JPH0373379B2 - - Google Patents
Info
- Publication number
- JPH0373379B2 JPH0373379B2 JP20351785A JP20351785A JPH0373379B2 JP H0373379 B2 JPH0373379 B2 JP H0373379B2 JP 20351785 A JP20351785 A JP 20351785A JP 20351785 A JP20351785 A JP 20351785A JP H0373379 B2 JPH0373379 B2 JP H0373379B2
- Authority
- JP
- Japan
- Prior art keywords
- coating
- ceramic
- weight
- mold
- metal
- 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.)
- Expired
Links
- 238000000576 coating method Methods 0.000 claims description 44
- 239000011248 coating agent Substances 0.000 claims description 41
- 239000000919 ceramic Substances 0.000 claims description 39
- 238000005507 spraying Methods 0.000 claims description 30
- 229910052751 metal Inorganic materials 0.000 claims description 28
- 239000002184 metal Substances 0.000 claims description 28
- 239000000843 powder Substances 0.000 claims description 21
- 229910010293 ceramic material Inorganic materials 0.000 claims description 18
- 229910004298 SiO 2 Inorganic materials 0.000 claims description 14
- 238000000034 method Methods 0.000 claims description 14
- 229910018072 Al 2 O 3 Inorganic materials 0.000 claims description 12
- 238000005266 casting Methods 0.000 claims description 12
- 150000001875 compounds Chemical class 0.000 claims description 12
- 239000000203 mixture Substances 0.000 claims description 12
- 238000007789 sealing Methods 0.000 claims description 12
- 239000003566 sealing material Substances 0.000 claims description 11
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 9
- 229910018487 Ni—Cr Inorganic materials 0.000 claims description 9
- 229910045601 alloy Inorganic materials 0.000 claims description 9
- 239000000956 alloy Substances 0.000 claims description 9
- 229910010413 TiO 2 Inorganic materials 0.000 claims description 7
- 239000002245 particle Substances 0.000 claims description 6
- 238000002844 melting Methods 0.000 claims description 5
- 238000007751 thermal spraying Methods 0.000 claims description 2
- 239000011148 porous material Substances 0.000 description 24
- 238000009413 insulation Methods 0.000 description 13
- 230000035939 shock Effects 0.000 description 12
- 229910000838 Al alloy Inorganic materials 0.000 description 11
- 239000000463 material Substances 0.000 description 10
- 239000010410 layer Substances 0.000 description 8
- 238000002156 mixing Methods 0.000 description 7
- 239000011247 coating layer Substances 0.000 description 4
- 239000007921 spray Substances 0.000 description 4
- 230000008018 melting Effects 0.000 description 3
