JPH07116773A - Production of casting mold for precision casting - Google Patents
Production of casting mold for precision castingInfo
- Publication number
- JPH07116773A JPH07116773A JP5262572A JP26257293A JPH07116773A JP H07116773 A JPH07116773 A JP H07116773A JP 5262572 A JP5262572 A JP 5262572A JP 26257293 A JP26257293 A JP 26257293A JP H07116773 A JPH07116773 A JP H07116773A
- Authority
- JP
- Japan
- Prior art keywords
- mold
- parts
- mullite
- casting mold
- silica
- 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.)
- Withdrawn
Links
- 238000005495 investment casting Methods 0.000 title claims abstract description 15
- 238000004519 manufacturing process Methods 0.000 title claims description 12
- 238000005266 casting Methods 0.000 title abstract description 17
- KZHJGOXRZJKJNY-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical compound O=[Si]=O.O=[Si]=O.O=[Al]O[Al]=O.O=[Al]O[Al]=O.O=[Al]O[Al]=O KZHJGOXRZJKJNY-UHFFFAOYSA-N 0.000 claims abstract description 50
- 229910052863 mullite Inorganic materials 0.000 claims abstract description 50
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims abstract description 35
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims abstract description 32
- 239000002245 particle Substances 0.000 claims abstract description 25
- 239000011230 binding agent Substances 0.000 claims abstract description 22
- RMAQACBXLXPBSY-UHFFFAOYSA-N silicic acid Chemical compound O[Si](O)(O)O RMAQACBXLXPBSY-UHFFFAOYSA-N 0.000 claims abstract description 22
- 239000000835 fiber Substances 0.000 claims abstract description 18
- 239000000377 silicon dioxide Substances 0.000 claims abstract description 17
- 239000002002 slurry Substances 0.000 claims abstract description 17
- 239000000843 powder Substances 0.000 claims abstract description 16
- GPRLSGONYQIRFK-UHFFFAOYSA-N hydron Chemical compound [H+] GPRLSGONYQIRFK-UHFFFAOYSA-N 0.000 claims abstract description 13
- 239000000463 material Substances 0.000 claims abstract description 7
- 239000000945 filler Substances 0.000 claims abstract description 6
- 239000000203 mixture Substances 0.000 abstract description 2
- 239000000919 ceramic Substances 0.000 description 9
- 238000005336 cracking Methods 0.000 description 6
- 238000006243 chemical reaction Methods 0.000 description 5
- 238000000034 method Methods 0.000 description 5
- 238000010438 heat treatment Methods 0.000 description 4
- 238000007598 dipping method Methods 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- 229910052845 zircon Inorganic materials 0.000 description 3
- GFQYVLUOOAAOGM-UHFFFAOYSA-N zirconium(iv) silicate Chemical compound [Zr+4].[O-][Si]([O-])([O-])[O-] GFQYVLUOOAAOGM-UHFFFAOYSA-N 0.000 description 3
- 229910000831 Steel Inorganic materials 0.000 description 2
- 230000002378 acidificating effect Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000001035 drying Methods 0.000 description 2
- 239000010419 fine particle Substances 0.000 description 2
- 238000013001 point bending Methods 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- 229910001208 Crucible steel Inorganic materials 0.000 description 1
- BOTDANWDWHJENH-UHFFFAOYSA-N Tetraethyl orthosilicate Chemical compound CCO[Si](OCC)(OCC)OCC BOTDANWDWHJENH-UHFFFAOYSA-N 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000008119 colloidal silica Substances 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000010304 firing Methods 0.000 description 1
- 239000000499 gel Substances 0.000 description 1
- 239000011268 mixed slurry Substances 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
Landscapes
- Molds, Cores, And Manufacturing Methods Thereof (AREA)
- Compositions Of Oxide Ceramics (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、精密鋳造用セラミック
鋳型、特に高温で軟化、変形しやすい比較的大型の精密
鋳造用鋳型の製造方法に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a precision casting ceramic mold, particularly a relatively large precision casting mold which is easily softened and deformed at a high temperature.
