JPH01282146A - High-strength magnesia sintered body and production thereof - Google Patents
High-strength magnesia sintered body and production thereofInfo
- Publication number
- JPH01282146A JPH01282146A JP63111521A JP11152188A JPH01282146A JP H01282146 A JPH01282146 A JP H01282146A JP 63111521 A JP63111521 A JP 63111521A JP 11152188 A JP11152188 A JP 11152188A JP H01282146 A JPH01282146 A JP H01282146A
- Authority
- JP
- Japan
- Prior art keywords
- magnesia
- sintered body
- primary particles
- strength
- sintering
- 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
- CPLXHLVBOLITMK-UHFFFAOYSA-N Magnesium oxide Chemical compound [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 title claims abstract description 116
- 239000000395 magnesium oxide Substances 0.000 title claims abstract description 58
- 238000004519 manufacturing process Methods 0.000 title claims description 6
- 239000002245 particle Substances 0.000 claims abstract description 27
- 239000000843 powder Substances 0.000 claims abstract description 25
- 239000011164 primary particle Substances 0.000 claims abstract description 17
- 238000000465 moulding Methods 0.000 claims abstract description 9
- 238000009792 diffusion process Methods 0.000 claims abstract description 6
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims abstract description 3
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 3
- 239000001301 oxygen Substances 0.000 claims abstract description 3
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 claims description 13
- 229910052749 magnesium Inorganic materials 0.000 claims description 13
- 239000011777 magnesium Substances 0.000 claims description 13
- 230000001590 oxidative effect Effects 0.000 claims description 2
- 238000005245 sintering Methods 0.000 abstract description 15
- 230000007797 corrosion Effects 0.000 abstract description 5
- 238000005260 corrosion Methods 0.000 abstract description 5
- 238000006243 chemical reaction Methods 0.000 abstract description 4
- 238000000034 method Methods 0.000 description 8
- 230000000052 comparative effect Effects 0.000 description 5
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 4
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 description 4
- 239000000919 ceramic Substances 0.000 description 4
- 238000002844 melting Methods 0.000 description 4
- 230000007423 decrease Effects 0.000 description 3
- 230000008018 melting Effects 0.000 description 3
- 238000002347 injection Methods 0.000 description 2
- 239000007924 injection Substances 0.000 description 2
- 159000000003 magnesium salts Chemical group 0.000 description 2
- 238000005979 thermal decomposition reaction Methods 0.000 description 2
- 238000007088 Archimedes method Methods 0.000 description 1
- 229910000873 Beta-alumina solid electrolyte Inorganic materials 0.000 description 1
- 235000008733 Citrus aurantifolia Nutrition 0.000 description 1
- 241000272476 Gyps Species 0.000 description 1
- 238000010793 Steam injection (oil industry) Methods 0.000 description 1
- 235000011941 Tilia x europaea Nutrition 0.000 description 1
- 229910052783 alkali metal Inorganic materials 0.000 description 1
- 150000001340 alkali metals Chemical class 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 229910003460 diamond Inorganic materials 0.000 description 1
- 239000010432 diamond Substances 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000001746 injection moulding Methods 0.000 description 1
- 229910000464 lead oxide Inorganic materials 0.000 description 1
- 239000004571 lime Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- YEXPOXQUZXUXJW-UHFFFAOYSA-N oxolead Chemical compound [Pb]=O YEXPOXQUZXUXJW-UHFFFAOYSA-N 0.000 description 1
- 238000013001 point bending Methods 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 239000002893 slag Substances 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 238000004901 spalling Methods 0.000 description 1
- 238000003826 uniaxial pressing Methods 0.000 description 1
Landscapes
- Compositions Of Oxide Ceramics (AREA)
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明は、緻密で機械的特性、耐蝕性、耐熱性に優れ、
高温における強度低下の少ない高強度マグネシア焼結体
及びその製造法に関する。さらに詳しくは、高純度、高
融点金属の溶融用、ＰＺＴセラミックス、β−アルミナ
セラミックス等の電子及び導電性セラミックスの焼結用
、更にはＹ−Ｂａ−Ｃｕ−０系等の超伝導セラミックス
の溶融用として優れた性能を有する高強度マグネシア焼
結体及びその製造法に関する。[Detailed Description of the Invention] (Industrial Application Field) The present invention is dense and has excellent mechanical properties, corrosion resistance, and heat resistance.
