JPH05330921A - Production of silicon nitride sintered compact - Google Patents
Production of silicon nitride sintered compactInfo
- Publication number
- JPH05330921A JPH05330921A JP4141733A JP14173392A JPH05330921A JP H05330921 A JPH05330921 A JP H05330921A JP 4141733 A JP4141733 A JP 4141733A JP 14173392 A JP14173392 A JP 14173392A JP H05330921 A JPH05330921 A JP H05330921A
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- Prior art keywords
- powder
- silicon nitride
- reaction
- weight
- nitrogen gas
- Prior art date
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Abstract
Description
【0001】[0001]
【産業上の利用分野】本発明は窒化ケイ素(以下、Si
3 N4 という)反応焼結体の製造方法に関する。BACKGROUND OF THE INVENTION The present invention relates to silicon nitride (hereinafter referred to as Si
3 N 4 ) and a method for producing a reaction sintered body.
【0002】[0002]
【従来の技術】従来、Si3 N4 反応焼結体の製造に当
っては、金属Si粉末よりなる成形体と窒素ガスとを反
応させてSi3 N4 を合成すると同時にそのSi3 N4
を焼結する、といった方法が一般に採用されている。2. Description of the Related Art Conventionally, in the production of a Si 3 N 4 reaction sintered body, a compact made of metallic Si powder and nitrogen gas are reacted to synthesize Si 3 N 4 , and at the same time the Si 3 N 4 is produced.
The method of sintering is generally adopted.
【0003】[0003]
【発明が解決しようとする課題】しかしながら従来法に
よると、焼結過程における寸法変化率が極めて小さいた
め最終形状またはそれに近い形状のSi3 N4 反応焼結
体を得ることができる、といった利点がある反面、窒化
の反応速度が速く早期に成形体表面にはSi3 N 4 が被
膜状に生成され、そのSi3 N4 により成形体内部への
窒素ガスの進入が妨害されるため、Si3 N4 反応焼結
体内部の窒化が不十分となってその窒化率が最大値でも
80%程度となり、高密度で、且つ高強度なSi3 N4
反応焼結体を得ることができない、という問題があっ
た。However, according to the conventional method,
According to the results, the dimensional change rate during the sintering process was extremely small.
The final shape or a shape close to it3NFourReaction sintering
While it has the advantage of being able to obtain a body, nitriding
The reaction speed of3N FourIs covered
It is generated in the form of a film and its Si3NFourTo the inside of the molded body
Since the entry of nitrogen gas is blocked, Si3NFourReaction sintering
Even if nitriding inside the body is insufficient and the nitriding rate is the maximum value,
About 80%, high density and high strength Si3NFour
There is a problem that a reaction sintered body cannot be obtained.
It was
【0004】本発明は前記に鑑み、特定の金属粉末を分
散させた原料粉末を用いることによって、成形体および
その構成要素である金属Si粉末(厳密に言えば、金属
Si粒子)をそれらの内部から窒化し得るようにし、こ
れにより高密度で、且つ高強度なSi3 N4 反応焼結体
を得ることのできる前記製造方法を提供することを目的
とする。In view of the above, the present invention uses a raw material powder in which a specific metal powder is dispersed to form a compact and its constituent metal Si powder (strictly speaking, metal Si particles) inside them. Therefore, it is an object of the present invention to provide the above-mentioned manufacturing method capable of obtaining a Si 3 N 4 reaction sintered body having a high density and a high strength.
【0005】[0005]
【課題を解決するための手段】本発明に係るSi3 N4
反応焼結体の製造方法は、金属Si粉末に、窒化促進用
金属粉末としてNi粉末を0.009重量%≦Ni粉末
≦2.2重量%分散させた原料粉末を用いて成形体を成
形する工程と、前記成形体と窒素ガスとを反応させてS
i3 N4 を合成する反応焼結処理を行う工程とを順次行
うことを特徴とする。Means for Solving the Problems Si 3 N 4 according to the present invention
In the method for producing the reaction sintered body, a green body is formed by using a raw material powder in which 0.009% by weight ≤ Ni powder ≤ 2.2% by weight of Ni powder as metal powder for nitriding promotion is dispersed in metallic Si powder. S, by reacting the process with the molded body and nitrogen gas
It is characterized in that a step of performing a reactive sintering process for synthesizing i 3 N 4 is sequentially performed.
【0006】この製造方法においては、Ni粉末に代え
て、Co粉末またはFe粉末が用いられる。この場合、
Co粉末およびFe粉末の添加量は0.01重量%≦C
o粉末またはFe粉末≦2重量%に設定される。In this manufacturing method, Co powder or Fe powder is used instead of Ni powder. in this case,
The addition amount of Co powder and Fe powder is 0.01% by weight ≦ C
o powder or Fe powder ≦ 2 wt%.
【0007】また本発明に係るSi3 N4 反応焼結体の
製造方法は、金属Si粉末に、窒化促進用金属粉末とし
てNi粉末を0.0085重量%≦Ni粉末≦5重量%
分散させた原料粉末を用いて成形体を成形する工程と、
前記成形体と窒素ガスとを反応させる1次反応焼結処理
を行うことにより合成Si3 N4 を含む中間体を得る工
程と、前記中間体に酸洗処理を施してその中間体からN
i成分を溶出させる工程と、前記中間体と窒素ガスとを
反応させてSi3 N4 を合成する2次反応焼結処理を行
う工程とを順次行うことを特徴とする。Further, the method for producing a Si 3 N 4 reaction sintered body according to the present invention is such that 0.0085 wt% ≦ Ni powder ≦ 5 wt% Ni powder is added to the metal Si powder as the metal powder for nitriding promotion.
A step of molding a molded body using the dispersed raw material powder,
A step of obtaining an intermediate containing synthetic Si 3 N 4 by performing a primary reaction sintering treatment in which the compact and nitrogen gas are reacted; and a step of subjecting the intermediate to a pickling treatment to remove N from the intermediate.
It is characterized in that the step of eluting the i component and the step of performing a secondary reaction sintering treatment of reacting the intermediate with nitrogen gas to synthesize Si 3 N 4 are sequentially performed.
【0008】この製造方法においては、Ni粉末に代え
て、Co粉末またはFe粉末が用いられる。この場合、
Co粉末の添加量は0.0085重量%≦Co粉末≦
4.5重量%に、またFe粉末の添加量は0.01重量
%≦Fe粉末≦4重量%にそれぞれ設定される。In this manufacturing method, Co powder or Fe powder is used instead of Ni powder. in this case,
The amount of Co powder added is 0.0085% by weight ≦ Co powder ≦
The amount of the Fe powder added is set to 4.5% by weight, and 0.01% by weight ≦ Fe powder ≦ 4% by weight is set.
【0009】[0009]
【作用】酸洗処理を行わない場合において、成形体内に
窒素ガスが進入すると、金属Si成分と窒素ガスとが直
接的に反応すると共にNi成分等が窒素の取籠み、その
窒素を金属Si成分に付与する、といった触媒的作用を
発揮するので成形体内部の窒化が発生する。当然に成形
体表面においても窒化が発生するので、その表面にはS
i3 N4 が被膜状に生成される。In the case where the pickling treatment is not carried out, when the nitrogen gas enters the compact, the metallic Si component and the nitrogen gas directly react with each other and the Ni component and the like traps the nitrogen, and the nitrogen is converted into the metallic Si. Since it exerts a catalytic action such as imparting to components, nitriding occurs inside the molded body. Of course, nitriding also occurs on the surface of the molded body, so S
i 3 N 4 is formed in a film form.
【0010】これらの窒化反応は発熱反応であるから、
金属Si成分が熱膨脹してNi成分等がその周囲の金属
Si成分により圧縮変形されると共にその一部が相隣る
両金属Si成分間から食出し、この食出し部分によって
被膜状のSi3 N4 が破られる。Since these nitriding reactions are exothermic reactions,
Metal Si component out food from between a part of the phase Tonariru both metal Si component with Ni component to thermal expansion or the like is compressed and deformed by the metal Si component of its surrounding coating like Si 3 N by the food out portion 4 is broken.
【0011】この段階では各金属Si成分の略全周にS
i3 N4 が生成されており、したがって成形体は合成S
i3 N4 を含む中間体に変化している。At this stage, S is distributed around the entire circumference of each metal Si component.
i 3 N 4 has been produced, so the molded body is a synthetic S
It has been transformed into an intermediate containing i 3 N 4 .