【０００２】[0002]
【従来の技術】精密鋳造用セラミックス鋳型は、一般に
ワックス模型をバインダとセラミック粉末（フィラ）と
よりなるスラリ中へ浸漬して、スラリを付着させ（ディ
ッピング）、その後、セラミック粒子を同スラリに付着
させ（サンディングあるいはスタッコイング）、この工
程を約７乃至１０数回繰り返して、所定厚さのセラミッ
ク層を形成する。2. Description of the Related Art A ceramic mold for precision casting is generally prepared by immersing a wax model in a slurry consisting of a binder and ceramic powder (filler) to adhere the slurry (dipping), and then attaching the ceramic particles to the slurry. (Sanding or stuccoing), and this process is repeated about 7 to 10 times to form a ceramic layer having a predetermined thickness.
【０００３】その後、ワックスを溶出し、所定温度（一
般に１０００℃前後）に加熱・焼成して、高温状態の鋳
型に溶鋼を注湯するようにしている。またバインダに
は、シリカゾル（コロイダルシリカあるいはエチルシリ
ケート）、スラリ中のセラミック（フィラ）には、ジル
コン粉末、スタッコ用セラミックには、ジルコン粒子あ
るいはムライト粒子が一般的に使用されている。After that, the wax is eluted, heated and fired at a predetermined temperature (generally around 1000 ° C.), and molten steel is poured into a high temperature mold. Generally, silica sol (colloidal silica or ethyl silicate) is used as a binder, zircon powder is used as a ceramic (filler) in a slurry, and zircon particles or mullite particles are used as a stucco ceramic.
【０００４】[0004]
【発明が解決しようとする課題】前記製造方法により製
造される精密鋳造用セラミックス鋳型の厚さは、約７乃
至１０数ｍｍであり、しかも鋳込み時の鋳型温度が１０
００℃前後で、鋳込み時には、鋳型がさらに加熱され
て、鋳物との接触面近傍では、１４００℃以上に加熱さ
れ、鋳型の肉厚中心部でも、１２００℃以上に加熱され
る。The thickness of the ceramic mold for precision casting manufactured by the above manufacturing method is about 7 to 10 mm, and the mold temperature during casting is 10 mm.
At around 00 ° C., the mold is further heated at the time of casting, is heated to 1400 ° C. or higher in the vicinity of the contact surface with the casting, and is heated to 1200 ° C. or higher even at the center of the wall thickness of the mold.
【０００５】シリカゾルをバインダとした鋳型では、バ
インダとしてのシリカが軟化、変形しやすいため、溶鋼
の静圧により鋳型が変形して、寸法精度上に問題が生じ
る。特に大型の精密鋳造品になる程、鋳型の変形量が大
きくなって、単に寸法精度だけでなく、鋳型が破損する
という問題もある。本発明は前記の問題点に鑑み提案す
るものであり、その目的とする処は、鋳型の変形及び鋳
型の割れを減少乃至防止できる。また鋳型の高温での耐
変形性、耐割れ性を向上できる。さらに鋳型の高温での
軟化変形及び割れを減少乃至防止できる精密鋳造用鋳型
の製造方法を提供しようとする点にある。In a mold using silica sol as a binder, silica as a binder is easily softened and deformed, so that the mold is deformed by the static pressure of molten steel, which causes a problem in dimensional accuracy. In particular, the larger the precision casting product, the greater the amount of deformation of the mold, which causes not only the dimensional accuracy but also the damage to the mold. The present invention is proposed in view of the above problems, and the object of the present invention is to reduce or prevent deformation of the mold and cracking of the mold. Also, the deformation resistance and crack resistance of the mold at high temperature can be improved. Another object of the present invention is to provide a method for producing a precision casting mold that can reduce or prevent softening deformation and cracking of the mold at high temperatures.
【０００６】[0006]
【課題を解決するための手段】上記の目的を達成するた
めに、本発明の精密鋳造用鋳型の製造方法は、水素イオ
ン濃度指数が２．５乃至４．５でアルミナ含有量が１０
乃至１１重量％のアルミナゾル４０乃至７０部と、水素
イオン濃度指数が２乃至４でシリカ含有量が２０乃至２
１重量％のシリカゾル６０乃至３０部とからなる混合バ
インダ１００部に対して、フィラとして粒径が４４μｍ
以下のムライト粉末を１００部乃至２００部及びムライ
ト繊維を５乃至２０部配合したスラリと、スタッコ材と
して粒径０．１乃至０．３ｍｍ及び０．５乃至１．０ｍ
ｍのムライト粒子とを組み合わせて鋳型を製作した後、
この鋳型を１２００℃で焼成することを特徴としてい
る。In order to achieve the above object, the method for producing a precision casting mold of the present invention has a hydrogen ion concentration index of 2.5 to 4.5 and an alumina content of 10.
