JPH082969A - Composite sintered compact and its use - Google Patents
Composite sintered compact and its useInfo
- Publication number
- JPH082969A JPH082969A JP6137547A JP13754794A JPH082969A JP H082969 A JPH082969 A JP H082969A JP 6137547 A JP6137547 A JP 6137547A JP 13754794 A JP13754794 A JP 13754794A JP H082969 A JPH082969 A JP H082969A
- Authority
- JP
- Japan
- Prior art keywords
- molten metal
- temperature
- protective tube
- composite sintered
- weight
- 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.)
- Granted
Links
Landscapes
- Measuring Temperature Or Quantity Of Heat (AREA)
- Ceramic Products (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、Ｓｉ3 Ｎ4 、ＡｌＮ、
Ａｌ2 Ｏ3 及びＢＮを含む混合粉末を焼結して得られた
複合焼結体とその用途に関する。詳しくは、溶融金属の
温度を放射温度計で繰返し測定するのに好適な耐食性、
耐熱衝撃性、耐酸化性に優れ、ガス発生の少ない複合焼
結体とその複合焼結体で構成された溶融金属測温用保護
管に関するものである。The present invention relates to Si 3 N 4 , AlN,
The present invention relates to a composite sintered body obtained by sintering a mixed powder containing Al 2 O 3 and BN and its use. Specifically, corrosion resistance suitable for repeatedly measuring the temperature of molten metal with a radiation thermometer,
The present invention relates to a composite sintered body which has excellent heat shock resistance and oxidation resistance and generates little gas, and a protective tube for molten metal temperature measurement which is composed of the composite sintered body.
【０００２】[0002]
【従来の技術】従来、溶融金属の測温については消耗型
浸漬熱電対による方法が知られている（例えば特公昭53
-47711号公報）。この熱電対は、ライフ１〜２回の消耗
型であるので容易に測温できるが繰返して使用すること
ができず、また外筒は紙であるので測温時に焼けたカス
が溶融金属内に混入する等の問題があった。また、熱電
対素線をＢＮ製保護管に差し込んで連続的に測温する技
術もあるが、熱電対保護管の取り付け構造が複雑になる
等の問題があった。2. Description of the Related Art Conventionally, a method using a consumable immersion thermocouple has been known for measuring the temperature of molten metal (for example, Japanese Patent Publication No. 53).
-47711 publication). Since this thermocouple is a consumable type with a life of 1 to 2 times, it can easily measure temperature, but it can not be used repeatedly, and since the outer cylinder is paper, burned debris at the time of temperature measurement is inside the molten metal. There was a problem such as mixing. Also, there is a technique for continuously measuring temperature by inserting a thermocouple wire into a BN protective tube, but there is a problem that the mounting structure of the thermocouple protective tube becomes complicated.
【０００３】一方、Ｓｉ3 Ｎ4 、ＡｌＮ、Ａｌ2 Ｏ3 及
びＢＮを複合した溶湯金属の耐食性部材については、以
下の公知がある。 （ａ）窒化珪素又はサイアロンからなる内層と窒化硼
素、二酸化珪素及び窒化アルミニウムを主成分とする外
層とからなり、前記内層と前記外層とが一体的に焼結さ
れてなる溶湯浸漬用部材（特開平２−３８３９１号公
報）。On the other hand, there are the following publicly known corrosion-resistant members of molten metal composed of Si 3 N 4 , AlN, Al 2 O 3 and BN. (A) A member for immersing molten metal, which is composed of an inner layer made of silicon nitride or sialon and an outer layer containing boron nitride, silicon dioxide and aluminum nitride as main components, and the inner layer and the outer layer are integrally sintered (special feature: (Kaihei 2-38391).