- 238000007711 solidification Methods 0.000 description 3
- 230000008023 solidification Effects 0.000 description 3
- 238000001816 cooling Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 230000008439 repair process Effects 0.000 description 2
- 230000008646 thermal stress Effects 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 229910019142 PO4 Inorganic materials 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 150000001298 alcohols Chemical class 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 description 1
- 239000010452 phosphate Substances 0.000 description 1
- 238000007750 plasma spraying Methods 0.000 description 1
- 235000019353 potassium silicate Nutrition 0.000 description 1
- NTHWMYGWWRZVTN-UHFFFAOYSA-N sodium silicate Chemical compound [Na+].[Na+].[O-][Si]([O-])=O NTHWMYGWWRZVTN-UHFFFAOYSA-N 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 230000035882 stress Effects 0.000 description 1
Landscapes
- Molds, Cores, And Manufacturing Methods Thereof (AREA)
Description
（産業上の利用分野）
本発明は、アルミニウム合金等の低融点金属を
鋳造する際に用いられる金型を、被覆する方法に
関する。
（従来の技術）
金型をアルミニウム合金の溶湯から保護するた
めに、被覆層を形成することは知られている。こ
の被覆層には次の要求を満たすことが望まれてい
る。
第１に、金型との密着性が良いこと。
第２に、熱衝撃に耐えられること。
第３に、溶湯が急速に凝固することがないよう
に、断熱性が良いこと。
第４に、アルミニウム合金鋳物に対して離型性
が良いこと。
従来の被覆方法として、耐火物粉末と、水ガラ
スやリン酸塩等の粘結剤とを、混合して水で薄
め、これをスプレーにより金型に付着させる方法
がある。また、ガス溶射によりNi系金属の溶射
皮膜を形成する方法がある。
（発明が解決しようとしている問題点）
上記スプレー方法によるものでは、断熱性およ
び離型性は良い。しかし、金型との密着性が弱
く、寿命はせいぜい300〜400シヨツト程度と短
い。特によく摩耗する部分（横型）では10〜15シ
ヨツト毎に補修が必要である。さらに、膜厚管理
が困難で作業者の熟練を必要とする。
上記ガス溶射による方法では、金型との密着性
が良く耐熱衝撃性があり、寿命が長い。しかし、
金属で形成されているため断熱性が悪い。
（問題点を解決するための手段）
本発明は上記問題点を解消するためになされた
もので、その要旨は、金型の内面に、Niが70〜
90重量％でCrが30〜10重量％の組成からなり粒
度が10〜44μｍからなるNi−Cr合金の粉体を溶射
して、厚さ10〜100μｍの金属溶射皮膜を形成し、
この金属溶射皮膜の上に、Al2O3が97重量％で
TiO2が３重量％の組成からなる混合セラミツク
材料、若しくは、Al2O3が90重量％でSi3N4が
10重量％の組成からなる混合セラミツク材料を、
溶射して、厚さ100〜200μｍのセラミツク溶射皮
膜を形成し、更にこのセラミツク溶射皮膜の上
に、ZrO2−SiO2化合物の粉体からなる封孔材料
をアルコールに混在させて塗布し、封孔層を形成
することを特徴とする低融点金属鋳造用金型の被
覆方法にある。
（作用）
金属溶射皮膜は、セラミツク溶射皮膜と金型と
の間の密着性を高めるとともに、耐熱衝撃性を高
めるのに寄与する。Al2O3−TiO2、若しくは、
Al2O3−Si3N4の混合セラミツク材料からなるセ
ラミツク溶射皮膜は極めて熱伝導率が低く、ま
た、単一のセラミツク材料からなるセラミツク溶
射皮膜よりも更に多孔質である。したがつて、上
記混合セラミツク材料からなるセラミツク溶射皮
膜は断熱性を高めるのに寄与する。封孔材料はセ
ラミツク溶射皮膜の表面に形成された微細な孔を
封じる。アルコールは塗布後に気化するので、溶
射皮膜の表面に形成される封孔層はZrO2−SiO2
化合物の粉体で構成されることになる。その結
果、溶射皮膜と鋳造品との間に存在する上記封孔
層は離型性を高めるのに寄与する。
（実施例）
以下、本発明の一実施例を図面を参照して説明
する。第１図中１０はアルミニウム合金を鋳造す
る際に用いる金型を示し、この金型１０はFe系
金属により形成されている。最初に、この金型１
０の内面に、粉状のNi−Cr合金をプラズマ溶射
することにより、金属溶射皮膜１１を形成する。
この金属溶射皮膜１１は、後述するセラミツク溶
射皮膜１２と金型１０との間の密着性を高めると
ともに、耐熱衝撃性を高めるのに寄与する。
なお、Ni−Cr合金の組成は、Niを70〜90重量
