JPH07138075A - Production of silicon nitride having high strength and high thermal expansion - Google Patents
Production of silicon nitride having high strength and high thermal expansionInfo
- Publication number
- JPH07138075A JPH07138075A JP5308603A JP30860393A JPH07138075A JP H07138075 A JPH07138075 A JP H07138075A JP 5308603 A JP5308603 A JP 5308603A JP 30860393 A JP30860393 A JP 30860393A JP H07138075 A JPH07138075 A JP H07138075A
- Authority
- JP
- Japan
- Prior art keywords
- silicon nitride
- powder
- strength
- nitrogen gas
- thermal expansion
- 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.)
- Pending
Links
Landscapes
- Ceramic Products (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】この発明は、高強度で高熱膨張の
窒化ケイ素の製造方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing silicon nitride having high strength and high thermal expansion.
【０００２】[0002]
【従来の技術】従来、窒化ケイ素は、Ｓｉ粉末を反応焼
結することによって作製されているが、通常、その機械
的強度は低く、しかもその熱膨張係数はほぼ２〜３×１
０- 6／℃程度である。2. Description of the Related Art Conventionally, silicon nitride has been produced by reacting and sintering Si powder, but its mechanical strength is usually low and its coefficient of thermal expansion is approximately 2 to 3 × 1.
0 - is a 6 / ℃ about.
【０００３】また、特開平３−２６１６６２号公報に
は、セラミック組成物及び該組成物によるセラミック部
材の製造方法が開示されている。該セラミック組成物に
よるセラミック部材の製造方法は、金属Ｓｉ粉末又は該
粉末にセラミック粉末を加えた混合粉末と、合計重量の
６〜２５ｗｔ％の添加量範囲の有機バインダ、解膠剤及
び水を含むセラミック組成物を成形型に注入して吸水固
化し、吸水固化した組成物を加熱して有機バインダを揮
発除去し、揮発除去した組成物を窒素ガス雰囲気中で焼
成して焼結体を作製するものである。Further, Japanese Patent Application Laid-Open No. 3-261662 discloses a ceramic composition and a method for producing a ceramic member using the composition. A method for manufacturing a ceramic member using the ceramic composition includes metal Si powder or a mixed powder obtained by adding ceramic powder to the powder, an organic binder, a deflocculant, and water in an addition amount range of 6 to 25 wt% of the total weight. The ceramic composition is poured into a mold to be solidified by absorbing water, the composition thus solidified by absorbing water is heated to volatilize and remove the organic binder, and the composition thus volatilized is fired in a nitrogen gas atmosphere to produce a sintered body. It is a thing.
【０００４】[0004]
【発明が解決しようとする課題】しかしながら、上記の
ような特性を有する窒化ケイ素は、エンジンにおけるピ
ストンピンのような高い曲げ強さと高い熱膨張が要求さ
れる部材に適用するには、強度及び熱膨張係数の点から
不適当である。更に、従来のように、Ｓｉ粉末を反応焼
結して作製した窒化ケイ素は、粒子のサイズがμｍオー
ダであり、しかもＳｉの純度の高い高級なＳｉ粉末を使
用しているのが現状である。However, the silicon nitride having the above-mentioned characteristics is required to have strength and heat resistance in order to be applied to a member such as a piston pin in an engine which is required to have high bending strength and high thermal expansion. Inappropriate in terms of expansion coefficient. Furthermore, silicon nitride produced by reacting and sintering Si powder as in the prior art has a particle size on the order of μm, and is currently using high-grade Si powder with high Si purity. .
【０００５】そこで、この発明の目的は、上記の問題を
解決するため、エンジンにおけるピストンピンのような
高い熱膨張係数が要求されるものに適用できるような高
い機械的強度と高い熱膨張係数を有する窒化ケイ素を、
高純度でないＳｉ粉末即ち低純度のＳｉ粉末を用いて安
価に製造することができる高強度で高熱膨張の窒化ケイ
素の製造方法を提供することである。In order to solve the above problems, an object of the present invention is to provide a high mechanical strength and a high coefficient of thermal expansion that can be applied to a piston pin in an engine that requires a high coefficient of thermal expansion. Having silicon nitride,
It is an object of the present invention to provide a method for producing high-strength, high-thermal-expansion silicon nitride that can be produced at low cost by using non-high-purity Si powder, that is, low-purity Si powder.
