JPH01179766A - Production of silicon carbide-sialon combined sintered compact - Google Patents
Production of silicon carbide-sialon combined sintered compactInfo
- Publication number
- JPH01179766A JPH01179766A JP63001325A JP132588A JPH01179766A JP H01179766 A JPH01179766 A JP H01179766A JP 63001325 A JP63001325 A JP 63001325A JP 132588 A JP132588 A JP 132588A JP H01179766 A JPH01179766 A JP H01179766A
- Authority
- JP
- Japan
- Prior art keywords
- sialon
- silicon carbide
- powder
- formula
- alpha
- 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
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 title claims abstract description 13
- 229910052710 silicon Inorganic materials 0.000 title claims abstract description 13
- 239000010703 silicon Substances 0.000 title claims abstract description 13
- 238000004519 manufacturing process Methods 0.000 title claims description 6
- 239000000843 powder Substances 0.000 claims abstract description 54
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 claims abstract description 34
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 claims abstract description 22
- 229910052581 Si3N4 Inorganic materials 0.000 claims abstract description 19
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims abstract description 19
- 239000001301 oxygen Substances 0.000 claims abstract description 19
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 19
- 239000002245 particle Substances 0.000 claims abstract description 13
- 238000005245 sintering Methods 0.000 claims abstract description 13
- 229910010271 silicon carbide Inorganic materials 0.000 claims abstract description 12
- 229910052751 metal Inorganic materials 0.000 claims abstract description 11
- 239000013078 crystal Substances 0.000 claims abstract description 9
- 239000002184 metal Substances 0.000 claims abstract description 9
- 239000011159 matrix material Substances 0.000 claims abstract description 5
- 229910052684 Cerium Inorganic materials 0.000 claims abstract description 3
- 229910052747 lanthanoid Inorganic materials 0.000 claims abstract description 3
- 150000002602 lanthanoids Chemical class 0.000 claims abstract description 3
- 229910052746 lanthanum Inorganic materials 0.000 claims abstract description 3
- 238000000034 method Methods 0.000 claims description 16
- 239000002131 composite material Substances 0.000 claims description 9
- 239000011812 mixed powder Substances 0.000 claims description 7
- 239000011521 glass Substances 0.000 claims description 4
- 229910052782 aluminium Inorganic materials 0.000 claims description 3
- 239000000203 mixture Substances 0.000 abstract description 12
- 238000002156 mixing Methods 0.000 description 13
- 239000012298 atmosphere Substances 0.000 description 11
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 8
- 238000010438 heat treatment Methods 0.000 description 8
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 229910003564 SiAlON Inorganic materials 0.000 description 3
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 3
- 229910021417 amorphous silicon Inorganic materials 0.000 description 3
- 239000000919 ceramic Substances 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 230000007797 corrosion Effects 0.000 description 3
- 238000005260 corrosion Methods 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- 239000012535 impurity Substances 0.000 description 3
- 239000007788 liquid Substances 0.000 description 3
- 239000002994 raw material Substances 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 229910001873 dinitrogen Inorganic materials 0.000 description 2
- 239000006185 dispersion Substances 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 229910002804 graphite Inorganic materials 0.000 description 2
- 239000010439 graphite Substances 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 229910044991 metal oxide Inorganic materials 0.000 description 2
- 150000004706 metal oxides Chemical class 0.000 description 2
- QJGQUHMNIGDVPM-UHFFFAOYSA-N nitrogen group Chemical group [N] QJGQUHMNIGDVPM-UHFFFAOYSA-N 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- 238000003825 pressing Methods 0.000 description 2
- 238000004062 sedimentation Methods 0.000 description 2
- 108091026815 Competing endogenous RNA (CeRNA) Proteins 0.000 description 1