【0012】以後、被膜状のSi3 N4 の破れ箇所から
中間体内部へ窒素ガスが進入するので、前記同様に窒化
が発生する。After that, since nitrogen gas penetrates into the intermediate from the broken portion of the film-like Si 3 N 4 , nitriding occurs similarly to the above.
【0013】前記窒化反応と同時に、Ni成分等が金属
Si粉末内に、それを貫通するように拡散して前記同様
の触媒的作用を発揮するので、金属Si粉末内部の窒化
が発生する。この窒化反応によって金属Si粉末は、外
周部全体にSi3 N4 を有する複数の微小片に分割され
る。Simultaneously with the nitriding reaction, the Ni component or the like diffuses into the metal Si powder so as to penetrate therethrough and exerts the same catalytic action as described above, so that nitriding occurs inside the metal Si powder. By this nitriding reaction, the metal Si powder is divided into a plurality of minute pieces having Si 3 N 4 in the entire outer peripheral portion.
【0014】このように成形体および金属Si粉末を、
それらの内部から効率良く窒化することによってSi3
N4 反応焼結体を製造するので、その窒化率AをA>8
0%に上昇させることが可能である。In this way, the compact and the metal Si powder are
By efficiently nitriding the inside of them, Si 3
Since a N 4 reaction sintered body is manufactured, its nitriding rate A is A> 8.
It is possible to raise it to 0%.
【0015】またNi成分等の前記触媒的作用によっ
て、成形体(または中間体)内部における窒化の反応速
度が抑制されるので、急速な発熱による成形体(または
中間体)の崩壊等を回避することができる。Further, since the reaction rate of nitriding inside the molded body (or intermediate) is suppressed by the catalytic action of the Ni component or the like, collapse of the molded body (or intermediate) due to rapid heat generation is avoided. be able to.
【0016】ただし、Ni粉末等の添加量が前記範囲を
逸脱すると、Si3 N4 反応焼結体における窒化率が大
幅に低下する。However, if the addition amount of Ni powder or the like deviates from the above range, the nitriding rate in the Si 3 N 4 reaction sintered body is significantly reduced.
【0017】酸洗処理を行う場合、その処理は前記中間
体に対して行われ、したがって中間体を得るまでの焼結
処理を1次反応焼結処理という。この場合、Ni粉末等
の添加量の範囲を酸洗処理を行わない場合よりも広げる
ことが可能であり、またNi成分等が溶出して形成され
る気孔は、2次反応焼結処理において中間体内部へのガ
ス進入路となるので、Si3 N4 反応焼結体における窒
化率AをA>80%、特にNi粉末またはCo粉末を用
いた場合にはA=100%まで上昇させることができ
る。 またNi成分等は、Si3 N4 反応焼結体におい
ては不純物とみなされるが、前記酸洗処理によってNi
成分等の溶出を行うと、Ni成分等による強度への影響
を緩和して、Si3 N4 反応焼結体の強度を酸洗処理を
行わなかった場合よりも高めることができる。When the pickling treatment is carried out, the treatment is carried out on the intermediate body. Therefore, the sintering treatment until the intermediate body is obtained is called a primary reaction sintering treatment. In this case, the range of the added amount of Ni powder or the like can be widened as compared with the case where the pickling treatment is not performed, and the pores formed by elution of the Ni component and the like are intermediate in the secondary reaction sintering treatment. The nitriding rate A in the Si 3 N 4 reaction sintered body can be increased to A> 80%, especially A = 100% when Ni powder or Co powder is used, because it serves as a gas entry path into the body. it can. Further, the Ni component and the like are regarded as impurities in the Si 3 N 4 reaction sintered body.
By elution of the components and the like, the influence of the Ni component and the like on the strength can be mitigated, and the strength of the Si 3 N 4 reaction sintered body can be increased as compared with the case where the pickling treatment is not performed.
【0018】なお、酸洗処理によって全部のNi成分等
が溶出されることは希であるが、残存するNi成分等
は、酸洗処理により、独立して存在している場合には微
細化され、また凝集した場合には再分散されると共に微
細化されるので、Si3 N4 反応焼結体の強度低下の原
因とはならない。It should be noted that although all the Ni components and the like are rarely eluted by the pickling treatment, the remaining Ni components and the like are finely divided by the pickling treatment when they exist independently. When agglomerated, the particles are re-dispersed and finely divided, which does not cause a decrease in strength of the Si 3 N 4 reaction sintered body.
【0019】ただし、Ni粉末等の添加量が前記範囲を
逸脱すると、Si3 N4 反応焼結体における窒化率が大
幅に低下し、したがってその反応焼結体の強度が極端に
低くなる。However, if the addition amount of Ni powder or the like deviates from the above range, the nitriding rate of the Si 3 N 4 reaction sintered body is significantly lowered, and therefore the strength of the reaction sintered body becomes extremely low.
【0020】[0020]
【実施例】先ず、図1,図2により窒化促進用金属粉末
としてNi粉末を用いたSi3 N 4 反応焼結体の製造過
程について説明する。なお、便宜上、成形体(または中
間体)内における金属Si成分と窒素ガスとの直接的な
反応についての説明は省略する。EXAMPLES First, referring to FIGS. 1 and 2, metal powder for nitriding promotion
Si using Ni powder as3N FourManufacturing of reaction sintered body
Will be described. For convenience, the molded body (or
Between the metallic Si component and nitrogen gas
A description of the reaction is omitted.
【0021】図1(a)において、金属Si粉末にNi
粉末を0.009重量%≦Ni粉末≦2.2重量%の範
囲で添加し、両粉末を十分に湿式混合して、金属Si粉
末にNi粉末を分散させた原料粉末を調製し、次いで原
料粉末を用いて圧縮成形を行うことにより成形体1を成
形し、その後成形体1を乾燥する。In FIG. 1 (a), Ni is added to metallic Si powder.
The powder is added in the range of 0.009% by weight ≤ Ni powder ≤ 2.2% by weight, and both powders are sufficiently wet mixed to prepare a raw material powder in which the Ni powder is dispersed in the metal Si powder. The molded body 1 is molded by performing compression molding using the powder, and then the molded body 1 is dried.
【0022】図1(b)において、成形体1を窒素ガス
雰囲気中にて昇温する。この昇温過程でNi成分Niが
金属Si粉末内に拡散するので、金属Si成分SiとN
i成分Niとが反応してケイ化物NiSi3 が生成され
る。In FIG. 1B, the temperature of the compact 1 is raised in a nitrogen gas atmosphere. During this temperature rising process, the Ni component Ni diffuses into the metal Si powder, so that the metal Si component Si and N
The i-component Ni reacts with each other to form a silicide NiSi 3 .
【0023】図1(c)において、相隣る両金属Si成
分Si間の間隙から窒素ガスN2 が成形体1内部に進入
してケイ化物NiSi3 に拡散し、ケイ化物NiSi3
の外周側が窒素拡散層NiSi3 −Nとなる。In FIG. 1 (c), the nitrogen gas N 2 enters the compact 1 through the gap between the two adjacent Si components Si, diffuses into the silicide NiSi 3 , and forms the silicide NiSi 3.
The outer peripheral side is a nitrogen diffusion layer NiSi 3 —N.
【0024】図1(d)において、金属Si成分Siと
窒素ガスN2 との反応によって成形体1表面にはSi3
N4 が被膜状に生成される。この場合、被膜状のSi3
N4により成形体1内部への窒素ガスN2 の進入が完全
に阻止される訳ではない。In FIG. 1D, the reaction of metallic Si component Si and nitrogen gas N 2 causes Si 3 on the surface of the compact 1.
N 4 is formed like a film. In this case, film-like Si 3
The N 4 does not completely prevent the nitrogen gas N 2 from entering the inside of the molded body 1.
【0025】図2(e)において、窒素拡散層NiSi
3 −Nでは、先ずNi成分とN成分とが反応する、つま
りNi成分によるN成分の取籠みが行われるので窒化物
NiNが生成される。この窒化物NiNは非平衡状態に
あるためN成分の解離が行われ、その解離N成分が金属
Si成分へ付与されるので、成形体1内部の窒化が行わ
れてSi3 N4 が合成される。In FIG. 2 (e), the nitrogen diffusion layer NiSi
In 3- N, first, the Ni component reacts with the N component, that is, the N component is trapped by the Ni component, so that nitride NiN is produced. Since this nitride NiN is in a non-equilibrium state, the N component is dissociated, and the dissociated N component is added to the metallic Si component, so that the inside of the compact 1 is nitrided to synthesize Si 3 N 4. It
【0026】このように成形体1の表面側および内部に
て発生する窒化反応は発熱反応であるから金属Si成分
Siが熱膨脹し、これによりNi成分Niがその周囲の
金属Si成分Siによって圧縮変形されると共にその一
部が相隣る両金属Si成分Si間から食出し、この食出
し部分aによって被膜状のSi3 N4 が破られる。図面
には、食出し部分aを1個のみ示したが、現実には食出
し部分aは多数発生し、被膜状のSi3 N4 は多数箇所
で破られる。Since the nitriding reaction occurring on the surface side and inside of the molded body 1 is an exothermic reaction as described above, the metal Si component Si thermally expands, whereby the Ni component Ni is compressed and deformed by the surrounding metal Si component Si. At the same time, a part of it is eroded from between the two metal Si components Si adjacent to each other, and the film-like Si 3 N 4 is broken by the eroded part a. Although only one protruding portion a is shown in the drawing, a large number of protruding portions a are actually generated, and the film-like Si 3 N 4 is broken at many places.
