JPH0544596B2 - - Google Patents
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- Publication number
- JPH0544596B2 JPH0544596B2 JP29867087A JP29867087A JPH0544596B2 JP H0544596 B2 JPH0544596 B2 JP H0544596B2 JP 29867087 A JP29867087 A JP 29867087A JP 29867087 A JP29867087 A JP 29867087A JP H0544596 B2 JPH0544596 B2 JP H0544596B2
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- JP
- Japan
- Prior art keywords
- coating layer
- crucible
- base material
- corrosion
- base
- Prior art date
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Description
［発明の目的］
（産業上の利用分野）
本発明は溶融金属に対する耐食性および耐熱性
コーテイング層を備えた金属溶解用るつぼに関す
る。
（従来の技術）
チタニウム、ジルコニウム、ウラニウムのよう
な化学的に活性で、かつ比較的融点の高い金属溶
解用るつぼ材としてはタングステン、タンタル、
モリブデン、ニオブ等の高融点金属またはグラフ
アイトが使用されている。しかし、これらの高融
点金属は上記のような活性金属と直接接触すると
反応したり、また合金化してるつぼが溶解した
り、浸食されるばかりでなく、溶湯中に解け出し
溶湯純度を低下させる要因となつている。
したがつて、これら高融点金属の基材内面には
溶融金属溶湯、ジルコニウム、ウラニウムに対し
て耐熱性、耐食性にすぐれたイツトリア
（Y2O3）、ハフニア（HfO2）等のセラミツクコー
テイング層を施している。また、この場合、イツ
トリア、ハフニア等のセラミツク・コーテイング
層と基材との熱膨脹係数の差に基づく熱応力によ
るコーテイング層が剥離するのを防止するため
に、セラミツクコーテイング層と基材との間に、
両者の中間的熱膨脹係数を有する高融点金属また
はセラミツクの下地層を設けたものが提案されて
いる。
このような耐食コーテイング層を有する耐熱部
材を採用した一例として、第５図に示すようにチ
タン金属溶解用るつぼがあげられる。このるつぼ
はグラフイツトによつて形成された基材１の内面
にニオブの下地コーテイング層２を施した上にイ
ツトリアのセラミツクコーテイング層３が設けら
れたもので、耐食コーテイング層３内にチタニウ
ム金属溶湯７を収容するようになつている。な
お、このるつぼは冷却機能を有した冷却用ハース
６の中に収納され使用される。
また、このような内面下地および耐食コーテイ
ング層２，３は、たとえばプラズマ溶射法によつ
て厚さ0.1〜5.0mm程度に形成され、第５図中のＢ
部を拡大した第６図ａに示されるように、通常、
そのコーテイング層２，３の内部に10〜30％の空
孔８を有している。
（発明が解決しようとする問題点）
たとえば上述のるつぼに収容されたチタニウム
の金属溶湯７が適宜の手段を用いて加熱、溶融さ
れると溶融したチタニウムの金属溶湯７と接する
コーテイング層３内面と冷却用ハース６と接する
基材１の外面との温度差は1500〜2200℃となる。
その際、耐食コーテイング層３のセラミツクコー
テイング層材イツトリアの熱伝導率は基材１であ
るグラフアイト、内面下地コーテイング層２のニ
オブに比べ著しく小さいため、るつぼの板厚方向
の温度分布は第６図ｂに示したようになる。すな
わち、前述の温度差のほとんどは耐食コーテイン
グ層３間で生じ、その熱圧力によりコーテイング
層３は剥離もしく破損する。
さらに上記コーテイング層２，３を形成する溶
射被膜内には10〜30％の空孔８を有しているの
で、このるつぼを用いてたとえばチタニウムを溶
解すると、溶解したチタニウムの金属溶湯７が空
孔８内に浸透し、下地コーテイング層２や基材１
と接触、反応し、溶融させることにより表面の耐
食コーテイング層３を剥離させるとともに基材１
を浸食する。
また、基材１とし下地コーテイング層２の界面
および下地コーテイング層２と耐食コーテイング
層３の界面のような溶射被膜界面は全く化学的反
応を伴わず、単に機械的に結合しているので、そ
の密着力は著しく低く、チタニウム金属溶湯７の
凝固時の収縮によりコーテイング層が引きはがさ
れるという問題点があつた。
本発明の目的は上記問題点を解決するためにな
されたもので、長時間の繰り返し活性金属の溶解
対する耐久性を著しく向上させたコーテイング層
を有するるつぼを提供することにある。
［発明の構成］
（問題点を解決するための手段）
本発明は、基材の内面にセラミツクス材からな
