JP4220772B2 - Ti-Sc shape memory alloy - Google Patents
Ti-Sc shape memory alloy Download PDFInfo
- Publication number
- JP4220772B2 JP4220772B2 JP2002370999A JP2002370999A JP4220772B2 JP 4220772 B2 JP4220772 B2 JP 4220772B2 JP 2002370999 A JP2002370999 A JP 2002370999A JP 2002370999 A JP2002370999 A JP 2002370999A JP 4220772 B2 JP4220772 B2 JP 4220772B2
- Authority
- JP
- Japan
- Prior art keywords
- alloy
- shape memory
- memory alloy
- effect
- shape
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Images
Landscapes
- Materials For Medical Uses (AREA)
Description
【0001】
【発明の属する技術分野】
本発明は、新規形状記憶合金に関するものである。
【0002】
【従来の技術】
TiNi合金をはじめとする形状記憶合金はマルテンサイト変態の逆変態に付随して顕著な形状記憶効果及び超弾性を示すことはよく知られている。なかでもTiNi合金は生活環境温度近傍で優れた機能を持つことから、電子レンジダンパー、エアコン風向制御、炊飯器蒸気調圧弁、建築用の換気口、携帯電話アンテナ、眼鏡フレームなど幅広い分野で使用されている。
【0003】
また、医療への応用は他の金属に例を見ない、優れたバネ特性(超弾性)から歯列矯正線、ガイドワイヤ、カテ−テルに使用され、更には血管拡張器具(ステント)への実用化が進んでいる。
【0004】
しかし、生体と直接接触する生体材料において、Niは忌避されており、TiNi合金に替わるNiフリー合金の出現が待望されている。これらの要請を受け、近年、Ti基合金によるNiフリー化の研究が盛んに行われるようになって来ている(例えば、特許文献1の「生体用形状記憶合金」、特許文献2の「高弾性変形能を有するチタン合金およびその製造方法」、参照)。
【特許文献1】
特開2001−329325号公報
【特許文献2】
特開2002−249836号公報
【0005】
【発明が解決しようとする課題】
ところで、生体との直接的な接触、即ち、メガネフレーム、ネックレス或いはインプラントヘのNi含有合金の応用は、Niイオン溶出に起因するアレルギー性などが懸念されている。
【0006】
そこで、本発明の技術的課題は、生体用として忌避されることの多いNiを合金の構成元素から除いた新規なTi基形状記憶合金を提供することにある。
【0007】
【課題を解決するための手段】
本発明によれば、TiとScを基本とした合金に第三元素(X:V、Nb、Mo、Ta)の一種若しくは数種の組み合わせからなる)を添加することで、Niを含まない良好な形状記憶合金が得られる。
【0008】
即ち、本発明において、前記Ti−Sc−X合金の組成は、1at%≦Sc≦30at%、1at%≦X≦15at%(但し、X=V,Nb,Mo,Taの内の一種若しくは数種の組み合わせ)、Ti残部及び不可避不純物からなる構成である。
【0009】
【発明の実施の形態】
まず、本発明について更に詳しく説明する。
【0010】
本発明のTi−Sc−X系形状記憶合金は、1at%≦Sc≦30at%、1at%≦X≦15at%(但し、X=V,Nb,Mo,Taの内の一種若しくは数種の組み合わせ)、Ti残部及び不可避不純物からなる組成を備えている。
【0011】
次に、本発明の形状記憶合金の製造の具体例について、各工程に沿って説明する。
【0012】
(I)合金の作製
アルゴンアーク溶解によって種々の合金を作製した。溶解はアルゴン雰囲気中で水冷銅ハースと非消耗型タングステン電極を用いたアーク溶解炉で行い、ボタンインゴットを作製した。
また、溶解前にTiゲッターを3分間溶解し、残存する不純物酸素などを取り除いた。次に、合金成分の偏析を少なくするため、インゴットの天地を逆転させ溶解、凝固を6回繰り返し行った。作製したインゴットは真空雰囲気中で1000℃×24時間の均質化処理を行い、炉冷した。