The present invention relates to a high-strength magnesia sintered body that exhibits little strength loss at high temperatures and a method for producing the same. More specifically, for melting high-purity, high-melting point metals, for sintering electronic and conductive ceramics such as PZT ceramics and β-alumina ceramics, and for melting superconducting ceramics such as Y-Ba-Cu-0 series. The present invention relates to a high-strength magnesia sintered body that has excellent performance in applications and a method for producing the same.
（従来の技術及びその問題点）
マグネシアは融点が２８００°Ｃと高く、アルカリ金属
、酸化鉛、塩基性スラグ等に対する耐蝕性に優れている
ため、ルツボや耐火レンガなどの高温耐蝕材料として使
用されている。しかしながら、マグネシアは機械的強度
や破壊靭性に劣るため、昇温、降温の繰り返しにより、
クランクが発生したり、スポーリングを起こしたりする
など実用上の問題がある。(Prior art and its problems) Magnesia has a high melting point of 2800°C and has excellent corrosion resistance against alkali metals, lead oxide, basic slag, etc., so it is used as a high-temperature corrosion-resistant material for crucibles, firebricks, etc. ing. However, magnesia has poor mechanical strength and fracture toughness, so repeated heating and cooling can cause
There are practical problems such as cranking and spalling.
これらの問題を改善する方法として、マグネシウム塩の
熱分解により微細で焼結性の優れたマグネシアを調製し
、これを焼結して緻密な焼結体を作る方法がある。しか
し、この方法によって得られる焼結体は、丸みを帯びた
粒子からなるため、高温で使用した場合、粒成長が進み
強度が低下するという問題がある。As a method to improve these problems, there is a method of preparing fine magnesia with excellent sinterability by thermal decomposition of magnesium salt, and sintering this to produce a dense sintered body. However, since the sintered body obtained by this method consists of rounded particles, there is a problem in that grain growth progresses and the strength decreases when used at high temperatures.
また、特開昭５９−１８２２６８号公報及び”ＧＹＰＳ
ＵＭ ＆ＬＩＭＥ” Ｎｏ、２０９．２１９−２２４（
１９８７）には、マグネシアにジルコニアを添加して焼
結させて、マグネシアの機械的性質を向上させる方法が
開示されている。Also, JP-A-59-182268 and “GYPS
UM & LIME” No, 209.219-224 (
(1987) discloses a method for improving the mechanical properties of magnesia by adding zirconia to magnesia and sintering it.
しかし、この方法に従って得られるマグネシア質焼結体
はジルコニアが含まれるため、マグネシア本来の優れた
耐蝕性を発揮することができないという欠点を有する。However, since the magnesia-based sintered body obtained according to this method contains zirconia, it has the drawback that it cannot exhibit the excellent corrosion resistance inherent to magnesia.
（問題点を解決するための技術的手段）本発明の目的は
、室温及び高温での機械的性質を改善したマグネシア焼
結体及びその製造法を提供することにある。(Technical means for solving the problems) An object of the present invention is to provide a magnesia sintered body with improved mechanical properties at room temperature and high temperature, and a method for producing the same.
本発明の上記目的は、曲率半径１０鮒以上の面で囲まれ
た粒径５μｍ以下のマグネシア多面体粒子からなる気孔
率２％以下のマグネシア焼結体によって達成される。The above object of the present invention is achieved by a magnesia sintered body having a porosity of 2% or less and consisting of magnesia polyhedral particles with a grain size of 5 μm or less surrounded by surfaces with a radius of curvature of 10 or more.