【０００４】（ｂ）一般式Ｓｉ6-Z ＡｌZ ＯZ Ｎ
8-Z （但しＺは０．８〜２．０）で表わされるβサイア
ロン４０〜８０重量％、六方晶窒化硼素８〜４０重量％
及びジルコニア１０〜４０重量％からなり、前記βサイ
アロンのマトリックス中に六方晶窒化硼素とジルコニア
が分散した焼結体によって構成されてなる水平連続鋳造
用ブレークリング（特開平２−２５５２４８号公報）。(B) General formula Si 6-Z Al Z O Z N
Β-sialon represented by 8-Z (where Z is 0.8 to 2.0) 40 to 80% by weight, hexagonal boron nitride 8 to 40% by weight
And 10 to 40% by weight of zirconia, and a break ring for horizontal continuous casting (Japanese Unexamined Patent Publication No. 2-255248), which is composed of a sintered body in which hexagonal boron nitride and zirconia are dispersed in the β-sialon matrix.
【０００５】しかしながら、（ａ）の技術では、高密度
（相対密度９９％）、高強度（曲げ強度８０ｋｇ／ｍｍ
2 ：常温及び１０００℃）の焼結体が得られる反面、耐
熱衝撃性ΔＴが６００℃と低いので鋳鉄、合金等の高融
点金属の温度を繰返し測定するには不適当である。However, in the technique (a), high density (relative density 99%) and high strength (flexural strength 80 kg / mm
2 : Sintered bodies at room temperature and 1000 ° C) can be obtained, but on the other hand, the thermal shock resistance ΔT is as low as 600 ° C, which is not suitable for repeatedly measuring the temperature of refractory metals such as cast iron and alloys.
【０００６】一方、（ｂ）の技術は、高融点金属に対す
る耐食性に優れている反面、水中急冷法による曲げ強度
が１０％劣化する温度が５８１〜６１４℃、３０％劣化
するする温度が６１８〜６７２℃であるので溶融金属の
温度を繰返し測定する保護管としては耐熱衝撃性が不充
分であった。On the other hand, the technique (b) is excellent in corrosion resistance to refractory metals, while the bending strength by the underwater quenching method deteriorates by 10% at 581 to 614 ° C. and the temperature at which it deteriorates by 30% at 618 to 618. Since it was 672 ° C, the thermal shock resistance was insufficient as a protective tube for repeatedly measuring the temperature of the molten metal.
【０００７】また、（ａ）、（ｂ）いずれの焼結体にお
いても溶融金属と接触するとガスが多く発生するので、
精度よく繰返して測温することができないという問題が
あった。Further, in both the sintered bodies (a) and (b), a large amount of gas is generated when the molten metal comes into contact,
There was a problem that it was not possible to repeat the temperature measurement accurately.
【０００８】[0008]
【発明が解決しようとする課題】本発明者等は、上記問
題を解消することを目的として種々検討した結果、以下
の事柄を見いだし、本発明を完成させたものである。As a result of various investigations aimed at solving the above problems, the present inventors have found the following matters and completed the present invention.
【０００９】（１）焼結体の構成成分は、Ｓｉ3 Ｎ4 、
ＡｌＮ、Ａｌ2 Ｏ3 及びＢＮの混合粉末を焼結して得ら
れたものが最適であり、それらの割合をＳｉ3 Ｎ4 ３０
〜５５重量％、ＡｌＮ５〜１５重量％、Ａｌ2 Ｏ3 １０
〜３０重量％及びＢＮ２０〜４０重量％とすることによ
って、溶融金属に対する耐食性、耐熱衝撃性、耐酸化性
のバランスに優れたものとなる。(1) The constituents of the sintered body are Si 3 N 4 and
The optimum one is obtained by sintering a mixed powder of AlN, Al 2 O 3 and BN, and the ratio thereof is Si 3 N 4 30
~ 55 wt%, AlN 5-15 wt%, Al 2 O 3 10
By setting the content to -30% by weight and BN to 20 to 40% by weight, the balance of corrosion resistance against molten metal, thermal shock resistance and oxidation resistance becomes excellent.
【００１０】（２）機械加工性と耐熱衝撃性の点から焼
結体の気孔率は１０〜３５％とするのがよい。(2) The porosity of the sintered body is preferably 10 to 35% from the viewpoint of machinability and thermal shock resistance.