40 to 70 parts by weight of alumina sol of 11 to 11% by weight, hydrogen ion concentration index of 2 to 4 and silica content of 20 to 2
The particle size is 44 μm as a filler with respect to 100 parts of a mixed binder composed of 60 to 30 parts of 1 wt% silica sol.
A slurry containing 100 to 200 parts of the following mullite powder and 5 to 20 parts of mullite fiber, and a stucco material having a particle size of 0.1 to 0.3 mm and 0.5 to 1.0 m.
After making a mold by combining with m mullite particles,
This mold is characterized by being baked at 1200 ° C.
【０００７】[0007]
【作用】本発明の精密鋳造用鋳型の製造方法は、アルミ
ナゾルとシリカゾルとを混合してバインダとし、このバ
インダを用いたセラミックスラリ及びスタッコ材により
造型した鋳型を１２００℃以上で１時間以上加熱し、バ
インダ中のアルミナとシリカとを反応させて、ムライト
（３Ａｌ2 Ｏ3 ・２ＳｉＯ2 ）に変化させる。このムラ
イトは、シリカに比べると、高温での軟化が小さい上
に、高温での強度が大きく、そのため、鋳型の変形及び
鋳型の割れが減少乃至防止される。The method for producing a mold for precision casting according to the present invention is such that alumina sol and silica sol are mixed as a binder, and the mold formed by the ceramic slurry and stucco material using this binder is heated at 1200 ° C. or higher for 1 hour or more. , Alumina in the binder is reacted with silica to change to mullite (3Al 2 O 3 .2SiO 2 ). Compared with silica, this mullite has a small softening property at high temperature and a large strength at high temperature. Therefore, the deformation and cracking of the mold are reduced or prevented.
【０００８】またアルミナゾル中のアルミナ及びシリカ
ゾル中のシリカの大きさは、数十ｎｍ（ナノメートル）
乃至数百ｎｍの微粒子であり、比表面積が大きく、その
ため、１２００℃以上で比較的短時間（約１時間）加熱
すれば、鋳型の焼成と同時に上記反応が進行し、高温で
軟化、変形しやすいシリカの一部がムライトに変化して
おり、鋳型の高温での耐変形性、耐割れ性が向上する。The size of alumina in the alumina sol and the size of silica in the silica sol are several tens nm (nanometers).
Since they are fine particles having a particle size of several hundreds of nanometers and a large specific surface area, therefore, if they are heated at 1200 ° C. or higher for a relatively short time (about 1 hour), the above reaction proceeds at the same time as the baking of the mold, resulting in softening and deformation at high temperatures. A part of the easy silica is changed to mullite, which improves the deformation resistance and crack resistance of the mold at high temperatures.
【０００９】またアスベクト比（粒子あるいは繊維の長
さと直径との比）の大きなムライト繊維を配合してお
り、鋳型の強度、即ち、鋳型の変形しようとするときの
抵抗が大きくなって、鋳型の高温での軟化変形及び割れ
が減少乃至防止される。Further, mullite fibers having a large asvect ratio (ratio of length of particles or fibers to diameter) are blended, and the strength of the mold, that is, the resistance when the mold is about to deform becomes large, and Softening deformation and cracking at high temperature are reduced or prevented.
【００１０】[0010]
（第１実施例）次に本発明の精密鋳造用鋳型の製造方法
の第１実施例を説明する。アルミナを約１０ｗｔ．％含
有し、水素イオン濃度指数（ｐＨ）が約３．５のアルミ
ナゾルと、シリカを約２０ｗｔ．％含有し、水素イオン
濃度指数が約３．０のシリカゾルとを図１の割合で配合
したバインダ１００部に対して、粒径が４４μｍ（ミク
ロンメートル）以下のムライト粉末を１２０部、さらに
直径が５μｍで長さが約２乃至５ｍｍのムライト繊維を
１０部配合して得た混合スラリに、１３０×１３０×１
０ｍｍのワックスを浸漬し（ディッピング）、その後、
粒径が０．１乃至０．３ｍｍのムライト粒子を付着させ
て、乾燥させた後、さらに同様の工程を１回繰り返し、
その後、さらに前記スラリに浸漬し、その後、粒径が
０．５乃至１．０ｍｍのムライト粒子を付着させて、乾
燥する工程を６回繰り返して、鋳型を製作した。(First Embodiment) Next, a first embodiment of the method for producing a precision casting mold of the present invention will be described. About 10 wt. %, And has a hydrogen ion concentration index (pH) of about 3.5 and silica of about 20 wt. %, And 120 parts of mullite powder having a particle size of 44 μm (micron meter) or less, and 100 parts of a binder mixed with silica sol having a hydrogen ion concentration index of about 3.0 at a ratio of FIG. 130 x 130 x 1 was added to a mixed slurry obtained by mixing 10 parts of mullite fiber having a length of 5 to 5 mm and a length of about 2 to 5 mm.