焼結体では、粒径および気孔率が小さいほど機械的性質
が向上するが、本発明のマグネシア焼結体は粒径５μｍ
以下、気孔率２％以下と小さく、従って優れた機械的性
質が発現する。In a sintered body, the mechanical properties are improved as the particle size and porosity are smaller, but the magnesia sintered body of the present invention has a particle size of 5 μm.
The porosity is as low as 2% or less, and therefore exhibits excellent mechanical properties.
さらに、一般に焼結体は１４面体粒子からなるが、その
面の曲率半径が小さいほど、高温で使用した場合に粒成
長が大きくなり、強度が低下するが、本発明のマグネシ
ア焼結体は曲率半径１０ｍｍ以上の面で囲まれた多面体
粒子からなるため、高温での粒成長による強度低下が少
ない。Furthermore, generally, sintered bodies are made of tetradecahedral grains, and the smaller the radius of curvature of the surface, the greater the grain growth and the lower the strength when used at high temperatures, but the magnesia sintered body of the present invention has Since it is composed of polyhedral particles surrounded by planes with a radius of 10 mm or more, there is little decrease in strength due to grain growth at high temperatures.
本発明のマグネシア焼結体は、粒径０．１〜１．０μｍ
の立方体状の一次粒子を３０〜８０重景％含重量残部が
粒径０．１μｍ以下の等軸状の一次粒子からなる、純度
９９．９％以上のマグネシア粉末を成形して得られる相
対密度５０％以上の成形体を１６００〜１８００℃の温
度で焼結することによって得られる。The magnesia sintered body of the present invention has a particle size of 0.1 to 1.0 μm.
Relative density obtained by molding magnesia powder with a purity of 99.9% or more, consisting of cubic primary particles with a weight content of 30 to 80% and the remainder consisting of equiaxed primary particles with a particle size of 0.1 μm or less. It is obtained by sintering 50% or more of the molded body at a temperature of 1600 to 1800°C.
本発明において、成形体の相対密度は次式で計算した値
を表す。In the present invention, the relative density of the molded body represents a value calculated using the following formula.
上記マグネシア粉末は、マグネシウム蒸気をノズルから
酸素含有雰囲気中に噴出し、長さ１０ｃｍ以上の層流拡
散火炎を形成させ、該火炎中でマグネシウム蒸気を酸化
することにより得られる。このように、長さ１０ｃｍ以
上の層流拡散火炎中でマグネシウム蒸気を酸化させると
、マグネシアの核の発生した位置により粒成長に差異が
生じ、例えば、ノズル付近の火炎で発生した核は、火炎
中での滞留時間が長くなるため、粒成長が進み、粒径０
．１〜１．０μｍの立方体状の一次粒子となり、−方、
火炎の先端付近で発生した核は火炎中での滞留時間が短
いため、粒成長が少なく、粒径０．１ｐｍ以下の等軸状
の一次粒子となる。The magnesia powder is obtained by ejecting magnesium vapor from a nozzle into an oxygen-containing atmosphere, forming a laminar diffusion flame with a length of 10 cm or more, and oxidizing the magnesium vapor in the flame. In this way, when magnesium vapor is oxidized in a laminar diffusion flame with a length of 10 cm or more, differences in grain growth occur depending on the position where the magnesia nuclei are generated.For example, the nuclei generated in the flame near the nozzle are As the residence time inside becomes longer, grain growth progresses and the grain size reaches 0.
．． It becomes a cubic primary particle of 1 to 1.0 μm,
Since the nuclei generated near the tip of the flame have a short residence time in the flame, grain growth is small and they become equiaxed primary particles with a grain size of 0.1 pm or less.