【００１１】（３）原料ＢＮ粉末として、結晶子（Ｌ
ａ）の大きさ８００Ａ以上の粒子を５０重量％以上含む
ものを用いると、溶融金属に対する耐食性と耐熱衝撃性
が特に優れる。(3) Crystalline (L
The use of particles of a) having a size of 800 A or more in an amount of 50% by weight or more is particularly excellent in corrosion resistance against molten metal and thermal shock resistance.
【００１２】（４）上記焼結体で構成された溶融金属測
温用保護管は、耐熱衝撃性、耐食性及び耐酸化性に優れ
ているので放射温度計で繰返し測温した場合に長寿命と
なり、しかもガスの発生が非常に少ないので精度よく測
温することができる。(4) Since the protective tube for measuring the temperature of the molten metal, which is made of the above-mentioned sintered body, has excellent thermal shock resistance, corrosion resistance and oxidation resistance, it has a long life when the temperature is repeatedly measured with a radiation thermometer. Moreover, since the generation of gas is very small, the temperature can be measured accurately.
【００１３】（５）上記焼結体で構成された溶融金属測
温用保護管であっても、特定形状からなるものは特に繰
返し測温した場合の耐熱衝撃性、耐荷重（溶湯に対する
耐衝撃強度）を高めることができるので更なる長寿命化
を図ることができる。(5) Even if the protective tube for molten metal temperature measurement composed of the above-mentioned sintered body has a specific shape, it is particularly resistant to thermal shock and load (impact against molten metal) when repeatedly measuring temperature. Since the strength) can be increased, the life can be further extended.
【００１４】[0014]
【課題を解決するための手段】すなわち、本発明は、Ｓ
ｉ3 Ｎ4 、ＡｌＮ、Ａｌ2 Ｏ3 及び結晶子の大きさ（Ｌ
ａ）８００Ａ以上の粒子を５０重量％以上含むＢＮから
なる混合粉末を焼結して得られたものであって、気孔率
１０〜３５％、温度１２００℃における酸化重量減少率
０．０３ｍｇ／ｃｍ2 ・Ｈｒ以下であることを特徴とす
る耐食性複合焼結体、この複合焼結体で構成されてなる
ことを特徴とする溶融金属測温用保護管、及びこの溶融
金属測温用保護管において、外壁の任意の部位から先端
部にかけてテーパーが施されてなり、しかも先端部位の
内寸／外寸の比が０．５〜０．７であることを特徴とす
る溶融金属測温用保護管である。That is, according to the present invention, S
i 3 N 4 , AlN, Al 2 O 3 and crystallite size (L
a) A powder obtained by sintering a mixed powder of BN containing particles of 800 A or more in an amount of 50% by weight or more, having a porosity of 10 to 35% and an oxidation weight reduction rate at a temperature of 1200 ° C. of 0.03 mg / cm 2. In a corrosion resistant composite sintered body characterized by being 2 · Hr or less, a protective tube for molten metal temperature measurement characterized by comprising this composite sintered body, and a protective tube for molten metal temperature measurement A protective tube for measuring a temperature of a molten metal, characterized in that a taper is applied from an arbitrary portion of an outer wall to a tip portion, and a ratio of inner dimension / outer dimension of the tip portion is 0.5 to 0.7. Is.
【００１５】以下、更に詳しく本発明を説明する。The present invention will be described in more detail below.
【００１６】本発明の複合焼結体は、Ｓｉ3 Ｎ4 、Ａｌ
Ｎ、Ａｌ2 Ｏ3 及びＢＮの混合粉末を焼結して得られた
ものである。これらの成分は、複合焼結体中にあっては
βサイアロンとＢＮの状態で存在していると考えられ
る。これらの成分のうち、Ｓｉ 3 Ｎ4 、ＡｌＮ及びＡｌ
2 Ｏ3 は溶融金属に対する耐食性と耐酸化性に寄与する
ものであり、ＢＮは耐熱衝撃性を向上させる。The composite sintered body of the present invention is made of Si3NFour, Al
N, Al2 O3Obtained by sintering a mixed powder of BN and BN
Things. These components are
presumed to exist in the state of β-sialon and BN
It Of these components, Si 3NFour, AlN and Al
2 O3Contributes to corrosion resistance and oxidation resistance to molten metal
BN improves thermal shock resistance.