％、Crを30〜10重量％とするのが好ましい。Cr
が30重量％を越えると熱衝撃に対して弱くなるか
らであり、Crが10重量％以下であると金属溶射
皮膜１１が酸化し易くなるからである。
また、Ni−Cr合金の粉体の粒度は10〜44μｍと
するのが好ましい。10μｍ未満では、プラズマ炎
中への供給が難しくなり歩留りが低下する上、金
属溶射皮膜１１の形成に支障を来すからであり、
粒度が44μｍを越えると密着性が悪くなるからで
ある。
また、金属溶射皮膜１１の厚さは10〜100μｍ
とするのが好ましい。厚さが10μｍ未満では、必
要とする密着性、耐熱衝撃性を得ることができな
いからであり、100μｍを越えるような必要以上
の厚さはコストアツプにつながるからである。
次に、上記金属溶射皮膜１１の上に粉体あるい
はウイスカー状のセラミツク材料の２種を混合し
たものをプラズマ溶射して、セラミツク溶射皮膜
１２を形成する。
上記セラミツク溶射皮膜１２は非常に熱伝導率
が低いので断熱性を高めるのに寄与する。特に、
このセラミツク溶射皮膜１２は２種類のセラミツ
ク材料が混合されて構成されているので、単一の
セラミツク材料からなる溶射皮膜に比べて気孔率
が非常に高い。ここで気孔率とは、溶射皮膜の表
面および内部に存在する微細な孔（以下、これを
気孔という）の存在割合のことをいう。この気孔
率の高さが断熱性をより向上させる。セラミツク
溶射皮膜１２の断熱性が向上することによつて、
アルミニウム合金の溶湯の凝固条件が改善され
る。また、セラミツク溶射皮膜１２は金属溶射皮
膜１１をアルミニウム合金の溶湯から保護するこ
とにも寄与している。
上記混合セラミツク材料としては、Al2O3の粉
体（90重量％）とTiO2の粉体（３重量％）とを
混合してなる混合セラミツク材料が最も好まし
い。Al2O3に対するTiO2の配合比率がこれより大
きいと、上記気孔率が小さくなつて断熱性が低下
し、TiO2の配合比率がこれより小さいと、気孔
率は良好であるが、セラミツク溶射皮膜１２の表
面の気孔径が過大になつて、後述する封孔処理を
行つても上記気孔を埋めるのが困難になるからで
ある。
また、上記混合セラミツク材料としては、
Al2O3の粉体（90重量％）とSi3N4のウイスカー
（10重量％）とを混合してなる混合セラミツク材
料も好ましい。Al2O3に対するSi3N4の配合比率
がこれより大きいと、セラミツク溶射皮膜１２の
表面の気孔径が過大になつて、封孔処理を行つて
も上記気孔を埋めるのが困難になるからであり、
Si3N4の配合比率がこれより小さいと、気孔径及
び気孔率がともに小さくなつて、必要十分な断熱
性を得ることができないからである。
上記セラミツク溶射皮膜１２は厚さ100〜200μ
ｍであるのが好ましい。というのは、この金型１
０を用いての鋳造中は、急加熱、急冷が行われる
ので、この際にセラミツク溶射皮膜１２に熱応力
が加わり、また、金型１０と金属溶射皮膜１１と
セラミツク溶射皮膜１２はそれぞれ熱膨張率が異
なり、この熱膨張率の差に起因した力がセラミツ
ク溶射皮膜１２に加わる。このような状況の時
に、セラミツク溶射皮膜１２の厚さが200μｍを
越えていると、セラミツク溶射皮膜１２がこれら
の力に耐えられず損傷する可能性があるからであ
る。一方、セラミツク溶射皮膜１２の厚さが
100μｍ未満であると、上述の熱応力、熱膨張に
よる損傷はないが、セラミツク溶射皮膜１２に形
成される気孔がこのセラミツク溶射皮膜１２を貫
通するようになつて、封孔孔処理を行つてもこの
気孔を埋めるのが困難になるからである。
次に、上記のセラミツク溶射皮膜１２の上に、
ZrO2−SiO2化合物の粉体からなる封孔材料をア
ルコールに混在させて塗布する。ZrO2−SiO2化
合物の粉体はアルコールとともに塗布されるの
で、セラミツク溶射皮膜１２の表面に形成された
気孔に非常に侵入し易くなる。そして、この気孔
は上記粉体によつて封じられる。したがつて、セ
ラミツク溶射皮膜１２の表面の気孔にアルミニウ
ム合金の溶湯が侵入できなくなる。また、この気
孔を含みセラミツク溶射皮膜１２の全表面にアル
コールに混在された封孔材料が塗布されるが、こ
のアルコールは塗布後に気化するので、アルコー
ルが気化した後にはセラミツク溶射皮膜１２の上
に封孔材料であるZrO2−SiO2化合物の粉体だけ
が残り、これによつて封孔層１３が形成されるこ
とになる。この封孔層１３は非常に滑り易いの
で、金型にアルミニウム合金の溶湯を充填して凝
固させた後、鋳造品を離型させる際の離型性が非
常に向上する。
上記封孔層１３は厚さ10μｍ以下例えば5μｍ程
度とするのが好ましい。なお、封孔材料がZrO2
−SiO2化合物の粉体で構成されていれば、ZrO2
とSiO2の配合比率に拘わりなく、上述の作用効
果を得ることができる。
上述した材料選択は、密着性、耐熱衝撃性、断
熱性、離型性の試験結果に基づいて、決定され
た。以下、これを詳述する。まず、金型と同材料
の基材に、表１に示す材料の金属溶射皮膜および
セラミツク溶射皮膜を形成してなるサンプルＡ〜
Ｈについて、剥離するまでの最大引張応力を測定
することにより、密着性の試験を行なつた。この
試験結果を第２図に示す。なお、表１において、
サンプルＡ、Ｄ、Ｅの「金属材料」の欄における
括弧内は、Ni−Cr合金の粉体の粒度を示してい
る。
また、同サンプルＡ〜Ｈについて、1000℃に加
熱した後水冷し、この熱サイクルを繰り返して剥
離するまでの回数を測定することにより、耐熱衝
撃性の試験を行なつた。この試験結果を第３図に
示す。
第２図、第３図に示す試験結果から、金属溶射
皮膜の材料としてNi−Cr合金を使用し、セラミ
ツク溶射皮膜としてAl2O3−TiO2の混合セラミツ
ク材料を用いたサンプルＡが、最も良好な密着
性、耐熱衝撃性を有することが明らかとなつた。