る下地コーテイング層を介して耐食コーテイング
層を設けた金属溶解用るつぼにおいて、前記下地
コーテイング層を前記基材の内、外面に設け、か
つ外面下地コーテイング層の外面に断熱コーテイ
ング層を設けてなることを特徴とする。また、本
発明では基材にセラミツク材をコーテイング層
後、加圧処理を施してなることを特徴とする。
（作用）
第１図のＡ部を拡大した第２図ａに、るつぼの
縦断面を拡大して示すように、基材１の内面に下
地コーテイング層２を介して耐食コーテイング層
３を施した後、るつぼ基材１の外面に高融点金属
などの外面下地コーテイング層４を施し、そのコ
ーテイング層４の外面にセラミツクの断熱コーテ
イング層５を設けることにより、るつぼ断面の温
度分布は第２図ｂに示したようになる。従来例で
は第６図ｂに示したように基材１の内面に設けた
耐食コーテイング層３が同時に断熱の役割をして
いたので、耐食コーテイング層３間の温度差が大
きく、その熱応力により破損していた。これに対
して本発明では、第２図ｂに示したように、外面
下地コーテイング層４の外面にも基材１より熱伝
導率が小さくかつ厚い断熱コーテイング層５を設
けることにより、同コーテイング層５内で大きな
温度勾配を持たせることができる。その結果、耐
食コーテイング層３内の温度低下を著しく低減で
き、熱応力による耐食コーテイング層３の破損を
完全に防止できる。
またプラズマ溶射などの比較的容易に膜厚をコ
ントロールできる手法を用いることにより、耐食
コーテイング層３および断熱コーテイング層５の
厚さを変えることができるので、溶解する材料、
金属溶湯７と耐食コーテイング層３の材料との反
応開始温度、各使用材料の熱伝導率等に合わせ
て、るつぼの熱伝導率を自由に決めることも可能
である。
さらに、このようなるつぼを熱間静水圧加圧法
（HIP）、冷間静水圧加圧法（CIP）、ホツトプレ
ス法等により加熱、加圧処理を施すことにより、
従来１〜30％存在していた溶射被膜中の空孔８を
数％以下に低減し、緻密化することで、金属溶湯
７の耐食コーテイング層３内への浸透を防止する
とともに、他に機械的アンカー効果により結合し
ていた基材１と下地コーテイング層２、下地コー
テイング層２と耐食コーテイング層３の界面を、
拡散反応により強固な結合力を得ることができ
る。その結果、従来の加圧・加熱処理を施さない
場合に比較るつぼの寿命は飛躍的に向上する。
（実施例）
以下、本発明に係る金属溶融用るつぼの一実施
例を、第１図を参照して説明する。
第１図においてＶ字形容器状にタングステンに
より形成した基材１の内面にニオブからなる内面
下地コーテイング層２と、イツトリアからなる耐
食コーテイング層３を施し、また基材１の外面に
同じくニオブの外面下地コーテイング層４とジル
コニアの断熱コーテイング層５を施した。
このようにして形成されたるつぼにおのおのコ
ーテイング層の緻密化と密着強度向上のためHIP
処理（熱間静水圧加圧法）を行つた。HIP処理は
このるつぼを窒化ボロン粉末とともに鉄製容器内
に真空封入し、Arガスを媒体として、加圧・加
熱処理を行つた。なおHIP処理は、1200〜1500
℃、1000〜1500KgＰ／cm2で、60〜120分間保持の
条件で行つた。
このようにして得られたるつぼは、冷却用の銅
製ハース６内に外壁が密着するような形で遅めら
れており、るつぼ内にはチタン７を収容してい
る。なお、基材１の内、外面の下地コーテイング
層２，４プラズマ溶射により施工し、また耐食コ
ーテイング層３の膜厚は200μｍ、断熱コーテイ
ング層５の膜厚は1000μｍにプラズマ溶射で形成
した。
しかして、本発明において、基材１はＷ、
Mo、Ta、Nb等の高融点金属およびグラフアイ
トが良いが、耐食コーテイング層３が破損し、溶
融金属が浸透した場合を考慮すると、Ti、Zr、
Ｕなどの金属溶湯７にある程度の耐食性を有して
いるＷまたはTaが望ましい。
基板１の内面に施す耐食コーテイング層３の材
質はTi、Zr、Ｕなどの溶湯に対し反応開始温度
ができるだけ高いものが良く、Y2O3以外にも
ThO2、UO2、HfO、BeO等であつても良い。ま
た、耐食コーテイング層５の材質は耐食コーテイ
ング層３と同じでも良いが金属溶湯７に対する耐
食性はあまり必要としないため、コーテイング層
が、容易でかつ薄膜でも充分な熱伝導率となる
ZrO2、Al2O3、MgO、TiO2、等が望ましい。
また、内外面のコーテイング層３，５の下地コ
ーテイング層２，４の材質としては融点が高く、
しかも基材１とコーテイング層３，５との中間的
な熱膨脹係数を有するものが適しており、Nb以
外に、Ti、Cr、Ｖ、Ru、Rh、およびAl2O3でも
良い。
このようにして基材１内の内、外両面にセラミ
ツクの下地コーテイング層２，４を設けることに
より、るつぼ断面方向の温度分布は第２図ｂ示し
たようになる。うなわち熱伝導率が小さく、大き
な温度勾配を生じるコーテイング層間の温度差を
従来例に比べ半減でき、その結果、熱対応力によ
るコーテイング層３，５の剥離、破損を完全に防
止できる。
さらに、基材１にコーテイング層２，３，４，