【００１７】溶融金属に対する耐食性、耐熱衝撃性、耐
酸化性のバランスのとれたものとするための好適な割合
は、Ｓｉ3 Ｎ4 ３０〜５５重量％、ＡｌＮ５〜１５重量
％、Ａｌ2 Ｏ3 １０〜３０重量％及びＢＮ２０〜４０重
量％である。A suitable ratio for achieving a good balance of corrosion resistance, thermal shock resistance and oxidation resistance with respect to molten metal is 30 to 55% by weight of Si 3 N 4, 5 to 15% by weight of AlN, Al 2 O 3 10 to 30% by weight and BN 20 to 40% by weight.
【００１８】ＢＮが２０重量％未満では耐熱衝撃性が不
足し保護管が短ライフとなるとともに機械加工性が低下
する。また、４０重量％をこえるとＳｉ3 Ｎ4 、ＡｌＮ
及びＡｌ2 Ｏ3 成分の合計量が相対的に不足するので耐
食性と耐酸化性が低下する。中でも、原料ＢＮ粉末とし
て、結晶子（Ｌａ）の大きさ８００Ａ以上の粒子を５０
重量％以上（１００％を含む）含むものを用いると上記
（３）の効果を有する複合焼結体を製造することができ
る。If the BN content is less than 20% by weight, the thermal shock resistance is insufficient, the life of the protective tube becomes short, and the machinability deteriorates. Further, if it exceeds 40% by weight, Si 3 N 4 , AlN
Since the total amount of Al 2 O 3 and Al 2 O 3 is relatively insufficient, the corrosion resistance and the oxidation resistance decrease. Among them, as the raw material BN powder, 50 particles having a crystallite (La) size of 800 A or more are used.
By using a material containing at least wt% (including 100%), a composite sintered body having the effect of (3) above can be manufactured.
【００１９】Ｓｉ3 Ｎ4 、ＡｌＮ及びＡｌ2 Ｏ3 が上記
割合未満では耐酸化性が低下し、また上記割合をこえる
と耐食性が低下する。If Si 3 N 4 , AlN and Al 2 O 3 are less than the above proportions, the oxidation resistance is lowered, and if it exceeds the above proportions, the corrosion resistance is lowered.
【００２０】Ｓｉ3 Ｎ4 、ＡｌＮ、Ａｌ2 Ｏ3 及びＢＮ
からなる混合粉末の粒度は微粉であることが好ましく、
１０μｍ以下特に５μｍ以下であることが好ましい。混
合粉末の調製は、乾式混合又はアルコール等の有機媒体
を用いた湿式混合により行うことができる。混合機とし
ては、ボールミル、振動ミル等が使用され、混合時間と
しては、０．５〜３時間程度が適切である。Si 3 N 4 , AlN, Al 2 O 3 and BN
The particle size of the mixed powder consisting of is preferably a fine powder,
It is preferably 10 μm or less, and particularly preferably 5 μm or less. The mixed powder can be prepared by dry mixing or wet mixing using an organic medium such as alcohol. As the mixer, a ball mill, a vibration mill or the like is used, and a mixing time of 0.5 to 3 hours is suitable.
【００２１】混合粉末は、窒素、アルゴン等の非酸化性
雰囲気下、温度１６００〜１９００℃程度でホットプレ
ス又は常圧焼結されて本発明の複合焼結体が製造され
る。The mixed powder is hot-pressed or pressure-sintered at a temperature of about 1600 to 1900 ° C. in a non-oxidizing atmosphere such as nitrogen or argon to produce the composite sintered body of the present invention.
