【発明の詳細な説明】[Detailed description of the invention]
〔産業上の利用分野〕
本発明は高強度が要求される各種工業用器具な
どに利用されている白金系合金に関するものであ
る。
〔従来の技術〕
従来の高強度白金系合金としては、白金−イリ
ジウム合金あるいは白金−ロジウム合金等が知ら
れており、その組成は90％Pt−Ir、90℃Pt−Rh
が最も一般的なものである。
しかし、これらの既知合金は、充分に満足でき
る硬さや引張り強さを具備しているとはいえず、
また高温度における強度や耐力が小さく、さらに
再結晶温度が低くて結晶粒が粗大化してしまう欠
陥があるだけでなく、鋳塊中にピンホールやブロ
ーホールが発生し易いなどの問題点がある。
〔発明が解決しようとする問題点〕
本発明は、上記高強度白金系合金のもつ難点に
つき検討を加え、Ptに新規な元素を適量だけ添加
して三元以上の合金とすることにより、前記従来
の欠陥を大巾に改善しようとするのが、その目的
である。
〔問題点を解決するための手段〕
本発明は、上記目的を達成するため、Pt中に、
Niが重量比で１〜15％と、Ru、Ir、Rh、Ｗの内
から選択された単数または複数の元素が重量比で
0.05〜５％添加されていることを特徴とする高強
度白金系合金を提供し得たものである。
〔作 用〕
本発明でPtと、これに添加するNiは全率固溶
型の合金系であり、PtにNiを加えることにより
マトリツクスが強化されることになり、さらにこ
れに加える元素を、Ru、Ir、Rh、Ｗの内から単
数または複数だけ選択することで、再結晶温度が
高くなつて微結晶質となり、このことが主要因と
なつて高温時のたわみ量も小さくなり高温時強度
も向上するものと考えられ、また前記の通り常温
における硬さや引張り強度などの機械特性が、後
述の如く著しく改善されたのは、NiとRu、Ir、
Rh、Ｗ群よりの選択元素との複合添加効果によ
つて、低温時効硬化能が飛躍的に向上したためと
思料される。
次に添加量としてNiをPtに対し１〜15％とし
たのは、15％を越えてしまうと白金合金として最
も重要な特性である耐食性が損われて実用上支障
を来たすからであり、１％未満の添加ではPtの地
の強化効果が発揮されないためである。
さらに後者の選択元素に係る添加量について
は、前記の５％を越えると、合金の鋳造性が阻害
され、加工硬化が激しくなつて塑性加工が困難と
なつてしまい、0.05未満であるとNiとの複合添加
効果が得られなくなる。
〔実施例〕
一試料の総量を400ｇとして、以下の(a)〜(f)に
示す白金系合金を、各組成毎に成分元素を秤量し
て、アーク溶解炉にて溶解、鋳造した。
(a) 従来例(1) 90％Pt−10％Rh
(b) 従来例(2) 90％Pt−10％Ir
(c) 本発明合金(1) 95％Pt−２％Ni−１％Ir−１
％Ru−１％Ｗ
(d) 本発明合金(2) 90％Pt−６％Ni−3.5％Rh−
0.5％Ｗ
(e) 本発明合金(3) 85％Pt−11％Ni−３％Ir−１
％Ｗ
(f) 本発明合金(4) 85％Pt−11％Ni−0.5％Rh3.5
％Ru
(g) 本発明合金(5) 84.5％Pt−15％Ni−0.1％Ru
−0.1％Ir−0.1％Rh−0.2％Ｗ
(h) 本発明合金(6) 88％Pt−10％Ni−２％Ru
(i) 本発明合金(7) 87％Pt−８％Ni−５％Rh
(j) 本発明合金(8) 88％Pt−６％Ni−0.5％Ir−
１％Rh−4.5％Ｗ
(k) 本発明合金(9) 90％Pt−５％Ni−５％Ir
(l) 本発明合金(10) 85％Pt−14.5％Ni−0.3％Ru
−0.2％Ir
(m) 本発明合金(11) 85％Pt−12％Ni−３％Ｗ
(n) 本発明合金〓 84.5％Pt−13％Ni−0.5％Ir
−２％Rh
(o) 本発明合金（13） 90.5％Pt−７％Ni−0.5
％Ru−0.2％Ｗ
上記の鋳塊を熱間鍜造と切削加工により、厚さ
10mm、幅30mm、長さ60mmの板状に成形し、これを
1000〜1200℃にて焼鈍と圧延加工を繰り返しなが
ら、0.5mmの厚さとなるまで加工したが、これら
各試料の加工工程は、すべて統一させ最終加工率
は65％とした。
このようにして得られた試料につき、各種の特
性を測定した結果が下表であるが、ここで従来例
(a)(b)および本発明合金(1)〜（13）については硬さ
と引張り強さの測定用試料として、400℃にて１
時間の時効処理を施したものが用いられた。
また高温強度の測定については、次のような方
法を採用した。
前記した試料を幅20mm、長さ60mmに切断し、こ
れに通孔１を第１図のように穿設した板２と、幅
20mm、長さ150mmに切断した同試料による板３と
を、同図の如くＴ字状となるように小型精密級ト
ーチバーナにより溶接部４にて固着し、次に通孔
１に貫装した吊持杆５により、これを高温炉内に
吊して1450℃で１時間保持し、冷却後第３図のよ
うに板３の正面から見た両端部３′，３′のたわみ
量を計測するようにした。
さらに、結晶粒度については、上記のようにた
わみテストを終つた試料につき、その断面を研
磨、エツチングし測微計にて測定した。
[Industrial Application Field] The present invention relates to a platinum-based alloy that is used in various industrial instruments that require high strength. [Prior art] Conventional high-strength platinum-based alloys include platinum-iridium alloys and platinum-rhodium alloys, whose compositions are 90% Pt-Ir and 90°C Pt-Rh.
is the most common one. However, these known alloys cannot be said to have sufficiently satisfactory hardness and tensile strength.