５を溶射施工後、加圧、加熱処理を施すことによ
り、溶射被膜コーテイング層内の空孔８の量を著
しく低減でき、また空孔８の形態も三次元的につ
ながつた開気孔へと変わるため、耐食コーテイン
グ層３内への金属溶湯７の浸透はなくなる。ま
た、溶射コーテイング層界面での拡散反応によ
り、その密着強度を著しく向上し、金属溶湯７の
凝固収縮に際しても耐食コーテイング層３が剥離
することはない。
上記実施例と従来例との比較実験を行つた際の
基材とコーテイング層材質の組合せを第１表に示
す。
[Object of the invention] (Industrial field of application) The present invention relates to a metal melting crucible provided with a corrosion-resistant and heat-resistant coating layer for molten metal. (Prior art) Tungsten, tantalum,
Refractory metals such as molybdenum and niobium or graphite are used. However, when these high-melting-point metals come into direct contact with the active metals mentioned above, they may react or become alloyed, causing the crucible to melt or erode, as well as melting into the molten metal and reducing the purity of the molten metal. It is becoming. Therefore, a ceramic coating layer such as yttoria (Y 2 O 3 ) or hafnia (HfO 2 ), which has excellent heat resistance and corrosion resistance against molten metal, zirconium, and uranium, is applied to the inner surface of the base material of these high-melting point metals. are giving. In this case, in order to prevent the coating layer from peeling off due to thermal stress due to the difference in coefficient of thermal expansion between the ceramic coating layer and the base material, such as itria or hafnia, there is a gap between the ceramic coating layer and the base material. ,
It has been proposed to provide an underlayer of a high melting point metal or ceramic having a coefficient of thermal expansion intermediate between the two. An example of a heat-resistant member having such a corrosion-resistant coating layer is a crucible for melting titanium metal, as shown in FIG. This crucible has a base coating layer 2 of niobium applied to the inner surface of a base material 1 made of graphite, and a ceramic coating layer 3 made of yttoria. It is designed to accommodate. Note that this crucible is used while being housed in a cooling hearth 6 having a cooling function. Further, such inner surface base and corrosion-resistant coating layers 2 and 3 are formed to a thickness of about 0.1 to 5.0 mm by, for example, plasma spraying, and are shown in B in FIG.