【０００６】[0006]
【課題を解決するための手段】この発明は、上記の目的
を達成するために、次のように構成されている。即ち、
この発明は、Ｓｉ粉末に総粉末重量に対して２０〜５０
ｗｔ％のＹ2 Ｏ3 ，Ａｌ2 Ｏ3 及び／又はＭｇＯの添加
剤を混合して混合物を作製し、該混合物を造粒処理した
粒状物をＣＩＰで成形して成形体を作製し、該成形体を
窒素ガス雰囲気で１１００〜１４５０℃で反応焼結して
Ｓｉ3 Ｎ4 焼成体を作製し、次いで該Ｓｉ3 Ｎ4 焼成体
を窒素ガス雰囲気より高圧の窒素ガス圧のもとでほぼ１
８００℃で熱処理してＳｉ3 Ｎ4 焼結体を作製したこと
を特徴とする高強度で高熱膨張の窒化ケイ素の製造方法
に関する。In order to achieve the above object, the present invention is configured as follows. That is,
This invention uses Si powder in an amount of 20 to 50 based on the total weight of the powder.
An additive of wt% Y 2 O 3 , Al 2 O 3 and / or MgO is mixed to prepare a mixture, and the mixture is granulated, and the granular material is molded by CIP to prepare a molded body. The molded body is reacted and sintered at 1100 to 1450 ° C. in a nitrogen gas atmosphere to produce a Si 3 N 4 fired body, and the Si 3 N 4 fired body is then heated under a nitrogen gas pressure higher than the nitrogen gas atmosphere. 1
The present invention relates to a method for producing high-strength, high-thermal-expansion silicon nitride, which is characterized by producing a Si 3 N 4 sintered body by heat treatment at 800 ° C.
【０００７】また、この高強度で高熱膨張の窒化ケイ素
の製造方法において、前記Ｓｉ粉末に含まれる大きな粒
子は４０μｍ程度である。Further, in this method for producing silicon nitride having high strength and high thermal expansion, the large particles contained in the Si powder are about 40 μm.
【０００８】また、この高強度で高熱膨張の窒化ケイ素
の製造方法において、前記Ｓｉ3 Ｎ4 焼成体を熱処理す
る窒素ガス圧は９．５ｋｇ／ｃｍ2 である。Further, in this method of manufacturing silicon nitride having high strength and high thermal expansion, the nitrogen gas pressure for heat-treating the Si 3 N 4 fired body is 9.5 kg / cm 2 .
【０００９】[0009]
【作用】この発明による高強度で高熱膨張の窒化ケイ素
の製造方法は、上記のように構成されており、次のよう
に作用する。即ち、この高強度で高熱膨張の窒化ケイ素
の製造方法は、Ｓｉ粉末を用い、該Ｓｉ粉末にＹ
2 Ｏ3 ，Ａｌ2 Ｏ3 及び／又はＭｇＯの添加剤を混合
し、窒素ガス雰囲気で反応焼結し、次いで、窒素ガス圧
の下で熱処理したので、大きな粒子を含むＳｉ粉末即ち
低純度のＳｉ粉末を用いることができ、材料費、製造コ
ストを低減でき、しかも１回目の反応焼結では熱収縮が
小さく、高精度のＳｉ3 Ｎ4 焼成体を得ることができ
る。また、Ｓｉ3 Ｎ4焼成体に対して２回目の熱処理を
行なうことによって、Ｓｉ3 Ｎ4 焼成体の気孔の大きさ
や気孔分布の不均一さを低減することができる。この製
造方法で作製した窒化ケイ素は、特に、機械的強度がほ
ぼ４００ＭＰａ以上という高強度になり、熱膨張係数が
４×１０- 6 ／℃以上の高熱膨張係数を有するものであ
る。The method for producing high-strength, high-thermal-expansion silicon nitride according to the present invention is configured as described above and operates as follows. That is, in this method for producing silicon nitride having high strength and high thermal expansion, Si powder is used, and Y powder is added to the Si powder.
2 O 3 , Al 2 O 3 and / or MgO additives were mixed, reaction sintered in a nitrogen gas atmosphere, and then heat-treated under a nitrogen gas pressure, so that Si powder containing large particles, that is, low-purity Since Si powder can be used, the material cost and the manufacturing cost can be reduced, and moreover, the first reaction sintering causes less thermal contraction, and a highly accurate Si 3 N 4 fired body can be obtained. Further, Si 3 N by performing the second heat treatment for the four fired body, it is possible to reduce the unevenness of size and pore distribution of pores the Si 3 N 4 sintered body. Silicon nitride manufactured in this manufacturing method, particularly, in a high intensity that the mechanical strength is substantially 400MPa or more, the thermal expansion coefficient of 4 × 10 - those having 6 / ° C. or more high thermal expansion coefficient.