また、金属溶射皮膜の材料としてNi−Cr合金を
使用し、セラミツク溶射皮膜としてAl2O3−
Si3N4の混合セラミツク材料を用いたサンプルＤ
が２番目に良好な密着性、耐熱衝撃性を有すこと
が明らかとなつた。
上記サンプルＡ、Ｄと同様の材料および方法に
より内面を被覆されたモデル金型A1，D1に、ア
ルミニウム合金の溶湯を充填してその凝固時間を
測定したところ、第４図の試験結果が得られた。
この第４図から、本発明方法によるモデル金型
A1，D1が、従来技術であるスプレー方式により
被覆されたモデル金型X1の試験結果と比較して
遜色なく優れた断熱性を有することが明らかとな
つた。
また、前記サンプルＡ、Ｄと同様の材料、方法
によつて被覆したモデル金型A2′，D2′と、モデル
金型A2′，D2′にZrO2−SiO2化合物の封孔材料を
塗布したモデル金型A2，D2と、スプレー方式の
モデル金型X2とに、アルミニウム合金の溶湯充
填して凝固させ、この鋳物を離型させるのに要す
る引き抜き荷重を測定したところ、第５図に示す
試験結果が得られた。この第５図から、ZrO2−
SiO2化合物の封孔材料を塗布したモデル金型A2，
D2がスプレー方式のモデル金型X2と遜色ない良
好な離型性を有することが明らかとなつた。
(Industrial Application Field) The present invention relates to a method of coating a mold used when casting a low melting point metal such as an aluminum alloy. (Prior Art) It is known to form a coating layer to protect a mold from molten aluminum alloy. This coating layer is desired to satisfy the following requirements. First, it has good adhesion to the mold. Second, it must be able to withstand thermal shock. Third, it must have good insulation so that the molten metal does not solidify rapidly. Fourth, it has good mold releasability for aluminum alloy castings. As a conventional coating method, there is a method in which refractory powder and a binder such as water glass or phosphate are mixed, diluted with water, and the mixture is applied to a mold by spraying. There is also a method of forming a sprayed coating of Ni-based metal by gas spraying. (Problems to be Solved by the Invention) The spray method described above has good heat insulation properties and mold release properties. However, the adhesiveness with the mold is weak, and the lifespan is short, at most 300 to 400 shots. Repairs are required every 10 to 15 shots, especially in areas that are subject to frequent wear (horizontal type). Furthermore, it is difficult to control the film thickness and requires the skill of the operator. The gas spraying method described above has good adhesion to the mold, has good thermal shock resistance, and has a long life. but,
Since it is made of metal, it has poor insulation properties. (Means for Solving the Problems) The present invention has been made to solve the above problems, and its gist is that the inner surface of the mold contains 70 to 70% Ni.
A Ni-Cr alloy powder having a composition of 90% by weight and 30% to 10% by weight of Cr and a particle size of 10 to 44 μm is thermally sprayed to form a metal sprayed coating with a thickness of 10 to 100 μm,
On top of this metal spray coating, 97% by weight of Al 2 O 3 is added.