As shown in FIG. 6a, which is an enlarged view of the
The coating layers 2 and 3 have 10 to 30% pores 8 inside. (Problems to be Solved by the Invention) For example, when the molten titanium metal 7 contained in the crucible described above is heated and melted using an appropriate means, the inner surface of the coating layer 3 in contact with the molten titanium metal 7. The temperature difference between the outer surface of the base material 1 in contact with the cooling hearth 6 is 1500 to 2200°C.
At this time, the thermal conductivity of the ceramic coating layer material Ittria of the corrosion-resistant coating layer 3 is significantly lower than that of graphite, which is the base material 1, and niobium, which is the inner surface base coating layer 2, so the temperature distribution in the thickness direction of the crucible is The result is as shown in Figure b. That is, most of the temperature difference mentioned above occurs between the corrosion-resistant coating layers 3, and the coating layer 3 is peeled off or damaged due to the thermal pressure. Furthermore, since the thermal spray coating forming the coating layers 2 and 3 has 10 to 30% pores 8, when titanium, for example, is melted using this crucible, the molten titanium metal 7 will have vacancies. Penetrates into the holes 8 and forms the base coating layer 2 and base material 1.
The corrosion-resistant coating layer 3 on the surface is peeled off by contacting, reacting with, and melting the base material 1.
erode. In addition, the thermal sprayed coating interfaces, such as the interface between the base material 1 and the base coating layer 2, and the interface between the base coating layer 2 and the corrosion-resistant coating layer 3, do not involve any chemical reaction and are simply mechanically bonded. The adhesion was extremely low, and there was a problem in that the coating layer was peeled off due to contraction during solidification of the molten titanium metal 7. The object of the present invention was to solve the above-mentioned problems, and it is an object of the present invention to provide a crucible having a coating layer that has significantly improved durability against repeated melting of active metals over a long period of time. [Structure of the Invention] (Means for Solving the Problems) The present invention provides a crucible for metal melting in which a corrosion-resistant coating layer is provided on the inner surface of a base material via a base coating layer made of a ceramic material. are provided on the inner and outer surfaces of the base material, and a heat insulating coating layer is provided on the outer surface of the outer surface base coating layer. Further, the present invention is characterized in that the base material is coated with a ceramic material and then subjected to pressure treatment. (Function) As shown in FIG. 2a, which is an enlarged view of part A in FIG. After that, an outer base coating layer 4 made of a high melting point metal or the like is applied to the outer surface of the crucible base material 1, and a heat insulating coating layer 5 made of ceramic is provided on the outer surface of the coating layer 4, so that the temperature distribution in the cross section of the crucible is as shown in FIG. 2b. The result will be as shown in . In the conventional example, as shown in FIG. 6b, the corrosion-resistant coating layer 3 provided on the inner surface of the base material 1 also served as a heat insulator, so the temperature difference between the corrosion-resistant coating layers 3 was large and the thermal stress caused It was damaged. In contrast, in the present invention, as shown in FIG. 2b, a heat insulating coating layer 5 having a thermal conductivity lower than that of the base material 1 and thicker is also provided on the outer surface of the outer surface base coating layer 4. It is possible to have a large temperature gradient within 5. As a result, the temperature drop within the corrosion-resistant coating layer 3 can be significantly reduced, and damage to the corrosion-resistant coating layer 3 due to thermal stress can be completely prevented. In addition, by using a method that allows relatively easy control of the film thickness, such as plasma spraying, the thickness of the corrosion-resistant coating layer 3 and the heat-insulating coating layer 5 can be changed.
It is also possible to freely determine the thermal conductivity of the crucible in accordance with the reaction start temperature between the molten metal 7 and the material of the corrosion-resistant coating layer 3, the thermal conductivity of each material used, etc. Furthermore, by heating and pressurizing such a crucible using hot isostatic pressing (HIP), cold isostatic pressing (CIP), hot pressing, etc.