Immerse (dipping) 0 mm wax, then
After adhering mullite particles having a particle size of 0.1 to 0.3 mm and drying the same, the same process is repeated once,
Then, the process of further immersing in the slurry, then adhering mullite particles having a particle size of 0.5 to 1.0 mm, and drying was repeated 6 times to manufacture a mold.
【００１１】その後、この鋳型を約１７０℃に加熱し
て、ワックスを流出し、鋳型を大気雰囲気の電気炉中で
１３００℃まで加熱し、１３００℃に１時間保持した
後、冷却した。この鋳型から幅２０ｍｍ、長さ１２０ｍ
ｍの試験片（厚さ約８ｍｍ）を製作し、この試験片を大
気雰囲気の電気炉中で図４に示すように支点間距離１０
０ｍｍの支点４上に設置して、１５００℃で１時間保持
した後、冷却し、最大変形量（たわみ量）を測定した。Thereafter, the mold was heated to about 170 ° C. to flow out the wax, and the mold was heated to 1300 ° C. in an electric furnace in the air atmosphere, kept at 1300 ° C. for 1 hour, and then cooled. Width 20mm, length 120m from this mold
m test piece (thickness: about 8 mm) was manufactured, and the test piece was placed in an electric furnace in an air atmosphere as shown in FIG.
The sample was placed on a fulcrum 4 of 0 mm, kept at 1500 ° C. for 1 hour, then cooled, and the maximum deformation amount (deflection amount) was measured.
【００１２】各条件でのたわみ量を図１に示す。これに
より、アルミナゾル量とシリカゾル量とがある範囲のと
き、たわみ量が小さくなり、アルミナゾルが多過ぎて
も、あるいはシリカゾルが多過ぎても、たわみ量が増大
する。即ち、１３００℃の焼成で、アルミナゾルの配合
割合が多いと（アルミナが多いと）、焼成後、ムライト
とアルミナとが存在しているが、アルミナの焼結温度が
高いため、粒子間の結合力が小さくて、高温での変形が
大きくなる。一方、アルミナゾルが少ないと（アルミナ
が相対的に少ないと）、ムライトの反応後の過剰のシリ
カが多く存在することになり、シリカが高温で変形しや
すいために変形が大きくなる。The amount of deflection under each condition is shown in FIG. As a result, when the amount of alumina sol and the amount of silica sol are within a certain range, the amount of deflection becomes small, and the amount of deflection increases even if there is too much alumina sol or too much silica sol. That is, if the mixing ratio of the alumina sol is high at 1300 ° C. (there is a large amount of alumina), mullite and alumina are present after the baking, but since the sintering temperature of alumina is high, the bonding force between particles is high. Is small and the deformation at high temperature is large. On the other hand, when the amount of alumina sol is small (when the amount of alumina is relatively small), there is a large amount of excess silica after the reaction of mullite, and the silica is likely to be deformed at a high temperature, resulting in large deformation.
【００１３】厳密な意味での適正なアルミナゾルとシリ
カゾルとの配合割合の決定は困難であるが、変形量の観
点から、本発明では、アルミナゾルが４０部乃至７０
部、シリカゾルが６０部乃至３０部になるアルミナゾル
とシリカゾルとの混合割合が好ましい範囲としている。
またシリカゾルには、各種の水素イオン濃度指数のもの
もあるが、使用したアルミナゾルの水素イオン濃度指数
は、約３．５で酸性であり、これにアルカリ性のシリカ
ゾルを混合すると、ゾルが急激にゲル化する。従って本
実施例では、水素イオン濃度指数が約３の酸性のシリカ
ゾルを使用している。Although it is difficult to determine the proper mixing ratio of the alumina sol and the silica sol in a strict sense, from the viewpoint of the amount of deformation, in the present invention, 40 parts to 70 parts of the alumina sol is used.