A mixed ceramic material with a composition of 3% by weight of TiO 2 or a composition of 90% by weight of Al 2 O 3 and Si 3 N 4
A mixed ceramic material consisting of a composition of 10% by weight,
A ceramic sprayed coating with a thickness of 100 to 200 μm is formed by thermal spraying, and a sealing material made of ZrO 2 -SiO 2 compound powder mixed with alcohol is applied on top of this ceramic sprayed coating. A method of coating a mold for casting a low melting point metal, which is characterized by forming a porous layer. (Function) The metal sprayed coating improves the adhesion between the ceramic sprayed coating and the mold, and contributes to increasing thermal shock resistance. Al 2 O 3 −TiO 2 , or
Ceramic sprayed coatings made of a mixed ceramic material of Al 2 O 3 --Si 3 N 4 have extremely low thermal conductivity and are also more porous than ceramic sprayed coatings made of a single ceramic material. Therefore, the ceramic spray coating made of the above-mentioned mixed ceramic material contributes to improving the heat insulation properties. The pore sealing material seals the fine pores formed on the surface of the ceramic spray coating. Since alcohol evaporates after application, the sealing layer formed on the surface of the sprayed coating is ZrO 2 −SiO 2
It will be composed of compound powder. As a result, the above-mentioned sealing layer existing between the thermal spray coating and the cast product contributes to improving the mold releasability. (Example) Hereinafter, an example of the present invention will be described with reference to the drawings. Reference numeral 10 in FIG. 1 indicates a mold used for casting aluminum alloy, and this mold 10 is made of Fe-based metal. First, this mold 1
A metal sprayed coating 11 is formed by plasma spraying a powdered Ni-Cr alloy onto the inner surface of the steel sheet.
This metal spray coating 11 contributes to increasing the adhesion between the ceramic spray coating 12 and the mold 10, which will be described later, as well as to increasing thermal shock resistance. The composition of the Ni-Cr alloy is preferably 70 to 90% by weight of Ni and 30 to 10% by weight of Cr. Cr
This is because if Cr exceeds 30% by weight, it becomes weak against thermal shock, and if Cr is less than 10% by weight, the metal sprayed coating 11 becomes easily oxidized. Further, the particle size of the Ni-Cr alloy powder is preferably 10 to 44 μm. If it is less than 10 μm, it will be difficult to supply it to the plasma flame, resulting in a decrease in yield, and will also hinder the formation of the metal spray coating 11.
This is because if the particle size exceeds 44 μm, the adhesion will deteriorate. In addition, the thickness of the metal spray coating 11 is 10 to 100 μm.
It is preferable that This is because if the thickness is less than 10 μm, the required adhesion and thermal shock resistance cannot be obtained, and if the thickness is more than 100 μm than necessary, the cost will increase. Next, a mixture of two ceramic materials in the form of powder or whiskers is plasma sprayed onto the metal sprayed coating 11 to form a ceramic sprayed coating 12. The ceramic sprayed coating 12 has a very low thermal conductivity, so it contributes to improving the heat insulation properties. especially,
Since this ceramic sprayed coating 12 is composed of a mixture of two types of ceramic materials, it has a much higher porosity than a sprayed coating made of a single ceramic material. Here, porosity refers to the proportion of fine pores (hereinafter referred to as pores) present on the surface and inside of the sprayed coating. This high porosity further improves the heat insulation properties. By improving the heat insulation properties of the ceramic spray coating 12,
Solidification conditions for molten aluminum alloy are improved. Further, the ceramic sprayed coating 12 also contributes to protecting the metal sprayed coating 11 from the molten aluminum alloy. The most preferable mixed ceramic material is a mixed ceramic material obtained by mixing Al 2 O 3 powder (90% by weight) and TiO 2 powder (3% by weight). If the blending ratio of TiO 2 to Al 2 O 3 is larger than this, the above porosity will become small and the insulation properties will deteriorate; if the blending ratio of TiO 2 is smaller than this, the porosity will be good but ceramic spraying will This is because the diameter of the pores on the surface of the film 12 becomes too large, making it difficult to fill the pores even if the pore sealing treatment described below is performed. In addition, as the above mixed ceramic material,
A mixed ceramic material made by mixing Al 2 O 3 powder (90% by weight) and Si 3 N 4 whiskers (10% by weight) is also preferred. If the blending ratio of Si 3 N 4 to Al 2 O 3 is larger than this, the pore size on the surface of the ceramic sprayed coating 12 will become too large and it will be difficult to fill the pores even if a pore sealing treatment is performed. and
This is because if the blending ratio of Si 3 N 4 is smaller than this, both the pore diameter and the porosity become small, making it impossible to obtain necessary and sufficient heat insulation properties. The ceramic spray coating 12 has a thickness of 100 to 200 μm.