【００２２】以上の条件で製造された複合焼結体であっ
ても、混合粉末の組成とその焼結条件によって種々の気
孔率と温度１２００℃における酸化重量減少率を持った
ものとなるが、本発明の複合焼結体は気孔率１０〜３５
％好ましくは２０〜３０％で、温度１２００℃における
酸化重量減少率０．０３ｍｇ／ｃｍ2 ・Ｈｒ以下のもの
である。Even the composite sintered body produced under the above conditions has various porosities and oxidation weight reduction rates at a temperature of 1200 ° C. depending on the composition of the mixed powder and the sintering conditions. The composite sintered body of the present invention has a porosity of 10 to 35.
%, Preferably 20 to 30%, and the oxidation weight loss rate at a temperature of 1200 ° C. is 0.03 mg / cm 2 · Hr or less.
【００２３】気孔率が１０％未満では、耐熱衝撃性と機
械加工性が低下し、また３５％をこえると溶融金属に対
する耐食性が悪化する。一方、温度１２００℃における
酸化重量減少率が０．０３ｍｇ／ｃｍ2 ・Ｈｒをこえる
とガスの発生が多くなり、溶融金属の測温を精度よく行
うことが困難となる。If the porosity is less than 10%, the thermal shock resistance and machinability deteriorate, and if it exceeds 35%, the corrosion resistance to molten metal deteriorates. On the other hand, when the oxidation weight loss rate at a temperature of 1200 ° C. exceeds 0.03 mg / cm 2 · Hr, more gas is generated, which makes it difficult to accurately measure the temperature of the molten metal.
【００２４】本発明における温度１２００℃における酸
化重量減少率（ｍｇ／ｃｍ2 ・Ｈｒ）は、２５×１３×
１ｍｍの供試体を温度１２００℃の空気雰囲気炉で１時
間保持後冷却した前後の重量を測定することによって算
出することができる。The oxidation weight loss rate (mg / cm 2 · Hr) at a temperature of 1200 ° C. in the present invention is 25 × 13 ×
It can be calculated by measuring the weight before and after cooling a 1 mm specimen in an air atmosphere furnace having a temperature of 1200 ° C. for 1 hour.
【００２５】複合焼結体の酸化重量減少とガス発生のメ
カニズムについては次のように説明することができる。
すなわち、４ＢＮ＋３Ｏ2 →２Ｂ2 Ｏ3 ＋２Ｎ2 の反応
によってＢＮはＢ2 Ｏ3 に転化し重量増加するはずであ
るが、実際には生成したＢ2Ｏ3 は約９００℃以上の温
度でガス化するので複合焼結体は重量減少する。The mechanism of reduction of the oxidized weight and gas generation of the composite sintered body can be explained as follows.
That is, BN should be converted to B 2 O 3 and the weight should be increased by the reaction of 4BN + 3O 2 → 2B 2 O 3 + 2N 2 , but the B 2 O 3 produced is actually gasified at a temperature of about 900 ° C. or higher. Therefore, the weight of the composite sintered body is reduced.
【００２６】本発明の複合焼結体の用途は、鋳造ノズ
ル、ブレークリング、溶解ルツボ、熱電対用又は測温用
の保護管等の溶融金属処理用治具であるが、本発明のよ
うに溶融金属に対する耐食性、耐熱衝撃性、耐酸化性に
優れ、ガスの発生も少ないという特性は特に溶融金属測
温用保護管として適しているものである。The application of the composite sintered body of the present invention is a jig for molten metal treatment such as a casting nozzle, a break ring, a melting crucible, a thermocouple or a protective tube for temperature measurement. The characteristics of excellent corrosion resistance to molten metal, thermal shock resistance, oxidation resistance, and less gas generation are particularly suitable as a protective tube for measuring temperature of molten metal.
