体積分率，回復歪量，磁化 'の強さに及ぼす Fe含有量の影響を表したグラフ Figure 1 is a graph showing the influence of Fe content on the volume fraction of the ε phase in the metallographic structure of a Co-Fe binary alloy, the amount of recovery strain, and the strength of magnetization.

図 2は、 Co-Ni二元合金の金属組織に占める ε相の.体積分率，回復歪量，磁化の強さに及ぼす Ni含有量の影響を表したグラフ Figure 2 is a graph showing the influence of Ni content on the volume fraction of the ε phase in the metallographic structure of a Co-Ni binary alloy, the amount of recovery strain, and the strength of magnetization.

図 3は、 CO-MD二元合金の金属組織に占める ε相の体積分率，回復歪量，磁化の強さに及ぼす Μη含有量の影響を表したグラフ Figure 3 is a graph showing the influence of the Μη content on the volume fraction of the ε phase in the metallographic structure of the CO-MD binary alloy, the amount of recovery strain, and the strength of magnetization.

図 4は、 h.c.p.構造の ε相が生成した金属組織をもつ Co-3.80%Fe合金の顕微鏡写真 Figure 4 is a microscopic photograph of a Co-3.80%Fe alloy with a metal structure in which an ε phase with an h.c.p. structure is formed.

図 5は、同 Co-3.80%Fe合金の応力-歪線図 Figure 5 is the stress-strain diagram of the same Co-3.80%Fe alloy.

図 6は、 o-Fe二元合金の金属^ a織に占る ε相の体積分率，回復歪量，磁化の強さに及ぼす溶体化処理条件の影響を表したグラフ Figure 6 is a graph showing the influence of solution treatment conditions on the volume fraction of the ε phase in the metal^a weave of the o-Fe binary alloy, the amount of recovery strain, and the strength of magnetization.

図.7は、 Co-Fe二元合金の金属組織に占める ε相の体積分率，回復歪量，磁化の強さに及ぼす冷間'加工率の影響を表したグラフ Figure 7 is a graph showing the influence of the cold working rate on the volume fraction of the ε phase in the metallographic structure of a Co-Fe binary alloy, the amount of recovery strain, and the strength of magnetization.

図 8は、 Co-Fe二元合金の金属組織に占める ε相の体積分率，回復歪量，磁化の強さに及ぼす時効処理条件の影饗を表したグラフ Figure 8 is a graph showing the effects of aging treatment conditions on the volume fraction of the ε phase in the metallographic structure of a Co-Fe binary alloy, the amount of recovery strain, and the strength of magnetization.

図 9は、 Co-Ni二元合金の金属組織に占める ε相の体積分率，回復歪量，磁化の強さに及ぼす溶体化処理条の影響を表したグラフ Figure 9 is a graph showing the effects of solution treatment on the volume fraction of the ε phase in the metallographic structure of a Co-Ni binary alloy, the amount of recovery strain, and the strength of magnetization.

図 10 は、 Co-Ni二元合金の金属組織に占める ε相の体積分率，回復歪量，磁化の強さに及ぼす冷間加工率の影響を表したグラフ Figure 10 is a graph showing the influence of the cold working rate on the volume fraction of the ε phase in the metallographic structure of a Co-Ni binary alloy, the amount of recovery strain, and the strength of magnetization.

図 11 は、 Co-Ni二元合金の金属組織に占める ε相の体積分率，回復歪量，磁化の強さに及ぼす時効処理条件の影響を表したグラフ Figure 11 is a graph showing the effects of aging treatment conditions on the volume fraction of the ε phase in the metallographic structure of a Co-Ni binary alloy, the amount of recovery strain, and the strength of magnetization.

図 12 は、 Co-Mn二元合金の金属組織に占める ε相の体積分率，回復歪量，磁化の強さに及ぼす溶体化処理条件の影響を表したグラフ Figure 12 is a graph showing the influence of solution treatment conditions on the volume fraction of the ε phase in the metallographic structure of a Co-Mn binary alloy, the amount of recovery strain, and the strength of magnetization.

図 13 は、 Co-Mn二元合金の金属組織に占める ε相の体積分率，回復歪量，磁化の強さに及ぼす冷間加工率の影響を表したグラフ Figure 13 shows the relationship between the volume fraction of the ε phase in the metallographic structure of the Co-Mn binary alloy, the amount of recovery strain, and the magnetic Graph showing the influence of cold working rate on the strength of hardening

図 14は、 Co-Mn二元合金の金属組織に占める ε相の体積分率，回復歪量, 磁化の強さに及ぼす時効処理条件の影響を表したグラフ Figure 14 is a graph showing the effects of aging treatment conditions on the volume fraction of the ε phase in the metallographic structure of a Co-Mn binary alloy, the amount of recovery strain, and the strength of magnetization.

図 15は、 Co-3.80%Fe合金の試験温度に応じた応力-歪線図発明を実施するための最良の形態 Figure 15 is a stress-strain diagram of Co-3.80%Fe alloy according to test temperature.

' 本発明者等は、弾性変形能が高く、磁場勾配の印加 ·除去により変位制御でき加工可能な材料を開発するため、強磁性元素である Coに種々の合金元素を添加し、組織と弾性変形能，磁気特性との関係を調査'検討した。その結果、適量の Fe, Ni, Mnの少なくとも一種又は二種以上を Coと合金化させると、加工性が改善された強磁性高弾性変形合金となることを解明した。 'The present inventors added various alloying elements to Co, a ferromagnetic element, in order to develop a material that has high elastic deformability, whose displacement can be controlled by applying and removing a magnetic field gradient, and which can be processed. The relationship between deformability and magnetic properties was investigated. As a result, we found that alloying an appropriate amount of at least one or more of Fe, Ni, and Mn with Co creates a ferromagnetic and highly elastic deformable alloy with improved workability.

強磁性材料は、

関係式に従い磁場勾配に応じた力を受けて変位することが知られている。この関係式は、所定の磁場勾配 dH/dxで得られる力 Fが磁化の強さ Mに比例することを意味する。材料に与える力 Fが大きいほど得られる歪量が大きくなるため、歪量の増大には磁化の強さ Mが大きい方がよく、変形に要する応力が高いと磁場による歪 *が小さくなるためヤング率は低いことが望ましい。しかし、弾性変形能が小さいと磁場勾配の除去により歪が残留する。そのため、磁場勾配の印加'除去により大きな可逆歪を得るには、大きな弾性変形能が必要となる。 Ferromagnetic materials are

It is known that displacement occurs in response to a force corresponding to the magnetic field gradient according to the relational formula. This relational expression means that the force F obtained at a given magnetic field gradient dH/dx is proportional to the magnetization strength M. The larger the force F applied to the material, the greater the amount of strain obtained, so it is better to increase the magnetization strength M to increase the amount of strain, and the higher the stress required for deformation, the smaller the strain * due to the magnetic field. A low Young's modulus is desirable. However, if the elastic deformability is small, distortion will remain due to the removal of the magnetic field gradient. Therefore, in order to obtain a large reversible strain by applying or removing a magnetic field gradient, a large elastic deformability is required.