- 230000002159 abnormal effect Effects 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- PMHQVHHXPFUNSP-UHFFFAOYSA-M copper(1+);methylsulfanylmethane;bromide Chemical compound Br[Cu].CSC PMHQVHHXPFUNSP-UHFFFAOYSA-M 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000000280 densification Methods 0.000 description 1
- 238000007580 dry-mixing Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 238000009760 electrical discharge machining Methods 0.000 description 1
- 238000011049 filling Methods 0.000 description 1
- 239000003779 heat-resistant material Substances 0.000 description 1
- 238000007731 hot pressing Methods 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- WABPQHHGFIMREM-UHFFFAOYSA-N lead(0) Chemical compound [Pb] WABPQHHGFIMREM-UHFFFAOYSA-N 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000003801 milling Methods 0.000 description 1
- 239000012299 nitrogen atmosphere Substances 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 238000010248 power generation Methods 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 239000006104 solid solution Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000005979 thermal decomposition reaction Methods 0.000 description 1
- 238000002525 ultrasonication Methods 0.000 description 1
- 238000001238 wet grinding Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/515—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics
- C04B35/58—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on borides, nitrides, i.e. nitrides, oxynitrides, carbonitrides or oxycarbonitrides or silicides
- C04B35/597—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on borides, nitrides, i.e. nitrides, oxynitrides, carbonitrides or oxycarbonitrides or silicides based on silicon oxynitride, e.g. SIALONS
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Ceramic Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Structural Engineering (AREA)
- Organic Chemistry (AREA)
- Ceramic Products (AREA)
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明は、高温高強度、高硬度及び高靭性を有する各種
エンジニアリングセラミックスを製造するために有用な
炭化珪素−サイアロン複合焼結体の製造方法に関する。Detailed Description of the Invention (Industrial Application Field) The present invention provides a method for producing a silicon carbide-sialon composite sintered body useful for producing various engineering ceramics having high-temperature high strength, high hardness, and high toughness. Regarding.
（従来技術及びその問題点）
α−サイアロンは、α型窒化珪素のＳｉ位置にＡ！が、
Ｎ位置に０が置換固溶すると同時に、他の金属元素が侵
入型固溶した物質であり、式Ｍｘ（Ｓ ｉ、 Ａｌ１）
＋□（０，Ｎ）＋６ （■）（式中、ＭはＬｉ、Ｍｇ
、Ｃａ、Ｙ、又はＬａ及びＣｅ以外のランタニド系金属
元素を示し、Ｘは０＜ｘ≦２を満足する数である。）で
表される。(Prior art and its problems) α-Sialon has A! at the Si position of α-type silicon nitride! but,
It is a substance in which 0 is substituted in the N position and at the same time other metal elements are interstitially dissolved, and has the formula Mx (S i, Al1)
+□(0,N)+6 (■) (In the formula, M is Li, Mg
, Ca, Y, or a lanthanide metal element other than La and Ce, and X is a number satisfying 0<x≦2. ).
このα−サイアロンは、高硬度、低熱膨張率、優れた耐
蝕性等のエンジニアリングセラミックスとしての特性を
有している。また、理論的には粒界相（ガラス相）がな
く、高温においても強度の低下が少ないのが特徴である
。This α-sialon has characteristics as an engineering ceramic, such as high hardness, low coefficient of thermal expansion, and excellent corrosion resistance. In addition, theoretically, there is no grain boundary phase (glass phase), and the strength decreases little even at high temperatures.
しかし、α−サイアロン相相体体焼結体は、結晶形が粒
状であるため、エンジニアリングセラミックスとしての
強度、破壊靭性等の特性が充分ではない。そこで、この
欠点を改良するために、α−サイアロン結晶と、β型窒
化珪素のＳｉ位置にＡ℃が、Ｎ位置に０が置換固溶した
式Ｓ Ｉ ６−２Ａ ｆｆ１ｚｏｚＮｅ−ｚ （ｎ
）（式中、２はＯ＜ｚ≦４．２を満足する数である。However, since the α-sialon phase body sintered body has a granular crystal shape, it does not have sufficient properties such as strength and fracture toughness as an engineering ceramic. Therefore, in order to improve this drawback, the formula SI 6-2A ff1zozNe-z (n
) (wherein, 2 is a number that satisfies O<z≦4.2.
）で表される針状のβ−サイアロン結晶とを複合化させ
ることを考え、特許出願（特願昭６２−１５１０５７号
）を行った。これによって、得られるサイアロン基焼結
体は、従来のサイアロン基焼結体と比較して高温強度、
破壊靭性等の機械的特性が向上している。しかし、発電
用ガスタービンブレード等の厳しい使用条件への応用を
考えれば、さらに高温高強度化及び高靭性化を図る必要
があった。), and filed a patent application (Japanese Patent Application No. 151057/1982). As a result, the resulting sialon-based sintered body has higher high-temperature strength and higher strength than conventional sialon-based sintered bodies.