By reducing the pores 8 in the thermal spray coating, which conventionally existed from 1 to 30%, to a few percent or less and making it denser, it is possible to prevent the molten metal 7 from penetrating into the corrosion-resistant coating layer 3, and to prevent other mechanical The interface between the base material 1 and the base coating layer 2, the base coating layer 2 and the corrosion-resistant coating layer 3, which were bonded by the physical anchor effect,
A strong bonding force can be obtained through a diffusion reaction. As a result, the life of the crucible is dramatically improved compared to the case where the conventional pressure and heat treatment is not performed. (Example) Hereinafter, an example of a metal melting crucible according to the present invention will be described with reference to FIG. 1. In FIG. 1, an inner surface base coating layer 2 made of niobium and a corrosion-resistant coating layer 3 made of yttoria are applied to the inner surface of a base material 1 formed of tungsten in the shape of a V-shaped container, and the outer surface of the base material 1 is also made of niobium. A base coating layer 4 and a heat insulating coating layer 5 of zirconia were applied. HIP is applied to the crucible formed in this way to make each coating layer denser and to improve adhesion strength.
Treatment (hot isostatic pressing method) was performed. In the HIP process, this crucible was vacuum-sealed together with boron nitride powder in an iron container, and pressure and heat treatment was performed using Ar gas as a medium. In addition, HIP processing is 1200 to 1500
The test was carried out under conditions of holding at 1000 to 1500 KgP/cm 2 for 60 to 120 minutes. The crucible thus obtained is slowed in such a way that its outer wall is in close contact with a copper hearth 6 for cooling, and titanium 7 is contained within the crucible. The base coating layers 2 and 4 on the inner and outer surfaces of the base material 1 were applied by plasma spraying, and the corrosion-resistant coating layer 3 was formed in a thickness of 200 μm, and the heat-insulating coating layer 5 was formed in a thickness of 1000 μm by plasma spraying. Therefore, in the present invention, the base material 1 is W,
High-melting point metals such as Mo, Ta, and Nb and graphite are good, but considering the case where the corrosion-resistant coating layer 3 is damaged and molten metal penetrates, Ti, Zr,
W or Ta, which has a certain degree of corrosion resistance to the molten metal 7 such as U, is preferable. The material for the corrosion-resistant coating layer 3 applied to the inner surface of the substrate 1 is preferably one that has a reaction initiation temperature as high as possible with respect to molten metals such as Ti, Zr, and U;
It may also be ThO 2 , UO 2 , HfO, BeO, etc. Further, the material of the corrosion-resistant coating layer 5 may be the same as that of the corrosion-resistant coating layer 3, but since corrosion resistance against the molten metal 7 is not required, the coating layer can be formed easily and has sufficient thermal conductivity even if it is a thin film.
ZrO 2 , Al 2 O 3 , MgO, TiO 2 , etc. are desirable. In addition, the material of the base coating layers 2 and 4 of the inner and outer coating layers 3 and 5 has a high melting point;
Moreover, a material having a thermal expansion coefficient intermediate between that of the base material 1 and the coating layers 3 and 5 is suitable, and in addition to Nb, Ti, Cr, V, Ru, Rh, and Al 2 O 3 may also be used. By providing the ceramic base coating layers 2 and 4 on both the inner and outer surfaces of the base material 1 in this manner, the temperature distribution in the cross-sectional direction of the crucible becomes as shown in FIG. 2b. In other words, the temperature difference between the coating layers, which have low thermal conductivity and cause a large temperature gradient, can be halved compared to the conventional example, and as a result, peeling and damage of the coating layers 3 and 5 due to thermal response force can be completely prevented. Furthermore, coating layers 2, 3, 4,
By applying pressure and heat treatment after thermal spraying 5, the amount of pores 8 in the thermal spray coating layer can be significantly reduced, and the shape of pores 8 changes to three-dimensionally connected open pores. Therefore, the penetration of the molten metal 7 into the corrosion-resistant coating layer 3 is eliminated. Further, due to the diffusion reaction at the interface of the thermally sprayed coating layer, the adhesion strength is significantly improved, and the corrosion-resistant coating layer 3 will not peel off even when the molten metal 7 solidifies and shrinks. Table 1 shows the combinations of base materials and coating layer materials used in comparative experiments between the above embodiment and the conventional example.