【0027】このような現象は、1250℃付近におい
て発生し、この段階では金属Si成分Siの略全周にS
i3 N4 が生成されており、したがって成形体1は合成
Si 3 N4 を含む中間体2に変化している。Such a phenomenon occurs near 1250 ° C.
Occurs in this stage, and at this stage, S is generated around the entire circumference of the metallic Si component Si.
i3NFourHas been generated, and thus the molded body 1 is a synthetic body.
Si 3NFourHas been changed to an intermediate 2 containing.
【0028】図2(f)において、窒素ガスが被膜状S
i3 N4 の破れ箇所からNi成分NiとSi成分Si回
りのSi3 N4 との間の間隙を通じて中間体2内部へ進
入し、Ni成分Ni回りのケイ化物NiSi3 に拡散し
て窒素拡散層NiSi3 −Nが生成される。In FIG. 2 (f), the nitrogen gas is coated with S.
From the broken portion of i 3 N 4 to the inside of the intermediate body 2 through the gap between the Ni component Ni and the Si 3 N 4 around the Si component Si, and diffuse into the silicide NiSi 3 around the Ni component Ni to diffuse nitrogen. A layer NiSi 3 —N is produced.
【0029】図2(g)において、窒素拡散層NiSi
3 −Nでは、前記同様にNi成分によるN成分の取籠
み、それに次ぐ解離N成分の金属Si成分への付与が行
われるのでSi3 N4 が合成される。In FIG. 2G, the nitrogen diffusion layer NiSi
In the case of 3- N, the N component is trapped by the Ni component and the dissociated N component is subsequently applied to the metallic Si component as in the above, so that Si 3 N 4 is synthesized.
【0030】また前記のようなSi3 N4 の合成と併行
して、図3に示すようなSi3 N4合成反応も行われ
る。説明を簡略化するため1個の金属Si粉末と1個の
Ni粉末との間で行われる反応について述べる。Further in parallel with the synthesis the Si 3 N 4 as described above, is also performed Si 3 N 4 synthesis reaction as shown in FIG. For simplification of description, the reaction performed between one metal Si powder and one Ni powder will be described.
【0031】図3(a)において、成形体を窒素ガス雰
囲気中にて昇温すると、この昇温過程でNi成分Niが
金属Si粉末内に、それを貫通するように拡散し、その
Ni成分NiとSi成分Siとが反応するので、金属S
i粉末を分割するようにケイ化物NiSi3 が生成され
る。In FIG. 3 (a), when the temperature of the molded body is raised in a nitrogen gas atmosphere, the Ni component Ni diffuses into the metal Si powder so as to penetrate therethrough, and the Ni component is increased. Since Ni reacts with Si component Si, metal S
A silicide NiSi 3 is generated so as to divide the i powder.
【0032】図3(b)において、窒素ガスN2 がケイ
化物NiSi3 内に拡散し、そのケイ化物NiSi3 の
主として外層側が窒素拡散層NiSi3 −Nとなる。窒
素拡散層NiSi3 −Nでは、先ずNi成分とN成分と
が反応する、つまりNi成分によるN成分の取籠みが行
われるので窒化物NiNが生成される。この窒化物Ni
Nは非平衡状態にあるためN成分の解離が行われ、その
解離N成分が金属Si成分へ付与されるので、窒化が行
われてケイ化物NiSi3 の周りにSi3 N4が合成さ
れる。また金属Si粉末の表面側では金属Si成分Si
と窒素ガスN2とが反応するのでSi3 N4 が被膜状に
形成される。[0032] In FIG. 3 (b), the nitrogen gas N 2 is diffused into the silicide NiSi 3, mainly the outer side of the silicide NiSi 3 is nitrogen diffusion layer NiSi 3 -N. In the nitrogen diffusion layer NiSi 3 -N, first, the Ni component and the N component react with each other, that is, the N component is trapped by the Ni component, so that the nitride NiN is generated. This nitride Ni
Since N is in a non-equilibrium state, the N component is dissociated, and the dissociated N component is added to the metallic Si component, so that nitriding is performed and Si 3 N 4 is synthesized around the silicide NiSi 3. .. On the surface side of the metal Si powder, the metal Si component Si
Since this reacts with nitrogen gas N 2 , Si 3 N 4 is formed into a film.
【0033】このような窒化反応によって金属Si粉末
は、外周部全体にSi3 N4 を有する複数の微小片に分
割される。By such a nitriding reaction, the metallic Si powder is divided into a plurality of fine pieces having Si 3 N 4 in the entire outer peripheral portion.
【0034】以上の各過程を経てSi3 N4 反応焼結体
3が製造されるもので、この反応焼結体3における窒化
率Aは、Ni粉末の添加量によって変化するが、80%
<A≦98%となる。The Si 3 N 4 reaction-sintered body 3 is manufactured through the above steps, and the nitriding rate A of the reaction-sintered body 3 varies depending on the amount of Ni powder added, but is 80%.
<A ≦ 98%.
【0035】Si3 N4 反応焼結体製造過程において、
酸洗処理によるNi成分の溶出は図2(e)段階終了
後、したがって1次反応焼結処理終了後の中間体2に施
される。この中間体2に酸洗処理を施すと、Ni成分の
溶出を比較的効率良く、且つ十分に行うことができる。
Ni成分の溶出により生じた気孔は、2次反応焼結処理
において中間体2内部へのガス進入路として窒化に寄与
し、最終的にはSi3 N 4 により埋められる。Si3NFourIn the reaction sintered body manufacturing process,
The elution of the Ni component by the pickling treatment is completed at the stage in Fig. 2 (e).
Therefore, the intermediate body 2 after the completion of the primary reaction sintering treatment is
To be done. When this intermediate body 2 is subjected to pickling treatment,
Elution can be performed relatively efficiently and sufficiently.
The porosity generated by the elution of the Ni component is the secondary reaction sintering process.
Contributes to nitriding as a gas entry path into the intermediate 2
And finally Si3N FourFilled by.
【0036】次に、金属Si粉末の粒度分布について考
察する。Next, the particle size distribution of the metal Si powder will be considered.
【0037】粉末を構成する粒子の半径が連続的に変化
する連続粒子系において、その粒子系が密充填をとると
きの充填式としてはアンドレアゼン(Andreasen)の充填
式が知られている。In a continuous particle system in which the radii of the particles constituting the powder are continuously changed, the Andreasen packing formula is known as a packing formula when the particle system is densely packed.
【0038】この充填式は、Dm=(R/Rmax)q
で表わされ、Rmaxは最大粒子半径、Rは任意の粒子
半径、qは係数、Dmは最大粒子半径Rmaxから任意
の粒子半径Rまでの粒子を用いて得られた成形体におけ
る充填率である。This filling formula is Dm = (R / Rmax) q
Where Rmax is the maximum particle radius, R is an arbitrary particle radius, q is a coefficient, and Dm is a packing rate in a compact obtained using particles from the maximum particle radius Rmax to an arbitrary particle radius R. .
【0039】しかしながら、金属Si粉末の粒度分布を
アンドレアゼンの充填式に則って設定すると、その式は
連続粒子系が密充填をとるときの充填式であるから、成
形体における充填率が高くなりすぎてしまい、金属Si
成分の窒化反応が前記のように発熱反応であることに起
因して、Si3 N4 反応焼結体に亀裂、崩壊等が発生す
る。However, if the particle size distribution of the metal Si powder is set in accordance with the Andreazen filling formula, that formula is the filling formula when the continuous particle system is densely packed, so that the filling rate in the compact becomes high. Too much, metal Si
Since the nitriding reaction of the components is an exothermic reaction as described above, cracks and collapses occur in the Si 3 N 4 reaction sintered body.