Part, the mixing ratio of the alumina sol and silica sol in which the silica sol is 60 to 30 parts is within the preferable range.
Although there are various types of hydrogen ion concentration index in silica sol, the hydrogen ion concentration index of the used alumina sol is about 3.5, which is acidic. When this is mixed with alkaline silica sol, the sol rapidly gels. Turn into. Therefore, in this embodiment, an acidic silica sol having a hydrogen ion concentration index of about 3 is used.
【００１４】アルミナとシリカとの反応によるムライト
（３Ａｌ2 Ｏ3 ・２ＳｉＯ2 ）化率は、加熱温度とその
温度での保持時間により決まる。アルミナゾル中のアル
ミナの大きさは、数十乃至１００ｎｍであるため、比較
低温且つ短時間でムライト化する。ムライト化の開始温
度は、約１２００℃であり、１３００℃で１時間加熱
（焼成）することにより、大半が反応して、ムライトに
変化することを確認した。本実施例での焼成温度を１３
００℃にしているが、本発明の鋳型の焼成温度は、少な
くとも１２００℃以上であることが必要である。The mullite (3Al 2 O 3 .2SiO 2 ) conversion rate due to the reaction between alumina and silica is determined by the heating temperature and the holding time at that temperature. Since the size of alumina in the alumina sol is several tens to 100 nm, mullite is formed at a comparatively low temperature in a short time. The starting temperature of mullite formation was about 1200 ° C., and it was confirmed that by heating (baking) at 1300 ° C. for 1 hour, most of them reacted to change to mullite. The firing temperature in this example is 13
Although the temperature is set to 00 ° C, the baking temperature of the mold of the present invention needs to be at least 1200 ° C or higher.
【００１５】（第２実施例）第１実施例と同様に、アル
ミナを約１０ｗｔ．％含有し、水素イオン濃度指数（ｐ
Ｈ）が約３．５のアルミナゾル５０部と、シリカを約２
０ｗｔ．％含有し、水素イオン濃度指数が約３．０のシ
リカゾル５０部とを配合したバインダ１００部に対し
て、粒径が４４μｍ以下のムライト粉末、及び直径が５
μｍで長さが約２乃至５ｍｍのムライト繊維とを各種の
割合に配合したスラリに、第１実施例と同一の１３０×
１３０×１０ｍｍのワックスを浸漬し（デイッピン
グ）、ワックスへのスラリの付着状況を評価した。(Second Embodiment) Similar to the first embodiment, about 10 wt. % Hydrogen ion concentration index (p
H) is about 3.5 parts of alumina sol and about 2 parts of silica.
0 wt. %, And 100 parts of a binder mixed with 50 parts of silica sol having a hydrogen ion concentration index of about 3.0, mullite powder having a particle size of 44 μm or less, and a diameter of 5
A slurry prepared by mixing mullite fibers having a length of 2 μm and a length of about 2 to 5 mm in various proportions was used, and the same 130 × as in the first embodiment was used.
A 130 × 10 mm wax was dipped (dipping), and the adhesion state of the slurry to the wax was evaluated.