【0013】
(II)塑性加工
前述の均質化がなされたインゴットから厚さ2〜3mmの板材を切り出し後、0.4mmまでの圧延加工を行い、試料片を得た。
【0014】
(III)形状記憶熱処理
最終熱処理として、上記の試料片を真空封入した石英管中に入れ1000℃で1時間、熱処理を行い、氷塩水中に焼入れた。
【0015】
(IV)形状記憶特性の評価
(i)操作:
上記試験片を用いて次のように、簡易曲げ試験を行なった。まず、ドライアイスアルコール漕中(約−70℃)で、厚さ0.4mmの板材を半径8mmの円柱に巻きつけた。このとき加えた曲げ歪みは、約2.5%である。試験片を漕中から取り出し、ライターで加熱し、形状回復の有無を調べた。
【0016】
(ii)結果
(イ)Scの効果:
Ti合金のβ安定化元素としてScを初めとしてV、Cr、Zr、Nb、Mo、Hf、Taなどがよく知られている。本発明では、これらの元素の中でScが形状記憶効果に不可欠であり、且つ他のβ安定化元素の共存も必須であることがわかった。即ち、Ti‐Sc合金ではSc量に関係なく顕著な形状記憶効果は示さない。またTi―X合金では、Xの量および組み合わせによっても顕著な形状記憶効果は示さない。Scは、Tiに全率固溶し、その量とともにヤング率を低下させる効果があるが、合金強度、経済性を考えると30at%が限度で、好ましくは2〜10at%である。
【0017】
(ロ)X元素効果(X=V,Nb,Mo,Ta):
Ti−Sc−X合金の形状記憶効果は、X元素の一種を含有する場合に限らず複数によっても得られる。しかし、その含有量が過度になると徐々に特性が劣化し15at%が限度と見られる。また、Xは、1at%未満ではその顕著な添加効果は認められない。
【0018】
V,Nb,TaのVa属元素では、Nb1〜15at%、Ta1〜15at%、V1〜10at%の一種もしくは数種であると良い。
【0019】
MoはTi合金の強度、加工性を向上させる元素であるが、10at%を越えると特にMoにおいて、過度の固溶強化がおこり、延性に欠けるようになるため、好ましくは、1〜10at%である。
【0020】
TiNi形状記憶合金は、不可避元素の他、Fe、Ni、Co、Al、B、W、Cu、Agなど数%添加しても形状回復温度に影響を及ぼすものの、本質釣な形状記憶効果は喪失しないことが知られている、本発明合金においても同様に、1,2at%の添加元素によってもその効果は失われない。
【0021】
(ハ)Ti−Sc−Mo合金:
本発明合金中のTi−Sc−Mo合金の例でその形状記憶効果の詳細を示した。下記表1に示す合金を前述した(I)〜(IV)の手順によって形状記憶特性を調べた。また、下記表2にドライアイスアルコール漕中変形後のライター加熱による形状回復の是非を示した。尚、表2において、○印は50%以上回復、△印については50%未満回復、×印は顕著な回復が見られないことをそれぞれ示している。
【0022】
更に詳細な形状記憶効果について調べる為に、No.5,6,7,8合金の室温変形後の加熱温度を変えてその挙動を調べた。
【0023】
図1はScの添加量と形状回復温度との関係を示している。また、図2はTi−Sc−Mo合金の形状回復挙動を示す図であり、(a)はTi6Mo4Sc(Ti−6at%Mo−4at%Sc)合金、(b)はTi6Mo7Sc(Ti−6at%Mo−7at%Sc)合金の変形前、室温変形後、加熱後の状態を夫々示している。
【0024】
図1及び図2に示すように、形状回復時の回復温度はScの添加量の増加に伴い低下した。Ti6Mo4Scでは、およそ300℃で形状回復するが、Scの増加により、Ti6Mo7Scでは100℃(沸騰水)で回復することが明らかとなった。
【0025】
【表1】
【0026】
【表2】
【0027】
【発明の効果】
以上に述べた通り、本発明の合金は、高温作動型形状記憶合金として防災用アクチュエータとして、或いは生体に有害な元素を含まない為に、新しい生体用部品として利用することが可能であるTi−Sc系形状記憶合金を提供することができる。
【図面の簡単な説明】
【図1】 Ti6Moに対するScの含有量と形状回復温度の関係を示す図である。
【図2】 図2はTi−Sc−Mo合金の形状回復挙動を示す図であり、(a)はTi6Mo4Sc合金、(b)はTi6Mo7Sc合金を夫々示している。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a novel shape memory alloy.