【００１０】[0010]
【実施例】以下、図面を参照して、この発明による高強
度で高熱膨張の窒化ケイ素の製造方法の実施例を説明す
る。図１はこの発明による高強度で高熱膨張の窒化ケイ
素の製造方法の工程を示す処理フロー図、及び図２はＳ
ｉ粉末へのＡｌ2 Ｏ3 の添加量に対する４点曲げ強度と
熱膨張係数を示すグラフである。Embodiments of the method for producing high-strength, high-thermal-expansion silicon nitride according to the present invention will be described below with reference to the drawings. FIG. 1 is a process flow chart showing steps of a method for producing high-strength, high-thermal-expansion silicon nitride according to the present invention, and FIG.
for the addition amount of Al 2 O 3 to i powder is a graph showing the 4-point bending strength and thermal expansion coefficient.
【００１１】この高強度で高熱膨張の窒化ケイ素の製造
方法は、図１に示すように、大きな粒子を含むＳｉ粉末
即ち低純度のＳｉ粉末にＹ2 Ｏ3 ，Ａｌ2 Ｏ3 及び／又
はＭｇＯの添加剤を混合して混合物を作製し、該混合物
をスプレードライヤによって造粒処理を行なって粒状物
を作製し、該粒状物をＣＩＰで成形して成形体を作製
し、該成形体を窒素ガス雰囲気で反応焼結してＳｉ3 Ｎ
4 焼成体を作製し、次いで該Ｓｉ3 Ｎ4 焼成体を窒素ガ
ス圧の下で熱処理してＳｉ3 Ｎ4 焼結体を作製するもの
である。As shown in FIG. 1, this method for producing high-strength, high-thermal-expansion silicon nitride is performed by adding Y 2 O 3 , Al 2 O 3 and / or MgO to Si powder containing large particles, that is, low-purity Si powder. The additive is mixed to prepare a mixture, and the mixture is granulated by a spray dryer to prepare granules, and the granules are molded by CIP to prepare a compact, and the compact is made with nitrogen. Si 3 N by reaction sintering in a gas atmosphere
4 sintered body is produced, and then the Si 3 N 4 sintered body is heat-treated under a nitrogen gas pressure to produce a Si 3 N 4 sintered body.
【００１２】この高強度で高熱膨張の窒化ケイ素の製造
方法において、大きな粒子を含むＳｉ粉末に総粉末重量
に対して２０〜５０ｗｔ％のＹ2 Ｏ3 ，Ａｌ2 Ｏ3 及び
／又はＭｇＯの添加剤を混合して混合物を作製するもの
である。この場合、Ｓｉ粉末は、粗い粒子サイズであ
り、大きな粒子の大きさは４０μｍである。また、Ｓｉ
粉末の純度は９８．５％のような低純度のものである。
そこで、このような配合で作製した混合物は、スプレー
ドライヤによって造粒処理を行なって粒状物にされ、次
いで、粒状物をＣＩＰで成形して成形体を作製する。Ｃ
ＩＰで成形した成形体は、窒素ガス雰囲気で１１００〜
１４５０℃で反応焼結してＳｉ粉末をＳｉ3 Ｎ4 焼成体
に転化させる。次いで、該Ｓｉ3 Ｎ4 焼成体は９．５ｋ
ｇ／ｃｍ2の窒素ガス圧の下で１８００℃で熱処理して
Ｓｉ3 Ｎ4 焼結体に焼結される。In this method for producing silicon nitride having high strength and high thermal expansion, 20 to 50 wt% of Y 2 O 3 , Al 2 O 3 and / or MgO is added to Si powder containing large particles with respect to the total powder weight. The agents are mixed to prepare a mixture. In this case, the Si powder has a coarse particle size and the large particle size is 40 μm. Also, Si
The purity of the powder is as low as 98.5%.
Therefore, the mixture prepared with such a composition is granulated by a spray dryer to be granulated, and then the granulated material is molded by CIP to manufacture a molded body. C
The molded body molded by IP is 1100 to 100 in a nitrogen gas atmosphere.
The Si powder is converted into a Si 3 N 4 fired body by reaction sintering at 1450 ° C. Then, the Si 3 N 4 fired body was 9.5 k
It is heat-treated at 1800 ° C. under a nitrogen gas pressure of g / cm 2 to be sintered into a Si 3 N 4 sintered body.
