JPH0458437B2 - - Google Patents
Info
- Publication number
- JPH0458437B2 JPH0458437B2 JP11708586A JP11708586A JPH0458437B2 JP H0458437 B2 JPH0458437 B2 JP H0458437B2 JP 11708586 A JP11708586 A JP 11708586A JP 11708586 A JP11708586 A JP 11708586A JP H0458437 B2 JPH0458437 B2 JP H0458437B2
- Authority
- JP
- Japan
- Prior art keywords
- tungsten
- weight
- present
- sintering
- temperature
- 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
Links
Landscapes
- Powder Metallurgy (AREA)
- Crystals, And After-Treatments Of Crystals (AREA)
Description
〔産業上の利用分野〕
本発明はタングステン単結晶の製造法に関す
る。尚、ここでいう単結晶は径に比較して十分に
大きな長さを持つ粗大結晶をも含むものとする。
〔従来の技術〕
通常のタングステンは、1800℃〜2000℃以上に
おいて再結晶を起こし高温強度の低下する欠点が
あつた。このため結晶粒界の少ない粗大結晶タン
グステンあるいは単結晶タングステンが高温材料
として有望視されているが、従来のゾーンメルト
による単結晶の製作では製品の寸法・形状が限定
され又、時間あたりの生産量も限られる等の難点
があつた。又再結晶法による単結晶の製法として
特開昭61−6197ではタングステンにカルシウム及
びマグネシウムを添加し、所定の大きさに加工し
た後この成形体を熱処理する方法が提供されてい
るが、これら酸化物は高温で揮発するため焼結を
1800℃〜2000℃の比較的低い温度で行なう必要が
あり、そのため焼結体の比重を十分に上げること
ができず以後の加工性が悪いという欠点があつ
た。
〔発明が解決しようとする問題点〕
本発明の目的は、加工性も容易で、結晶粒界の
少ないタングステン単結晶の製造方法を提供する
ことにある。
〔問題点を解決するための手段〕
本発明の特徴は、Al2O3、K2O、SiO2を添加し
た通常のドープタングステンにZrO2を0.01重量％
〜0.05重量％添加してプレス焼結した後所定の大
きさまで加工し、次いで2600℃以上の温度に加熱
することにある。
〔作用〕
通常のタングステン材料は圧粉体を水素雰囲気
中約3000℃で焼結して成形体を得、次いで該成形
体を熱間および温間で加工することにより得られ
る。タングステン材料の製造に際し、しばしば
Al2O3、K2O、SiO2を単独又は複合で0.01重量％
〜1.0重量％添加したいわゆるドープタングステ
ンが用いられる。これらドープタングステンはタ
ングステン材料の加工性の向上に寄与する。本発
明の目的とするタングステン単結晶は、これらド
ープタングステンに更にZrO2を0.01重量％〜0.05
重量％添加し、通常の方法により所定の大きさま
で加工した後2600℃以上の温度に加熱することに
より得られる。本発明の方法に用いるZrO2は融
点が2700℃と高く通常の焼結においてもその大部
分は飛散することなく残留する。そのため焼結温
度を十分に高くすることが出来、焼結体の密度も
理論密度の90％以上となり加工性も良好である。
本発明の方法によるタングステン材料は1900℃付
近から再結晶を開始するが、2600℃以下の再結晶
粒は微細で粒状であるが2600℃以上では微細な再
結晶粒の粒界が消滅して粗大な単結晶を形成す
る。
以下実施例にそつて本発明の方法をより詳細に
説明する。
〔実施例〕
Al2O3、K2O、SiO2を複合で計0.63％添加した
ドープタングステンにZrO2を表１に示すような
割合で添加した後、圧力1.3t／cm2で成形した後、
水素中約3000℃で焼結して焼結体を得た。次いで
該焼結体を通常の方法で転打加工し線引して
φ0.39mmのワイヤーとし、水素中各温度で熱処理
して結晶粒の大きさを見た。結果はまとめて表１
に示す。
[Industrial Field of Application] The present invention relates to a method for producing tungsten single crystals. It should be noted that the term "single crystal" here includes coarse crystals having a sufficiently large length compared to the diameter. [Prior Art] Ordinary tungsten has the disadvantage that it recrystallizes at temperatures above 1800°C to 2000°C, resulting in a decrease in high-temperature strength. For this reason, coarse-crystal tungsten with few grain boundaries or single-crystal tungsten are considered promising as high-temperature materials, but the conventional method of manufacturing single crystals using zone melting limits the size and shape of the product, and the production volume per hour is limited. There were some drawbacks, such as limited availability. Furthermore, as a method for producing single crystals by recrystallization, Japanese Patent Application Laid-Open No. 61-6197 provides a method in which calcium and magnesium are added to tungsten, the molded body is processed to a predetermined size, and then the formed body is heat-treated. Sintering is necessary because the substance evaporates at high temperatures.