【表】
本実施例では第１表に示した構成を有する第１
図に示したような内径４０mm、高さ35mmのるつぼ
を形成し、そのるつぼ内にチタニムを入れ、電子
ビームで溶解した。その際、室温（RT）と1800
℃（るつぼ内面温度）との間を繰り返し加熱し、
目視により耐食コーテイング層に割れまたは剥離
が生じるまでの回数を測定した結果を第３図に示
す。第３図中、よこ軸は従来例と実施例を、たて
軸は亀裂または剥離発生での繰り返し加熱回数で
ある。
第３図から有らかなように、内面のみ耐食コー
テイング層を施した従来例では全べて１〜２回の
加熱により、内面コーテイング層に亀裂が発生し
た。これに対して内、外面にコーテイング層を施
した本発明例では20回以上の繰り返しに耐え、コ
ーテイング層の破壊形態も熱応力による亀裂の発
生は認められなかつた。
また、基材の内外面にセラミツクをコーテイン
グ層後、HIP処理を施して形成したるつぼ（実施
例）はコーテイング層の密着強度が向上し、コ
ーテイング層が剥離するまでの加熱繰り返し数
は、同じ構成でHIP処理しない場合（実施例）
に比較して1.5倍近くであつた。
さらに、実施例と実施例の構成を有するる
つぼを用い、るつぼの内面温度を1800℃と一定と
した場合の腐食減量を第４図に示す。なお、第４
図よこ軸は浸漬時間、たて軸は腐食減量を示して
いる。第４図から明らかのようにHIP処理を実施
しなかつた実施例の場合には溶融チタニウムコ
ーテイング層内の空孔を浸透し、基材と反応、溶
解することによりコーテイング層が剥離したた
め、腐食減量に増加するのが認められた。これに
対し、HIP処理を施した実施例の場合には空孔
が著しく低減されているため、溶融チタニウムの
空孔内へ浸透は起こらず腐食減量はほとんど認め
られなかつた。
［発明の効果］
本発明によれば長時間かつ繰り返しの高湿負荷
に対して耐久性も向上させた寿命の長い活性金属
溶解用るつぼを提供することができる。[Table] In this example, the first
A crucible with an inner diameter of 40 mm and a height of 35 mm as shown in the figure was formed, and titanium was placed in the crucible and melted with an electron beam. At that time, room temperature (RT) and 1800
℃ (inner surface temperature of the crucible) repeatedly.
FIG. 3 shows the results of visually measuring the number of times it takes for the corrosion-resistant coating layer to crack or peel. In FIG. 3, the horizontal axis represents the conventional example and the example, and the vertical axis represents the number of repeated heating times at which cracks or peeling occurred. As is obvious from FIG. 3, in all conventional examples in which a corrosion-resistant coating layer was applied only to the inner surface, cracks occurred in the inner surface coating layer after heating once or twice. On the other hand, the example of the present invention in which a coating layer was applied to the inner and outer surfaces was able to withstand more than 20 repetitions, and no cracking due to thermal stress was observed in the coating layer. In addition, in the crucible (example) formed by applying HIP treatment after coating the inner and outer surfaces of the base material with ceramic, the adhesion strength of the coating layer is improved, and the number of heating cycles until the coating layer peels off is the same as that of the same structure. When HIP processing is not performed (example)
It was nearly 1.5 times that of the previous year. Further, FIG. 4 shows the corrosion loss when crucibles having the configurations of Examples and Examples were used and the internal temperature of the crucible was kept constant at 1800°C. In addition, the fourth
The horizontal axis of the figure shows the immersion time, and the vertical axis shows the corrosion loss. As is clear from Figure 4, in the case of the example in which HIP treatment was not performed, the molten titanium penetrated through the pores in the coating layer, reacted with the base material, and dissolved, causing the coating layer to peel off, resulting in corrosion loss. was observed to increase. On the other hand, in the case of the example in which HIP treatment was performed, the pores were significantly reduced, so that molten titanium did not penetrate into the pores and almost no corrosion loss was observed. [Effects of the Invention] According to the present invention, it is possible to provide a crucible for melting active metals with a long life and improved durability against long-term and repeated high-humidity loads.