【００２７】本発明の溶融金属測温用保護管の断面形状
としては、特開昭55-160401 号公報に記載のように円
形、楕円形、矩形等のいずれであってもよいが、好まし
くは外壁の任意の部位から先端部にかけてテーパーが施
されてなり、しかも先端部位の内寸／外寸比が０．５〜
０．７であるものであって、このものは繰返し測温した
場合の保護管先端部の耐熱衝撃性と保護管のテーパー開
始部付近の耐荷重を更に高めることができる。The cross-sectional shape of the protective tube for measuring the temperature of the molten metal of the present invention may be any of a circular shape, an elliptical shape, a rectangular shape, etc., as described in JP-A-55-160401, but it is preferable. The outer wall is tapered from any part to the tip, and the inside / outside ratio of the tip is 0.5-
It is 0.7, which can further increase the thermal shock resistance of the tip of the protective tube and the withstand load near the taper start portion of the protective tube when the temperature is repeatedly measured.
【００２８】先端部位の内寸／外寸比が０．５未満では
肉厚が厚くなりすぎて熱応答速度が悪くなり、また０．
７をこえると肉厚が薄くなりすぎて耐荷重が低下する。
外壁に施されるテーパーは、外壁の任意の部位すなわち
上部開口部又は任意の中間部から先端部にわたって形成
されるが、好ましくは保護管長さの３０〜７０％特に４
０〜６０％の部位から先端部にわたって形成されている
ことである。テーパーの傾斜程度については、保護管先
端部（テーパー終了部）の肉厚に対するテーパー開始部
の肉厚の比が１．５〜２．０となるようにすることが好
ましい。この比が１．５未満では耐荷重が不足してテー
パー開始部付近が折損し易くなり、また２．０をこえる
とテーパー開始部の肉厚が厚くなって耐熱衝撃性が低下
する。If the inner dimension / outer dimension ratio of the tip portion is less than 0.5, the wall thickness becomes too thick and the thermal response speed deteriorates.
If it exceeds 7, the wall thickness becomes too thin and the withstand load decreases.
The taper applied to the outer wall is formed from any portion of the outer wall, that is, from the upper opening or any middle portion to the tip portion, but preferably 30 to 70% of the protective tube length, especially 4
That is, it is formed from the portion of 0 to 60% to the tip portion. With respect to the degree of taper inclination, it is preferable that the ratio of the wall thickness of the taper start portion to the wall thickness of the protective tube front end portion (taper end portion) is 1.5 to 2.0. If this ratio is less than 1.5, the withstand load is insufficient, and the area near the taper start portion is likely to break, while if it exceeds 2.0, the wall thickness of the taper start portion becomes large and the thermal shock resistance deteriorates.
【００２９】このような形状の保護管は、溶融金属に浸
漬して使用されるが、その浸漬深さとしては、湯面が保
護管長さの３０〜７０％特に４０〜６０％となる位置、
特に湯面がテーパー開始部付近となる位置であることが
好ましい。The protective tube having such a shape is used by immersing it in molten metal. The immersion depth is 30 to 70% of the length of the protective tube, especially 40 to 60%,
Particularly, it is preferable that the molten metal surface is near the taper start portion.
【００３０】[0030]
【実施例】以下、実施例、比較例をあげて更に具体的に
本発明を説明する。EXAMPLES The present invention will be described more specifically with reference to Examples and Comparative Examples.
【００３１】実施例１ Ｓｉ3 Ｎ4 粉（平均粒径１μｍ）、ＡｌＮ粉（平均粒径
１０μｍ）、Ａｌ2 Ｏ 3 粉（平均粒径０．３μｍ）及び
ＢＮ粉（Ｌａ９００Ａの粒子８０重量％、Ｌａ６００Ａ
の粒子２０重量％であり、平均粒径１０μｍ）を表１に
示す割合で混合し、混合粉末を調製した。これを黒鉛ダ
イスに充填し、温度１８００℃、圧力１００ｋｇ／ｃｍ
2 でホットプレス焼結して複合焼結体（直径２５０ｍｍ
×高さ２００ｍｍ）を製造した。この成分をＸ線回折に
より分析したところ、ＢＮとβサイアロンが同定され
た。Example 1 Si3NFourPowder (average particle size 1 μm), AlN powder (average particle size
10 μm), Al2 O 3Powder (average particle size 0.3 μm) and
BN powder (80% by weight of La900A particles, La600A
Is 20% by weight, and the average particle size is 10 μm) in Table 1.
