JPH048495B2

JPH048495B2 -

Info

Publication number: JPH048495B2
Application number: JP57038886A
Authority: JP
Priority date: 1982-03-13
Filing date: 1982-03-13
Publication date: 1992-02-17
Also published as: JPS58157936A

Description

[Detailed description of the invention]

本発明は、Ni52重量％を越え62重量％以下、
残部Tiからなる合金、またはNi52重量％を越え
62重量％以下、20重量％以下のＸ（Ｘ＝Fe、Co、
Cu）、残部Tiからなる合金に、Ｂ、Si、P.S、の
１種または２種以上を、合計量で0.5〜10重量％
前記NiまたはTiと置換して含有せしめたことを
特徴とする形成記憶合金に関するものである。高温でCsCl型の体心立方構造をもち熱弾性型
のマルテンサイト変態を生ずる合金は殆ど形状記
憶効果を示すことが知られており、これまでに
Ti−Ni合金およびTi−Ni−Ｘ（Ｘ＝Fe、Co、
Cu）合金（以下Ti−Ni系合金と呼ぶ）をはじめ
としてCu−Zn−Al、Cu−Zn−Au、Cu−Al−
Ni、Cu−Zn−Ga、Cu−Zn−Sn、Cu−Zn−Si、
Cu−Sn、Ag−Cd、Au−Cd等の合金が見いださ
れている。一般に形状記憶合金は単結晶でないと形状記憶
効果を示さないために、実用上問題がある。しか
し、Ti−Ni系合金は例外であり、多結晶体で形
状記憶効果を有しており、極めて実用的であり、
上記合金の中では最も広範囲な検討が成されてい
るものである。このようにTi−Ni系合金は実用上有利な材料
であるが、その繰り返し形状記憶性については未
だ十分な信頼性があるとは言い難く、このため高
信頼性を要求される応用部品、特に形状記憶効果
を可逆的に繰り返し生じさせることを利用した応
用品等への使用には問題が残されている。しかして、前記Ti−Ni系合金の組成は、たと
えば特公昭40−6611号公報、特公昭40−14842号
公報、米国特許第3174851号明細書等で周知のよ
うに、Ni52〜62重量％、残部Tiからなることを
基本組成するものである。本発明者等はこうしたTi−Ni系合金の繰り返
し形状記憶性を向上させるために、Ｂ、Si、Ｐ、
Ｓを添加した合金を作製したところ、この添加が
合金の繰り返し形状記憶回復性に有益な効果をも
たらすことを見いだしたものである。次に本発明における添加元素の含有量の範囲の
限定理由について述べる。合計量が10重量％を越える含有量においては、
介在物等が多く存在するようになり、合金の脆化
を招き、加工性を著しく劣化させる。また0.5重
量％未満の微量含有では効果があまり認められな
いので、添加元素は0.5重量％以上含有させるこ
とがよく、好ましくは１〜３重量％の範囲である
ことが望ましい。以下に本発明を実施例に基づき説明する。実施例第１表に示す種々の合金をアルゴン中にてアー
ク溶解した後、1000℃にて２時間真空焼鈍を行つ
て均一化処理を施し、その後700〜800℃にて熱間
スウエージングを行い3φの丸棒とした。この丸棒を更に600〜800℃で歪取焼鈍を繰り返
しながら冷間伸線を行い、0.5φの細線に加工し
た。次にこの細線を750℃にて１時間真空焼鈍を
行い、その後300℃にて１時間形状記憶処理を行
い真つすぐな細線を作製した。 In the present invention, Ni is more than 52% by weight and less than 62% by weight,
Alloys with balance Ti or more than 52% Ni by weight
62% by weight or less, 20% by weight or less of X (X = Fe, Co,
0.5 to 10% by weight of one or more of B, Si, and PS in an alloy consisting of Cu), the balance being Ti.
This invention relates to a formation memory alloy characterized in that it is contained in place of Ni or Ti. It is known that most alloys that have a CsCl-type body-centered cubic structure and undergo thermoelastic martensitic transformation at high temperatures exhibit a shape memory effect.
Ti-Ni alloy and Ti-Ni-X (X=Fe, Co,
Cu) alloy (hereinafter referred to as Ti-Ni alloy), Cu-Zn-Al, Cu-Zn-Au, Cu-Al-
Ni, Cu−Zn−Ga, Cu−Zn−Sn, Cu−Zn−Si,
Alloys such as Cu-Sn, Ag-Cd, and Au-Cd have been found. In general, shape memory alloys do not exhibit shape memory effects unless they are single crystals, which poses a practical problem. However, Ti-Ni alloys are an exception; they are polycrystalline and have a shape memory effect, making them extremely practical.
Among the above alloys, this is the one that has been studied most extensively. Although Ti-Ni alloys are practically advantageous materials, their repeated shape memory properties are still not sufficiently reliable. Problems remain in its use in applied products that utilize the ability to reversibly and repeatedly produce a shape memory effect. The composition of the Ti-Ni alloy is, for example, 52 to 62% by weight Ni, as is well known in Japanese Patent Publication No. 40-6611, Japanese Patent Publication No. 40-14842, US Pat. No. 3,174,851, etc. The basic composition is that the remainder consists of Ti. In order to improve the repeated shape memory properties of these Ti-Ni alloys, the present inventors have studied B, Si, P,
After producing an alloy to which S was added, it was discovered that this addition had a beneficial effect on the repeated shape memory recovery properties of the alloy. Next, the reason for limiting the content range of the additive element in the present invention will be described. If the total content exceeds 10% by weight,
Many inclusions etc. become present, leading to embrittlement of the alloy and significantly deteriorating workability. In addition, if the content is in a trace amount of less than 0.5% by weight, the effect is not so noticeable, so the content of the additional element is preferably 0.5% by weight or more, preferably in the range of 1 to 3% by weight. The present invention will be explained below based on examples. Examples Various alloys shown in Table 1 were arc melted in argon, vacuum annealed at 1000°C for 2 hours for homogenization, and then hot swaged at 700-800°C. It was made into a 3φ round bar. This round bar was further subjected to cold wire drawing while repeating strain relief annealing at 600 to 800°C, and processed into a thin wire of 0.5φ. Next, this thin wire was vacuum annealed at 750°C for 1 hour, and then subjected to shape memory treatment at 300°C for 1 hour to produce a straight thin wire.