前記マグネシア粉末は、粒径０．１〜１．０μｍの立方
体状の一次粒子を３０〜８０重量％含み、残部が粒径０
．１μ臀以下の等軸状の一次粒子からなる。このマグネ
シア粉末を焼結させると、立方体状の粒子がその形状を
ある程度保ったままで緻密化が進むので、曲率半径１０
閤以上で粒径５μｍ以下のマグネシア多面体粒子からな
る気孔率２％以下のマグネシア焼結体が得られる。The magnesia powder contains 30 to 80% by weight of cubic primary particles with a particle size of 0.1 to 1.0 μm, and the remainder has a particle size of 0.
．． Consists of equiaxed primary particles with a diameter of 1μ or less. When this magnesia powder is sintered, the cubic particles maintain their shape to some extent and become denser, so the radius of curvature is 10.
A magnesia sintered body having a porosity of 2% or less, which is composed of magnesia polyhedral particles with a grain size of 5 μm or more, is obtained.
粒径０．１〜１．０μｍの立方体状の一次粒子が８０重
量％より多くなると、焼結の駆動力となる表面エネルギ
ーが小さくなるため、気孔率２％以下の緻密な焼結体が
得られない、また、３０重量％より少ないと、曲率半径
が１０ａ＊以上の多面体粒子からなる焼結体が得られな
い。When the amount of cubic primary particles with a particle size of 0.1 to 1.0 μm exceeds 80% by weight, the surface energy that is the driving force for sintering decreases, so a dense sintered body with a porosity of 2% or less can be obtained. Moreover, if it is less than 30% by weight, a sintered body made of polyhedral particles with a radius of curvature of 10a* or more cannot be obtained.
また、本発明で使用されるマグネシア粉末のマグネシア
含有量は９９．９％以上である必要がある。Further, the magnesia content of the magnesia powder used in the present invention needs to be 99.9% or more.
マグネシア含有量が９９．９％より少ないと、焼結の際
に粒成長が進み、マグネシア焼結体中の粒子が５μｍよ
り大きくなってしまう。If the magnesia content is less than 99.9%, grain growth will proceed during sintering, and the particles in the magnesia sintered body will become larger than 5 μm.
前記マグネシア粉末は、成形して相対密度５０％以上の
成形体とする必要がある。成形体の相対密度が５０％よ
り小さいと、焼結の際に気孔が十分に排除されず気孔率
２％以下の緻密な焼結体が得られない。The magnesia powder needs to be molded into a molded body having a relative density of 50% or more. If the relative density of the molded body is less than 50%, pores will not be sufficiently eliminated during sintering, and a dense sintered body with a porosity of 2% or less will not be obtained.
マグネシア粉末はそのまま成形してもよく、成形に先立
ってそれ自体公知の方法に従って造粒してもよい。The magnesia powder may be molded as it is, or prior to molding, it may be granulated according to a method known per se.
マグネシア粉末から成形体を作製する方法については特
に制限はなく、それ自体公知の方法、例えば、−軸加工
成形、ラバープレス成形、押出成形、射出成形、鋳込成
形などの方法を適宜採用することができる。There are no particular restrictions on the method of producing a molded body from magnesia powder, and methods known per se, such as -shaft processing molding, rubber press molding, extrusion molding, injection molding, and cast molding, may be appropriately adopted. I can do it.
次に、成形体を１６００〜１８００°Ｃの温度で焼結す
ることによって、本発明のマグネシア焼結体が得られる
。Next, the magnesia sintered body of the present invention is obtained by sintering the molded body at a temperature of 1600 to 1800°C.
焼結温度が１６００°Ｃ未満であると焼結の駆動力が小
さいため、気孔率２％以下の緻密な焼結体が得られない
。焼結温度が１８００℃を超えると、粒成長が進み、マ
グネシア焼結体中の粒子が５μｍより大きくなってしま
う。If the sintering temperature is less than 1600°C, the driving force for sintering will be small, making it impossible to obtain a dense sintered body with a porosity of 2% or less. When the sintering temperature exceeds 1800°C, grain growth progresses and the grains in the magnesia sintered body become larger than 5 μm.