Mechanical properties such as fracture toughness are improved. However, considering the application to severe usage conditions such as gas turbine blades for power generation, it was necessary to further increase the strength and toughness at high temperatures.
（発明の目的）
本発明の目的は、高温強度及び靭性の高いサイアロン基
焼結体の製造方法を提供することである。(Object of the Invention) An object of the present invention is to provide a method for producing a sialon-based sintered body having high high-temperature strength and toughness.
（発明の要旨）
本発明によれば、前記式（１）で表されるα−サイアロ
ンを主たる相とし、かつ弐〔Ｉ）で規定される理論酸素
量に対して８重量％以下の過剰酸素を含有するα−サイ
アロン粉末と、窒化珪素粉末、及び炭化珪素粉末又は炭
化珪素ウィスカーの混合粉末を焼結することを特徴とす
る、α−サイアロンの粒状結晶、前記式（ＩＩ）で表さ
れるβ−サイアロンの針状結晶及び前記金属Ｍを含むガ
ラス相からなるマトリックスに炭化珪素粒子又は炭化珪
素ウィスカーが分散した炭化珪素−サイアロン複合焼結
体の製造方法が提供される。(Summary of the Invention) According to the present invention, α-sialon represented by the above formula (1) is the main phase, and excess oxygen is 8% by weight or less with respect to the theoretical oxygen amount defined by 2 [I]. A granular crystal of α-sialon, represented by the above formula (II), characterized by sintering a mixed powder of α-sialon powder containing α-sialon powder, silicon nitride powder, and silicon carbide powder or silicon carbide whiskers. A method for manufacturing a silicon carbide-sialon composite sintered body in which silicon carbide particles or silicon carbide whiskers are dispersed in a matrix consisting of a glass phase containing β-sialon needle crystals and the metal M is provided.
（発明の詳細な説明）
本発明で使用されるα−サイアロン粉末は、式〔■〕で
表されるα−サイアロンを主たる相とする粉末であれば
いかなる粉末でも良いが、本出願人が先に提案した特願
昭６１−６０６４０号の発明に従って調製した粉末が好
適である。この提案の方法は、
（ａ）非晶質窒化珪素粉末、
（ｂ）金属アルミニウム又は窒化アルミニウム、（Ｃ）
α−サイアロンの格子間に侵入型固溶する金属の酸化物
及び／又はこの金属酸化物を生成する金属塩類、及び必
要に応じて、
（ｄ）アルミニウム又は珪素の酸素含有化合物を所望の
α−サイアロン組成になるように混合し、混合物を窒素
含有雰囲気下で１３００〜１９００°Ｃの範囲の温度に
加熱することにより、α−サイアロン粉末を製造する方
法である。この方法で得られるα−サイアロン粉末は、
−成粒子の大きさが０．２〜２μｍの微細かつ均一粒度
の粉末であって、遊離炭素及び金属不純物を殆ど含有し
ないので、気孔及び異常粒成長のない焼結体を与えるこ
とができる。(Detailed Description of the Invention) The α-sialon powder used in the present invention may be any powder having α-sialon as a main phase represented by the formula [■]. Powders prepared according to the invention of Japanese Patent Application No. 61-60640 proposed in 1983 are suitable. This proposed method consists of (a) amorphous silicon nitride powder, (b) metallic aluminum or aluminum nitride, (C)
A metal oxide which forms an interstitial solid solution in the interstitial space of α-Sialon and/or a metal salt that forms this metal oxide, and if necessary, (d) an oxygen-containing compound of aluminum or silicon, is added to the desired α-sialon. This is a method for producing α-SiAlON powder by mixing to obtain a SiAlON composition and heating the mixture to a temperature in the range of 1300 to 1900°C under a nitrogen-containing atmosphere. The α-sialon powder obtained by this method is
- It is a fine and uniform powder with a particle size of 0.2 to 2 μm, and contains almost no free carbon and metal impurities, so it is possible to provide a sintered body free of pores and abnormal grain growth.
α−サイアロン粉末の焼結性を高めると同時に高強度の
サイアロン基焼結体を得るためには、焼結原料のα−サ
イアロン粉末が式〔Ｉ〕で規定される理論酸素量に対し
て８重量％以下の過剰酸素を含有していることが必要で
ある。In order to improve the sinterability of the α-sialon powder and at the same time obtain a high-strength sialon-based sintered body, the α-sialon powder as a sintering raw material must be It is necessary to contain no more than % by weight of excess oxygen.