【0040】そこで、前記窒化反応による体積増加率が
25%であることを考慮して、成形体の相対密度を75
%、したがって充填率を0.75に設定し、また窒化を
100%進行させれば、亀裂等の欠陥がなく、且つ気孔
のないSi3 N4 反応焼結体を得ることができる。Therefore, taking into account that the volume increase rate due to the nitriding reaction is 25%, the relative density of the molded body is set to 75%.
%, Therefore, the filling rate is set to 0.75, and nitriding is allowed to proceed 100% to obtain a Si 3 N 4 reaction sintered body having no defects such as cracks and no pores.
【0041】このようなことから本発明者等は金属Si
粉末の最大粒子半径Rmaxおよび最小粒子半径Rmi
nを所定値に設定し、また成形体における充填率Dmを
0.75に設定して数多の実験を行った結果、アンドレ
アゼンの充填式を、Dm=1−(R/Rmax)q (た
だし、Dm≦0.75)と修整し、最大粒子半径Rma
xが一定であるとき、係数qを0.25≦q≦0.5に
設定すると、金属Si粉末の粒度分布を最適にして高密
度で、且つ高強度なSi3 N4 反応焼結体を得ることが
できることを究明した。From the above, the inventors of the present invention have found that metallic Si
Maximum particle radius Rmax and minimum particle radius Rmi of powder
As a result of conducting a number of experiments by setting n to a predetermined value and the filling rate Dm in the molded body to 0.75, the Andreazen filling formula was calculated as Dm = 1− (R / Rmax) q ( However, Dm ≦ 0.75) was modified and the maximum particle radius Rma
When x is constant and the coefficient q is set to 0.25 ≦ q ≦ 0.5, the particle size distribution of the metallic Si powder is optimized to obtain a high density and high strength Si 3 N 4 reaction sintered body. I have determined that I can get it.
【0042】図4は、成形体における充填率Dm=0.
75において、金属Si粉末の最大粒子半径Rmaxを
10μmに設定し、また係数qを0.25〜0.6の範
囲で変化させた場合の粒度分布を示す。図4より、係数
qが大きくなるに従って曲線が立つ傾向にあり、したが
って充填率Dm=0.75を得るための最小粒子半径R
minが大きくなる傾向がある。FIG. 4 shows the filling rate Dm = 0.
No. 75 shows the particle size distribution when the maximum particle radius Rmax of the metal Si powder is set to 10 μm and the coefficient q is changed in the range of 0.25 to 0.6. From FIG. 4, the curve tends to stand as the coefficient q increases, and therefore the minimum particle radius R for obtaining the filling rate Dm = 0.75.
min tends to increase.
【0043】係数qを0.25≦q≦0.5に設定する
と、最小粒子半径側の粒子が適当な大きさとなるため、
成形体における気孔が、窒化に適するような大きさに調
節されると共にその分散が図られ、これにより効率的な
窒化が行われるのでSi3 N 4 反応焼結体の高密度化お
よび高強度化が達成される。Set the coefficient q to 0.25≤q≤0.5
And, since the particle on the minimum particle radius side has an appropriate size,
The pores in the compact should be sized to suit nitriding.
And is distributed, which makes it more efficient
Since nitriding is performed, Si3N FourIncreasing the density of the reaction sintered body
And high strength is achieved.
【0044】係数qがq>0.5になると、最小粒子半
径側の粒子が大きすぎるため気孔が大きくなると共にそ
の分散が不十分となり、これにより窒化効率が低下して
Si 3 N4 反応焼結体の密度および強度が低くなる。一
方、係数qがq<0.25になると、最小粒子半径側の
粒子が小さすぎるため、気孔が小さくなって成形体内へ
の窒素ガスの進入が阻害され、これによりSi3 N4 反
応焼結体が低密度且つ低強度となる。When the coefficient q becomes q> 0.5, the minimum particle half
Since the particles on the diameter side are too large, the pores become large and
Dispersion is insufficient, which reduces nitriding efficiency.
Si 3NFourThe density and strength of the reaction sintered body are lowered. one
On the other hand, when the coefficient q becomes q <0.25, the minimum particle radius side
Since the particles are too small, the pores become smaller and enter the molded body.
Of nitrogen gas in the3NFourAnti
The sintered body has low density and low strength.
【0045】〔実施例1〕最大粒子半径10μm、最小
粒子半径0.15μm、係数q=0.33(図4に表
示)の粒度分布を有する純度99.5%の金属Si粉末
に、窒化促進用金属粉末として平均粒子半径0.1μm
のNi粉末を0.005重量%≦Ni粉末≦8重量%の
範囲で添加し、両粉末を十分に湿式混合して各種原料粉
末を調製した。 各原料粉末を用い、加圧力120MP
aの条件下で圧縮成形を行うことにより縦6mm、横22
mm、長さ74mmの板状成形体を成形し、各成形体に11
0℃、4時間の乾燥処理を施した。各成形体の充填率D
mは0.68〜0.72(相対密度68〜72%)であ
った。[Example 1] A metal Si powder having a maximum particle radius of 10 µm, a minimum particle radius of 0.15 µm, and a particle size distribution of coefficient q = 0.33 (shown in Fig. 4) having a purity of 99.5% was subjected to nitriding promotion. Average particle radius of 0.1μm
Ni powder was added in the range of 0.005% by weight ≦ Ni powder ≦ 8% by weight, and both powders were sufficiently wet mixed to prepare various raw material powders. Using each raw material powder, pressing force 120MP
By performing compression molding under the condition of a, length 6 mm, width 22
mm-shaped, 74 mm long plate-shaped molded body
It was dried at 0 ° C. for 4 hours. Filling ratio D of each molded product
m was 0.68 to 0.72 (relative density 68 to 72%).
【0046】各成形体を焼結炉内に設置して窒素ガス雰
囲気中にて昇温し、各成形体と窒素ガスとを反応させて
Si3 N4 を合成する反応焼結処理を行い、次いで炉冷
することによって各種Si3 N4 反応焼結体を得た。Each compact was placed in a sintering furnace and heated in a nitrogen gas atmosphere to carry out a reaction sintering process for reacting each compact with nitrogen gas to synthesize Si 3 N 4 . Then, various Si 3 N 4 reaction sintered bodies were obtained by furnace cooling.
【0047】昇温条件は、図5に示すように、昇温速度
10℃/min で650℃まで昇温してその温度に0.5
時間保持→同一昇温速度で1000℃まで昇温してその
温度に0.5時間保持→同一昇温速度で1200℃まで
昇温してその温度に0.5時間保持→同一昇温速度で1
250℃まで昇温してその温度に0.5時間保持→昇温
速度5℃/min で1350℃まで昇温してその温度に1
時間保持→昇温速度2℃/min で1400℃まで昇温し
てその温度に0.5時間保持→同一昇温速度で1450
℃まで昇温してその温度に1時間保持、に設定された。As shown in FIG. 5, the temperature raising condition is that the temperature is raised to 650 ° C. at a temperature raising rate of 10 ° C./min, and the temperature is raised to 0.5.
Hold time → Raise the temperature to 1000 ° C. at the same heating rate and hold at that temperature for 0.5 hours → Raise to 1200 ° C. at the same heating rate and hold at that temperature for 0.5 hours → At the same heating rate 1
Temperature is raised to 250 ° C and kept at that temperature for 0.5 hours → Temperature is raised to 1350 ° C at a temperature rising rate of 5 ° C / min and the temperature is set to 1
Hold for a while → raise the temperature to 1400 ° C at a heating rate of 2 ° C / min and hold at that temperature for 0.5 hours → 1450 at the same heating rate
The temperature was raised to 0 ° C. and the temperature was maintained for 1 hour.
【0048】また各種原料粉末として、前記金属Si粉
末に、前記と同一の平均粒子半径を有するCo粉末を前
記と同一の添加範囲で分散させたもの、および前記金属
Si粉末に、前記と同一の平均粒子半径を有するFe粉
末を前記と同一の添加範囲で分散させたものを調製し、
これら原料粉末を用いて前記と同一条件下で各種Si 3
N4 反応焼結体を得た。Further, as various raw material powders, the metal Si powder is used.
At the end, Co powder with the same average particle radius as above
Dispersed in the same addition range as described above, and the metal
Fe powder having the same average particle radius as above in Si powder
Prepare the powder dispersed in the same addition range as above,
Using these raw material powders, under the same conditions as above, various Si 3
NFourA reaction sintered body was obtained.