Mixing was carried out at the ratios shown to prepare a mixed powder. This is graphite
Fill the chair, temperature 1800 ℃, pressure 100kg / cm
2 Hot-press sinter with a composite sintered body (diameter 250 mm
X height 200 mm) was produced. X-ray diffraction of this component
Further analysis identified BN and β-sialon
Was.
【００３２】次いで、複合焼結体から保護管（外径１６
ｍｍ、内径１０ｍｍ、長さ１８０ｍｍ）を機械加工し、
アルキメデス法による気孔率と上記した温度１２００℃
における重量減少率（ｍｇ／ｃｍ2 ・Ｈｒ）を耐酸化性
として測定した。Next, a protective tube (outer diameter 16
mm, inner diameter 10 mm, length 180 mm),
Porosity by Archimedes method and the above temperature 1200 ℃
The weight loss rate (mg / cm 2 · Hr) was measured as the oxidation resistance.
【００３３】更に、保護管を温度１５００℃の鋳鉄に３
０秒間浸漬（浸漬深さ８０ｍｍ）し温度を測定する操作
を繰り返し行い、クラックの発生又は溶損したときの繰
り返し使用回数（保護管のライフ）を測定した。また、
測温中のガスの発生の有無を観察した。これらの結果を
表１に示す。Further, the protection tube is made of cast iron having a temperature of 1500 ° C.
The operation of immersing for 0 seconds (immersion depth of 80 mm) and measuring the temperature was repeated, and the number of times of repeated use (life of protective tube) when cracks occurred or melted was measured. Also,
Whether or not gas was generated during the temperature measurement was observed. Table 1 shows the results.
【００３４】実施例２〜３ 混合粉末の割合を表１のようにしたこと以外は、実施例
１と同様にして保護管を製作した。Examples 2 to 3 A protective tube was manufactured in the same manner as in Example 1 except that the ratio of the mixed powder was as shown in Table 1.
【００３５】実施例４ ホットプレス温度を１７００℃としたこと以外は、実施
例１と同様にして保護管を製作した。Example 4 A protective tube was manufactured in the same manner as in Example 1 except that the hot pressing temperature was set to 1700 ° C.
【００３６】実施例５ ホットプレス焼結のかわりに常圧焼結（混合粉末をスリ
ップキャスト成形しそれを窒素雰囲気下、温度１８５０
℃で焼結）したこと以外は、実施例１と同様にして保護
管を製作した。Example 5 Instead of hot press sintering, pressureless sintering (slip-cast molding of mixed powder, which was carried out under nitrogen atmosphere at temperature 1850)
A protective tube was manufactured in the same manner as in Example 1 except that the protective tube was sintered.
【００３７】実施例６ 保護管の外壁に、上部開口部１００ｍｍの位置から先端
部にわたってテーパーを施したこと以外は、実施例１と
同様にして保護管を製作した。なお、テーパーの傾斜
は、テーパー終了部の肉厚に対するテーパー開始部の肉
厚の比が１．７となるようにした。Example 6 A protective tube was produced in the same manner as in Example 1 except that the outer wall of the protective tube was tapered from the position of the upper opening of 100 mm to the tip thereof. The taper was inclined such that the ratio of the wall thickness at the taper end portion to the wall thickness at the taper end portion was 1.7.
【００３８】比較例１〜４ 混合粉末の割合とそのホットプレス温度を表１のように
したこと以外は、実施例１と同様にして保護管を製作し
た。Comparative Examples 1 to 4 A protective tube was manufactured in the same manner as in Example 1 except that the ratio of the mixed powder and the hot pressing temperature were set as shown in Table 1.