α−サイアロン粉末に過剰の酸素を含有させる方法とし
ては、例えば、α−サイアロン粉末の調製段階で非晶質
窒化珪素に珪素又はアルミニウムの酸素含有化合物を過
剰量添加する方法、α−サイアロン粉末を酸素含有雰囲
気中で加熱する方法が採用される。後者の一例としては
、α−サイアロン粉末を酸素含有雰囲気中で８００〜１
２００゛Ｃの範囲の温度に加熱して、理論量より過剰の
酸素をα−サイアロン粉末に含有させる方法が挙げられ
る。加熱時間は通常０．５〜５時間である。この処理は
、例えばα−サイアロン粉末を保持板上に薄く乗せて酸
素含有雰囲気中に放置する方法、α−サイアロン粉末を
酸素含有雰囲気中で流動化させる方法によって行うこと
ができる。Examples of methods for making α-sialon powder contain excess oxygen include adding an excessive amount of an oxygen-containing compound of silicon or aluminum to amorphous silicon nitride in the preparation stage of α-sialon powder; A method of heating in an oxygen-containing atmosphere is employed. As an example of the latter, α-Sialon powder is heated to 800-1 in an oxygen-containing atmosphere.
An example is a method of heating the α-sialon powder to a temperature in the range of 200° C. to cause the α-sialon powder to contain oxygen in excess of the stoichiometric amount. Heating time is usually 0.5 to 5 hours. This treatment can be carried out, for example, by placing α-sialon powder thinly on a holding plate and leaving it in an oxygen-containing atmosphere, or by fluidizing α-sialon powder in an oxygen-containing atmosphere.
過剰酸素量は８重量％以下、好ましくは１〜６．５重量
％、特に好ましくは２〜４重景％である。The amount of excess oxygen is 8% by weight or less, preferably 1 to 6.5% by weight, particularly preferably 2 to 4% by weight.
過剰酸素量が過度に多いと焼結体中に融点の低い相が多
く残留し、高温での機械特性が損なわれるようになる。If the amount of excess oxygen is too large, many phases with low melting points remain in the sintered body, and mechanical properties at high temperatures are impaired.
本発明で使用される窒化珪素粉末は、焼結性の面で１μ
ｍ以下の粒径を有していることが好ましく、さらに得ら
れる焼結体の高温での強度、耐触性、耐酸化性を損なう
不純物の含有量が１重量％以下であることが好ましい。The silicon nitride powder used in the present invention has a sinterability of 1μ
It is preferable that the particles have a particle size of not more than m, and it is further preferable that the content of impurities that impair the strength, corrosion resistance, and oxidation resistance at high temperatures of the obtained sintered body is not more than 1% by weight.
α−サイアロン粉末と窒化珪素粉末との混合物中の窒化
珪素粉末の配合割合は８０重量％以下、好ましくは３０
〜７５重景％、さらに好ましくは４０〜６５重景％であ
る。上記範囲内において窒化珪素粉末の配合割合を高め
るに従って生成サイアロン基焼結体中のβ−サイアロン
相の割合が増大する。窒化珪素粉末の配合割合が８０重
量％を超えると、混合物の焼結性が低下し焼結体の緻密
化が進行しなくなる。The blending ratio of silicon nitride powder in the mixture of α-sialon powder and silicon nitride powder is 80% by weight or less, preferably 30% by weight or less.
The ratio is 75% to 75%, more preferably 40 to 65%. Within the above range, as the blending ratio of silicon nitride powder increases, the ratio of the β-sialon phase in the produced sialon-based sintered body increases. When the blending ratio of silicon nitride powder exceeds 80% by weight, the sinterability of the mixture decreases and the densification of the sintered body does not proceed.
本発明で使用される炭化珪素粉末は、焼結性の面で１μ
ｍ以下の粒径を有していることが好ましく、さらに得ら
れる焼結体の高温での強度、耐触性、耐酸化性を損なう
不純物の含有量が１重量％以下であることが好ましい。The silicon carbide powder used in the present invention has a sinterability of 1μ
It is preferable that the particles have a particle size of not more than m, and it is further preferable that the content of impurities that impair the strength, corrosion resistance, and oxidation resistance at high temperatures of the obtained sintered body is not more than 1% by weight.