[0002]
[Prior art]
It is well known that shape memory alloys such as TiNi alloys exhibit a remarkable shape memory effect and superelasticity accompanying the reverse transformation of the martensitic transformation. Among them, TiNi alloy has excellent functions near the living environment temperature, so it is used in a wide range of fields such as microwave oven dampers, air conditioner wind direction control, rice cooker steam pressure regulating valves, architectural vents, mobile phone antennas, and spectacle frames. ing.
[0003]
In addition, it is used for orthodontic wires, guide wires, and catheters because of its excellent spring characteristics (superelasticity), which is unprecedented in other metals for medical applications, and even for vasodilators (stents). Practical use is progressing.
[0004]
However, in biomaterials that are in direct contact with the living body, Ni is avoided and the appearance of a Ni-free alloy that replaces the TiNi alloy is expected. In response to these demands, research on Ni-free using Ti-based alloys has been actively carried out in recent years (for example, “shape memory alloy for living body” in Patent Document 1 and “high” in Patent Document 2). (See Titanium alloy having elastic deformability and method for producing the same).
[Patent Document 1]
JP 2001-329325 A [Patent Document 2]
Japanese Patent Laid-Open No. 2002-249836
[Problems to be solved by the invention]
By the way, the direct contact with the living body, that is, the application of the Ni-containing alloy to the spectacle frame, necklace or implant, is concerned about allergenicity caused by Ni ion elution.
[0006]
Therefore, a technical problem of the present invention is to provide a novel Ti-based shape memory alloy obtained by removing Ni, which is often avoided for living organisms, from the constituent elements of the alloy.
[0007]
[Means for Solving the Problems]
According to the present invention, by adding a third element (consisting of one or several combinations of X: V, Nb, Mo, Ta) to an alloy based on Ti and Sc, it does not contain Ni A shape memory alloy can be obtained.
[0008]
That is, in the present invention, the composition of the Ti—Sc—X alloy is 1 at% ≦ Sc ≦ 30 at%, 1 at% ≦ X ≦ 15 at% (provided that X = V, Nb, Mo, Ta or one or more of them) A combination of seeds), Ti balance and inevitable impurities.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
First, the present invention will be described in more detail.
[0010]
The Ti—Sc—X shape memory alloy of the present invention has 1 at% ≦ Sc ≦ 30 at%, 1 at% ≦ X ≦ 15 at% (provided that X = V, Nb, Mo, Ta, or a combination of several kinds) ), A composition composed of Ti balance and inevitable impurities.
[0011]
Next, a specific example of manufacturing the shape memory alloy of the present invention will be described along each step.
[0012]
(I) Preparation of alloys Various alloys were prepared by argon arc melting. Melting was performed in an arc melting furnace using a water-cooled copper hearth and a non-consumable tungsten electrode in an argon atmosphere to produce a button ingot.
Further, the Ti getter was dissolved for 3 minutes before the dissolution to remove the remaining impurity oxygen and the like. Next, in order to reduce segregation of the alloy components, the top and bottom of the ingot were reversed and melted and solidified repeatedly. The produced ingot was homogenized at 1000 ° C. for 24 hours in a vacuum atmosphere and cooled in the furnace.
[0013]
(II) Plastic processing After cutting out a plate material having a thickness of 2 to 3 mm from the homogenized ingot, rolling to 0.4 mm was performed to obtain a sample piece.
[0014]
(III) Shape memory heat treatment As the final heat treatment, the sample piece was placed in a quartz tube sealed in a vacuum and heat treated at 1000 ° C. for 1 hour and quenched in ice-salt water.