第１図は本発明に係る金属溶解用るつぼの一実
施例を示す縦断面図、第２図ａは第１図のＡ部を
拡大して示す部分断面図、第２図ｂは第２図ａに
対応した断面の温度分布を示す特性図、第３図は
従来例と本発明例との亀裂または剥離発生状態を
比較して示す特性図、第４図は本発明例における
浸漬時間と腐食減量との関係を示す特性図、第５
図は従来の活性金属溶解用るつぼを示す縦断面
図、第６図ａは第５図のＢ部を拡大して示す部分
断面図、第６図ｂは第６図ａに対応した断面の温
度の分布を示す特性図である。
１……基材、２……内面下地コーテイング層、
３……耐食コーテイング層、４……外面下地コー
テイング層、５……断熱コーテイング層、６……
冷却用ハース、７……金属溶湯、８……空孔。
FIG. 1 is a vertical sectional view showing an embodiment of a metal melting crucible according to the present invention, FIG. Figure 3 is a characteristic diagram showing the temperature distribution of the cross section corresponding to a. Figure 3 is a characteristic diagram comparing the occurrence of cracks or peeling between the conventional example and the example of the present invention. Figure 4 is the immersion time and corrosion in the example of the present invention. Characteristic diagram showing the relationship with weight loss, 5th
The figure is a vertical cross-sectional view showing a conventional crucible for melting active metals, Figure 6a is a partial cross-sectional view showing an enlarged section B in Figure 5, and Figure 6b is the temperature of the cross section corresponding to Figure 6a. FIG. 1...Base material, 2...Inner base coating layer,
3...Corrosion-resistant coating layer, 4...External base coating layer, 5...Heat-insulating coating layer, 6...
Cooling hearth, 7... Molten metal, 8... Hole.
Claims (1)
下地コーテイング層を介して耐食コーテイング層
を設けた金属溶解用るつぼにおいて、前記下地コ
ーテイング層を前記基材の内、外面に設け、かつ
外面下地コーテイング層の外面に断熱コーテイン
グ層を設けてなることを特徴とする金属溶解用る
つぼ。 ２ 前記基材はＷ、Ta、Mo、Nbおよびこれら
を主成分とする合金、またはグラフアイトから選
択された少なくとも１種からなるものであること
を特徴とする特許請求の範囲第１項記載の金属溶
解用るつぼ。 ３ 前記耐食コーテイング層は、Y2O3、ThO2、
UO2、HfO2、BeO、TaC、HfC、Ho2O3、
Tm2O3、Er2O3、Nd2O3から選択された少なくと
も１種からなるものであることを特徴とする特許
請求の範囲第１項記載の金属溶解用るつぼ。 ４ 前記断熱コーテイング層は安定化ZrO2、
ThO2、MgO、TiO2、Y2O3、ZrSiO4から選択さ
れた少なくとも１種からなるものであることを特
徴とする特許請求の範囲第１項記載の金属溶解用
るつぼ。 ５ 前記基材耐食コーテイング層および基材と断
熱コーテイング層の下地コーテイング層として
は、Ta、Nb、Ti、Ｖ、RhおよびAl2O3から選択
された少なくとも１種からなるものであることを
特徴とする特許請求の範囲第１項記載の金属溶解
用るつぼ。 ６ 前記基材にコーテイング層を施した後、加
熱、加圧処理が施されたことを特徴とする特許請
求の範囲第１項記載の金属溶解用るつぼ。 ７ 前記加熱、加圧処理手段として熱間静水圧加
圧法、冷間静水圧加圧法、ホツトプレス法のいず
れかを用いられることを特徴とする特許請求の範
囲第６項記載の金属溶解用るつぼ。[Scope of Claims] 1. A crucible for metal melting in which a corrosion-resistant coating layer is provided on the inner surface of a crucible base material via a base coating layer made of a ceramic material, the base coating layer being provided on the inner and outer surfaces of the base material, A crucible for metal melting, characterized in that a heat insulating coating layer is provided on the outer surface of the outer surface base coating layer. 2. The base material according to claim 1, wherein the base material is made of at least one selected from W, Ta, Mo, Nb, alloys containing these as main components, or graphite. Crucible for metal melting. 3 The corrosion-resistant coating layer contains Y 2 O 3 , ThO 2 ,
UO2 , HfO2 , BeO, TaC, HfC, Ho2O3 ,
The crucible for metal melting according to claim 1, characterized in that it is made of at least one selected from Tm 2 O 3 , Er 2 O 3 , and Nd 2 O 3 . 4. The thermal insulation coating layer is stabilized ZrO 2 ,