また、本発明で使用される炭化珪素ウィスカーは、その
８０％以上が直径０．１〜１０ ｐ ｍ程度、長さ３０
〜１００μｍ程度の範囲に入るものが好ましい。In addition, more than 80% of the silicon carbide whiskers used in the present invention have a diameter of about 0.1 to 10 pm and a length of 30 pm.
It is preferable that the thickness falls within the range of about 100 μm.
α〜サイアロン粉末と窒化珪素粉末との混合粉末に対す
る炭化珪素粉末又は炭化珪素ウィスカーの配合割合は５
〜５０重量％、特に２０〜４０重量％が好ましい。α ~ The blending ratio of silicon carbide powder or silicon carbide whiskers to the mixed powder of sialon powder and silicon nitride powder is 5
~50% by weight, especially 20-40% by weight is preferred.
α−サイアロン粉末、窒化珪素粉末及び炭化珪素粉末の
混合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、乾式混合する方法、不活性液体中で湿式混
合した後、不活性液体を除去する方法等を適宜採用する
ことができる。混合装置としてはＶ型混合機、ボールミ
ル等が便利に使用される。There are no particular restrictions on the method of mixing α-sialon powder, silicon nitride powder, and silicon carbide powder, and methods known per se may be used, such as dry mixing, wet mixing in an inert liquid, and then removing the inert liquid. The method of doing so can be adopted as appropriate. As a mixing device, a V-type mixer, a ball mill, etc. are conveniently used.
また、α−サイアロン粉末、窒化珪素粉末及び炭化珪素
ウィスカーの混合方法については、α−サイアロン粉末
及び窒化珪素粉末をあらかじめ前記の混合方法で均一混
合し、これに分散処理を施した炭化珪素ウィスカーを加
え、さらに前記の混合方法で混合する。炭化珪素ウィス
カーの分散処理は、不活性液体中での超音波処理や解膠
剤の添加等によってウィスカー同士の物理的なからみを
除き、得られる焼結体中に欠陥として残るのを防ぐため
のものである。Regarding the mixing method of α-sialon powder, silicon nitride powder, and silicon carbide whiskers, α-sialon powder and silicon nitride powder are uniformly mixed in advance by the above-mentioned mixing method, and then silicon carbide whiskers are mixed by dispersion treatment. In addition, the mixture is further mixed using the mixing method described above. Dispersion treatment of silicon carbide whiskers involves removing physical entanglement between whiskers by ultrasonication in an inert liquid, adding a deflocculant, etc., and preventing them from remaining as defects in the resulting sintered body. It is something.
混合粉末の加熱焼結は雰囲気加圧焼結又はホントプレス
が使用される。雰囲気加圧焼結は、混合粉末をそのまま
乾式あるいは湿式で所定の形状に成形し、湿式で成形し
た場合は乾燥処理を行った後に、窒素含有ガス雰囲気下
で加圧焼結する。また、ホットプレスは、原料粉末を所
定の形状のダイスに充填して行われる。雰囲気加圧焼結
における圧力は１〜１００気圧、ポットプレスの加圧力
は１００〜４００ｋｇ／ｃボが望ましい。For heating and sintering the mixed powder, atmosphere pressure sintering or real press is used. In the atmosphere pressure sintering, the mixed powder is directly shaped into a predetermined shape using a dry or wet process, and in the case of wet forming, it is subjected to a drying process and then pressure sintered in a nitrogen-containing gas atmosphere. Further, hot pressing is performed by filling a die having a predetermined shape with raw material powder. The pressure in the atmosphere pressure sintering is preferably 1 to 100 atm, and the pressure of the pot press is preferably 100 to 400 kg/cm.
焼結に必要な最高温度（以下、焼結温度という）は通常
１７００〜２０００°Ｃであり、その温度での保持時間
（以下、焼結時間という）は通常０．５〜１０時間であ
る。焼結温度が１７００°Ｃより低いと焼結が十分に進
行せず、また２０００°Ｃより高いと焼結体に熱分解に
よる組成変化が生じたり、炭化珪素の粒成長が起こり、
焼結体の強度低下を招くおそれがある。The maximum temperature required for sintering (hereinafter referred to as sintering temperature) is usually 1700 to 2000°C, and the holding time at that temperature (hereinafter referred to as sintering time) is usually 0.5 to 10 hours. If the sintering temperature is lower than 1,700°C, sintering will not proceed sufficiently, and if it is higher than 2,000°C, composition changes will occur in the sintered body due to thermal decomposition, and grain growth of silicon carbide will occur.