In addition, the strength and yield strength at high temperatures are low, and the recrystallization temperature is low, causing defects such as coarsening of crystal grains, as well as problems such as pinholes and blowholes easily forming in the ingot. . [Problems to be Solved by the Invention] The present invention has investigated the drawbacks of the above-mentioned high-strength platinum-based alloys, and has solved the above-mentioned problems by adding an appropriate amount of a new element to Pt to create a ternary or higher alloy. Its purpose is to significantly improve the deficiencies of the past. [Means for solving the problems] In order to achieve the above object, the present invention includes Pt,
Ni is 1 to 15% by weight, and one or more elements selected from Ru, Ir, Rh, and W are by weight
This provides a high-strength platinum-based alloy characterized by the addition of 0.05 to 5%. [Function] In the present invention, Pt and Ni added to it are all solid solution type alloys, and by adding Ni to Pt, the matrix is strengthened. By selecting only one or more of Ru, Ir, Rh, and W, the recrystallization temperature becomes high and the material becomes microcrystalline.This is the main factor that reduces the amount of deflection at high temperatures and increases the strength at high temperatures. Also, as mentioned above, the mechanical properties such as hardness and tensile strength at room temperature were significantly improved as described below because of Ni, Ru, Ir,
It is thought that this is because the low temperature age hardening ability was dramatically improved due to the combined addition effect with elements selected from the Rh and W groups. Next, the reason why the amount of Ni to be added is 1 to 15% relative to Pt is because if it exceeds 15%, corrosion resistance, which is the most important property for a platinum alloy, will be impaired, causing a practical problem. This is because if less than % of Pt is added, the effect of reinforcing the Pt base will not be exhibited. Furthermore, regarding the addition amount of the latter selected element, if it exceeds the above 5%, the castability of the alloy will be inhibited and work hardening will become severe, making plastic working difficult.If it is less than 0.05, Ni The combined effect of addition cannot be obtained. [Example] The total amount of one sample was 400 g, and the platinum-based alloys shown in (a) to (f) below were melted and cast in an arc melting furnace after weighing the component elements for each composition. (a) Conventional example (1) 90%Pt-10%Rh (b) Conventional example (2) 90%Pt-10%Ir (c) Invention alloy (1) 95%Pt-2%Ni-1%Ir -1
%Ru−1%W (d) Invention alloy (2) 90%Pt−6%Ni−3.5%Rh−
0.5%W (e) Invention alloy (3) 85%Pt-11%Ni-3%Ir-1
%W (f) Invention alloy (4) 85%Pt-11%Ni-0.5%Rh3.5
%Ru (g) Invention alloy (5) 84.5%Pt-15%Ni-0.1%Ru
-0.1%Ir-0.1%Rh-0.2%W (h) Invention alloy (6) 88%Pt-10%Ni-2%Ru (i) Invention alloy (7) 87%Pt-8%Ni-5 %Rh (j) Invention alloy (8) 88%Pt−6%Ni−0.5%Ir−
1%Rh-4.5%W (k) Invention alloy (9) 90%Pt-5%Ni-5%Ir (l) Invention alloy (10) 85%Pt-14.5%Ni-0.3%Ru