【００１３】また、この高強度で高熱膨張の窒化ケイ素
の製造方法において、大きな粒子を含むＳｉ粉末は、比
較的多くの不純物（特に、鉄＞１．５〜４％）を含むも
のであり、コスト的には安価な材料である。また、Ｓｉ
粉末の粒子の最大サイズは、４０μｍ程度のサイズを有
するものである。次いで、Ｓｉ3 Ｎ4 焼成体に対する２
回目の熱処理工程は、気孔の大きさや気孔分布の不均一
さを低減するために行なわれ、それによって、機械的性
能を強化することができる。更に、重要なことに、この
発明の高強度、高熱膨張率を有するＳｉ3 Ｎ4 の焼結体
は、反応焼結における密度を高める工程における収縮が
最小なため、複雑な形の構造部品にも適用できる。それ
故に、Ｓｉ3 Ｎ4 焼結体の機械加工は最小でよく、部品
の信頼性を向上し、更に製造コストも低減できる。Further, in this method for producing silicon nitride having high strength and high thermal expansion, the Si powder containing large particles contains a relatively large amount of impurities (especially iron> 1.5 to 4%), It is an inexpensive material in terms of cost. Also, Si
The maximum size of powder particles is about 40 μm. Then, 2 for the Si 3 N 4 fired body
The second heat treatment step is performed in order to reduce the non-uniformity of the pore size and the pore distribution, thereby enhancing the mechanical performance. Further, importantly, the Si 3 N 4 sintered body having high strength and high coefficient of thermal expansion of the present invention has a minimum shrinkage in the step of increasing the density in the reaction sintering, so that it can be formed into a structural part having a complicated shape. Can also be applied. Therefore, the machining of the Si 3 N 4 sintered body is minimal, which improves the reliability of the parts and also reduces the manufacturing cost.
【００１４】この高強度で高熱膨張の窒化ケイ素の製造
方法では、窒化ケイ素の熱膨張係数を大きくするため
に、Ａｌ2 Ｏ3 ，Ｙ2 Ｏ3 やＭｇＯのような添加剤が用
いられた。ここで、Ａｌ2 Ｏ3 の熱膨張係数は８×１０
- 6 ／℃、Ｙ2 Ｏ3 の熱膨張係数は９．３×１０- 6 ／
℃、及びＭｇＯの熱膨張係数は１４×１０- 6 ／℃であ
る。更に、２回目の熱処理は、反応焼結で作製されたＳ
ｉ3 Ｎ4 焼成体に対して行なわれ、この焼成プロセスで
は機械的強度を向上するために有効である。Ｓｉ粉末
は、純度が９８．５％での低級粉末であり、粒子のサイ
ズが粗大な（最大の粒子サイズは４０μｍに達し、粒子
サイズの分布が広い領域）ものであり、該Ｓｉ粉末を使
用することによって材料費を低減することができる。In this method for producing high-strength, high-thermal-expansion silicon nitride, additives such as Al 2 O 3 , Y 2 O 3 and MgO were used in order to increase the thermal expansion coefficient of silicon nitride. Here, the coefficient of thermal expansion of Al 2 O 3 is 8 × 10.
- 6 / ° C., the thermal expansion coefficient of the Y 2 O 3 is 9.3 × 10 - 6 /
C. and the coefficient of thermal expansion of MgO are 14.times.10.sup.- 6 / .degree. Further, the second heat treatment was performed on the S produced by reaction sintering.
This is performed on the i 3 N 4 fired body, and this firing process is effective for improving the mechanical strength. The Si powder is a low-grade powder having a purity of 98.5% and has a coarse particle size (the maximum particle size reaches 40 μm and the particle size distribution is wide), and the Si powder is used. By doing so, the material cost can be reduced.