Co は高いキュリー温度を有する強磁性元素であるが、純 Co は加工性に乏しく、磁化率も低い。 Coは高温で fc.c.構造の γ相であり、冷却中に 420°C付近で h.c.p.構造の ε相にマルテンサイト変態する。 Coに種々の合金元素を添加して γ相と ε相の相安定性を調査した結果、 γ相を安定化し、加工性を向上させる種々の元素を特定できた。 Co is a ferromagnetic element with a high Curie temperature, but pure Co has poor workability and low magnetic susceptibility. Co has a γ phase with an fc.c. structure at high temperatures, and transforms into a martensitic ε phase with an h.c.p. structure at around 420°C during cooling. As a result of investigating the phase stability of the γ and ε phases by adding various alloying elements to Co, we were able to identify various elements that stabilize the γ phase and improve workability.

γ相は不規則構造の f.c.c.のため加工性が良好であるが、 ε相は弾性変形量を大きくする効果を有する相であるものの加工硬化しやすく、加工割れ等の欠陥を発生させやすい。そこで、 γ相に固溶して安定化させる元素を添加すると常温でも γ 相が残留し Co基合金の加工性向上を期待できる。なかでも、磁気モーメントをもつ Fe, Ni, Mnは、加工性向上の外に、 Co基合金の磁気特性改善にも有効である。 The γ phase has an irregular structure of fcc and has good workability, but the ε phase has the effect of increasing the amount of elastic deformation, but is easily work hardened and prone to defects such as work cracks. . Therefore, if an element is added to stabilize the γ phase by solid solution, the γ phase will remain even at room temperature, which can be expected to improve the workability of Co-based alloys. Among them, Fe, Ni, and Mn, which have magnetic moments, are effective not only in improving processability but also in improving the magnetic properties of Co-based alloys. be.

成分整，製造条件等で ε相の体積分率を 10体積。/。以上に調整すると、高弾性変形の効果が顕著になる。ただし、 ε相の過剰^^布は残留 γ相の加工性向上効果を相殺するので、 ε相の上限を好ましくは 99体積％とする。基本的には h.c.p.構造の ε相と残りが f.c.c.構造の γ相の複相組織を有する Co基合金であるが、高弾性特性，磁気特性，加工性等に悪影響を及ぼさない限り異相の存在を許容する。 '異相には、第三成分の添加で生じる金属間化合物，炭化物， α相 (b.c.c.構造)等がある。 The volume fraction of the ε phase was set to 10 volumes depending on the composition and manufacturing conditions. /. When adjusted above, the effect of high elastic deformation becomes noticeable. However, since an excess of ε phase cancels out the workability improvement effect of the residual γ phase, the upper limit of ε phase is preferably set at 99% by volume. Basically, it is a Co-based alloy with a dual-phase structure consisting of an ε phase with an h.c.p. structure and the rest with a γ phase with an f.c.c. structure, but different phases may be used as long as it does not adversely affect the high elastic properties, magnetic properties, workability, etc. Allow existence. 'Heterogeneous phases include intermetallic compounds, carbides, α-phase (b.c.c. structure), etc. that occur when a third component is added.

Fe を添加した Co合金は特に優れた磁気特性を示す。磁場印加による変位制御素子としての用途では比較的低い磁場で大きな磁化の強さを示すことが好ましいが、本発明 Co基合金の磁化曲線を測定すると、 0.2T (テスラ)の外部磁場に対し 30 emu/_g以上の磁化の強さを示し、変位制御素子として有望な材料といえる。 Co alloys with Fe added exhibit particularly excellent magnetic properties. When used as a displacement control element by applying a magnetic field, it is preferable to show a large magnetization strength in a relatively low magnetic field, but when measuring the magnetization curve of the Co-based alloy of the present invention, it was found that an external magnetic field of 0.2 T (tesla) It exhibits a magnetization strength of 30 emu/ _g or more, making it a promising material as a displacement control element.

Ni, Mnは、磁化の強さを弱める作用を呈するものの、依然として磁化の強さが高レベルに保たれるので変位制御素子としての要求特性が付与される。 Although Ni and Mn have the effect of weakening the strength of magnetization, the strength of magnetization is still maintained at a high level, giving the required characteristics as a displacement control element.

一方、組織と弾性変形挙動との関係を調鸾した結果、次のようなことが解明された。 On the other hand, as a result of investigating the relationship between the structure and elastic deformation behavior, the following findings were clarified.

焼鈍された Feや Co等の金属材料の弾性限歪は通常 0.3%程度であり、冷間加ェを施すと加工硬化してヒり変形が抑制され、硬度，引張り強さの上昇と共に降伏応力，弾性限が高くなる。他方、本発明 . Co基合金は、たとえば 1%の曲げ変形に対し通常の弾性歪量を超える 0.4%以上の歪が回復する。しかも、液体窒素温度 (_ 196°C)から 400°Cまでの広い温度範囲で適用できる。 The elastic limit strain of annealed metal materials such as Fe and Co is usually around 0.3%, and cold working hardens the material, suppresses heel deformation, and yields as the hardness and tensile strength increase. Stress and elastic limit increase. On the other hand, the Co-based alloy of the present invention recovers from a bending deformation of, for example, 1% by 0.4% or more, which exceeds the normal amount of elastic strain. Moreover, it can be applied over a wide temperature range from liquid nitrogen temperature (_196°C) to 400°C.

しかし、変形に要する応力が髙いと磁場による変位が得にくぐなるためヤング率は低い方が望ましい。ヤング率は原子間の凝集力に関わる物性値であり、加工や熱処理では制御し難いと考えられている。この点、本発明では、マルテンサイト変態時の格子軟化，マルテンサイトバリアントの方位性等を制御することにより、低ヤング率を達成している。 However, if the stress required for deformation is high, the displacement caused by the magnetic field will be difficult to overcome, so a low Young's modulus is desirable. Young's modulus is a physical property value related to the cohesive force between atoms, and is considered difficult to control through processing or heat treatment. In this regard, the present invention achieves a low Young's modulus by controlling lattice softening during martensitic transformation, orientation of martensitic variants, etc.

マルテンサイト変態では、変態に伴う前駆現象の一つとしてマルテンサイト変態温度から数 10〜100°C程度の幅をもつた温度域で弾性定数が低下する格子軟化 (lattice softening)現象がみられる。格子軟化を Co基合金に利用すると、マルテンサイト変態温度 Msの近傍でヤング率の低下が予測される。 In martensitic transformation, one of the precursor phenomena associated with the transformation is lattice softening, in which the elastic constant decreases in a temperature range of several tens to 100°C from the martensitic transformation temperature. . When lattice softening is applied to Co-based alloys, Marte A decrease in Young's modulus is predicted near the site transformation temperature Ms.