（実施例）
以下に本発明の実施例及び比較例を示す。以下において
、成形体の嵩密度は寸法と重量から求め、焼結体の嵩密
度はアルキメデス法によって測定し、それぞれ理論密度
に対する百分率で示した。焼結体の曲げ強度はＪＩＳ
Ｒ１６０１に従い、焼結体から３Ｘ４Ｘ４０ｍｍの棒状
試験片を切り出し、表面をダイヤモンド砥石で研磨した
後、スパン３０則、クロスヘツドスピード０．５ ｒｒ
ａ ／分の条件で室温及び１２００°Ｃで３点曲げ試験
を行い測定した。また、焼結体の高温での強度劣化を調
べるため、１４００°Ｃ５２４時間加熱した後に、上記
焼結体の評価を行った。(Example) Examples and comparative examples of the present invention are shown below. In the following, the bulk density of the molded body was determined from the dimensions and weight, and the bulk density of the sintered body was measured by the Archimedes method, and each is expressed as a percentage of the theoretical density. The bending strength of the sintered body is JIS
According to R1601, a 3 x 4 x 40 mm rod-shaped test piece was cut out from the sintered body, and the surface was polished with a diamond grindstone, followed by a span rule of 30 and a crosshead speed of 0.5 rr.
A three-point bending test was performed at room temperature and 1200°C under the conditions of α/min. In addition, in order to examine the strength deterioration of the sintered body at high temperatures, the sintered body was evaluated after being heated at 1400° C. for 524 hours.
実施例１
第１図に示す装置を用いて、マグネシア粉末を製造した
。マグネシウム蒸気噴射ノズル１の口径は９■、反応室
４の内径は１８０ａｍ、長さは１０００■であった。Example 1 Magnesia powder was produced using the apparatus shown in FIG. The diameter of the magnesium vapor injection nozzle 1 was 9 mm, the inner diameter of the reaction chamber 4 was 180 mm, and the length was 100 mm.
レトルト３内にマグネシウム７を入れ、電気炉６によっ
て１２００°Ｃに加熱して、発生したマグネシウム蒸気
をマグネシウム蒸気噴射ノズル１から２０ｍ／ｓの流速
で反応室４へ噴射させた。同時に管２がら空気を２００
１／分で導入して、マグネシウム蒸気を燃焼させて、長
さ５０Ｃ１１の層流拡散火炎を形成させた。生成したマ
グネシア粉末は捕集器５で捕集した。Magnesium 7 was placed in the retort 3 and heated to 1200°C by the electric furnace 6, and the generated magnesium vapor was injected from the magnesium vapor injection nozzle 1 into the reaction chamber 4 at a flow rate of 20 m/s. At the same time, 200 liters of air is pumped through tube 2.
The magnesium vapor was combusted to form a laminar diffusion flame with a length of 50C11. The generated magnesia powder was collected by a collector 5.
得られたマグネシア粉末は、純度９９．９％以上であり
、粒径０．１〜１．０μｍの立方体状の一次粒子を６０
重蓋％含み、残部が粒径０．１μｍ以下の等軸状の一次
粒子からなるものであった。得られたマグネシア粉末の
透過型電子顕微鏡（ＴＥＭ）写真を第２図に示す。The obtained magnesia powder has a purity of 99.9% or more, and contains 60 cubic primary particles with a particle size of 0.1 to 1.0 μm.
% of heavy caps, and the remainder consisted of equiaxed primary particles with a particle size of 0.1 μm or less. A transmission electron microscope (TEM) photograph of the obtained magnesia powder is shown in FIG.
このマグネシア粉末をエタノール溶媒を用いて６時間ボ
ールミルした後、エタノールを除去し、解砕して造粒粉
とした。This magnesia powder was ball milled for 6 hours using an ethanol solvent, the ethanol was removed, and the powder was crushed to obtain a granulated powder.