[0015]
(IV) Evaluation of shape memory characteristics (i) Operation:
A simple bending test was performed using the above test piece as follows. First, in a dry ice alcohol bowl (about −70 ° C.), a thickness of 0 . A 4 mm plate was wound around a cylinder with a radius of 8 mm. The bending strain applied at this time is about 2.5%. The test piece was taken out of the cage and heated with a lighter to examine the presence or absence of shape recovery.
[0016]
(Ii) Result (b) Effect of Sc:
V, Cr, Zr, Nb, Mo, Hf, Ta, etc. are well known as Sc-stabilizing elements in Ti alloys. In the present invention, it has been found that among these elements, Sc is indispensable for the shape memory effect, and the coexistence of other β-stabilizing elements is also essential. That is, the Ti—Sc alloy does not show a significant shape memory effect regardless of the amount of Sc. In addition, the Ti—X alloy does not show a significant shape memory effect depending on the amount and combination of X. Sc has the effect of solid-dissolving all in Ti and lowering the Young's modulus along with the amount thereof, but considering the alloy strength and economy, it is limited to 30 at%, preferably 2 to 10 at%.
[0017]
(B) X element effect (X = V, Nb, Mo, Ta ):
The shape memory effect of the Ti—Sc—X alloy is not limited to the case of containing one kind of X element, and can be obtained by a plurality. However, when the content becomes excessive, the characteristics are gradually deteriorated, and 15 at% is regarded as the limit. Further, when X is less than 1 at%, the remarkable effect of addition is not recognized.
[0018]
In the Va group element of V, Nb, and Ta, one or several of Nb1 to 15 at%, Ta1 to 15 at%, and V1 to 10 at% may be used .
[0019]
Mo is the intensity of the Ti alloy is an element for improving the processability, in particular Mo exceeds 10at%, occurs strengthen excessive solid solution, since so lacking in ductility, preferably, in 1 ~10at% is there.
[0020]
TiNi shape memory alloy, in addition to inevitable elements, may affect the shape recovery temperature even if Fe, Ni, Co, Al, B, W, Cu, Ag, etc. are added in a few percent, but the shape memory effect that is essentially fishing is lost. Similarly, in the alloy of the present invention, which is known not to be effective, the effect is not lost even by the addition of 1,2 at% of the additive element.
[0021]
(C) Ti—Sc—Mo alloy:
The details of the shape memory effect are shown in the example of the Ti—Sc—Mo alloy in the alloy of the present invention. The shape memory characteristics of the alloys shown in Table 1 below were examined by the procedures (I) to (IV) described above. Table 2 below shows the probabilities of shape recovery by lighter heating after deformation in a dry ice alcohol bottle. In Table 2, ◯ indicates that the recovery is 50% or more, Δ indicates that the recovery is less than 50%, and X indicates that no significant recovery is observed.
[0022]
In order to investigate more detailed shape memory effect, The behavior of the 5, 6, 7, and 8 alloys was investigated by changing the heating temperature after deformation at room temperature.
[0023]
FIG. 1 shows the relationship between the amount of Sc added and the shape recovery temperature. Moreover, FIG. 2 is a figure which shows the shape recovery behavior of a Ti-Sc-Mo alloy, (a) is a Ti6Mo4Sc (Ti-6at% Mo-4at% Sc) alloy, (b) is Ti6Mo7Sc (Ti-6at% Mo). −7 at% Sc) Before the deformation of the alloy, after deformation at room temperature, and after heating, respectively.
[0024]
As shown in FIGS. 1 and 2, the recovery temperature at the time of shape recovery decreased as the amount of Sc added increased. In Ti6Mo4Sc, the shape recovered at about 300 ° C., but it became clear that Ti6Mo7Sc recovered at 100 ° C. (boiling water) due to the increase in Sc.
[0025]
[Table 1]
[0026]
[Table 2]
[0027]
【The invention's effect】
As described above, the alloy of the present invention can be used as a high temperature operation type shape memory alloy as a disaster prevention actuator or as a new living body part because it does not contain elements harmful to living bodies. An Sc-based shape memory alloy can be provided.
[Brief description of the drawings]
FIG. 1 is a graph showing the relationship between the content of Sc relative to Ti6Mo and the shape recovery temperature.