【００１５】この発明による高強度で高熱膨張の窒化ケ
イ素の製造方法の実施例を図１を参照して説明する。こ
こで、出発材料としてのＳｉ粉末は、大きなもので４０
μｍ程度であり、平均粒度は１５μｍであった。Ｓｉ粉
末の純度は、Ｘ線蛍光分析によって測定され、Ｓｉ粉末
の純度は９６〜９８％の範囲のものであった。Ｓｉ粉末
における主な不純物は、鉄であった。Ｓｉ粉末への添加
剤は、Ａｌ2 Ｏ3 ，ＭｇＯ及びＹ2 Ｏ3 であり、それら
の熱膨張係数の範囲は、８〜１３×１０-6／℃であっ
た。この発明による窒化ケイ素の製造方法で使用された
粉末混合物は、表１に示されている。An embodiment of the method for producing high-strength, high-thermal-expansion silicon nitride according to the present invention will be described with reference to FIG. Here, the Si powder used as the starting material is 40
The average particle size was 15 μm. The purity of the Si powder was measured by X-ray fluorescence analysis and the purity of the Si powder was in the range of 96-98%. The main impurity in Si powder was iron. Additives to the Si powder were Al 2 O 3 , MgO and Y 2 O 3 , and their thermal expansion coefficient range was 8 to 13 × 10 −6 / ° C. The powder mixture used in the method for producing silicon nitride according to the present invention is shown in Table 1.
【表１】 [Table 1]
【００１６】Ｓｉ粉末にＡｌ2 Ｏ3 とＭｇＯの種々の量
を配合した粒状の粉末混合物は、造粒処理された後、粒
状物を２０００ｋｇ／ｃｍ2 の平衡状態でＣＩＰで冷間
加工によって成形した。次いで、成形体を６００℃で脱
脂し、窒素ガス雰囲気で１４００°まで温度上昇させ、
反応焼結してＳｉをＳｉ3 Ｎ4 に転化させた。反応焼結
されたＳｉ3 Ｎ4 焼成体のサンプルの特性を調べるため
試験した。この段階でのＳｉ3 Ｎ4 焼成体は、機械加工
が可能である。次いで、このＳｉ3 Ｎ4 焼成体を、９．
５ｋｇ／ｃｍ2 の窒素ガス圧の下で、１８００℃まで温
度上昇させて熱処理して焼結してＳｉ3 Ｎ4 焼結体を作
製した。このＳｉ3 Ｎ4 焼結体から試験片を切り出し、
該試験片の機械的特性及び熱的特性を測定し、その結果
を表２及び表３に示す。また、試験片の断面を光学電子
顕微鏡によって観察した。A granular powder mixture of Si powder mixed with various amounts of Al 2 O 3 and MgO was granulated, and then the granular material was formed by cold working by CIP at an equilibrium state of 2000 kg / cm 2. did. Next, the molded body is degreased at 600 ° C., the temperature is raised to 1400 ° in a nitrogen gas atmosphere,
Si was converted to Si 3 N 4 by reaction sintering. Tests were conducted to characterize samples of reaction sintered Si 3 N 4 fired bodies. The Si 3 N 4 fired body at this stage can be machined. Next, this Si 3 N 4 fired body was subjected to 9.
Under a nitrogen gas pressure of 5 kg / cm 2, the temperature was raised to 1800 ° C., heat treatment was performed, and sintering was performed to produce a Si 3 N 4 sintered body. A test piece was cut out from this Si 3 N 4 sintered body,
The mechanical properties and thermal properties of the test piece were measured, and the results are shown in Tables 2 and 3. Moreover, the cross section of the test piece was observed by an optical electron microscope.
【表２】 [Table 2]
【表３】 [Table 3]
【００１７】表２から分かるように、このＳｉ3 Ｎ4 焼
結体の４点曲げ強度ＭＰａは、４７０ＭＰａという高い
強度が得られた。焼結されたＳｉ3 Ｎ4 セラミックス
は、金属よりもかなり軽く、ほぼ３ｇ／ｃｍ2 という平
均密度を有している。更に、この発明による窒化ケイ素
の製造方法における後焼結されたＳｉ3 Ｎ4 焼結体は、
ワイブル係数ｍが１２以上であり、強度のバラツキが小
さく高い信頼性を有すると共に、破壊靱性値ＫI C が
３．１ＭＰａ・ｍ1 / 2 という高い値を有する。As can be seen from Table 2, the 4-point bending strength MPa of this Si 3 N 4 sintered body was as high as 470 MPa. Sintered Si 3 N 4 ceramics are much lighter than metals and have an average density of approximately 3 g / cm 2 . Further, the post-sintered Si 3 N 4 sintered body in the method for producing silicon nitride according to the present invention is
It has a Weibull coefficient m of 12 or more, has small variations in strength and high reliability, and has a fracture toughness value K IC as high as 3.1 MPa · m 1/2 .