【表】【table】

【表】この真つすぐな細線に引張応力を加えることに
より８％の歪を付加した後、100℃に加熱し元の
長さに回復させる操作を繰り返し行い、形状回復
率を測定した。その結果を第１図に無添加の合金
と比較して示す。第１図から明らかなように無添加の合金では、
15回以上のサイクルにおいて回復率の低下を生じ
るが、Ｂ、Si、Ｐ、Ｓを添加した合金では、15回
以上のサイクルにおいても回復率が増大してお
り、繰り返し形状記憶回復性に優れているもので
ある。[Table] After adding 8% strain to this straight thin wire by applying tensile stress, the operation of heating it to 100°C and recovering it to its original length was repeated, and the shape recovery rate was measured. The results are shown in FIG. 1 in comparison with the alloy without additives. As is clear from Figure 1, in the alloy without additives,
The recovery rate decreases after 15 cycles or more, but in the case of alloys containing B, Si, P, and S, the recovery rate increases even after 15 cycles or more, indicating excellent repeated shape memory recovery. It is something that exists.

[Brief explanation of drawings]

第１図は、本発明合金の回復率とサイクル数と
の関係を示す図である。 FIG. 1 is a diagram showing the relationship between the recovery rate and the number of cycles for the alloy of the present invention.

Claims

[Claims]

1 An alloy consisting of more than 52% Ni by weight and less than 62% by weight, the balance being Ti, or more than 52% by weight Ni and less than 62% by weight
Hereinafter, in an alloy consisting of 20% by weight or less of X (X = Fe, Co, Cu) and the balance Ti, one or more of B, Si, and PS is added in a total amount of 0.5 to 10% by weight of the Ni or Ti. A shape memory alloy characterized in that it is contained in substitution with.