This may lead to a decrease in the strength of the sintered body.
本発明によって得られる炭化珪素−サイアロン複合焼結
体は、α−サイアロンと窒化珪素との反応によって生成
すると考えられる、β−サイアロン相の針状結晶、式（
１）における金属Ｍを含むガラス相、及び原料のα−サ
イアロンの組成より式〔■〕のＸが若干低いα−サイア
ロン相をマトリックスとして、これに炭化珪素粒子又は
炭化珪素ウィスカーが均一に分散した状態となっている
。The silicon carbide-sialon composite sintered body obtained by the present invention is composed of needle-like crystals of β-sialon phase, which is thought to be produced by the reaction between α-sialon and silicon nitride, and has the formula (
Silicon carbide particles or silicon carbide whiskers are uniformly dispersed in the glass phase containing the metal M in 1) and the α-sialon phase with a slightly lower X in formula [■] from the composition of the raw material α-sialon as a matrix. It is in a state.
このように、炭化珪素粒子又は炭化珪素ウィスカーが均
一に分散することにより、クランクのピン止め効果や屈
曲効果、炭化珪素ウィスカーの引き抜き効果等の機構が
働き、これにより、サイアロン基焼結体の機械的特性に
比べて本発明の炭化珪素−サイアロン複合焼結体の機械
的特性が向上するものと考えられる。特に高温強度の向
上が顕著に認められるが、これは、炭化珪素の熱膨張係
数がサイアロンのそれよりも大きいため、高温になると
サイアロンマトリックスと炭化珪素との界面の物理的結
合が強まるためと推測される。In this way, by uniformly dispersing silicon carbide particles or silicon carbide whiskers, mechanisms such as the pinning effect of the crank, the bending effect, and the pulling effect of the silicon carbide whiskers work, and thereby the machine of the sialon-based sintered body It is considered that the mechanical properties of the silicon carbide-sialon composite sintered body of the present invention are improved compared to the physical properties. In particular, a remarkable improvement in high-temperature strength is observed, and this is presumed to be because the thermal expansion coefficient of silicon carbide is larger than that of Sialon, which strengthens the physical bond at the interface between the Sialon matrix and silicon carbide at high temperatures. be done.
（発明の効果）
本発明で得られる炭化珪素−サイアロン複合焼結体は、
従来のサイアロン基焼結体と比較して、高温強度、破壊
靭性、硬度等の機械的特性が向上しているので、信頼性
の高い構造材料、特に切削チップ、ロール、ダイス、ノ
ズル等の耐摩耗、耐熱材料として好適に使用することが
できる。特に本発明の炭化珪素−サイアロン複合焼結体
は、導電性を示すため、より精密な放電加工が可能とな
り、機械用材料としての応用が広がるものである。(Effects of the invention) The silicon carbide-sialon composite sintered body obtained by the present invention is
Compared to conventional sialon-based sintered bodies, mechanical properties such as high-temperature strength, fracture toughness, and hardness are improved, making it a highly reliable structural material, especially for cutting chips, rolls, dies, nozzles, etc. It can be suitably used as a wear and heat resistant material. In particular, since the silicon carbide-sialon composite sintered body of the present invention exhibits electrical conductivity, more precise electrical discharge machining is possible, and its application as a material for machinery is expanded.
（実施例） 以下に実施例及び比較例を示す。(Example) Examples and comparative examples are shown below.
実施例１〜３及び比較例１
非晶質窒化珪素粉末４７９．２ ｇ−、Ｙ２Ｏ３粉末５
９、４ ｇ及び金属ＡＩ鉛粉末３ｇを窒素ガス雰囲気下
に振動ミルで１時間混合した。混合粉末をカーボン製ル
ツボに充填して抵抗加熱式高温炉にセットし、窒素ガス
雰囲気下、室温から１２００°Ｃ迄を１時間、１２００
°Ｃから１４００°Ｃ迄を４時間、さらに１４００°Ｃ
から１６００°Ｃ迄を２時間の昇温スケジュールで加熱
することにより結晶化させ、Ｙ系α−サイアロン粉末を
得た。得られたα−サイアロン粉末の特性を以下に示す
。Examples 1 to 3 and Comparative Example 1 Amorphous silicon nitride powder 479.2 g-, Y2O3 powder 5
9,4 g and 3 g of metal AI lead powder were mixed for 1 hour in a vibrating mill under a nitrogen gas atmosphere. The mixed powder was filled into a carbon crucible, set in a resistance heating high temperature furnace, and heated from room temperature to 1200°C for 1 hour at 1200°C in a nitrogen gas atmosphere.