【００１８】また、この窒化ケイ素の製造方法におい
て、Ｓｉ3 Ｎ4 の線熱膨張係数は、添加剤の含有量によ
ってコントロールできることが分かった。図２に示すよ
うに、熱膨張係数は、Ｓｉ粉末への添加剤Ａｌ2 Ｏ
3 （又はＭｇＯ）の含有量が増えるほど大きくなる。そ
して、この窒化ケイ素の製造方法では、Ｓｉ3 Ｎ4 の熱
膨張係数は、２×１０- 6 ／℃から７×１０- 6 ／℃以
上のものが得られたが、主として、４×１０- 6 ／℃以
上であった。更に、この発明による窒化ケイ素の製造方
法では、低級の純度の低いＳｉ粉末を用いて高い機械的
な強度を有し且つ信頼性に富むＳｉ3 Ｎ4 を得ることが
できる。Further, in this method for producing silicon nitride, it was found that the linear thermal expansion coefficient of Si 3 N 4 can be controlled by the content of the additive. As shown in FIG. 2, the coefficient of thermal expansion is determined by the additive Al 2 O added to the Si powder.
It increases as the content of 3 (or MgO) increases. In the method for producing silicon nitride, the coefficient of thermal expansion of Si 3 N 4 was 2 × 10 −6 / ° C. to 7 × 10 −6 / ° C. or more, but mainly 4 × 10 −4. It was 6 / ° C or higher. Further, in the method for producing silicon nitride according to the present invention, Si 3 N 4 having high mechanical strength and high reliability can be obtained by using low-grade low-purity Si powder.
【００１９】後焼結されたＳｉ3 Ｎ4 の顕微鏡組織を観
察すると、μｍオーダのサイズでＳｉ3 Ｎ4 粒子が互い
に絡み合って強力に結合していることが確認できた。ま
た、長く延びているβ−Ｓｉ3 Ｎ4 粒子は、Ｘ線回折メ
ータによって確認され、後焼結されたＳｉ3 Ｎ4 焼結体
の微細組織がはっきりと確認できた。ＥＰＭＡによる研
磨したサンプルの要素解析によって、母材中に添加剤
が、Ｓｉ−Ａｌ−Ｙとして均一に分散されていることが
確認できた。When the microstructure of the post-sintered Si 3 N 4 was observed, it was confirmed that the Si 3 N 4 particles having a size of the order of μm were entangled with each other and strongly bonded. Further, the elongated β-Si 3 N 4 particles were confirmed by an X-ray diffractometer, and the microstructure of the post-sintered Si 3 N 4 sintered body was clearly confirmed. Elemental analysis of the polished sample by EPMA confirmed that the additive was uniformly dispersed as Si-Al-Y in the base material.
【００２０】この窒化ケイ素の製造方法において、Ｓｉ
粉末及び添加剤を反応焼結した後における密度は、ほぼ
２．５ｋｇ／ｃｍ2 であることから判断して、Ｓｉ3 Ｎ
4 焼成体を後焼結した後のＳｉ3 Ｎ4 焼結体は、ほぼ５
〜８％の収縮をしたものと考えられる。本発明で得られ
たＳｉ3 Ｎ4 焼成体の寸法精度及びサイズは、良好にコ
ントロールでき、それ故に、ほとんど機械加工を要さず
に最終製品を得ることができ、機械加工費を低減でき
る。特に、本発明の窒化ケイ素の製造方法を用いれば、
一層複雑な形状の製品を得ることができ、コストダウン
が必要なその他のセラミック部品を作製する場合にも適
用できる。In this method for producing silicon nitride, Si
Judging from the fact that the density of the powder and the additive after the reaction sintering is about 2.5 kg / cm 2 , the density of Si 3 N
The Si 3 N 4 sintered body after the 4 sintered body was post-sintered had approximately 5
It is considered that the shrinkage was up to 8%. The dimensional accuracy and size of the Si 3 N 4 fired body obtained in the present invention can be well controlled, and therefore, the final product can be obtained with almost no machining and the machining cost can be reduced. In particular, if the method for producing silicon nitride of the present invention is used,
It is possible to obtain a product having a more complicated shape, and it can be applied to the case of manufacturing other ceramic parts which require cost reduction.