【0049】各種Si3 N4 反応焼結体について、Ni
粉末、Co粉末およびFe粉末の添加量と窒化率Aとの
関係を求めたところ、図6の結果が得られた。図中、線
NiはNi粉末を用いた場合に、線CoはCo粉末を用
いた場合に、線FeはFe粉末を用いた場合にそれぞれ
該当する。窒化率Aは、金属Si成分の窒化反応による
重量増加率が66.4%であることから、この重量増加
率を示すSi3 N4 反応焼結体の窒化率AをA=100
%として求められた。Regarding various Si 3 N 4 reaction sintered bodies,
When the relationship between the amounts of powder, Co powder and Fe powder added and the nitriding ratio A was determined, the results shown in FIG. 6 were obtained. In the figure, the line Ni corresponds to the case where Ni powder is used, the line Co corresponds to the case where Co powder is used, and the line Fe corresponds to the case where Fe powder is used. The nitriding ratio A is 66.4% due to the nitriding reaction of the metal Si component. Therefore, the nitriding ratio A of the Si 3 N 4 reaction-sintered body showing this weight increasing ratio is A = 100.
Was calculated as a percentage.
【0050】図6から明らかなように、Ni粉末につい
てはその添加量を0.009重量%≦Ni粉末≦2.2
重量%に設定し、またCo粉末およびFe粉末について
はそれらの添加量を0.01重量%≦Co粉末またはF
e粉末≦2重量%に設定することによって、各Si3 N
4 反応焼結体の窒化率AをA>80%にすることができ
る。これら粉末の窒化促進効果はFe粉末、Co粉末、
Ni粉末の順に高くなり、Ni粉末を用いた場合には窒
化率Aを98%程度まで高めることが可能である。また
Ni粉末等の添加量を前記範囲に設定されたSi3 N4
反応焼結体には亀裂、崩壊等の欠陥は生じていなかっ
た。As is clear from FIG. 6, the amount of Ni powder added was 0.009% by weight ≦ Ni powder ≦ 2.2.
%, And for Co powder and Fe powder, the addition amount thereof is 0.01% by weight ≦ Co powder or F
By setting powder ≦ 2% by weight, each Si 3 N
4 The nitriding rate A of the reaction sintered body can be set to A> 80%. The nitriding promotion effect of these powders is Fe powder, Co powder,
The Ni powder increases in order, and when the Ni powder is used, the nitriding rate A can be increased to about 98%. The Si 3 N 4 which is set the amount of such the Ni powder to the range
Defects such as cracks and collapse did not occur in the reaction sintered body.
【0051】なお、Ni粉末等の添加量が下限値未満と
なるか、または上限値を超えると、Si3 N4 反応焼結
体の窒化率AがA<80%となるだけでなく、その反応
焼結体が崩壊した。これは、前記下限値未満では成形体
内部の窒化反応が急速に進行するからであり、また前記
上限値を超えると、金属間化合物、即ちNiSi3 等の
生成量が増大するからであると思われる。When the addition amount of Ni powder or the like is less than the lower limit value or exceeds the upper limit value, not only the nitriding rate A of the Si 3 N 4 reaction sintered body becomes A <80%, but also The reaction sintered body collapsed. This is because the nitriding reaction inside the molded body rapidly progresses below the lower limit, and the production amount of the intermetallic compound, that is, NiSi 3, increases when the upper limit is exceeded. Be done.
【0052】Ni粉末またはCo粉末を用いたSi3 N
4 反応焼結体のうち、その窒化率AがA≧95%である
ものについて、その物性を調べたところ表1の結果が得
られた。曲げ強さは常温下での3点曲げ試験により測定
された。Si 3 N using Ni powder or Co powder
When the nitriding rate A of the four- reaction sintered body was A ≧ 95%, its physical properties were examined, and the results shown in Table 1 were obtained. The bending strength was measured by a three-point bending test at room temperature.
【0053】[0053]
【表1】 表1より、各Si3 N4 反応焼結体は気孔量が少なく、
高強度であることが判る。なお、Ni粉末等の添加量が
上限値を超えると、Si3 N4 反応焼結体の強度が極端
に低下し、また1%以上の熱膨脹率を生じる。[Table 1] From Table 1, each Si 3 N 4 reaction sintered body has a small amount of pores,
It can be seen that the strength is high. If the addition amount of Ni powder or the like exceeds the upper limit, the strength of the Si 3 N 4 reaction-sintered body is extremely lowered, and the coefficient of thermal expansion is 1% or more.
【0054】〔実施例2〕実施例1におけるNi粉末を
分散させた各種原料粉末、Co粉末を分散させた各種原
料粉末およびFe粉末を分散させた各種原料粉末を用い
て実施例1と同様の成形体を得た。Example 2 The same as Example 1 was carried out by using the various raw material powders in which the Ni powder was dispersed, the various raw material powders in which the Co powder was dispersed, and the various raw material powders in which the Fe powder was dispersed in Example 1. A molded body was obtained.
【0055】各成形体を焼結炉内に設置して窒素ガス雰
囲気中にて昇温し、各成形体と窒素ガスとを反応させる
1次反応焼結処理を行い、次いで炉冷することによって
合成Si3 N4 を含む各種中間体を製造した。By placing each compact in a sintering furnace and raising the temperature in a nitrogen gas atmosphere to perform a primary reaction sintering treatment for reacting each compact with nitrogen gas, and then cooling the furnace. Various intermediates including synthetic Si 3 N 4 were prepared.
【0056】各中間体に酸洗処理を施して、その中間体
からNi成分等を溶出させ、次いで各中間体を十分に乾
燥した。この酸洗処理には、塩酸と硝酸とを容量比で7
対3に混合した5%混酸水溶液が用いられた。Each intermediate was subjected to pickling treatment to elute the Ni component and the like from the intermediate, and then each intermediate was thoroughly dried. For this pickling treatment, hydrochloric acid and nitric acid were mixed in a volume ratio of 7
A 5% aqueous solution of mixed acid mixed with 3 to 3 was used.
【0057】各中間体を再び焼結炉内に設置して窒素ガ
ス雰囲気中にて昇温し、各中間体と窒素ガスとを反応さ
せてSi3 N4 を合成する2次反応焼結処理を行い、次
いで炉冷することによって各種Si3 N4 反応焼結体を
得た。Secondary reaction sintering treatment in which each intermediate is again installed in the sintering furnace and heated in a nitrogen gas atmosphere to react each intermediate with nitrogen gas to synthesize Si 3 N 4. And then cooled in a furnace to obtain various Si 3 N 4 reaction sintered bodies.
【0058】1次反応焼結処理における昇温条件は、図
5の前半と同じである。即ち、昇温速度10℃/min で
650℃まで昇温してその温度に0.5時間保持→同一
昇温速度で1000℃まで昇温してその温度に0.5時
間保持→同一昇温速度で1200℃まで昇温してその温
度に0.5時間保持→同一昇温速度で1250℃まで昇
温してその温度に0.5時間保持、に設定された。The temperature rising conditions in the primary reaction sintering process are the same as those in the first half of FIG. That is, the temperature is raised to 650 ° C. at a temperature rising rate of 10 ° C./min and kept at that temperature for 0.5 hour → the temperature is raised to 1000 ° C. at the same temperature raising rate and kept at that temperature for 0.5 hour → the same temperature rise The temperature was raised to 1200 ° C. and kept at that temperature for 0.5 hour, and the temperature was raised to 1250 ° C. at the same rate and kept at that temperature for 0.5 hour.
【0059】2次反応焼結処理における昇温条件は図5
の後半と略同じである。即ち、昇温速度5℃/min で1
350℃まで昇温してその温度に1時間保持→昇温速度
2℃/min で1400℃まで昇温してその温度に0.5
時間保持→同一昇温速度で1450℃まで昇温してその
温度に1時間保持、に設定された。The temperature rising conditions in the secondary reaction sintering process are shown in FIG.
It is almost the same as the latter half of. That is, 1 at a heating rate of 5 ° C / min
Raise to 350 ° C and hold at that temperature for 1 hour → Raise to 1400 ° C at a temperature rising rate of 2 ° C / min and raise to 0.5
Hold for time → The temperature was raised to 1450 ° C. at the same temperature rising rate and kept at that temperature for 1 hour.
【0060】各種Si3 N4 反応焼結体について、Ni
粉末、Co粉末およびFe粉末の添加量と窒化率Aとの
関係を求めたところ、図7の結果が得られた。図中、線
NiはNi粉末を用いた場合に、線CoはCo粉末を用
いた場合に、線FeはFe粉末を用いた場合にそれぞれ
該当する。窒化率Aは、実施例1と同様の方法で求めら
れた。Regarding various Si 3 N 4 reaction sintered bodies,
When the relationship between the nitriding ratio A and the added amount of the powder, the Co powder, and the Fe powder was determined, the result of FIG. 7 was obtained. In the figure, the line Ni corresponds to the case where Ni powder is used, the line Co corresponds to the case where Co powder is used, and the line Fe corresponds to the case where Fe powder is used. The nitriding rate A was obtained by the same method as in Example 1.