【００３９】比較例５ 結晶子（Ｌａ）の大きさが９００Ａの粒子２０重量％、
６００Ａの粒子８０重量％であり、平均粒径１０μｍで
あるＢＮ粉末を用いたこと以外は、実施例１と同様にし
て保護管を製作した。Comparative Example 5 20% by weight of particles having a crystallite (La) size of 900 A,
A protective tube was manufactured in the same manner as in Example 1 except that BN powder having a particle diameter of 600A of 80% by weight and an average particle diameter of 10 μm was used.
【００４０】[0040]
【表１】 [Table 1]
【００４１】[0041]
【発明の効果】本発明によれば、溶融金属に対する耐食
性、耐熱衝撃性、耐酸化性のバランスに優れ、ガス発生
の少ない複合焼結体と溶融金属測温用保護管が提供され
る。According to the present invention, there is provided a composite sintered body which has an excellent balance of corrosion resistance against molten metal, thermal shock resistance, and oxidation resistance, and produces little gas, and a protective tube for measuring the temperature of molten metal.
Claims (3)
晶子の大きさ（Ｌａ）８００Ａ以上の粒子を５０重量％
以上含むＢＮからなる混合粉末を焼結して得られたもの
であって、気孔率１０〜３５％、温度１２００℃におけ
る酸化重量減少率０．０３ｍｇ／ｃｍ2 ・Ｈｒ以下であ
ることを特徴とする耐食性複合焼結体。1. 50% by weight of Si 3 N 4 , AlN, Al 2 O 3 and particles having a crystallite size (La) of 800 A or more.
It is obtained by sintering a mixed powder of BN containing the above, and is characterized by having a porosity of 10 to 35% and an oxidation weight reduction rate at a temperature of 1200 ° C. of 0.03 mg / cm 2 · Hr or less. Corrosion resistant composite sintered body.
なることを特徴とする溶融金属測温用保護管。2. A protective tube for measuring the temperature of a molten metal, comprising the composite sintered body according to claim 1.
ーパーが施されてなり、しかも先端部位の内寸／外寸の
比が０．５〜０．７であることを特徴とする請求項２記
載の溶融金属測温用保護管。3. A taper is applied from an arbitrary portion of the outer wall to the tip portion, and the inner / outer dimension ratio of the tip portion is 0.5 to 0.7. Protective tube for measuring temperature of molten metal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13754794A JP3449439B2 (en) | 1994-06-20 | 1994-06-20 | Composite sintered body and its use |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13754794A JP3449439B2 (en) | 1994-06-20 | 1994-06-20 | Composite sintered body and its use |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH082969A true JPH082969A (en) | 1996-01-09 |
| JP3449439B2 JP3449439B2 (en) | 2003-09-22 |
Family
ID=15201253
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP13754794A Expired - Fee Related JP3449439B2 (en) | 1994-06-20 | 1994-06-20 | Composite sintered body and its use |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3449439B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002316897A (en) * | 2001-04-13 | 2002-10-31 | Nikon Corp | Manufacturing method and manufacturing apparatus for fluoride single crystal |
| WO2010113555A1 (en) * | 2009-03-31 | 2010-10-07 | 三井金属鉱業株式会社 | Silicon nitride-based composite ceramic and process for producing same |
| US8354353B2 (en) * | 2008-09-17 | 2013-01-15 | Diamond Innovations, Inc. | Cubic boron nitride ceramic composites and methods of making thereof |
-
1994
- 1994-06-20 JP JP13754794A patent/JP3449439B2/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002316897A (en) * | 2001-04-13 | 2002-10-31 | Nikon Corp | Manufacturing method and manufacturing apparatus for fluoride single crystal |
| US8354353B2 (en) * | 2008-09-17 | 2013-01-15 | Diamond Innovations, Inc. | Cubic boron nitride ceramic composites and methods of making thereof |
| WO2010113555A1 (en) * | 2009-03-31 | 2010-10-07 | 三井金属鉱業株式会社 | Silicon nitride-based composite ceramic and process for producing same |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3449439B2 (en) | 2003-09-22 |
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