Preferably, it is m. This is because this mold 1
During casting using 0, rapid heating and cooling are performed, so thermal stress is applied to the ceramic sprayed coating 12 at this time, and the mold 10, metal sprayed coating 11, and ceramic sprayed coating 12 undergo thermal expansion, respectively. The thermal expansion coefficients are different, and a force due to this difference in thermal expansion coefficient is applied to the ceramic sprayed coating 12. In such a situation, if the thickness of the ceramic spray coating 12 exceeds 200 μm, the ceramic spray coating 12 may not be able to withstand these forces and may be damaged. On the other hand, the thickness of the ceramic spray coating 12 is
If it is less than 100 μm, there will be no damage due to the above-mentioned thermal stress and thermal expansion, but the pores formed in the ceramic sprayed coating 12 will penetrate through the ceramic sprayed coating 12, even if pore sealing treatment is performed. This is because it becomes difficult to fill these pores. Next, on the ceramic sprayed coating 12,
A pore-sealing material made of powder of a ZrO 2 −SiO 2 compound is mixed with alcohol and applied. Since the powder of the ZrO 2 --SiO 2 compound is applied together with alcohol, it is very easy to penetrate into the pores formed on the surface of the ceramic spray coating 12. The pores are then sealed by the powder. Therefore, the molten aluminum alloy cannot enter the pores on the surface of the ceramic sprayed coating 12. Further, a pore sealing material mixed with alcohol is applied to the entire surface of the ceramic sprayed coating 12 including these pores, but since this alcohol evaporates after application, after the alcohol has vaporized, the ceramic sprayed coating 12 is coated with a pore sealing material. Only the ZrO 2 -SiO 2 compound powder, which is the pore sealing material, remains, and the pore sealing layer 13 is thereby formed. Since this sealing layer 13 is very slippery, the mold releasability when releasing the cast product after filling the mold with molten aluminum alloy and solidifying it is greatly improved. The sealing layer 13 preferably has a thickness of 10 μm or less, for example, about 5 μm. In addition, the sealing material is ZrO 2
-ZrO 2 if composed of SiO 2 compound powder
The above effects can be obtained regardless of the blending ratio of SiO 2 and SiO 2 . The above-mentioned material selection was determined based on test results of adhesion, thermal shock resistance, heat insulation, and mold releasability. This will be explained in detail below. First, Sample A~ is made by forming a metal spray coating and a ceramic spray coating of the materials shown in Table 1 on a base material made of the same material as the mold.
For H, an adhesion test was conducted by measuring the maximum tensile stress until peeling. The test results are shown in FIG. In addition, in Table 1,
The numbers in parentheses in the "metal material" column for samples A, D, and E indicate the particle size of the Ni-Cr alloy powder. Further, the same samples A to H were tested for thermal shock resistance by heating to 1000° C., cooling with water, repeating this thermal cycle, and measuring the number of times until peeling occurred. The test results are shown in FIG. From the test results shown in Figures 2 and 3, sample A, which used a Ni-Cr alloy as the metal spray coating material and a mixed ceramic material of Al 2 O 3 -TiO 2 as the ceramic spray coating, was the most effective. It was revealed that it had good adhesion and thermal shock resistance.
In addition, Ni-Cr alloy is used as the material for the metal spray coating, and Al 2 O 3 − is used as the ceramic spray coating material.
Sample D using Si 3 N 4 mixed ceramic material
It was revealed that the adhesive had the second best adhesion and thermal shock resistance. Model molds A 1 and D 1 whose inner surfaces were coated with the same material and method as Samples A and D above were filled with molten aluminum alloy and the solidification time was measured, and the test results shown in Figure 4 were obtained. Obtained.
From this Fig. 4, it can be seen that the model mold made by the method of the present invention
It has become clear that A 1 and D 1 have excellent heat insulation properties comparable to the test results of model mold X 1 coated by the conventional spray method. In addition, model molds A 2 ′ and D 2 ′ were coated using the same materials and methods as samples A and D, and the model molds A 2 ′ and D 2 ′ were sealed with a ZrO 2 -SiO 2 compound. Model molds A 2 and D 2 coated with the material and model mold X 2 using the spray method were filled with molten aluminum alloy and allowed to solidify, and the pullout load required to release the castings was measured. The test results shown in FIG. 5 were obtained. From this Figure 5, ZrO 2 −
Model mold A 2 coated with SiO 2 compound sealing material,
It became clear that D 2 had good mold release properties comparable to spray type model mold X 2 .