純 Coではマルテンサイ卜変態による格子軟化が 420°C近傍で生じるが、 Fe, Ni， Mnの添加で変態温度が低下する。変態温度の低下に伴い、所望の温度範囲において低いヤング率が得られる。更に、 Co-X (X : Fe， Ni, Mn)系のマルテンサイト変態は非熱弹性型であるためヒステリシスが約 150°C であり、加工によりヒステリシスが更に広がるので、広い温度幅で低ヤング率を実現するのに適 'している。 In pure Co, lattice softening due to martensitic transformation occurs around 420°C, but the addition of Fe, Ni, and Mn lowers the transformation temperature. As the transformation temperature decreases, a lower Young's modulus is obtained in the desired temperature range. Furthermore, since the martensitic transformation of the Co-X (X: Fe, Ni, Mn) system is non-thermal, the hysteresis is approximately 150°C, and the hysteresis is further expanded by processing, so it is possible to achieve low hysteresis over a wide temperature range. It is suitable for achieving Young's modulus.

Co基合金のマルテンサイト変態では、 Fe合金等と同様に十分に Ms温度以下に冷却しても試料全体がマルテンサイト相に変^するわけではなく、母相がある程度残留する 6 そのため、溶体化処理後の加工によってマルテンサイト相が応力誘起されるが、応力に対して Schmid因子の最も大きなバリアントが優先的に生成される。また、熱的に誘起されたマルテンサイト相に応力を加えると、マルテ. ンサイト相の一部が応力方向に優先的なバリアントに再配列される。これらの優先的バリアントが応力方向に対し低い変形応力を示^"ことも、 Co基合金が低ャング率を汞す原因の一つと考えられる。、 In the martensitic transformation of Co-based alloys, the entire sample does not transform into the martensitic phase even if sufficiently cooled below the Ms temperature, as with Fe alloys, etc., and a certain amount of the parent phase remains. 6 Therefore, the solution Although the martensitic phase is induced by stress during processing after oxidation treatment, the variant with the largest Schmid factor is preferentially generated in response to stress. Additionally, when stress is applied to the thermally induced martensitic phase, some of the martensitic phase rearranges into preferential variants in the stress direction. The fact that these preferential variants exhibit low deformation stress in the stress direction is also considered to be one of the reasons why Co-based alloys exhibit low Young's modulus.

Co-Ni-Al系合金 (文献 4, 5)は、 β相又は β+γ相の組織を有し、 β相のマルテンサイト変態'逆変態を形状記憶特性付与に利用しているが、 γ相が ε相に変態することはない。延性に乏しい Β2構造の β相が存在することは加工性低下の原因にもなるが、本発明の Co基合金は β相が存在しない点でも延性に優れた材料といえる。しかも、強磁性であるものの磁化の強さが小さい Co-Ni-Al系合金に比較し、本発明の Co基合金は磁化の強さが極めて大きいため、磁場勾配による変位制御を行う上で優れた性能を発揮する。 Co-Ni-Al alloys (References 4, 5) have a β phase or β+γ phase structure, and the martensitic transformation of the β phase is used to impart shape memory properties. The phase never transforms into the ε phase. The presence of the β phase with the B2 structure, which has poor ductility, causes a decrease in workability, but the Co-based alloy of the present invention can also be said to be a material with excellent ductility in the absence of the β phase. Furthermore, compared to Co-Ni-Al alloys, which are ferromagnetic but have low magnetization strength, the Co-based alloy of the present invention has extremely high magnetization strength, making it excellent for controlling displacement using magnetic field gradients. Demonstrates excellent performance.

形状記憶特性を有する文献 6の Co基合金では、形状記憶効果に優れているが超弾性が得られず、極めて小さな磁歪のために磁場による変位制御も困難である。これは、形状記憶効果，超弾性，磁場による変位制御がそれぞれ異なる現象に由来する結果である。すなわち、形状記憶効果は、マルテンサイト相状態で変形を与え、母相にマルテンサイト逆変態させることにより形状回復する現象である。超弾性は、母相状態で応力を与えると応力誘起のマルテンサイ卜変態をし、応力を除荷すると母相へマルテンサイト逆変態するために形状回復する現象である。他方、強磁性形状記憶合金における大きな磁歪は、均一磁場によるマルテンサイトバリアントの再配列や磁場誘起マルテンサイト変態により得られる現象である。本特許の Co基合金は、主に加工硬化により大きな弾性変形能を実現したものであり、応力の負荷'除荷によるマルテンサイト相の可逆的な変態'逆変態が明確に検出されない点で超弾性と本質的に異なり、マルテンサイト相 (ε相)はヤング率を低く保ちながら弾性変形能を補助するのみである。更に、加工性が改善され、磁化の強さも増大しているので、磁場勾配の印加 '除去による変位制御が可能な材料として優れた機能を発揮する。本発明の Co基合金は、 Fe： 0.01〜： 10%, Ni： 0.01〜30%, Mn： 0.01~25% から選ばれた一種又は二種以上を含む Co合金を基本とする。 The Co-based alloy described in Reference 6, which has shape memory properties, has an excellent shape memory effect, but does not have superelasticity, and its extremely small magnetostriction makes it difficult to control displacement using a magnetic field. This is a result of the shape memory effect, superelasticity, and displacement control using magnetic fields all being caused by different phenomena. In other words, the shape memory effect is a phenomenon in which shape is recovered by applying deformation in the martensitic phase state and causing reverse martensitic transformation to the parent phase. Superelasticity is a phenomenon in which stress-induced martensitic transformation occurs when stress is applied in the matrix state, and shape recovery occurs due to martensitic reverse transformation to the matrix state when the stress is removed. On the other hand, large magnetostriction in ferromagnetic shape memory alloys is a phenomenon obtained by rearrangement of martensitic variants by a uniform magnetic field and magnetic field-induced martensitic transformation. The Co-based alloy of this patent has achieved large elastic deformability mainly through work hardening, and is extremely unique in that the reversible transformation and reverse transformation of the martensitic phase due to stress loading and unloading cannot be clearly detected. Essentially different from elasticity, the martensitic phase (ε phase) only supports elastic deformability while keeping Young's modulus low. Furthermore, its workability has been improved and its magnetization strength has increased, making it an excellent material that can control displacement by applying or removing a magnetic field gradient. The Co-based alloy of the present invention is based on a Co alloy containing one or more selected from Fe: 0.01 to 10%, Ni: 0.01 to 30%, and Mn: 0.01 to 25%.

Fe, Ni, Mn は、マルテンサイト変態温度を低下させ、延性，加工性の向上に寄与し、磁化率を高める効果を奏する。このような効果は、 0.01 %以上の Fe， Ni又は Mn添加で顕著になる。しかし、過剰添加はマルテンサイト及び磁気変態温度を室温以下に下げ、 ε相の生成抑制，，磁気特性の低下を招くので、 Fe： 10% , Ni： 30% , Mn： 25 %を上限とした。 Fe, Ni, Mn の二種又は三種を添加する場合、合計含有量を 0.02〜50%の範囲に収めることが好ましい。 Fe, Ni, Mnそれぞれの含有！:は、好ましくは 1~8%, 1〜25%, 1〜20%、更に好ましくは 2〜6%, 5〜20%, 5 15%の範囲で定める。 Fe, Ni, and Mn have the effect of lowering the martensitic transformation temperature, contributing to improving ductility and workability, and increasing magnetic susceptibility. Such effects become noticeable when Fe, Ni, or Mn is added in an amount of 0.01% or more. However, excessive addition lowers the martensite and magnetic transformation temperature below room temperature, suppressing the formation of the ε phase, and deteriorating the magnetic properties. did. When adding two or three of Fe, Ni, and Mn, the total content is preferably within the range of 0.02 to 50%. Contains each of Fe, Ni, and Mn! : is preferably set in the range of 1 to 8%, 1 to 25%, 1 to 20%, more preferably 2 to 6%, 5 to 20%, 5 to 15%.