二〇造粒粉５０ｇを８０Ｘ５４ｍ＋ｓの金型に充填し、
１００ｋｇ／ｄで一軸加圧成形した後に、１．５ｔｏｎ
／ｃｄの圧力でラバープレスして成形体を得た。20 Fill 50g of granulated powder into an 80x54m+s mold,
After uniaxial pressure molding at 100kg/d, 1.5ton
A molded body was obtained by rubber pressing at a pressure of /cd.
次にこの成形体を電気炉に入れ、１６５０°Ｃで４時間
焼結して、マグネシア焼結体を製造した。Next, this molded body was placed in an electric furnace and sintered at 1650°C for 4 hours to produce a magnesia sintered body.
得られたマグネシア焼結体の評価結果を第１表に示す。Table 1 shows the evaluation results of the obtained magnesia sintered body.
実施例２
実施例１において、管２からの空気導入量を４００１２
７分に変えて、マグネシウム蒸気を燃焼させて、長さ３
０Ｃ１１の層流拡散火炎を形成させて、マグネシア粉末
を製造した。Example 2 In Example 1, the amount of air introduced from pipe 2 was set to 40012
Change to 7 minutes, burn magnesium vapor, length 3
Magnesia powder was produced by forming an 0C11 laminar diffusion flame.
得られたマグネシア粉末は、純度９９．９％以上であり
、粒径０．１〜１．０μｍの立方体状の一次粒子を４０
重量％含み、残部が粒径０．１μｍ以下の等軸状の一次
粒子からなるものであった。The obtained magnesia powder has a purity of 99.9% or more, and contains 40 cubic primary particles with a particle size of 0.1 to 1.0 μm.
% by weight, and the remainder consisted of equiaxed primary particles with a particle size of 0.1 μm or less.
この粉末を用いて、実施例１と同様にしてマグネシア焼
結体を製造した。結果を第１表に示す。Using this powder, a magnesia sintered body was produced in the same manner as in Example 1. The results are shown in Table 1.
比較例１
１００ｋｇ／ｃｄの圧力で一軸加圧して得られた成形体
を用いた以外は実施例１と同様にしてマグネシア焼結体
を製造した。結果を第１表に示す。Comparative Example 1 A magnesia sintered body was produced in the same manner as in Example 1, except that a molded body obtained by uniaxial pressing at a pressure of 100 kg/cd was used. The results are shown in Table 1.
比較例２
焼結温度を１５００°Ｃに変えた以外は実施例１と同様
にしてマグネシア焼結体を製造した。結果を第１表に示
す。Comparative Example 2 A magnesia sintered body was produced in the same manner as in Example 1 except that the sintering temperature was changed to 1500°C. The results are shown in Table 1.
比較例３
焼結温度を１９００℃に変えた以外は実施例１と同様に
してマグネシア焼結体を製造した。結果を第１表に示す
。Comparative Example 3 A magnesia sintered body was produced in the same manner as in Example 1 except that the sintering temperature was changed to 1900°C. The results are shown in Table 1.
比較例４
マグネシウム塩の熱分解により得られた平均粒径０．１
μｍの等軸状のマグネシア粉末を用いた以外は実施例１
と同様にしてマグネシア焼結体を製造した。結果を第１
表に示す。Comparative Example 4 Average particle size obtained by thermal decomposition of magnesium salt: 0.1
Example 1 except that μm equiaxed magnesia powder was used.
A magnesia sintered body was produced in the same manner. Results first
Shown in the table.
第１図は、本発明を実施する際に使用される装置の一例
を示す概略図である。
ｌ・・・・・・マグネシウム蒸気噴射ノズル、２・・・
・・・管３・・・・・・レトルト、４・・・・・・反応
室、５・・・・・・捕集器６・・・・・・電気炉、７・
・・・・・マグネシウム第２図は、本発明の実施例１で
用いたマグネシア粉末の粒子形状を示す図面に代えるＴ
ＥＭ写真である。
特許出願人 宇部興産株式会社FIG. 1 is a schematic diagram showing an example of an apparatus used in carrying out the present invention. l...Magnesium steam injection nozzle, 2...