The crucible for metal melting according to claim 1, characterized in that it is made of at least one selected from ThO 2 , MgO, TiO 2 , Y 2 O 3 and ZrSiO 4 . 5. The base coating layer of the base material corrosion-resistant coating layer and the base material and heat-insulating coating layer is made of at least one selected from Ta, Nb, Ti, V, Rh, and Al 2 O 3 . A crucible for metal melting according to claim 1. 6. The metal melting crucible according to claim 1, wherein the base material is subjected to heating and pressure treatment after the coating layer is applied thereto. 7. The metal melting crucible according to claim 6, wherein any one of a hot isostatic pressing method, a cold isostatic pressing method, and a hot pressing method is used as the heating and pressurizing treatment means.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP29867087A JPH01139988A (en) | 1987-11-26 | 1987-11-26 | Crucible for melting metal |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP29867087A JPH01139988A (en) | 1987-11-26 | 1987-11-26 | Crucible for melting metal |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01139988A JPH01139988A (en) | 1989-06-01 |
| JPH0544596B2 true JPH0544596B2 (en) | 1993-07-06 |
Family
ID=17862748
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP29867087A Granted JPH01139988A (en) | 1987-11-26 | 1987-11-26 | Crucible for melting metal |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH01139988A (en) |
Families Citing this family (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20080292804A1 (en) | 2007-04-30 | 2008-11-27 | Bernard Patrick Bewlay | Methods for making refractory crucibles for melting titanium alloys |
| US8048365B2 (en) * | 2007-04-30 | 2011-11-01 | General Electric Company | Crucibles for melting titanium alloys |
| JP5572296B2 (en) * | 2008-08-11 | 2014-08-13 | 株式会社アルバック | Water-cooled crucible and electron beam melting furnace |
| DE102011000502A1 (en) * | 2011-02-04 | 2012-08-09 | Solibro Gmbh | Separator and method of making a crucible therefor |
| US8858697B2 (en) | 2011-10-28 | 2014-10-14 | General Electric Company | Mold compositions |
| US9011205B2 (en) | 2012-02-15 | 2015-04-21 | General Electric Company | Titanium aluminide article with improved surface finish |
| US8932518B2 (en) | 2012-02-29 | 2015-01-13 | General Electric Company | Mold and facecoat compositions |
| US20150128849A1 (en) * | 2012-04-17 | 2015-05-14 | Plansee Se | Crucible for the manufacture of oxide ceramic single crystals |
| US8906292B2 (en) | 2012-07-27 | 2014-12-09 | General Electric Company | Crucible and facecoat compositions |
| US8992824B2 (en) | 2012-12-04 | 2015-03-31 | General Electric Company | Crucible and extrinsic facecoat compositions |
| US9592548B2 (en) | 2013-01-29 | 2017-03-14 | General Electric Company | Calcium hexaluminate-containing mold and facecoat compositions and methods for casting titanium and titanium aluminide alloys |
| US9511417B2 (en) | 2013-11-26 | 2016-12-06 | General Electric Company | Silicon carbide-containing mold and facecoat compositions and methods for casting titanium and titanium aluminide alloys |
| US9192983B2 (en) | 2013-11-26 | 2015-11-24 | General Electric Company | Silicon carbide-containing mold and facecoat compositions and methods for casting titanium and titanium aluminide alloys |
| US10391547B2 (en) | 2014-06-04 | 2019-08-27 | General Electric Company | Casting mold of grading with silicon carbide |
| CN105732061A (en) * | 2016-03-11 | 2016-07-06 | 江苏航泰新材料有限公司 | Lithium fluoride-doped zirconia crucible and method for producing lithium fluoride-doped zirconia crucible by hot-pressing sintering |
-
1987
- 1987-11-26 JP JP29867087A patent/JPH01139988A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPH01139988A (en) | 1989-06-01 |
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