FIG. 2 is a diagram showing the shape recovery behavior of a Ti—Sc—Mo alloy, in which (a) shows a Ti6Mo4Sc alloy and (b) shows a Ti6Mo7Sc alloy.
Claims (1)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2002370999A JP4220772B2 (en) | 2002-12-20 | 2002-12-20 | Ti-Sc shape memory alloy |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2002370999A JP4220772B2 (en) | 2002-12-20 | 2002-12-20 | Ti-Sc shape memory alloy |
Publications (2)
Publication Number | Publication Date |
---|---|
JP2004204245A JP2004204245A (en) | 2004-07-22 |
JP4220772B2 true JP4220772B2 (en) | 2009-02-04 |
Family
ID=32810007
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP2002370999A Expired - Fee Related JP4220772B2 (en) | 2002-12-20 | 2002-12-20 | Ti-Sc shape memory alloy |
Country Status (1)
Country | Link |
---|---|
JP (1) | JP4220772B2 (en) |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2006314525A (en) * | 2005-05-12 | 2006-11-24 | Tohoku Univ | Tool to be inserted into tubular organ |
GB2562703A (en) * | 2017-03-10 | 2018-11-28 | Ilika Tech Limited | Titanium Alloys |
-
2002
- 2002-12-20 JP JP2002370999A patent/JP4220772B2/en not_active Expired - Fee Related
Also Published As
Publication number | Publication date |
---|---|
JP2004204245A (en) | 2004-07-22 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP3884316B2 (en) | Superelastic titanium alloy for living body | |
US7722805B2 (en) | Titanium alloy with extra-low modulus and superelasticity and its producing method and processing thereof | |
EP2500443B1 (en) | NI-TI semi-finished products and related methods | |
CN101768685B (en) | Biomedical titanium-niobium-based shape memory alloy as well as preparation method, processing method and application method thereof | |
WO2006007434A1 (en) | β TITANIUM COMPOSITIONS AND METHODS OF MANUFACTURE THEREOF | |
JP2007520630A (en) | Beta titanium composition and method for producing the same | |
US20040052676A1 (en) | beta titanium compositions and methods of manufacture thereof | |
JPH0762472A (en) | Copper-based shape memory alloy having high workability and its production | |
JP2009024223A (en) | Dental wire, and method for producing the same | |
JP2006089825A (en) | Superelastic titanium alloy for living body | |
JP4220772B2 (en) | Ti-Sc shape memory alloy | |
JP5107661B2 (en) | Ti-based alloy | |
JP4554250B2 (en) | Ti-based alloy shape memory element | |
JP2009215650A (en) | Shape memory alloy | |
US20070044868A1 (en) | Ti-based shape memory alloy article | |
JP4477297B2 (en) | Ti-Mo base alloy spring material | |
JPH11106880A (en) | Production of shape-memory alloy cast member | |
JP2004197112A (en) | Method of producing biological superelastic titanium alloy | |
JPH09316569A (en) | Copper alloy for lead frame and its production | |
JPH11269585A (en) | Titanium-vanadium-aluminum superelastic alloy and its production | |
JP2004124156A (en) | METHOD FOR MANUFACTURING SUPERELASTIC TiNbSn ALLOY FOR ORGANISM | |
Wu et al. | Pseudoelastic beta Ti-Mo-V-Nb-Al Alloys | |
JPH03150333A (en) | Shape memory alloy and its manufacture | |
JPH0463139B2 (en) | ||
JP2602652B2 (en) | Super-elastic TiNiA Cr Cr alloy |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20051011 |
|
A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20061201 |
|
A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20080709 |
|
A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20080908 |
|
TRDD | Decision of grant or rejection written | ||
A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20081022 |
|
A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 |
|
A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20081114 |
|
FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20111121 Year of fee payment: 3 |
|
R150 | Certificate of patent or registration of utility model |
Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20111121 Year of fee payment: 3 |
|
R154 | Certificate of patent or utility model (reissue) |
Free format text: JAPANESE INTERMEDIATE CODE: R154 |
|
FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20121121 Year of fee payment: 4 |
|
FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20131121 Year of fee payment: 5 |
|
R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
LAPS | Cancellation because of no payment of annual fees |