Al, Cr, V, Ti, Mo, Nb, Zr, W, Ta, Hf, Si, C, B, P, ミッシュメタルから選ばれた一種又は二種以上の第三成分を必要に応じて Co-(Fe，Mn,Ni)系に添加できる。複数の第三成分を添加する場合には、 0.002〜50% (好ましくは、 0.005〜30%)の範囲で合計含有量を選定する。 Co-co- Can be added to (Fe, Mn, Ni) systems. When adding a plurality of third components, the total content is selected in the range of 0.002 to 50% (preferably 0.005 to 30%).

A1, V， Tiは、マルテンサイト変態温度を低下させる成分である。しかし、過剰添加は γ相を安定化させ ε相の体積分率を低下させるので、添加する場合には A1 : 0.01〜： 10% , V : 0.01〜20%， Ti： 0.01〜： 15%の範囲で Al, V, Ti の含有量を定める。 A1, V, and Ti are components that lower the martensitic transformation temperature. However, excessive addition stabilizes the γ phase and reduces the volume fraction of the ε phase, so when adding A1: 0.01~: 10%, V: 0.01~20%, Ti: 0.01~: 15%. The content of Al, V, and Ti is determined within the range of .

Cr, Moは耐食性の向上に有効な成分であるが、過剰添加は延性の著しい劣化を招く。添加する場合、 Cr : 0.01~35% , Mo： 0.01〜30%の範囲で含有量を選定する。 Cr and Mo are effective components for improving corrosion resistance, but excessive addition leads to significant deterioration of ductility. When adding, select the content within the range of Cr: 0.01~35%, Mo: 0.01~30%. Set.

Nb, Zr, W, Ta, Hfは材料の強化に有効な成分であるが、過剰添加は延性の著しい劣化を招くので、添加する場合には b： 0.01〜10% , Zr： 0.01-3% , W : 0.01〜30% , Ta： 0.01- 10% , Hf： 0.01〜5%の範囲で含有量を選定する。 Nb, Zr, W, Ta, and Hf are effective components for strengthening materials, but excessive addition causes a significant deterioration of ductility, so when adding them, b: 0.01-10%, Zr: 0.01-3% , W: 0.01-30%, Ta: 0.01-10%, Hf: Select the content within the range of 0.01-5%.

Si はマルテンサイト変態温度を上昇させる成分であるが、過剰添加は延性の著しい劣化を招くので、添加する場合には Si： 0.01〜8%の範囲で含有量を選定 'する。 Si is a component that increases the martensitic transformation temperature, but excessive addition causes a significant deterioration of ductility, so when adding Si, the content should be selected within the range of 0.01 to 8%.

C, B, P, ミッシュメタルは結晶粒微細化に有効な成分であるが、過剰添加は延性の著しい劣化を招く。そこで、 C, B， P, ミッシュメタルを添加する場合には C： 0.001〜3 % , B : 0.001〜3%， P : 0.001〜3 % , ミッシュメタル： 0.001〜3%の範囲で含有量を選定する。所定組成に調整された Co基合金を溶解した後、鎵造，.鍛造，熱間圧延等を経て圧延，引抜き，鍛造等の冷間加工によって目標サイズの板材，線材，管材等に成形される。冷間加王された Co基合金を温度： 900〜： 140CTCで溶体化処理すると、冷間加工までの工程で導入された歪が除去され材料が均質化される。溶体化温度は、十分に再結晶温度以上である必要があるため 900°C 以上、融点以下 (具体的には、 1400°C 下)が必要であり、好ましくは 1000〜1250°Cの範囲に設定される。 C, B, P, and misch metal are effective ingredients for grain refinement, but excessive addition causes a significant deterioration of ductility. Therefore, when adding C, B, P, and misch metal, the content should be within the range of C: 0.001 to 3%, B: 0.001 to 3%, P: 0.001 to 3%, and misch metal: 0.001 to 3%. Select. After melting the Co-based alloy adjusted to a predetermined composition, it is formed into plate materials, wire rods, pipe materials, etc. of the target size by cold processing such as rolling, drawing, and forging after being molten, forged, hot rolled, etc. Ru. When a cold-worked Co-based alloy is solution-treated at a temperature of 900 to 140 CTC, the strain introduced in the process up to cold working is removed and the material is homogenized. The solution temperature needs to be well above the recrystallization temperature, so it needs to be at least 900°C and below the melting point (specifically, below 1400°C), preferably in the range of 1000 to 1250°C. is set to .

溶体化温虔から室温に冷却する過程で、 f.c.c.構造の γ相から h.c.p.構造の ε相にマルテンサイト変態する。マルテンサイト変態点 (Ms温度)が室温より高い場合でも、 Fe, Ni， Mn により γ相が安定化されるので冷却後の組織が ε相に単相化することはない。 In the process of cooling from solution temperature to room temperature, the γ phase with an f.c.c. structure undergoes martensitic transformation to the ε phase with an h.c.p. structure. Even if the martensitic transformation point (Ms temperature) is higher than room temperature, the γ phase is stabilized by Fe, Ni, and Mn, so the structure after cooling does not become a single ε phase.

溶体化処理された Co基合金に圧延，鍛造，曲げ加工，絞り等の加工を施してもよい。加工温度は常温が通常であるが、 700°C以下にも設定できる。マルテンサイト変態には、 Ms温度以下に冷却することにより生じる熱誘起変態の他に応力誘起変態もあり、加工は ε相の体積分率を増加させる有効な手段である。 The solution-treated Co-based alloy may be subjected to processing such as rolling, forging, bending, drawing, etc. The processing temperature is normally room temperature, but it can also be set below 700°C. Martensitic transformation includes stress-induced transformation as well as thermally induced transformation caused by cooling below the Ms temperature, and processing is an effective means of increasing the volume fraction of the ε phase.

応力誘起変態は Ms温度以上の環境で応力を負荷したときに生じる変態であるが、加工に伴う動的再結晶や析出等が懸念される熱間加工は好ましくない。熱間加工が通常 0.6TM(TM：融点)以上の温度での加工と定義されていることを考慮し、加工温度を 0.6TM以下，具体的には 700Ό以下に設定する。 ε相の誘起効果は加工率の増加に応じて顕著にな §ので、冷間加工時の加工率を 10%以上に設定する。加工設備の能力に応じて加工率の上限が定められるが、過剰な加工率では加ェ設備の負担が大きくなるので 90%を上限とすることが好ましい。 Stress-induced transformation is a transformation that occurs when stress is applied in an environment above the Ms temperature, but hot working is undesirable due to concerns about dynamic recrystallization and precipitation during processing. hot Considering that processing is normally defined as processing at a temperature of 0.6TM (TM: melting point) or higher, the processing temperature is set to 0.6TM or lower, specifically 700Ό or lower. The induced effect of the ε phase becomes more pronounced as the working rate increases, so the working rate during cold working is set to 10% or more. The upper limit of the processing rate is determined according to the capacity of the processing equipment, but an excessive processing rate will increase the burden on the processing equipment, so it is preferable to set the upper limit to 90%.