【0061】図7から明らかなように、Ni粉末につい
てはその添加量を0.0085重量%≦Ni粉末≦5重
量%に設定し、またCo粉末についてはその添加量を
0.0085重量%≦Co粉末≦4.5重量%に設定
し、さらにFe粉末についてはその添加量を0.01重
量%≦Fe粉末≦4重量%に設定することによって、各
Si3 N4 反応焼結体の窒化率AをA>80%にするこ
とができる。これら粉末の窒化促進効果はFe粉末、C
o粉末、Ni粉末の順に高くなり、Ni粉末を用いた場
合には、その添加量を0.03重量%≦Ni粉末≦4重
量%に、またCo粉末を用いた場合にはその添加量を
0.05重量%≦Co粉末≦0.4重量%にそれぞれ設
定することによって、Si3 N4 反応焼結体の窒化率A
をA=100%にすることができる。さらにFe粉末を
用いた場合にはその添加量を0.07重量%≦Fe粉末
≦0.3重量%に設定することによってSi3 N4 反応
焼結体の窒化率Aを97%≦A≦98%に高めることが
可能である。またNi粉末等の添加量を前記範囲に設定
されたSi3 N4 反応焼結体には亀裂、崩壊等の欠陥は
生じていなかった。As is apparent from FIG. 7, the addition amount of Ni powder is set to 0.0085% by weight ≦ Ni powder ≦ 5% by weight, and the addition amount of Co powder is 0.0085% by weight ≦ 0.0085% by weight. Ni powder of each Si 3 N 4 reaction sintered body is set by setting Co powder ≦ 4.5% by weight and further adding Fe powder in an amount of 0.01% by weight ≦ Fe powder ≦ 4% by weight. The rate A can be A> 80%. The nitriding promoting effect of these powders is Fe powder, C
o powder and Ni powder in that order, and when Ni powder was used, the addition amount was 0.03% by weight ≦ Ni powder ≦ 4% by weight, and when Co powder was used, the addition amount was increased. By setting 0.05% by weight ≦ Co powder ≦ 0.4% by weight, respectively, the nitriding rate A of the Si 3 N 4 reaction sintered body is set.
Can be A = 100%. Further, when Fe powder is used, the nitriding rate A of the Si 3 N 4 reaction sintered body is 97% ≦ A ≦ by setting the addition amount to 0.07% by weight ≦ Fe powder ≦ 0.3% by weight. It is possible to raise it to 98%. In addition, defects such as cracks and collapses did not occur in the Si 3 N 4 reaction sintered body in which the amount of Ni powder or the like added was set within the above range.
【0062】Ni粉末等の添加量を前記範囲に設定され
たSi3 N4 反応焼結体の物性を調べたところ、気孔
量、Si3 N4 の結晶形、収縮率および熱膨脹率につい
ては酸洗処理を行わなかったとき(表1)と略同様であ
ったが、Ni成分等は微細化されており、例えば、添加
量0.1重量%以下の場合にはNi成分等の大きさは4
0〜50mμであり、また強度は酸洗処理を行わなかっ
たときよりも高く、その上ばらつきも少なかった。例え
ば、0.2重量%のNi粉末を用いた場合、Si 3 N4
反応焼結体における常温下での3点曲げ試験による曲げ
強さは460MPaであった。The amount of Ni powder added is set within the above range.
Si3NFourWhen the physical properties of the reaction sintered body were examined, it was found that the pores were
Amount, Si3NFourThe crystal form, shrinkage rate and coefficient of thermal expansion of
The same as when no pickling treatment was performed (Table 1).
However, the Ni component, etc. is made finer.
When the amount is 0.1% by weight or less, the size of the Ni component is 4
0 to 50 mμ, and strength is not pickled
It was higher than when I was there, and there was less variation. example
For example, when 0.2% by weight of Ni powder is used, Si 3NFour
Bending of reaction-sintered body by 3-point bending test at room temperature
The strength was 460 MPa.
【0063】〔実施例3〕前記修整アンドレアゼンの充
填式、Dm=1−(R/Rmax)q に則って粒度分布
を調整された純度99.5%の金属Si粉末に、平均粒
子半径0.1μmのNi粉末を0.2重量%分散させて
各種原料粉末(1)〜(17)を調製した。各原料粉末
(1)〜(17)における金属Si粉末の粒度分布は表
2および図8に示す通りである。Example 3 A metallic Si powder having a purity of 99.5% whose particle size distribution was adjusted according to the modified Andreazen filling formula, Dm = 1- (R / Rmax) q , had an average particle radius of 0. Various raw material powders (1) to (17) were prepared by dispersing 0.2 μ% of 1 μm Ni powder. The particle size distribution of the metal Si powder in each of the raw material powders (1) to (17) is as shown in Table 2 and FIG.
【0064】[0064]
【表2】 各原料粉末(1)〜(17)を用い、実施例2と同様の
方法、つまり酸洗処理を行う方法で各種Si3 N4 反応
焼結体(1)〜(17)〔各Si3 N4 反応焼結体
(1)〜(17)は各原料粉末(1)〜(17)に対応
する〕を得た。これらSi3 N4 反応焼結体(1)〜
(17)における窒化率Aは97%≦A≦100%であ
った。[Table 2] Using the respective raw material powders (1) to (17), various Si 3 N 4 reaction sintered bodies (1) to (17) [each Si 3 N] were prepared by the same method as in Example 2, that is, a method of performing pickling treatment. 4 reaction sintered bodies (1) to (17) correspond to the respective raw material powders (1) to (17)] were obtained. These Si 3 N 4 reaction sintered bodies (1)
The nitriding ratio A in (17) was 97% ≦ A ≦ 100%.
【0065】比較のため、前記と同一純度の三種の市販
金属Si粉末に前記と同一のNi粉末を前記と同一量分
散させて三種の原料粉末(18)〜(20)を調製し
た。市販金属Si粉末において、原料粉末(18)に用
いられたものは最大粒子半径が5μmであり、また原料
粉末(19),(20)に用いられたものは最大粒子半
径がそれぞれ2.5μmであった。For comparison, three kinds of raw material powders (18) to (20) were prepared by dispersing the same amount of Ni powder as described above in three kinds of commercially available metal Si powders having the same purity as described above. Among the commercially available metal Si powders, the one used for the raw material powder (18) has a maximum particle radius of 5 μm, and the one used for the raw material powders (19) and (20) has a maximum particle radius of 2.5 μm, respectively. there were.
【0066】図9は、各市販金属Si粉末の粒度分布を
示す。本図において、各線の符号は、便宜上各原料粉末
の符号(18)〜(19)と一致させてある。図8と図
9とを比較すると、図8においては粒度調整がなされて
いるので最大粒子半径から最小粒子半径に至る変化がな
めらかな曲線を描くが、図9においては粒度調整がなさ
れていないので最大粒子半径から最小粒子半径に至る変
化がぎくしゃくした折線を描く。FIG. 9 shows the particle size distribution of each commercially available metal Si powder. In this figure, the symbols of the lines are made to coincide with the symbols (18) to (19) of the raw material powders for convenience. Comparing FIG. 8 and FIG. 9, since the particle size is adjusted in FIG. 8, a smooth curve is drawn from the maximum particle radius to the minimum particle radius, but in FIG. 9, the particle size is not adjusted. Draw a jagged line that shows the change from the maximum particle radius to the minimum particle radius.
【0067】各原料粉末(18)〜(20)を用い、実
施例2と同様の方法で各種Si3 N 4 反応焼結体(1
8)〜(20)〔各Si3 N4 反応焼結体(18)〜
(20)は各原料粉末(18)〜(20)に対応する〕
を得た。Using each raw material powder (18) to (20),
Various types of Si are manufactured by the same method as in Example 2.3N FourReaction sintered body (1
8) to (20) [Each Si3NFourReaction sintered body (18)
(20) corresponds to each raw material powder (18) to (20)]
Got
【0068】また各市販金属Si粉末を原料粉末(2
1)〜(23)として用い、実施例1と同様の方法、つ
まり酸洗処理を行わない方法で三種のSi3 N4 反応焼
結体(21)〜(23)〔各Si3 N4 反応焼結体(2
1)〜(23)は各原料粉末(21)〜(23)に対応
する〕を得た。この場合、各原料粉末(21)〜(2
3)は各原料粉末(18)〜(20)の金属Si粉末に
対応する。Further, each commercially available metal Si powder is used as a raw material powder (2
1) to (23) and the same method as in Example 1, that is, a method without performing pickling treatment, three kinds of Si 3 N 4 reaction sintered bodies (21) to (23) [each Si 3 N 4 reaction Sintered body (2
1) to (23) correspond to the respective raw material powders (21) to (23). In this case, each raw material powder (21) to (2
3) corresponds to the metal Si powder of each raw material powder (18) to (20).