【００１６】ムライト繊維を配合しない場合の、即ち、
バインダ中にムライト粉末だけを配合した場合の、ムラ
イト粉末の配合割合の適正値（ワックスへのスラリの付
着性を目視により評価した）は、アルミナゾルとシリカ
ゾルとの混合バインダ１００部に対して、ムライト粉末
量１５０部乃至３００部が良好であったが、ムライト繊
維を配合することにより、その分、ムライト粉末量を減
少させる必要がある。本発明では、バインダ１００部に
対して、ムライト粉末１００乃至２００部、ムライト繊
維５乃至２０部を適正な配合割合スラリにしている。即
ち、ムライト繊維を配合することにより、高温での鋳型
の変形が抑制されるが、その効果は、ムライト繊維の配
合割合が５部以上（バインダ量に対して）で認められ、
また図２に示すようにムライト繊維の配合割合がある程
度多くなると、スラリの付着性（スラリの粘性）の観点
から、ムライト粉末配合割合を減少させる必要があり、
そのため、逆に鋳型の緻密性が低下して、高温での鋳型
強度（３点曲げ強度）が減少することになる。When mullite fiber is not blended, that is,
When only the mullite powder is mixed in the binder, the appropriate value of the mixing ratio of the mullite powder (the adhesiveness of the slurry to the wax was visually evaluated) is mullite based on 100 parts of the mixed binder of alumina sol and silica sol. A powder amount of 150 to 300 parts was good, but it is necessary to reduce the amount of mullite powder by adding mullite fiber. In the present invention, 100 to 200 parts of mullite powder and 5 to 20 parts of mullite fibers are used in an appropriate mixing ratio slurry with respect to 100 parts of the binder. That is, by mixing the mullite fiber, the deformation of the mold at high temperature is suppressed, but the effect is recognized when the mixing ratio of the mullite fiber is 5 parts or more (relative to the binder amount),
Further, as shown in FIG. 2, when the mixing ratio of the mullite fiber is increased to some extent, it is necessary to decrease the mixing ratio of the mullite powder from the viewpoint of the adhesiveness of the slurry (viscosity of the slurry).
Therefore, on the contrary, the compactness of the mold is lowered, and the mold strength at high temperature (three-point bending strength) is decreased.
【００１７】このような観点から、前述のようにバイン
ダ１００部に対するムライト繊維の配合割合の適正値
は、５乃至２０部であり、またこのときのムライト粉末
の配合割合は、スラリの粘性及びワックスなどへの付着
性の点から、バインダ１００部に対して２００部乃至１
００部が適正範囲である。 （第３実施例）第１実施例及び第２実施例と同一のアル
ミナゾル５０部とシリカゾル５０部とを配合したバイン
ダ１００部に対して、ムライト粉末１２０部及びムライ
ト繊維１０部を配合したスラリと、第１回目（初層目）
及び第２回目（２層目）用スタッコ材として粒径が０．
１乃至０．３ｍｍの粒子から構成されるムライト粒子、
第３回目（３層目）から第８回目（８層目）のスタッコ
材として粒径０．５乃至１．０ｍｍのムライト粒子を使
用して、図３に示す形状の鋳物用鋳型を製作し、この鋳
型を１３００℃で１時間焼成した後、１６２０℃のＳＣ
Ｓ１３（１８Ｃｒ−８Ｎｉステンレス鋳鋼）を鋳造し
た。その際の鋳物の最大肉厚（ｍｍ）を図５に示した。From such a point of view, as described above, the proper value of the mixing ratio of the mullite fiber to 100 parts of the binder is 5 to 20 parts, and the mixing ratio of the mullite powder at this time is the viscosity of the slurry and the wax. From the viewpoint of adhesion to 100 parts of binder, 200 parts to 1 part
00 is the proper range. (Third Example) A slurry prepared by mixing 120 parts of mullite powder and 10 parts of mullite fibers with 100 parts of a binder containing 50 parts of the same alumina sol and 50 parts of silica sol as in the first and second embodiments. , 1st time (first layer)
And the grain size of the stucco material for the second time (second layer) is 0.
Mullite particles composed of particles of 1 to 0.3 mm,
As a stucco material from the third time (third layer) to the eighth time (eighth layer), mullite particles having a particle diameter of 0.5 to 1.0 mm were used to manufacture a casting mold having the shape shown in FIG. , This mold was baked at 1300 ° C. for 1 hour, then SC at 1620 ° C.
S13 (18Cr-8Ni stainless cast steel) was cast. The maximum wall thickness (mm) of the casting at that time is shown in FIG.
【００１８】またシリカゾル単独をバインダとし、フィ
ラ材としてジルコン粉末、スタッコ材としてムライト粒
子を使用し、ムライト繊維を配合しない従来の鋳型によ
り、鋳物を鋳造した。その際の鋳物の最大肉厚（ｍｍ）
を図５に示した。本発明での鋳型の変形量は、従来の鋳
型の変形量に比べて顕著に減少しており、比較的大型の
精密鋳造品において寸法精度の向上が可能である。The silica sol was used as a binder, zircon powder was used as a filler, and mullite particles were used as a stucco material, and a casting was cast by a conventional mold containing no mullite fiber. Maximum wall thickness of the casting at that time (mm)
Is shown in FIG. The amount of deformation of the mold in the present invention is significantly smaller than the amount of deformation of the conventional mold, and it is possible to improve the dimensional accuracy in a relatively large precision casting.