弾性変形能の向上，ヤング率の低下に及ぼす ε相の影響は、金属組織全体に ε '相が占める体積分率を 10体積％以上とすることにより顕著になる。ただし、 ε 相の過剰分布はヤング率低下の効果を弱め、却って加工性向上に有効な γ相の体積分率を相対的に減らすことになるので、 ε相の上限を好ましくは 99体積％とする。 The influence of the ε phase on the improvement of elastic deformability and the decrease of Young's modulus becomes significant when the volume fraction occupied by the ε ' phase in the entire metal structure is 10% by volume or more. However, excessive distribution of the ε phase weakens the effect of lowering Young's modulus and, on the contrary, relatively reduces the volume fraction of the γ phase, which is effective in improving workability, so the upper limit of the ε phase is preferably set at 99% by volume. do.

900〜1400°Cでの溶体化， 700°C以下の温度で 10%以上の加工の後に、 300〜 800°C (圩ましくは、 400〜700°C)で時効処理してもよい。時効処理を施すと、歪時効効果や回復，再結晶により強度を上昇又は低下させることができる。コットレル効果，鈴木効果等が起こる場合に強度が上昇し、回復や再結晶が起こる場合に強度が低下する。時効処理には少なくとも.原子の短距離拡散が必要なため時効温度を 300°C以上とするが、 800°Cを超える.高温加熱では十分な弾性歪が得られない。 After solution treatment at 900 to 1400°C and processing of 10% or more at a temperature below 700°C, aging treatment may be performed at 300 to 800°C (preferably 400 to 700°C). Aging treatment can increase or decrease the strength due to the strain aging effect, recovery, and recrystallization. Strength increases when Cottrell effect, Suzuki effect, etc. occur, and decreases when recovery or recrystallization occurs. Aging treatment requires at least short-distance diffusion of atoms, so the aging temperature is set at 300°C or higher, but heating at high temperatures above 800°C does not produce sufficient elastic strain.

以下、実施例によ-り本発明の作用 ·効果を具体的に説明するが、実施例は本発明の具体的な理解を助けるものであり本発明の技術的範囲に何ら影響を及ぼすものでないことは勿論である。実施例 1 Hereinafter, the functions and effects of the present invention will be specifically explained using examples. However, the examples are intended to help a concrete understanding of the present invention, and are not intended to have any influence on the technical scope of the present invention. Of course, this is not the case. Example 1

表 1〜3の Co基合金を溶解し、铸造，熱間圧延を経て板厚： 0.5mmまで冷間圧延し、更に 1200°CX 15分で溶体化した。 The Co-based alloys shown in Tables 1 to 3 were melted, cast, hot rolled, and then cold rolled to a plate thickness of 0.5 mm, and then solution-treated at 1200°C for 15 minutes.

表 1の F1〜F8は Co-Fe系，表 2の Nl〜N8は Co-Ni系，表 3の M1〜M8 は Co-Mn系を基本とする合金設計である。 F1 to F8 in Table 1 are Co-Fe based, Nl to N8 in Table 2 are Co-Ni based, and M1 to M8 in Table 3 are Co-Mn based alloy designs.

表 1〜3には、各 Co基合金の室温における ε相の体積分率，回復歪量，磁化の強さを調査した結果を併せ示す。比較のため、純 Co, 純 Fe, SUS316Lの同様な特性を表 4に示す。また、 Fe， Ni, Mnの ε相の体積分率，回復歪量，磁化の強さに及ぼす影響を図 1〜3にグラフ化した。 Tables 1 to 3 also show the results of investigating the volume fraction of the ε phase, amount of recovery strain, and magnetization strength at room temperature for each Co-based alloy. For comparison, Table 4 shows similar properties of pure Co, pure Fe, and SUS316L. In addition, the volume fraction of the ε phase of Fe, Ni, and Mn, the amount of recovery strain, and the magnetization The effects on strength are graphed in Figures 1-3.

ε相の体積分率 X_eは X 線回折による（200)_γと（10Ϊ0)_εの積分強度 Ι(200)_γと 1(1010)_£を次式に代入し算出した。

The volume fraction of the ε phase, X _e , was calculated by substituting the integrated intensities Ι(200) _γ and 1(1010) _£ of (200) _γ and (10Ϊ0) _ε obtained by X-ray diffraction into the following equation.

回復歪量は、三点曲げ試験で 1%の曲げ歪量を与えた後、除荷したときに戻る The amount of recovery strain returns when the load is unloaded after applying 1% bending strain in a three-point bending test.

'形状歪量とした。 'The amount of shape distortion.

磁化の強さは、振動試料型磁力計を用いて磁場を印加し、 0.2T のときの磁化の強さとした。， The strength of magnetization was determined by applying a magnetic field using a vibrating sample magnetometer and taking the strength of magnetization at 0.2T. ，

表 1~3，図 1〜3にみられるように、 Co-Fe, Co-Ni, Co-Mn何れの合金系においても、金属組織全体の 10 .体積％以上を ε相で占めていたが、 Fe， Ni, Mn の増量に応じて ε相の体積分率, 回復歪量が低下する傾向にあった。 As seen in Tables 1 to 3 and Figures 1 to 3, the ε phase accounts for more than 10% by volume of the entire metal structure in any of the Co-Fe, Co-Ni, and Co-Mn alloy systems. However, the volume fraction of the ε phase and the amount of recovery strain tended to decrease as the amounts of Fe, Ni, and Mn increased.

Fe： 3.80%の Co-Fe系合金 (F2)では図 4にみられるように、 ε相がバンド状に存在していた。回復歪量は ε相が多いほど大きくなる傾向にあり、 10体積％以上の ε相で 0.4%以上の回復歪量が得られた。 In the Co-Fe alloy (F2) with Fe: 3.80%, the ε phase existed in a band shape, as seen in Figure 4. The amount of recovery strain tends to increase as the amount of ε phase increases, and recovery strain of 0.4% or more was obtained with ε phase of 10% by volume or more.

Co-Fe 系では、磁化の強さが Fe の増量に伴い増加し、 7.61 %(No.F4)で最大値を示し、優れた磁気特性であった。 Co-Ni系， Co-Mn系では、 Ni, Mn の増量に応じ磁化の強さに低下がみられたが、依然として 43.9 emu/g以上の大きな磁化の強さが維持されていた。 In the Co-Fe system, the magnetization strength increased as the amount of Fe increased, reaching a maximum value at 7.61% (No.F4), indicating excellent magnetic properties. In the Co-Ni and Co-Mn systems, the strength of magnetization decreased as the amount of Ni and Mn increased, but a large magnetization strength of 43.9 emu/g or more was still maintained.