【００２１】[0021]
【発明の効果】この発明による高強度で高熱膨張の窒化
ケイ素の製造方法は、上記のように構成されており、次
のような効果を有する。即ち、この発明は、Ｓｉ粉末を
用い、該Ｓｉ粉末にＹ2 Ｏ3 ，Ａｌ2 Ｏ3 及び／又はＭ
ｇＯの添加剤を混合し、窒素ガス雰囲気で反応焼結し、
次いで、窒素ガス圧の下で熱処理したので、大きな粒子
を含む低純度のＳｉ粉末を用いることができ、材料費、
製造コストを低減できる。また、混合物からなる成形体
の１回目の反応焼結では熱収縮が小さく、また、焼成体
の２回目の熱処理工程では、焼成体の気孔の大きさや気
孔分布の不均一さを低減することができ、特に、機械的
強度をほぼ４００ＭＰａという高強度にでき、熱膨張係
数を４×１０- 6 ／℃以上の高熱膨張係数を有するＳｉ
3 Ｎ4 焼結体を得ることができる。The method for producing high-strength, high-thermal-expansion silicon nitride according to the present invention is constructed as described above and has the following effects. That is, the present invention uses Si powder, and Y 2 O 3 , Al 2 O 3 and / or M is added to the Si powder.
gO additive is mixed, and reaction sintering is performed in a nitrogen gas atmosphere,
Then, since it was heat-treated under a nitrogen gas pressure, it is possible to use a low-purity Si powder containing large particles.
Manufacturing cost can be reduced. Further, the first reaction sintering of the molded body made of the mixture has a small heat shrinkage, and the second heat treatment step of the fired body can reduce the size of the pores of the fired body and the non-uniformity of the pore distribution. can, in particular, can the mechanical strength substantially high strength of 400 MPa, the thermal expansion coefficient of the 4 × 10 - 6 / ℃ Si having a high thermal expansion coefficient of the above
A 3 N 4 sintered body can be obtained.
【図１】この発明による高強度で高熱膨張の窒化ケイ素
の製造方法の製造工程を示す処理フロー図である。FIG. 1 is a process flow chart showing manufacturing steps of a method for manufacturing high-strength, high-thermal-expansion silicon nitride according to the present invention.
【図２】Ｓｉ粉末への添加剤の添加量に対する４点曲げ
強度と熱膨張係数の関係を示すグラフである。FIG. 2 is a graph showing the relationship between the four-point bending strength and the thermal expansion coefficient with respect to the amount of additive added to Si powder.
Claims (3)
０ｗｔ％のＹ2 Ｏ3，Ａｌ2 Ｏ3 及び／又はＭｇＯの添
加剤を混合して混合物を作製し、該混合物を造粒処理し
た粒状物をＣＩＰで成形して成形体を作製し、該成形体
を窒素ガス雰囲気で１１００〜１４５０℃で反応焼結し
てＳｉ3 Ｎ4 焼成体を作製し、次いで該Ｓｉ3 Ｎ4 焼成
体を窒素ガス雰囲気より高圧の窒素ガス圧のもとでほぼ
１８００℃で熱処理してＳｉ3 Ｎ4 焼結体を作製したこ
とを特徴とする高強度で高熱膨張の窒化ケイ素の製造方
法。1. Si powder to 20 to 5 relative to the total powder weight
0 wt% Y 2 O 3 , Al 2 O 3 and / or MgO additives are mixed to prepare a mixture, and the mixture is granulated to form granules by CIP to prepare a compact, The molded body is reacted and sintered at 1100 to 1450 ° C. in a nitrogen gas atmosphere to produce a Si 3 N 4 fired body, and the Si 3 N 4 fired body is then heated under a nitrogen gas pressure higher than the nitrogen gas atmosphere. A method for producing high-strength, high-thermal-expansion silicon nitride, characterized by producing a Si 3 N 4 sintered body by heat treatment at 1800 ° C.
０μｍ程度であることを特徴とする請求項１に記載の高
強度で高熱膨張の窒化ケイ素の製造方法。2. The large particles contained in the Si powder are 4
The method for producing high-strength, high-thermal-expansion silicon nitride according to claim 1, wherein the thickness is about 0 μm.