【0069】各Si3 N4 反応焼結体(1)〜(1
7),(18)〜(20),(21)〜(23)につい
て、常温下で3点曲げ試験を行い、それらの曲げ強さを
測定したところ、図10に示す結果が得られた。Each Si 3 N 4 reaction sintered body (1) to (1
7), (18) to (20), (21) to (23) were subjected to a three-point bending test at room temperature, and their bending strengths were measured. The results shown in FIG. 10 were obtained.
【0070】図10から明らかなように、各Si3 N4
反応焼結体(1)〜(17)においては、金属Si粉末
の最大粒子半径が大きくなるに従って強度が下がる傾向
があり、また同一最大粒子半径を有する金属Si粉末を
用いた場合には係数qが大きくなるに従って強度が下が
る傾向がある。As is clear from FIG. 10, each Si 3 N 4
In the reaction sintered bodies (1) to (17), the strength tends to decrease as the maximum particle radius of the metal Si powder increases, and when the metal Si powder having the same maximum particle radius is used, the coefficient q Tends to decrease with increasing.
【0071】Si3 N4 反応焼結体に対する要求強度に
もよるが、金属Si粉末としては、、最大粒子半径Rm
axが一定であるとき係数qが0.25≦q≦0.5で
ある粒度分布を有するものを用いると、高強度なSi3
N4 反応焼結体を得ることができる。As the metal Si powder, the maximum particle radius Rm depends on the strength required for the Si 3 N 4 reaction sintered body.
When a particle size distribution with a coefficient q of 0.25 ≦ q ≦ 0.5 when ax is constant is used, high strength Si 3
An N 4 reaction sintered body can be obtained.
【0072】金属Si粉末の最大粒子半径および最小粒
子半径について特に制限はないが、最大粒子半径を大き
くすると、それに伴い成形体における気孔の粗大化およ
び窒素の拡散距離の増加を招来するため、残存粗大気孔
量および未反応Si量が増す。一方、最小粒子半径を小
さくすると、それに伴い金属Si粉末の取扱い性が悪化
し、また金属Si粉末が大気中の酸素と反応して酸化膜
が形成され、この酸化膜により窒化が妨げられる。これ
らの点を考慮すると、金属Si粉末の最大粒子半径の上
限値は22μm、最小粒子半径の下限値は0.025μ
mであることが望ましい。There is no particular limitation on the maximum particle radius and the minimum particle radius of the metal Si powder, but when the maximum particle radius is increased, the pores in the molded body become coarser and the diffusion distance of nitrogen increases, so that the residual particles remain. The amount of coarse air holes and the amount of unreacted Si increase. On the other hand, when the minimum particle radius is reduced, the handling property of the metal Si powder is deteriorated accordingly, and the metal Si powder reacts with oxygen in the atmosphere to form an oxide film, which prevents nitriding. Considering these points, the upper limit of the maximum particle radius of the metal Si powder is 22 μm, and the lower limit of the minimum particle radius is 0.025 μm.
It is desirable that it is m.
【0073】比較例である各Si3 N4 反応焼結体(1
8)〜(20),(21)〜(23)については、金属
Si粉末が前記のような粒度分布を有する関係から成形
体における充填率が0.48〜0.52(相対密度48
%〜52%)であって、本発明における充填率Dm=
0.68〜0.72に比べて極めて低く、また窒化率A
もNi粉末を用いたもの(18)〜(20)で58%≦
A≦65%、一方、Ni粉末を用いなかったもの(2
1)〜(23)で50%≦A≦60%と悪いことが判明
した。Each Si 3 N 4 reaction sintered body (1
Regarding 8) to (20) and (21) to (23), the filling rate in the molded body is 0.48 to 0.52 (relative density 48 because the metallic Si powder has the above-mentioned particle size distribution).
% To 52%), and the filling rate Dm in the present invention is
It is extremely low compared with 0.68 to 0.72, and the nitriding rate A
Also using Ni powder (18) to (20) 58% ≦
A ≦ 65%, on the other hand, without Ni powder (2
In 1) to (23), it was found that 50% ≦ A ≦ 60%, which was bad.
【0074】これらに起因して、各Si3 N4 反応焼結
体(18)〜(20),(21)〜(23)の強度は、
粒度分布を前記のように調整された金属Si粉末を用い
た各Si3 N4 反応焼結体(1)〜(17)に比べて低
くなる。Due to these, the strength of each Si 3 N 4 reaction sintered body (18) to (20), (21) to (23) is
The particle size distribution is lower than that of each Si 3 N 4 reaction sintered body (1) to (17) using the metal Si powder adjusted as described above.
【0075】[0075]
【発明の効果】本発明によれば、金属Si粉末に、窒化
促進用金属粉末としてNi粉末、Co粉末またはFe粉
末を特定量分散させた原料粉末を用いることによって、
高密度で、且つ高強度なSi3 N4 反応焼結体を得るこ
とができる。According to the present invention, by using a raw material powder in which a specific amount of Ni powder, Co powder or Fe powder is dispersed as metal nitriding promoting metal powder in metal Si powder,
It is possible to obtain a high density and high strength Si 3 N 4 reaction sintered body.
【0076】また製造過程に酸洗処理を組込むことによ
って、Si3 N4 反応焼結体の一層の高密度化および高
強度化を図ることができる。Further, by incorporating a pickling treatment in the manufacturing process, it is possible to further increase the density and strength of the Si 3 N 4 reaction sintered body.
【0077】さらに、金属Si粉末として、前記のよう
に特定された粒度分布を有するものを用いることによ
り、成形体における気孔の大きさおよび気孔の分散を窒
化に最適な状態にして、Si3 N4 反応焼結体の高密度
化および高強度化を達成することができる。Further, by using a metal Si powder having a particle size distribution specified as described above, the size of the pores and the dispersion of the pores in the compact are optimized for nitriding, and Si 3 N 4 High density and high strength of the reaction sintered body can be achieved.
【図1】Si3 N4 反応焼結体の製造過程の前半を示す
説明図である。FIG. 1 is an explanatory view showing the first half of a manufacturing process of a Si 3 N 4 reaction sintered body.
【図2】Si3 N4 反応焼結体の製造過程の後半を示す
説明図である。FIG. 2 is an explanatory view showing the latter half of the manufacturing process of the Si 3 N 4 reaction sintered body.
【図3】Si3 N4 反応焼結体の製造過程の要部を示す
説明図である。FIG. 3 is an explanatory diagram showing a main part of a manufacturing process of a Si 3 N 4 reaction sintered body.
【図4】金属Si粉末の粒度分布の一例を示すグラフで
ある。FIG. 4 is a graph showing an example of particle size distribution of metallic Si powder.
【図5】Si3 N4 反応焼結体の昇温条件を示すグラフ
である。FIG. 5 is a graph showing a temperature rising condition of a Si 3 N 4 reaction sintered body.
【図6】Ni粉末、Co粉末またはFe粉末の添加量と
窒化率との関係の一例を示すグラフである。FIG. 6 is a graph showing an example of the relationship between the addition amount of Ni powder, Co powder or Fe powder and the nitriding rate.
【図7】Ni粉末、Co粉末またはFe粉末の添加量と
窒化率との関係の他例を示すグラフである。FIG. 7 is a graph showing another example of the relationship between the added amount of Ni powder, Co powder or Fe powder and the nitriding rate.
【図8】金属Si粉末の粒度分布の他例を示すグラフで
ある。FIG. 8 is a graph showing another example of particle size distribution of metallic Si powder.
【図9】市販金属Si粉末の粒度分布を示すグラフであ
る。FIG. 9 is a graph showing the particle size distribution of commercially available metal Si powder.
【図10】金属Si粉末の最大粒子半径と曲げ強さとの
関係を示すグラフである。FIG. 10 is a graph showing the relationship between the maximum particle radius of metal Si powder and bending strength.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 太田 直樹 埼玉県狭山市新狭山1丁目10番地1 ホン ダエンジニアリング株式会社内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Naoki Ota 1-10-1 Shin-Sayama, Sayama City, Saitama Prefecture Honda Engineering Co., Ltd.