一方、比較例 C1 (純 Co)は全体の 93体積％を£相で占めているが、回復歪量は本発明材よりも低くなつていた。比較例 C2(純 Fe)は磁化の強さは大きいものの、 ε 相が存在しておらず、回復歪量も更に低くなつていた。常磁性材料である比較例 On the other hand, in Comparative Example C1 (pure Co), 93% by volume of the total was occupied by the carbon phase, but the amount of recovery strain was lower than that of the present invention material. Comparative example C2 (pure Fe) had a high magnetization strength, but no ε phase existed, and the amount of recovery strain was even lower. Comparative example of paramagnetic material

C3(SUS316L)は、 0.2Tでの磁化の強さはほぼ 0に近く、回復歪量も低い値であつた。表 1 ： Co-Fe系合金溶体化材の ε相と弹性変形能，磁匕の強; For C3 (SUS316L), the magnetization strength at 0.2T was close to 0, and the amount of recovery strain was also low. Table 1: ε phase, bending deformability, and magnetic strength of Co-Fe alloy solution treated materials;

表 3： Co-Mn系合金溶体化材の _ε相と弾性変形能，磁 1 ί匕の強さ

Table 3: _ε phase, elastic deformability, and magnetic strength of solution-treated Co-Mn alloys

合金合金成分, 含有量 (％) (残部は Co) ε相回復歪量磁化の強さ. Alloy Alloy component, content (%) (remainder is Co) ε phase Recovery strain amount Magnetization strength.

No. Fe Ni Mn (体積⁰ /₀) (%) (emu/g) No. Fe Ni Mn (Volume ⁰ / ₀ ) (%) (emu/g)

Ml - - 2.80 93 0.52 108.6 Ml - - 2.80 93 0.52 108.6

M2 - - 5.62 89 0.48 96.2 M2 - - 5.62 89 0.48 96.2

M3 - - 9.39 73 0.43 79.7 M3 - - 9.39 73 0.43 79.7

M4 - - 14.13 69 0.43 59.1 M4 - - 14.13 69 0.43 59.1

M5 - - 22.74 40 0.42 43.9 M5 - - 22.74 40 0.42 43.9

M6 1.91 - 9.40 71 0.43 87.0 M6 1.91 - 9.40 71 0.43 87.0

M7 - 5.01 9.39 65 0.43 78.1 M7 - 5.01 9.39 65 0.43 78.1

M8 1.91 5.02 9.40 60 0.43 83.9 M8 1.91 5.02 9.40 60 0.43 83.9

表 4：比較材の ε相と弹性変形能, -磁化の強さ Table 4: ε phase and deformability of comparative materials, -strength of magnetization

合金 ε相回復歪量磁化の強さ Alloy ε phase Recovery strain amount Magnetization strength

材質 Material

No. (体積⁰ /₀) (%) (emu/g) No. (Volume ⁰ / ₀ ) (%) (emu/g)

C1 純 Co 93 0.35 70.4 C1 Pure Co 93 0.35 70.4

C2 純 Fe 0 0.21 154.5 C2 Pure Fe 0 0.21 154.5

C3 SUS316L 0 0.24 〜0 C3 SUS316L 0 0.24 ~ 0

次に、 1200°CX 15分で溶体化した各 Co基合金を圧下率： 40%で冷間圧延し、同様な試験で ε相の体積分率，回復歪量，磁化の強さを求め、調査結果を表 5〜7 に示す。 Next, each Co-based alloy that had been solutionized at 1200°C for 15 minutes was cold rolled at a reduction rate of 40%, and the volume fraction of the ε phase, the amount of recovery strain, and the strength of magnetization were determined using a similar test. The survey results are shown in Tables 5-7.

Co-Fe, Co-Ni, Co-Mn何れの合金系においても、冷間圧延を施していない材料 (表 1~3)に比較して ε相の体積分率が増加していた。また、合金 F2の応力-歪線図 (図 5)にみられるように、 1 %の歪印加に対して除荷時に 0.61%の回復歪を示している。超弾性材料に比較してより線形的である点も特長である。他の合金系 Co-Ni, Co-Mnでも冷間圧延により回復歪量は増加し、 0.6%前後の回^歪量が得られた冷間圧延による磁気特性の変化は磁化の強さが数 emu/g程度低下レたに留まり、依然として優れた磁気特性を有していた。 In all of the Co-Fe, Co-Ni, and Co-Mn alloy systems, the volume fraction of the ε phase increased compared to the non-cold-rolled materials (Tables 1 to 3). In addition, as seen in the stress-strain diagram (Figure 5) for alloy F2, the recovery strain is 0.61% upon unloading when 1% strain is applied. Another feature is that it is more linear than superelastic materials. Other alloy systems Even for Co-Ni and Co-Mn, the amount of recovered strain increases with cold rolling, and a degree of strain of around 0.6% was obtained.The change in magnetic properties due to cold rolling is that the strength of magnetization is about several emu/g. The decrease remained at a low level, and it still had excellent magnetic properties.

一方、比較例 CI, C2では冷間圧延による ε相分率の変化がみられず、回復歪量は発明材に比較して小さかった。 C3は大きな回復歪量が得られたが、 0.2Τの外部磁場を印加したときの磁化の強さがほぼゼ口であった。表 5： Co-Fe系合金冷延材の弹性変形能，磁化の強さ（冷間圧延率： 40%) On the other hand, in Comparative Examples CI and C2, no change in the ε phase fraction was observed due to cold rolling, and the amount of recovery strain was smaller than that of the invention material. Although a large amount of recovery strain was obtained for C3, the strength of magnetization when an external magnetic field of 0.2 T was applied was almost zero. Table 5: Deformability and magnetization strength of cold-rolled Co-Fe alloy materials (cold rolling ratio: 40%)

表 6： Co-Ni系合金冷延材の弾性変形能，磁化の強さ（冷間圧延率： 40%) Table 6: Elastic deformability and magnetization strength of cold rolled Co-Ni alloy material (cold rolling ratio: 40%)

表 8：比較冷延材の弾性変形能，磁化の強さ（冷間圧延率： 40%)

Table 8: Elastic deformability and magnetization strength of comparative cold-rolled materials (cold rolling ratio: 40%)

実施例 2

Example 2

表 1の F2, 表 2の N4, 表 3の M3をそれぞれ Co-Fe系， Co Ni系， Co-Mn 系合金の代表として選択し、溶体化後に冷間加工，時効処理を施した。 F2 in Table 1, N4 in Table 2, and M3 in Table 3 were selected as representative of Co-Fe, Co Ni, and Co-Mn alloys, respectively, and were subjected to cold working and aging treatment after solution treatment.

製造条件と物性値との関係を表 9 に示す。また、 Co:Fe 系， Co-Ni 系， Co- Mn系それぞれについて、 ε相の体積分率，回復歪量，磁化の強さに及ぼす溶体化処理条件の影響 (冷間加工率： 40%, 時効処理条件： 700Ό Χ 2 時間に固定），冷間JQ工率の影響 (溶体化処理条件： 1200°C X 15 分，時効処理条件： 700°C X 2 時間に固定)，時効処理条件の影響 (溶体化処理条件： 1200°C X 15 分，冷間加工率： 40%又は 80%に固定を図 6〜： 14にグラフ化した。 Table 9 shows the relationship between manufacturing conditions and physical property values. In addition, the influence of solution treatment conditions on the volume fraction of ε phase, amount of recovery strain, and strength of magnetization for Co:Fe system, Co-Ni system, and Co-Mn system (cold working rate: 40%) , Aging treatment conditions: Fixed at 700Ό Χ 2 hours), Effect of cold JQ processing rate (Solution treatment conditions: 1200°C x 15 minutes, Aging treatment conditions: Fixed at 700°C x 2 hours), Effect of aging treatment conditions (Solution treatment conditions: 1200°C x 15 minutes, cold working rate: fixed at 40% or 80% are graphed in Figures 6 to 14.