ガス圧は９．５ｋｇ／ｃｍ2 であることを特徴とする請
求項１に記載の高強度で高熱膨張の窒化ケイ素の製造方
法。3. The method for producing high-strength, high-thermal expansion silicon nitride according to claim 1, wherein the nitrogen gas pressure for heat-treating the Si 3 N 4 fired body is 9.5 kg / cm 2 .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5308603A JPH07138075A (en) | 1993-11-16 | 1993-11-16 | Production of silicon nitride having high strength and high thermal expansion |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5308603A JPH07138075A (en) | 1993-11-16 | 1993-11-16 | Production of silicon nitride having high strength and high thermal expansion |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH07138075A true JPH07138075A (en) | 1995-05-30 |
Family
ID=17983030
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5308603A Pending JPH07138075A (en) | 1993-11-16 | 1993-11-16 | Production of silicon nitride having high strength and high thermal expansion |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH07138075A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006199520A (en) * | 2005-01-18 | 2006-08-03 | Zikusu Kogyo Kk | Ceramic tool and method of manufacturing the same |
| JP2007197229A (en) * | 2006-01-24 | 2007-08-09 | National Institute Of Advanced Industrial & Technology | High-thermal conductive silicon nitride substrate and method of manufacturing the same |
| KR101233744B1 (en) * | 2011-01-27 | 2013-02-18 | 한국기계연구원 | Manufacturing method of pre-sintered porous Si-mixture granules for porous sintered reaction-bonded silicon nitride, pre-sintered porous granules therefrom, and method manufacturing the porous sintered reaction-bonded silicon nitride |
| KR20160083551A (en) * | 2014-12-31 | 2016-07-12 | 서울대학교산학협력단 | Fabricating method for nitride reinforced metal matrix composite materials by spontaneous substitution reaction and composite materials fabricated by the method |
| KR20180081642A (en) * | 2017-01-06 | 2018-07-17 | 국방과학연구소 | Method for manufacturing the reaction bonding silicon nitride |
-
1993
- 1993-11-16 JP JP5308603A patent/JPH07138075A/en active Pending
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006199520A (en) * | 2005-01-18 | 2006-08-03 | Zikusu Kogyo Kk | Ceramic tool and method of manufacturing the same |
| JP2007197229A (en) * | 2006-01-24 | 2007-08-09 | National Institute Of Advanced Industrial & Technology | High-thermal conductive silicon nitride substrate and method of manufacturing the same |
| KR101233744B1 (en) * | 2011-01-27 | 2013-02-18 | 한국기계연구원 | Manufacturing method of pre-sintered porous Si-mixture granules for porous sintered reaction-bonded silicon nitride, pre-sintered porous granules therefrom, and method manufacturing the porous sintered reaction-bonded silicon nitride |
| KR20160083551A (en) * | 2014-12-31 | 2016-07-12 | 서울대학교산학협력단 | Fabricating method for nitride reinforced metal matrix composite materials by spontaneous substitution reaction and composite materials fabricated by the method |
| KR20180081642A (en) * | 2017-01-06 | 2018-07-17 | 국방과학연구소 | Method for manufacturing the reaction bonding silicon nitride |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Kim et al. | Effect of initial α‐phase content on microstructure and mechanical properties of sintered silicon carbide | |
| US3953221A (en) | Fully dense ceramic article and process employing magnesium oxide as a sintering aid | |
| JP5062402B2 (en) | Reaction sintered silicon nitride-based sintered body and method for producing the same | |
| JP3559382B2 (en) | Method for producing silicon nitride based sintered body | |
| JPH07138075A (en) | Production of silicon nitride having high strength and high thermal expansion | |
| US4889834A (en) | SiC-Al2 O3 composite sintered bodies and method of producing the same | |
| JP3149827B2 (en) | Silicon nitride based sintered body and method for producing the same | |
| KR970009988B1 (en) | HIGH CORROSION - RESISTANT Ñß-SLALON SINTER AND PRODUCTION THEREOF | |
| JP5161060B2 (en) | Heat resistant black member and method for producing the same | |
| JPS5826076A (en) | Ceramic sintered body and manufacture | |
| US5545362A (en) | Production method of sintered silicon nitride | |
| JP2661761B2 (en) | Silicon nitride sintered body and method for producing the same | |
| JPH1179848A (en) | Silicon carbide sintered compact | |
| JPH03177361A (en) | Production of beta-sialon-boron nitride-based conjugate sintered compact | |
| JPH06279124A (en) | Production of silicon nitride sintered compact | |
| JP2826080B2 (en) | Silicon nitride / silicon carbide composite sintered body and method for producing composite powder | |
| JP2706302B2 (en) | Method for producing high-density silicon nitride sintered body | |
| JP2881189B2 (en) | Method for producing silicon nitride-silicon carbide composite ceramics | |
| JPH0193470A (en) | Ceramic sintered material | |
| JP2581128B2 (en) | Alumina-sialon composite sintered body | |
| JPH0559074B2 (en) | ||
| JPH05117030A (en) | Complex ceramic and its production | |
| JPH0687664A (en) | Production of silicon nitride sintered compact | |
| JPH06116038A (en) | Production of silicon nitride-silicon carbide composite sintered compact | |
| JPH0559073B2 (en) |