... Tube 3 ... Retort, 4 ... Reaction chamber, 5 ... Collector 6 ... Electric furnace, 7.
・・・・・・Magnesium Figure 2 is a T instead of a drawing showing the particle shape of the magnesia powder used in Example 1 of the present invention.
This is an EM photo. Patent applicant: Ube Industries, Ltd.
Claims (3)
以下のマグネシア多面体粒子からなる気孔率２％以下の
高強度マグネシア焼結体。(1) Grain size 5 μm surrounded by a surface with a radius of curvature of 10 mm or more
A high-strength magnesia sintered body with a porosity of 2% or less, consisting of the following magnesia polyhedral particles.
３０〜８０重量％含み、残部が粒径０．１μｍ以下の等
軸状の一次粒子からなる、純度９９．９％以上のマグネ
シア粉末を成形して得られる相対密度５０％以上の成形
体を１６００〜１８００℃の温度で焼結することを特徴
とする特許請求の範囲第１項記載の高強度マグネシア焼
結体の製造法。(2) Contains 30 to 80% by weight of cubic primary particles with a particle size of 0.1 to 1.0 μm, and the remainder consists of equiaxed primary particles with a particle size of 0.1 μm or less, with a purity of 99.9% or more Production of a high-strength magnesia sintered body according to claim 1, characterized in that a molded body having a relative density of 50% or more obtained by molding magnesia powder is sintered at a temperature of 1600 to 1800°C. Law.
酸素含有雰囲気中に噴出し、長さ１０ｃｍ以上の層流拡
散火炎を形成させ、該火炎中でマグネシウム蒸気を酸化
することにより得られることを特徴とする特許請求の範
囲第２項記載の高強度マグネシア焼結体の製造法。(3) The magnesia powder is obtained by ejecting magnesium vapor from a nozzle into an oxygen-containing atmosphere, forming a laminar diffusion flame with a length of 10 cm or more, and oxidizing the magnesium vapor in the flame. A method for producing a high-strength magnesia sintered body according to claim 2.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63111521A JPH0676251B2 (en) | 1988-05-10 | 1988-05-10 | High strength magnesia sintered body and its manufacturing method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63111521A JPH0676251B2 (en) | 1988-05-10 | 1988-05-10 | High strength magnesia sintered body and its manufacturing method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01282146A true JPH01282146A (en) | 1989-11-14 |
| JPH0676251B2 JPH0676251B2 (en) | 1994-09-28 |
Family
ID=14563434
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63111521A Expired - Lifetime JPH0676251B2 (en) | 1988-05-10 | 1988-05-10 | High strength magnesia sintered body and its manufacturing method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0676251B2 (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS50144705A (en) * | 1974-05-13 | 1975-11-20 | ||
| JPS61155253A (en) * | 1984-12-27 | 1986-07-14 | 旭硝子株式会社 | Mgo sintered body for insulation base material and manufacture |
| JPS6212659A (en) * | 1985-07-09 | 1987-01-21 | 旭硝子株式会社 | Magnesia base ceramic sintered body for electric insulation material |
-
1988
- 1988-05-10 JP JP63111521A patent/JPH0676251B2/en not_active Expired - Lifetime
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS50144705A (en) * | 1974-05-13 | 1975-11-20 | ||
| JPS61155253A (en) * | 1984-12-27 | 1986-07-14 | 旭硝子株式会社 | Mgo sintered body for insulation base material and manufacture |
| JPS6212659A (en) * | 1985-07-09 | 1987-01-21 | 旭硝子株式会社 | Magnesia base ceramic sintered body for electric insulation material |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0676251B2 (en) | 1994-09-28 |
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