【００１９】[0019]
【発明の効果】本発明の精密鋳造用鋳型の製造方法は前
記のようにアルミナゾルとシリカゾルとを混合してバイ
ンダとし、このバインダを用いたセラミックスラリ及び
スタッコ材により造型した鋳型を１２００℃以上で１時
間以上加熱し、バインダ中のアルミナとシリカとを反応
させて、ムライトに変化させる。このムライトは、シリ
カに比べると、高温での軟化が小さい上に、高温での強
度が大きく、そのため、鋳型の変形及び鋳型の割れを減
少乃至防止できる。As described above, the method for producing a mold for precision casting according to the present invention is a mixture of alumina sol and silica sol as a binder as described above. After heating for 1 hour or more, alumina and silica in the binder are reacted with each other to change to mullite. Compared with silica, this mullite has less softening at high temperature and higher strength at high temperature. Therefore, deformation and cracking of the mold can be reduced or prevented.
【００２０】またアルミナゾル中のアルミナ及びシリカ
ゾル中のシリカの大きさは、数十ｎｍ乃至数百ｎｍの微
粒子であり、比表面積が大きく、そのため、１２００℃
以上で比較的短時間（約１時間）加熱すれば、鋳型の焼
成と同時に上記反応が進行し、高温で軟化、変形しやす
いシリカの一部がムライトに変化しており、鋳型の高温
での耐変形性、耐割れ性を向上できる。The size of alumina in the alumina sol and the size of silica in the silica sol are fine particles of several tens nm to several hundreds nm and have a large specific surface area.
By heating for a relatively short time (about 1 hour) as described above, the above reaction proceeds at the same time as the baking of the mold, and a part of silica, which is easily softened and deformed at high temperature, is changed to mullite. Deformation resistance and crack resistance can be improved.
【００２１】またアスベクト比（粒子あるいは繊維の長
さと直径との比）の大きなムライト繊維を配合してお
り、鋳型の強度、即ち、鋳型の変形しようとするときの
抵抗を大きくできて、鋳型の高温での軟化変形及び割れ
を減少乃至防止できる。Further, mullite fibers having a large asvect ratio (ratio of the length of particles or fibers to the diameter) are mixed, and the strength of the mold, that is, the resistance when the mold is about to be deformed can be increased, and It is possible to reduce or prevent softening deformation and cracking at high temperature.
【図１】本発明の精密鋳造用鋳型の製造方法で得られた
鋳型（試験片）のたわみ量の測定結果を示す説明図であ
る。FIG. 1 is an explanatory view showing a measurement result of a deflection amount of a mold (test piece) obtained by the method for manufacturing a precision casting mold of the present invention.
【図２】上記鋳型の３点曲げ強度とたわみ量との測定結
果を示す説明図である。FIG. 2 is an explanatory diagram showing the measurement results of the three-point bending strength and the amount of deflection of the mold.
【図３】鋳物用鋳型の一例を示す説明図である。FIG. 3 is an explanatory view showing an example of a casting mold.
【図４】上記鋳型のたわみ量の測定要領を示す説明図で
ある。FIG. 4 is an explanatory diagram showing a measurement procedure of the amount of deflection of the mold.
【図５】鋳物の最大肉厚を示す説明図である。FIG. 5 is an explanatory view showing the maximum wall thickness of a casting.
Claims (1)
でアルミナ含有量が１０乃至１１重量％のアルミナゾル
４０乃至７０部と、水素イオン濃度指数が２乃至４でシ
リカ含有量が２０乃至２１重量％のシリカゾル６０乃至
３０部とからなる混合バインダ１００部に対して、フィ
ラとして粒径が４４μｍ以下のムライト粉末を１００部
乃至２００部及びムライト繊維を５乃至２０部配合した
スラリと、スタッコ材として粒径０．１乃至０．３ｍｍ
及び０．５乃至１．０ｍｍのムライト粒子とを組み合わ
せて鋳型を製作した後、この鋳型を１２００℃で焼成す
ることを特徴とした精密鋳造用鋳型の製造方法。1. The hydrogen ion concentration index is 2.5 to 4.5.