【表】【table】
【表】
本発明は上記実施例に制約されず種々の態様が
可能である。例えば、本発明は、アルミニウム合
金鋳造用金型のスプルービツシユ（金型の一部と
解釈する）にも適用できる。また、他の低融点金
属を鋳造する金型にも適用することができる。
（発明の効果）
以上説明したように、本発明方法によつて金型
に形成された被覆層は、密着性、耐熱衝撃性に優
れているため、寿命が長くなつて補修回数を減ら
すことができ、鋳造の生産性を向上できる。ま
た、混合セラミツク材料からなるセラミツク溶射
皮膜は単一のセラミツク材料からなる溶射皮膜に
比べて多孔質となり、より断熱性に優れたものと
なるので凝固条件を改善できる。また、セラミツ
ク溶射皮膜の表面の気孔が封孔材料であるZrO2
−SiO2化合物の粉体によつて封じられ、さらに
封孔層はアルコールの気化に伴いZrO2−SiO2化
合物の粉体によつて構成されることになるので、
滑り易く離型性に優れたものとなる。また、各皮
膜は溶射によるので膜厚管理が簡単で、安定した
鋳物品質を維持できる。[Table] The present invention is not limited to the above embodiments, and various embodiments are possible. For example, the present invention can also be applied to a sprue bit (interpreted as a part of the mold) of an aluminum alloy casting mold. It can also be applied to molds for casting other low melting point metals. (Effects of the Invention) As explained above, the coating layer formed on the mold by the method of the present invention has excellent adhesion and thermal shock resistance, so it has a longer service life and can reduce the number of repairs. This can improve casting productivity. Further, a ceramic sprayed coating made of a mixed ceramic material is more porous than a sprayed coating made of a single ceramic material, and has better heat insulation properties, so that solidification conditions can be improved. In addition, the pores on the surface of the ceramic sprayed coating are made of ZrO 2 which is a sealing material.
The pores are sealed by the ZrO 2 -SiO 2 compound powder, and the sealing layer is formed by the ZrO 2 -SiO 2 compound powder as the alcohol evaporates.
It becomes slippery and has excellent mold releasability. Furthermore, since each coating is thermally sprayed, it is easy to control the coating thickness, and stable casting quality can be maintained.
第１図は、本発明方法によつて形成された金型
の被覆層を示す拡大断面図、第２図は密着性の試
験結果を示すグラフ、第３図は耐熱衝撃性の試験
結果を示すグラフ、第４図は断熱性の試験結果を
示すグラフ、第５図は離型性の試験結果を示すグ
ラフである。
１０……金型、１１……金属溶射皮膜、１２…
…セラミツク溶射皮膜、１３……封孔層。
Fig. 1 is an enlarged cross-sectional view showing the coating layer of a mold formed by the method of the present invention, Fig. 2 is a graph showing the adhesion test results, and Fig. 3 is the thermal shock resistance test results. FIG. 4 is a graph showing the test results for heat insulation properties, and FIG. 5 is a graph showing the test results for mold releasability. 10...Mold, 11...Metal spray coating, 12...
...Ceramic spray coating, 13...Sealing layer.
Claims (1)
〜10重量％の組成からなり粒度が10〜44μｍから
なるNi−Cr合金の粉体を溶射して、厚さ10〜
100μｍの金属溶射皮膜を形成し、この金属溶射
皮膜の上に、Al2O3が97重量％でTiO2が３重量％
の組成からなる混合セラミツク材料を溶射して、
厚さ100〜200μｍのセラミツク溶射皮膜を形成
し、更にこのセラミツク溶射皮膜の上に、ZrO2
−SiO2化合物の粉体からなる封孔材料をアルコ
ールに混在させて塗布し、封孔層を形成すること
を特徴とする低融点金属鋳造用金型の被覆方法。 ２ 金型の内面に、Niが70〜90重量％でCrが30
〜10重量％の組成からなり粒度が10〜44μｍから
なるNi−Cr合金の粉体を溶射して、厚さ10〜
100μｍの金属溶射皮膜を形成し、この金属溶射
皮膜の上に、Al2O3が90重量％でSi3N4が10重量
％の組成からなる混合セラミツク材料を溶射し
て、厚さ100〜200μｍのセラミツク溶射皮膜を形
成し、更にこのセラミツク溶射皮膜の上に、
ZrO2−SiO2化合物の粉体からなる封孔材料をア
ルコールに混在させて塗布し、封孔層を形成する
ことを特徴とする低融点金属鋳造用金型の被覆方
法。[Claims] 1. On the inner surface of the mold, Ni is 70 to 90% by weight and Cr is 30% by weight.
A Ni-Cr alloy powder with a composition of ~10% by weight and a particle size of 10~44μm is thermally sprayed to a thickness of 10~10% by weight.
A 100 μm metal spray coating was formed, and on top of this metal spray coating, 97% by weight of Al 2 O 3 and 3% by weight of TiO 2 were added.