-0.2%Ir (m) Invention alloy (11) 85%Pt-12%Ni-3%W (n) Invention alloy 84.5%Pt-13%Ni-0.5%Ir
-2%Rh (o) Invention alloy (13) 90.5%Pt-7%Ni-0.5
%Ru−0.2%W The above ingot was hot-formed and cut to a thickness of
Form into a plate shape of 10 mm, width 30 mm, and length 60 mm.
The specimens were processed by repeating annealing and rolling at 1000-1200°C until they reached a thickness of 0.5 mm, but the processing steps for these samples were all unified and the final processing rate was 65%. The table below shows the results of measuring various properties of the samples obtained in this way.
(a)(b) and alloys (1) to (13) of the present invention were used as samples for measuring hardness and tensile strength.
A material that had been subjected to a time-aging treatment was used. In addition, the following method was adopted for measuring high-temperature strength. The above-mentioned sample was cut to a width of 20 mm and a length of 60 mm, and a plate 2 with a through hole 1 as shown in Fig. 1 was cut into a piece with a width of 20 mm and a length of 60 mm.
A plate 3 made of the same sample cut into pieces of 20 mm and 150 mm in length was fixed at the welding part 4 with a small precision torch burner to form a T-shape as shown in the figure, and then a suspension penetrating through the through hole 1 was attached. This is suspended in a high-temperature furnace using a holding rod 5 and held at 1450°C for 1 hour. After cooling, the amount of deflection of both ends 3' and 3' as seen from the front of the plate 3 is measured as shown in Figure 3. I did it like that. Furthermore, the crystal grain size was measured using a micrometer after polishing and etching the cross section of the sample that had undergone the deflection test as described above.
〔発明の効果〕〔Effect of the invention〕
本発明は前記のように構成され、上記実施例の
如く具現できるものであるから、従来例に比し機
械特性は、常温ではもちろん、高温域においても
極めて優れており、結晶粒度も小さく、しかも前
記した溶解、鋳造時にあつても、ガス抜けが良好
で、ピンホールやブローホールの発生が少なく
て、加工性もよく、鋳塊表面の鋳肌も滑らかであ
ることを確認することができた。
Since the present invention is configured as described above and can be implemented as in the above embodiments, the mechanical properties are extremely superior not only at room temperature but also in a high temperature range, and the crystal grain size is small, as compared to the conventional example. Even during the above-mentioned melting and casting process, it was confirmed that gas release was good, there were few pinholes and blowholes, workability was good, and the casting surface of the ingot was smooth. .
【図面の簡単な説明】[Brief explanation of the drawing]
第１図は本発明による白金系合金により形成し
た高温強度の測定用資材を示す斜視図、第２図は
同資材に吊持杆を貫装した斜視図、第３図は第２
図のものの高温処理後における正面図である。
Fig. 1 is a perspective view showing a material for measuring high-temperature strength made of a platinum-based alloy according to the present invention, Fig. 2 is a perspective view of the same material with a hanging rod inserted through it, and Fig. 3 is a
FIG. 3 is a front view of the one shown in the figure after high-temperature treatment.