試験 No.4, 6, 7 'では、冷間加工率、時効処理条件を固定し、溶体化温度を変 '化させたが、 ε相の体積分率、回復歪量、磁化の強さの何れにも大きな変化はみられなかった。この関係は、試験 yo.l2， 13及び試験 Νο.19， 20においても同様であり、図 6， 9, 12 からも理解できる。また、溶体化温度が高すぎる試験 No.2では液相が出現して部分溶融してしまった。 In test Nos. 4, 6, and 7', the cold working rate and aging treatment conditions were fixed, and the solution temperature was varied, but the volume fraction of the ε phase, the amount of recovery strain, and the strength of magnetization were No major changes were observed in either case. This relationship is the same for tests yo.l2 and 13 and tests Νο.19 and 20, and can also be understood from Figures 6, 9, and 12. Furthermore, in Test No. 2, where the solution temperature was too high, a liquid phase appeared and partial melting occurred.

試験 No.ll. 12, 14, 15 では、溶体化処理条件，時効処理条件を固定し、冷間加工率を変化させた。冷間加工率が高いほど ε相の体積分率が高く、回復歪量も大きくなつていた。磁化の強さは僅かに減少するが、大きな減少ではなかった。この関係は、試験 No.4, 5及び試験 No.19, 21でもみられ、図 7， 10, 13からも理解できる。 In Test Nos. ll. 12, 14, and 15, the solution treatment conditions and aging treatment conditions were fixed, and the cold working rate was varied. The higher the cold working rate, the higher the volume fraction of the ε phase and the greater the amount of recovery strain. Although the strength of magnetization decreased slightly, it was not a large decrease. This relationship is also seen in Test Nos. 4 and 5 and Tests No. 19 and 21, and can also be understood from Figures 7, 10, and 13.

試験 No.16〜； 19, 22, 23 では、溶体化処理条件、冷間加工率を固定し、時効処理条件を変化させた。時効温度の上昇に伴い ε相の体積分率，回復歪量が減少する傾向にあった。回復歪量は冷間加工まま材に比較して小さく、試験 No.. 17 〜19, 22 では溶体化まま材と溶体化 +冷間加工材で得られる回復歪量の中間の値であった。磁化の強さには顕著な変化がみられなかった。この関係は、試験 No.l, 3, 4及び試験 No.8, 10, 12においても同様である。 In Test Nos. 16 to 19, 22, and 23, the solution treatment conditions and cold working rate were fixed, and the aging treatment conditions were varied. As the aging temperature increases, the volume fraction of the ε phase and the amount of recovery strain decrease. There was a tendency to The amount of recovery strain was smaller than that of the as-cold-worked material, and in Test Nos. 17 to 19 and 22, the amount of recovery strain was between the values obtained for the as-solution-treated material and the solution-treated + cold-worked material. . No significant change was observed in the strength of magnetization. This relationship is the same for Test Nos. 1, 3, 4 and Tests No. 8, 10, 12.

加工率が 80%と大きな試験 No.9, 15 では、時効処理により回復歪量が高くなっている。一方、試験 No.23 は冷間加工後の時効による回復歪量が表 3 に示 'す加工前のものと同等であり、顕著な時効効果が得られなかった。 In Test Nos. 9 and 15, where the processing rate was large at 80%, the amount of recovered strain was high due to the aging treatment. On the other hand, in Test No. 23, the amount of recovery strain due to aging after cold working was the same as that before working shown in Table 3, and no significant aging effect was obtained.

以上の結果は、'適切な時効により回復歪量の調整が可能なことを意味し、図 8, 11, 14によっても支持される。 The above results imply that it is possible to adjust the amount of recovery strain through appropriate aging, which is also supported by Figures 8, 11, and 14.

表 9： I ^条件が物性に及ぼす影響 Table 9: Effect of I^ conditions on physical properties

実施例 3

Example 3

Co-2.05%Fe, Co-10%Ni, Co-5%Mn をそれぞれ Co-Fe 系， Co'Ni 系， Co- Co-2.05%Fe, Co-10%Ni, and Co-5%Mn were used as Co-Fe system, Co'Ni system, and Co-

Mn系の基本組成とし、第三成分を添加して種々の Co基合金を調製した。溶解後、実施例 1 と同様に銃造，熱間圧延を経て板厚： 0.5mmに冷間圧延し、溶体化処理，冷間圧延，時効処理を施した。 Various Co-based alloys were prepared by using a Mn-based basic composition and adding a third component. After melting, it was gun-formed and hot-rolled in the same manner as in Example 1, then cold-rolled to a plate thickness of 0.5 mm, and then subjected to solution treatment, cold rolling, and aging treatment.

得られた各 Co基合金について ε相の体積分率，回復歪量，磁化の強さを測定した結果を表 10(Co-Fe系)，表 ll(Co-Ni系)，表 12(Co-Mn系)に示す。 Table 10 (Co-Fe system), Table ll (Co-Ni system), and Table 12 (Co -Mn series).

表 10〜： 12の調査結果にみられるように、第三成分の添加で延性，磁性，耐食性，強度等が改善された Co基合金は、何れの溶体化材でも ε相が 50体積％以上存在し、 1%歪印加に対し 0.41 %以上の回復歪量が得られた。また、 0.2Τの磁場印加に対し 69.9 emu/g以上の高い磁化の強さも有していた。 40%の冷間圧延により ε相の体積分率が何れも増加し、磁化の強さを大きく損なうことなく 0.6%前後の高い回復歪量が得られるようになった。更に時効処理を施すことにより、回復歪量を調節できた。 As seen in the survey results in Tables 10 to 12, Co-based alloys whose ductility, magnetism, corrosion resistance, strength, etc. have been improved by the addition of a third component have an ε phase of 50% by volume in all solution-treated materials. A recovery strain of 0.41% or more was obtained when 1% strain was applied. It also had a high magnetization strength of more than 69.9 emu/g when a magnetic field of 0.2 T was applied. By cold rolling to 40%, the volume fraction of the ε phase increased in both cases, and it became possible to obtain a high recovery strain of around 0.6% without significantly reducing the strength of magnetization. Furthermore, by applying aging treatment, the amount of recovery strain could be adjusted.