°C to 1400°C for 4 hours, then 1400°C
The mixture was crystallized by heating from 1,600°C to 1,600°C on a 2-hour heating schedule to obtain Y-based α-sialon powder. The properties of the obtained α-sialon powder are shown below.
理論組成 ＹＯ，５ｓｉｑ、 ７５Δ１２．２５００．
７５Ｎ＋５．２５比表面積 ２．５ｎ（／ｇ
粒 形 等軸結晶
生成相 α相２９０％
生成物組成（凶ｔ″Ａ）
Ｙニア、２ Ｓｉ：４４．２ Δ１：９．８ ０：
４．９ Ｎ：３３．９過剰酸素量 ２．９重量％
上記α−サイアロン粉末、窒化珪素粉末（遠心沈降法に
よる平均粒径：０．５μｍ、比表面積：１１ポ／ｇ）、
及び炭化珪素（平均粒径：０．３μｍ、比表面積：２１
ｒｄ／ｇ）を用い、α−サイアロン粉末と窒化珪素粉末
との配合比は４０：６０（重量％）とし、これに炭化珪
素粉末を第１表に示す割合で添加し、媒体としてエタノ
ールを用い４８時間湿式ミリングした後、８０°Ｃで真
空乾燥した。Theoretical composition YO, 5siq, 75Δ12.2500.
75N + 5.25 Specific surface area 2.5n (/g Grain shape Equiaxed crystal formation phase α phase 290% Product composition (A) Y near, 2 Si: 44.2 Δ1: 9.8 0:
4.9 N: 33.9 Excess oxygen amount 2.9% by weight The above α-sialon powder, silicon nitride powder (average particle size by centrifugal sedimentation method: 0.5 μm, specific surface area: 11 po/g),
and silicon carbide (average particle size: 0.3 μm, specific surface area: 21
rd/g), the blending ratio of α-sialon powder and silicon nitride powder was 40:60 (wt%), and silicon carbide powder was added in the ratio shown in Table 1, using ethanol as a medium. After wet milling for 48 hours, it was vacuum dried at 80°C.
得られた粉末４０ｇを８０Ｘ４４ｍｍの金型を使用して
１５０ ｋｇ／ｃ＋ｆｌの圧力で一軸プレスした後、１
５００ ｋｇ／ｃ＋ｆｌの圧力でラバープレスして成形
体を得た。この成形体を黒鉛ルツボに入れ、１０気圧の
窒素雰囲気中、１９５０°Ｃで４時間保持した。After uniaxially pressing 40 g of the obtained powder at a pressure of 150 kg/c+fl using an 80 x 44 mm mold, 1
A molded article was obtained by rubber pressing at a pressure of 500 kg/c+fl. This molded body was placed in a graphite crucible and held at 1950°C for 4 hours in a nitrogen atmosphere of 10 atm.
得られた炭化珪素−サイアロン複合焼結体の特性を第１
表に示す。The characteristics of the obtained silicon carbide-sialon composite sintered body were first evaluated.
Shown in the table.
実施例４〜６及び比較例２
前記実施例で得られたα−サイアロン粉末、窒化珪素粉
末（遠心沈降法による平均粒径：０．５μｍ、比表面積
：１１ｒｒｆ／ｇ）、及び炭化珪素ウィスカー（直径：
０．１〜１．０ ｐ ｍ、長さ二３０〜１００μｍ、
アスペクト比：５０〜２００）を用い、まず、α−サイ
アロン粉末と窒化珪素粉末との配合比４０：６０（重量
％）の混合粉末を、媒体としてエタノールを用い４８時
間湿式ミリングした。Examples 4 to 6 and Comparative Example 2 The α-SiAlON powder obtained in the above example, silicon nitride powder (average particle size by centrifugal sedimentation method: 0.5 μm, specific surface area: 11 rrf/g), and silicon carbide whiskers ( diameter:
0.1-1.0 pm, length 230-100μm,
First, a mixed powder of α-sialon powder and silicon nitride powder at a blending ratio of 40:60 (weight %) was wet-milled for 48 hours using ethanol as a medium.