Claims (6)
してNi粉末を0.009重量%≦Ni粉末≦2.2重
量%分散させた原料粉末を用いて成形体を成形する工程
と、前記成形体と窒素ガスとを反応させて窒化ケイ素を
合成する反応焼結処理を行う工程とを順次行うことを特
徴とする窒化ケイ素反応焼結体の製造方法。1. A step of forming a compact using a raw material powder in which 0.009% by weight ≦ Ni powder ≦ 2.2% by weight of Ni powder as a metal powder for nitriding promotion is dispersed in metallic Si powder, A method for producing a silicon nitride reaction sintered body, which comprises sequentially performing a reaction sintering process of reacting a compact with nitrogen gas to synthesize silicon nitride.
してCo粉末およびFe粉末の一方を0.01重量%≦
Co粉末またはFe粉末≦2重量%分散させた原料粉末
を用いて成形体を成形する工程と、前記成形体と窒素ガ
スとを反応させて窒化ケイ素を合成する反応焼結処理を
行う工程とを順次行うことを特徴とする窒化ケイ素反応
焼結体の製造方法。2. One of Co powder and Fe powder as a nitriding promoting metal powder is added to the metal Si powder in an amount of 0.01% by weight ≦.
A step of forming a compact using a raw material powder in which Co powder or Fe powder ≦ 2% by weight is dispersed, and a step of performing a reaction sintering process of reacting the compact with nitrogen gas to synthesize silicon nitride. A method for producing a silicon nitride reaction sintered body, which is characterized in that the steps are sequentially performed.
してNi粉末を0.0085重量%≦Ni粉末≦5重量
%分散させた原料粉末を用いて成形体を成形する工程
と、前記成形体と窒素ガスとを反応させる1次反応焼結
処理を行うことにより合成窒化ケイ素を含む中間体を得
る工程と、前記中間体に酸洗処理を施してその中間体か
らNi成分を溶出させる工程と、前記中間体と窒素ガス
とを反応させて窒化ケイ素を合成する2次反応焼結処理
を行う工程とを順次行うことを特徴とする窒化ケイ素反
応焼結体の製造方法。3. A step of forming a compact using a raw material powder in which 0.0085% by weight ≦ Ni powder ≦ 5% by weight of Ni powder as a nitriding-promoting metal powder is dispersed in metallic Si powder; A step of obtaining an intermediate body containing synthetic silicon nitride by performing a first reaction sintering treatment of reacting nitrogen gas with nitrogen gas; and a step of subjecting the intermediate body to a pickling treatment to elute the Ni component from the intermediate body. And a step of performing a secondary reaction sintering process of synthesizing silicon nitride by reacting the intermediate with nitrogen gas, the method of manufacturing a silicon nitride reaction sintered body.
してCo粉末を0.0085重量%≦Co粉末≦4.5
重量%分散させた原料粉末を用いて成形体を成形する工
程と、前記成形体と窒素ガスとを反応させる1次反応焼
結処理を行うことにより合成窒化ケイ素を含む中間体を
得る工程と、前記中間体に酸洗処理を施してその中間体
からCo成分を溶出させる工程と、前記中間体と窒素ガ
スとを反応させて窒化ケイ素を合成する2次反応焼結処
理を行う工程とを順次行うことを特徴とする窒化ケイ素
反応焼結体の製造方法。4. A metal Si powder containing 0.0085% by weight of Co powder as a nitriding promoting metal powder ≦ Co powder ≦ 4.5.
Forming a molded body using the raw material powder dispersed by weight%; and obtaining a intermediate body containing synthetic silicon nitride by performing a primary reaction sintering process of reacting the molded body with nitrogen gas, A step of subjecting the intermediate to a pickling treatment to elute the Co component from the intermediate and a step of performing a secondary reaction sintering treatment of reacting the intermediate with nitrogen gas to synthesize silicon nitride are sequentially performed. A method for producing a silicon nitride reaction-sintered body, which comprises:
してFe粉末を0.01重量%≦Fe粉末≦4重量%分
散させた原料粉末を用いて成形体を成形する工程と、前
記成形体と窒素ガスとを反応させる1次反応焼結処理を
行うことにより合成窒化ケイ素を含む中間体を得る工程
と、前記中間体に酸洗処理を施してその中間体からFe
成分を溶出させる工程と、前記中間体と窒素ガスとを反
応させて窒化ケイ素を合成する2次反応焼結処理を行う
工程とを順次行うことを特徴とする窒化ケイ素反応焼結
体の製造方法。5. A step of forming a compact using a raw material powder in which 0.01% by weight ≦ Fe powder ≦ 4% by weight of Fe powder as metal powder for nitriding is dispersed in metallic Si powder, A step of obtaining a synthetic silicon nitride-containing intermediate by performing a primary reaction sintering process of reacting nitrogen gas with nitrogen gas; and a step of subjecting the intermediate to a pickling treatment to remove Fe from the intermediate.
A method for producing a silicon nitride reaction sintered body, which comprises sequentially performing a step of eluting the components and a step of performing a secondary reaction sintering process of reacting the intermediate with nitrogen gas to synthesize silicon nitride. ..
式、 Dm=1−(R/Rmax)q (ただし、Rmaxは最大粒子半径、Rは任意の粒子半
径、qは係数、Dmは最大粒子半径Rmaxから任意の
粒子半径Rまでの粒子を用いて得られた成形体における
充填率であって、Dm≦0.75である)において、金
属Si粉末の粒度分布を、最大粒子半径Rmaxが一定
であるとき係数qが0.25≦q≦0.5となるように
設定する、請求項1,2,3,4または5記載の窒化ケ
イ素反応焼結体の製造方法。6. A modified Andreasen filling formula, Dm = 1- (R / Rmax) q (where Rmax is a maximum particle radius, R is an arbitrary particle radius, q is a coefficient, and Dm is a maximum particle radius. (Filling ratio in a molded body obtained by using particles from Rmax to an arbitrary particle radius R, Dm ≦ 0.75), the particle size distribution of the metal Si powder is The method for producing a silicon nitride reaction sintered body according to claim 1, 2, 3, 4, or 5, wherein the coefficient q is set to be 0.25 ≤ q ≤ 0.5 at some time.
Priority Applications (1)
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JP14173392A JP3214729B2 (en) | 1992-06-02 | 1992-06-02 | Method for producing silicon nitride reaction sintered body |
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JP14173392A JP3214729B2 (en) | 1992-06-02 | 1992-06-02 | Method for producing silicon nitride reaction sintered body |
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JP3214729B2 JP3214729B2 (en) | 2001-10-02 |
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JP14173392A Expired - Fee Related JP3214729B2 (en) | 1992-06-02 | 1992-06-02 | Method for producing silicon nitride reaction sintered body |
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Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2014192149A1 (en) * | 2013-05-31 | 2014-12-04 | 京セラ株式会社 | Ceramic sintered body, and anticorrosion member, filter and antihalation member formed using same |
FR3045598A1 (en) * | 2015-12-21 | 2017-06-23 | Herakles | PROCESS FOR PRODUCING A CERAMIC FROM A CHEMICAL REACTION |
-
1992
- 1992-06-02 JP JP14173392A patent/JP3214729B2/en not_active Expired - Fee Related
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2014192149A1 (en) * | 2013-05-31 | 2014-12-04 | 京セラ株式会社 | Ceramic sintered body, and anticorrosion member, filter and antihalation member formed using same |
JPWO2014192149A1 (en) * | 2013-05-31 | 2017-02-23 | 京セラ株式会社 | Ceramic sintered body, corrosion resistant member, filter and antihalation member using the same |
FR3045598A1 (en) * | 2015-12-21 | 2017-06-23 | Herakles | PROCESS FOR PRODUCING A CERAMIC FROM A CHEMICAL REACTION |
WO2017109373A1 (en) * | 2015-12-21 | 2017-06-29 | Safran Ceramics | Method for producing a ceramic from a chemical reaction |
CN108698940A (en) * | 2015-12-21 | 2018-10-23 | 赛峰航空陶瓷技术公司 | By the method for chemical reaction production ceramics |
JP2019507083A (en) * | 2015-12-21 | 2019-03-14 | サフラン セラミクス | Process for producing ceramics from chemical reactions |
US10723658B2 (en) | 2015-12-21 | 2020-07-28 | Centre National De La Recherche Scientifique | Method of fabricating a ceramic from a chemical reaction |
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JP3214729B2 (en) | 2001-10-02 |
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