表 10：第≡fi£分の »が Co-2.05%Fe合金の物性に及ぼす影響 Table 10: Effect of the ≡th fraction on the physical properties of Co-2.05%Fe alloy

表 11：第三の^ ¾Πが Co-10%Ni合金の物性に及ぼす Table 11: Effect of third ^ ¾Π on physical properties of Co-10%Ni alloy

表 12：第分の翻 Πが Co-5%Mn合金の難に及ぼす影響 Table 12: Effect of minute conversion Π on the difficulty of Co-5%Mn alloy

実施例 4 Example 4

表 1の F2合金を選択し、铸造，熱間圧延を経て板厚： 0.33mmまで冷間圧延し、更に 1200°C X 15分で溶体化し、最後に圧下率： 20%で冷間圧延した。 The F2 alloy shown in Table 1 was selected and cold-rolled to a plate thickness of 0.33 mm through casting and hot rolling, and then solution-treated at 1200°C for 15 minutes, and finally cold-rolled at a rolling reduction of 20%.

得られた Co-Fe系合金について、 -50°C， 25°C, 100°C, 200°C の各温度における ε相の体積分率，回復歪量，磁化の強さを求めた。回復歪量は、各温度での引張り試験で 1%の歪量を与えた後、除荷したときに戻る形状歪量とした。 ε相 'の体積分率，回復歪量，磁化の強さについては、各温度において実施例 1 と同じ方法で求めた。 For the obtained Co-Fe alloy, the volume fraction of the ε phase, amount of recovery strain, and magnetization strength were determined at each temperature of -50°C, 25°C, 100°C, and 200°C. . The amount of recovery strain was defined as the amount of shape strain that returned when the load was removed after a 1% strain was applied in a tensile test at each temperature. The volume fraction of the ε phase, the amount of recovery strain, and the strength of magnetization were determined at each temperature using the same method as in Example 1.

表 13の調査結果にみられるように、 ε相の体積分率は- 50°Cから 200°C までの温度範囲で大きく変化していない。回復歪量は試験温度が上昇すると低下する傾向にあつたが、 200°Cにおいても依然大きな回復歪を示した。 As seen in the survey results in Table 13, the volume fraction of the ε phase does not change significantly in the temperature range from -50°C to 200°C. Although the amount of recovery strain tended to decrease as the test temperature increased, it still showed a large recovery strain even at 200°C.

形状記憶合金では、，変形応ガが温度に対して大きく変化し、たとえば Ti-Ni系合金では見掛け上の降伏応力の温度依存性は約 5MPa/°C である。一方、本発明の Co-Fe系合金は応力-歪線図 (図 15)にみられるように応力の温度依存性が小さく、約 0:5MPa/°Cと Ti-Ni系合金の約 10分の 1程度であるので、室温以下から高温までの広い温度範囲にわたる利用にも適している。また、キュリー温度が非常に高いため、 200°Cでも大きな磁化の強さを示した。 In shape memory alloys, the deformation stress varies greatly with temperature; for example, in Ti-Ni alloys, the temperature dependence of the apparent yield stress is approximately 5 MPa/°C. On the other hand, as seen in the stress-strain diagram (Fig. 15), the Co-Fe alloy of the present invention has a small stress dependence on temperature, about 0:5 MPa/°C, which is about 0.5 MPa/°C. Since it is about 1/10th the temperature, it is suitable for use over a wide temperature range from below room temperature to high temperatures. In addition, because the Curie temperature was extremely high, it exhibited large magnetization strength even at 200°C.

同じ条件下で製造た表 2の N4合金冷延材，表 3の M3合金冷延材についても同じ試験で温度による影響を調査し、調査結果を表 13 に併せ示した。 Co-Ni 系， Co-M_n系でも大半を ε相で占める金属組織を有し、回復歪量，磁化の強さ共に大きな値を示した。 The effect of temperature was also investigated in the same test for the N4 alloy cold-rolled materials in Table 2 and the M3 alloy cold-rolled materials in Table 3, which were manufactured under the same conditions, and the results of the investigation are also shown in Table 13. The Co-Ni and Co-M _n systems also had metal structures in which the majority was composed of the ε phase, and both the amount of recovery strain and the strength of magnetization showed large values.

表 13：試験温度が物性に及ぼす影響 Table 13: Effect of test temperature on physical properties

以上に説明したように、 Fe, Ni, Mn の一種又は二種以上適量添加して ε相の生成量を制御することにより、高弾性変形能が付与された Co基合金が得られる。得られた Co基合金の磁気特性を利用すると、磁場印加により変位制御できるァクチユエータ，センサ一等として重宝される機能材料が提供される。

As explained above, by controlling the amount of ε phase produced by adding appropriate amounts of one or more of Fe, Ni, and Mn, a Co-based alloy with high elastic deformability can be obtained. Utilizing the magnetic properties of the obtained Co-based alloy will provide functional materials that are useful as actuators and sensors that can control displacement by applying a magnetic field.

Claims

1. 質量比で Pe： 0.01〜10%, Ni： 0.01~30%, Mn： 0.01〜 25%力ら選ばれた一種又は二種以上を含み、残部が不可避的不純物を除き Co の組成をもち、熱誘起又は応力誘起された h.c.p.構造の ε相が金属組織全体の 10体積％以上を占めていることを特徴とする弹性変形能の高い Co基合金。 1. Contains one or more selected from Pe: 0.01~10%, Ni: 0.01~30%, Mn: 0.01~25% in mass ratio, and the balance has a composition of Co excluding inevitable impurities. A Co-based alloy with high bending deformability characterized by a thermally or stress-induced ε phase with an h.c.p. structure accounting for 10% by volume or more of the entire metal structure.

2. 更に質量比で A1： 0.01~ 10%, Cr： 0·01〜35%, V： 0.01~20%, Ti： 0.01 ~ 15%, Mo： 0·01〜30%, Nb： 0.01 ~ 10%, Zr： 0.01~3%, W： 0.01~30%, Ta： 0.01~ 10%, Hf： 0.01〜5%， Si： 0.01〜8%, C： 0.001〜3%, B： 0.001 〜3°ん P： 0.001〜3%, ミッシュメタル： 0.001〜3%から選ばれた一種又は二種以上を合計含有量： 0.001〜50%の範囲で含む請求項 1記載の Co基合金。 2. Furthermore, mass ratio A1: 0.01~10%, Cr: 0·01~35%, V: 0.01~20%, Ti: 0.01~15%, Mo: 0·01~30%, Nb: 0.01 ~ 10 %, Zr: 0.01~3%, W: 0.01~30%, Ta: 0.01~ 10%, Hf: 0.01~5%, Si: 0.01~8%, C: 0.001~3%, B: 0.001~3° The Co-based alloy according to claim 1, containing one or more selected from P: 0.001 to 3% and misch metal: 0.001 to 3% in a total content of 0.001 to 50%.

3. 請求項 1又は 2記載の組成をもつ Co基合金を 900 1400°Cで溶体化処理することを特徴とする弾性変形能の高い Co筹合金の製造 ^法。 3. A method for producing a Co cocoon alloy with high elastic deformability, characterized by subjecting a Co-based alloy having the composition according to claim 1 or 2 to solution treatment at 900 to 1400°C.

4. 溶体化処理後、加工率： 10%以上で加！:する請求項 3記載の製造方法。 4. After solution treatment, processing rate: 10% or more! : The manufacturing method according to claim 3.

5. 加工後、 300〜800°Cで時効処理する請求項 4記載の製造方法。 5. The manufacturing method according to claim 4, wherein after processing, aging treatment is performed at 300 to 800°C.