別に第１表に示す割合の炭化珪素ウィスカーに対して解
膠剤としてセルナＤ５０３ （中東油脂製）を０．５重
量％添加し、エタノール中で４時間混式ミリングした。Separately, 0.5% by weight of Cerna D503 (manufactured by Middle East Oil Co., Ltd.) as a deflocculant was added to the silicon carbide whiskers in the proportions shown in Table 1, and mixed milling was carried out in ethanol for 4 hours.
次いで両者を混合し、エタノール中で４時間混式ミリン
グした後、８０°Ｃで真空乾燥した。得られた粉末３０
ｇを内径５０ｍｍの黒鉛製のダイスに充填し、１８５０
°Ｃで２時間ホットプレスした。加圧力は２５０ｋｇ／
ｃｆとした。Next, the two were mixed, mixed milled in ethanol for 4 hours, and then vacuum dried at 80°C. Obtained powder 30
Fill a graphite die with an inner diameter of 50 mm with 1850
Hot pressed for 2 hours at °C. Pressure force is 250kg/
cf.
得られた炭化珪素−サイアロン複合焼結体の特性を第１
表に示す。The characteristics of the obtained silicon carbide-sialon composite sintered body were first evaluated.
Shown in the table.
Claims (1)
式中、ＭはＬｉ、Ｍｇ、Ｃａ、Ｙ、又はＬａ及びＣｅ以
外のランタニド系金属元素を示し、ｘは０＜ｘ≦２を満
足する数である。）で表されるα−サイアロンを主たる
相とし、かつ上記式で規定される理論酸素量に対して８
重量％以下の過剰酸素を含有するα−サイアロン粉末、
窒化珪素粉末、及び炭化珪素粉末又は炭化珪素ウィスカ
ーの混合粉末を焼結することを特徴とする、α−サイア
ロンの粒状結晶、式Ｓｉ＿６＿−＿ｚＡｌ＿ｚＯ＿ｚＮ
＿８＿−＿ｚ（式中、ｚは０＜ｚ≦４．２を満足する数
である。）で表されるβ−サイアロンの針状結晶及び上
記金属Ｍを含むガラス相からなるマトリックスに炭化珪
素粒子又は炭化珪素ウィスカーが分散した炭化珪素−サ
イアロン複合焼結体の製造方法。Formula M_x(Si,Al)_1_2(O,N)_1_6(
In the formula, M represents Li, Mg, Ca, Y, or a lanthanide metal element other than La and Ce, and x is a number satisfying 0<x≦2. ) with α-sialon as the main phase, and 8 to the theoretical oxygen amount defined by the above formula.
alpha-sialon powder containing less than % by weight of excess oxygen;
Granular crystals of α-sialon, formula Si_6_−_zAl_zO_zN, characterized by sintering a mixed powder of silicon nitride powder and silicon carbide powder or silicon carbide whiskers.
Silicon carbide particles in a matrix consisting of a glass phase containing β-sialon needle crystals and the metal M, represented by _8_−_z (where z is a number satisfying 0<z≦4.2). Or a method for manufacturing a silicon carbide-sialon composite sintered body in which silicon carbide whiskers are dispersed.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63001325A JPH01179766A (en) | 1988-01-08 | 1988-01-08 | Production of silicon carbide-sialon combined sintered compact |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63001325A JPH01179766A (en) | 1988-01-08 | 1988-01-08 | Production of silicon carbide-sialon combined sintered compact |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH01179766A true JPH01179766A (en) | 1989-07-17 |
Family
ID=11498346
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63001325A Pending JPH01179766A (en) | 1988-01-08 | 1988-01-08 | Production of silicon carbide-sialon combined sintered compact |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH01179766A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5656217A (en) * | 1994-09-13 | 1997-08-12 | Advanced Composite Materials Corporation | Pressureless sintering of whisker reinforced alumina composites |
-
1988
- 1988-01-08 JP JP63001325A patent/JPH01179766A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5656217A (en) * | 1994-09-13 | 1997-08-12 | Advanced Composite Materials Corporation | Pressureless sintering of whisker reinforced alumina composites |
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