It is necessary to carry out the process at a relatively low temperature of 1800°C to 2000°C, which has the disadvantage that the specific gravity of the sintered body cannot be sufficiently increased and subsequent workability is poor. [Problems to be Solved by the Invention] An object of the present invention is to provide a method for producing a tungsten single crystal that is easy to process and has few grain boundaries. [Means for Solving the Problems] The feature of the present invention is that 0.01% by weight of ZrO 2 is added to ordinary doped tungsten to which Al 2 O 3 , K 2 O, and SiO 2 are added.
The method involves adding ~0.05% by weight, press sintering, processing to a predetermined size, and then heating to a temperature of 2600°C or higher. [Function] Ordinary tungsten materials are obtained by sintering a green compact at about 3000° C. in a hydrogen atmosphere to obtain a compact, and then hot and warm processing the compact. When manufacturing tungsten materials, often
Al 2 O 3 , K 2 O, SiO 2 alone or in combination 0.01% by weight
So-called doped tungsten added in an amount of ~1.0% by weight is used. These doped tungstens contribute to improving the workability of tungsten materials. The tungsten single crystal that is the object of the present invention further contains ZrO 2 in an amount of 0.01% to 0.05% by weight in addition to these doped tungstens.
It is obtained by adding % by weight, processing it to a predetermined size by a conventional method, and then heating it to a temperature of 2600°C or higher. ZrO 2 used in the method of the present invention has a high melting point of 2700°C, and most of it remains without scattering even during normal sintering. Therefore, the sintering temperature can be made sufficiently high, and the density of the sintered body is 90% or more of the theoretical density, resulting in good workability.
The tungsten material produced by the method of the present invention starts recrystallization at around 1900°C, but at temperatures below 2600°C the recrystallized grains are fine and granular, but at temperatures above 2600°C the grain boundaries of the fine recrystallized grains disappear and become coarse. form a single crystal. The method of the present invention will be explained in more detail below with reference to Examples. [Example] After adding ZrO 2 to doped tungsten containing a total of 0.63% of Al 2 O 3 , K 2 O, and SiO 2 in the proportions shown in Table 1, it was molded at a pressure of 1.3 t/cm 2 rear,
A sintered body was obtained by sintering in hydrogen at about 3000°C. The sintered body was then rolled and drawn in a conventional manner to form a wire with a diameter of 0.39 mm, and the wire was heat treated in hydrogen at various temperatures to examine the size of crystal grains. The results are summarized in Table 1.
Shown below.
以上述べてきたように本発明の方法によれば比
較的容易にタングステン単結晶を得ることがで
き、本発明の工業的利用価値は大きいと考える。
As described above, according to the method of the present invention, tungsten single crystals can be obtained relatively easily, and the present invention is considered to have great industrial utility value.
Claims (1)
量％〜1.0重量％添加したドープタングステンに
ZrO2を0.01重量％〜0.05重量％添加し、該タング
ステン粉末をプレス焼結して所定の大きさまで加
工した後2600℃以上の温度に加熱することを特徴
とするタングステン単結晶の製造法。1 Doped tungsten containing 0.01% to 1.0% by weight of Al 2 O 3 , K 2 O, and SiO 2 alone or in combination
A method for producing a tungsten single crystal, which comprises adding 0.01% to 0.05% by weight of ZrO 2 , press-sintering the tungsten powder, processing it to a predetermined size, and then heating it to a temperature of 2600° C. or higher.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11708586A JPS62275091A (en) | 1986-05-20 | 1986-05-20 | Production of tungsten single crystal |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11708586A JPS62275091A (en) | 1986-05-20 | 1986-05-20 | Production of tungsten single crystal |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS62275091A JPS62275091A (en) | 1987-11-30 |
| JPH0458437B2 true JPH0458437B2 (en) | 1992-09-17 |
Family
ID=14703021
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP11708586A Granted JPS62275091A (en) | 1986-05-20 | 1986-05-20 | Production of tungsten single crystal |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS62275091A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02160694A (en) * | 1988-12-14 | 1990-06-20 | Nippon Tungsten Co Ltd | Manufacturing method of tungsten single crystal |
| JP2794846B2 (en) * | 1989-09-28 | 1998-09-10 | 東ソー株式会社 | Giant grains or single crystals of chromium and methods for their production |
| CN102358826B (en) * | 2011-08-19 | 2013-08-07 | 湖南皓志新材料股份有限公司 | A kind of preparation method of aluminum-doped zirconia composite polishing powder |
-
1986
- 1986-05-20 JP JP11708586A patent/JPS62275091A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS62275091A (en) | 1987-11-30 |
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