And 100 parts of a mixed binder composed of 40 to 70 parts of an alumina sol having an alumina content of 10 to 11% by weight and 60 to 30 parts of a silica sol having a hydrogen ion concentration index of 2 to 4 and a silica content of 20 to 21% by weight. On the other hand, a slurry containing 100 to 200 parts of mullite powder having a particle size of 44 μm or less and 5 to 20 parts of mullite fibers as a filler, and a particle size of 0.1 to 0.3 mm as a stucco material.
And a mullite particle having a size of 0.5 to 1.0 mm to form a mold, and then baking the mold at 1200 ° C. for manufacturing a precision casting mold.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5262572A JPH07116773A (en) | 1993-10-20 | 1993-10-20 | Production of casting mold for precision casting |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5262572A JPH07116773A (en) | 1993-10-20 | 1993-10-20 | Production of casting mold for precision casting |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH07116773A true JPH07116773A (en) | 1995-05-09 |
Family
ID=17377672
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5262572A Withdrawn JPH07116773A (en) | 1993-10-20 | 1993-10-20 | Production of casting mold for precision casting |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH07116773A (en) |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003326335A (en) * | 2002-05-15 | 2003-11-18 | Howmet Research Corp | Reinforced shell mold and method |
| JP2005324253A (en) * | 2004-05-12 | 2005-11-24 | Snecma Moteurs | Lost wax casting method |
| JP2005349472A (en) * | 2004-05-12 | 2005-12-22 | Snecma Moteurs | Lost wax casting method using contact layer |
| JP2009208152A (en) * | 1997-09-23 | 2009-09-17 | Howmet Res Corp | Method for producing ceramic investment shell mold |
| WO2014057913A1 (en) * | 2012-10-09 | 2014-04-17 | 三菱重工業株式会社 | Mold for precision casting, and method for producing same |
| CN104718034A (en) * | 2012-10-09 | 2015-06-17 | 三菱日立电力系统株式会社 | Mold for precision casting, and method for producing same |
| JP2017222544A (en) * | 2016-06-16 | 2017-12-21 | イビデン株式会社 | Ceramic matrix composite and method for producing the same |
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-
1993
- 1993-10-20 JP JP5262572A patent/JPH07116773A/en not_active Withdrawn
Cited By (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009208152A (en) * | 1997-09-23 | 2009-09-17 | Howmet Res Corp | Method for producing ceramic investment shell mold |
| JP2003326335A (en) * | 2002-05-15 | 2003-11-18 | Howmet Research Corp | Reinforced shell mold and method |
| JP4574954B2 (en) * | 2002-05-15 | 2010-11-04 | ハウメット リサーチ コーポレイション | Reinforced shell mold and method |
| JP2005324253A (en) * | 2004-05-12 | 2005-11-24 | Snecma Moteurs | Lost wax casting method |
| JP2005349472A (en) * | 2004-05-12 | 2005-12-22 | Snecma Moteurs | Lost wax casting method using contact layer |
| JP2014076458A (en) * | 2012-10-09 | 2014-05-01 | Mitsubishi Heavy Ind Ltd | Mold for precision casting and method for producing the same |
| WO2014057913A1 (en) * | 2012-10-09 | 2014-04-17 | 三菱重工業株式会社 | Mold for precision casting, and method for producing same |
| KR20150054916A (en) * | 2012-10-09 | 2015-05-20 | 미츠비시 히타치 파워 시스템즈 가부시키가이샤 | Mold for precision casting, and method for producing same |
| CN104703724A (en) * | 2012-10-09 | 2015-06-10 | 三菱日立电力系统株式会社 | Mold for precision casting, and method for producing same |
| CN104718034A (en) * | 2012-10-09 | 2015-06-17 | 三菱日立电力系统株式会社 | Mold for precision casting, and method for producing same |
| JP2017222544A (en) * | 2016-06-16 | 2017-12-21 | イビデン株式会社 | Ceramic matrix composite and method for producing the same |
| CN113385640A (en) * | 2021-04-29 | 2021-09-14 | 洛阳双瑞精铸钛业有限公司 | Preparation method of reinforcing layer type shell for casting thick-wall small and medium-sized titanium alloy |
| CN113385640B (en) * | 2021-04-29 | 2022-11-11 | 洛阳双瑞精铸钛业有限公司 | Preparation method of reinforcing layer shell for casting thick-wall medium and small titanium alloy |
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