By thermal spraying a mixed ceramic material with the composition of
A ceramic sprayed coating with a thickness of 100 to 200 μm is formed, and ZrO 2 is further applied on top of this ceramic sprayed coating.
- A method for coating a mold for casting a low-melting point metal, which comprises applying a sealing material made of powder of a SiO 2 compound mixed with alcohol to form a sealing layer. 2 The inner surface of the mold contains 70 to 90% by weight of Ni and 30% of Cr.
A Ni-Cr alloy powder with a composition of ~10% by weight and a particle size of 10~44μm is thermally sprayed to a thickness of 10~10% by weight.
A 100 μm metal spray coating is formed, and a mixed ceramic material having a composition of 90% Al 2 O 3 and 10% Si 3 N 4 by weight is sprayed onto the metal spray coating to a thickness of 100 μm to 100 μm. A 200μm ceramic sprayed coating is formed, and on top of this ceramic sprayed coating,
A method for coating a mold for casting a low-melting point metal, comprising applying a sealing material made of a powder of a ZrO 2 -SiO 2 compound mixed with alcohol to form a sealing layer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP20351785A JPS6264449A (en) | 1985-09-17 | 1985-09-17 | Coating method for metallic mold for casting low melting metal |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP20351785A JPS6264449A (en) | 1985-09-17 | 1985-09-17 | Coating method for metallic mold for casting low melting metal |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6264449A JPS6264449A (en) | 1987-03-23 |
| JPH0373379B2 true JPH0373379B2 (en) | 1991-11-21 |
Family
ID=16475461
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP20351785A Granted JPS6264449A (en) | 1985-09-17 | 1985-09-17 | Coating method for metallic mold for casting low melting metal |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6264449A (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AUPS329202A0 (en) * | 2002-07-01 | 2002-07-18 | Cast Centre Pty Ltd | Coatings for articles used with molten metal |
| AUPS329102A0 (en) * | 2002-07-01 | 2002-07-18 | Cast Centre Pty Ltd | Sealer coating for use on low draft areas of die cavities |
| DE102007002806A1 (en) * | 2007-01-18 | 2008-07-24 | Sms Demag Ag | Mold with coating |
| JP2010222177A (en) * | 2009-03-23 | 2010-10-07 | Biotope:Kk | Release coating agent |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS4936542A (en) * | 1972-08-10 | 1974-04-04 | ||
| JPS4997733A (en) * | 1973-01-23 | 1974-09-17 | ||
| JPS568920Y2 (en) * | 1975-07-15 | 1981-02-26 | ||
| JPS5490317A (en) * | 1977-12-28 | 1979-07-18 | Nippon Tungsten | Treatment of ceramic spray coating |
-
1985
- 1985-09-17 JP JP20351785A patent/JPS6264449A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6264449A (en) | 1987-03-23 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US6238807B1 (en) | Thermal spraying composite material containing molybdenum boride and a coat formed by thermal spraying | |
| CN106238670B (en) | Foundry facing and preparation method and application | |
| CN104909793B (en) | Ablation resistance composite material and preparation method thereof | |
| JPH0373379B2 (en) | ||
| US5039477A (en) | Powdered metal spray coating material | |
| US3588028A (en) | Coated metal mold | |
| US2568364A (en) | Process of making investment mold | |
| JPH0337454B2 (en) | ||
| JPS6213236A (en) | Metallic mold for casting and its production | |
| JP2698186B2 (en) | Manufacturing method of casting nozzle member | |
| CA1111673A (en) | Metal casting with hardened surface layer and method for the manufacture thereof | |
| JPH0517305B2 (en) | ||
| JPS5819376B2 (en) | Composite coating agent for centrifugal casting | |
| US3489202A (en) | Production of castings | |
| US5194339A (en) | Discontinuous casting mold | |
| JPH0517306B2 (en) | ||
| JPS5838219B2 (en) | Method for manufacturing cast steel parts with wear resistance on the surface layer | |
| JPS6079945A (en) | Manufacture of ceramics-metal composite body | |
| JPH04314851A (en) | Die for casting copper alloy | |
| JPS61186190A (en) | Composite filter rod for building up by welding | |
| JPH0517304B2 (en) | ||
| JPS62187560A (en) | Metal cladding and casting method | |
| JPS6254543A (en) | Production of casting mold | |
| JPH04317461A (en) | Casting mold material for casting high melting point metal | |
| JPH0325505B2 (en) |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| EXPY | Cancellation because of completion of term |