JPH03106553A - Manufacture of hollow member having heat insulating ceramic covering layer on inside surface - Google Patents
Manufacture of hollow member having heat insulating ceramic covering layer on inside surfaceInfo
- Publication number
- JPH03106553A JPH03106553A JP23098789A JP23098789A JPH03106553A JP H03106553 A JPH03106553 A JP H03106553A JP 23098789 A JP23098789 A JP 23098789A JP 23098789 A JP23098789 A JP 23098789A JP H03106553 A JPH03106553 A JP H03106553A
- Authority
- JP
- Japan
- Prior art keywords
- ceramic
- layer
- core
- heat insulating
- 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.)
- Pending
Links
- 239000000919 ceramic Substances 0.000 title claims abstract description 106
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 11
- 229910052751 metal Inorganic materials 0.000 claims abstract description 54
- 239000002184 metal Substances 0.000 claims abstract description 54
- 239000002002 slurry Substances 0.000 claims abstract description 28
- 239000010410 layer Substances 0.000 claims description 99
- 238000005524 ceramic coating Methods 0.000 claims description 30
- 238000005507 spraying Methods 0.000 claims description 27
- 239000011247 coating layer Substances 0.000 claims description 26
- 238000000034 method Methods 0.000 claims description 13
- 238000005266 casting Methods 0.000 claims description 8
- 238000009413 insulation Methods 0.000 claims description 7
- 239000000463 material Substances 0.000 description 21
- 239000004576 sand Substances 0.000 description 17
- 230000000694 effects Effects 0.000 description 16
- 230000000052 comparative effect Effects 0.000 description 11
- 229910000838 Al alloy Inorganic materials 0.000 description 6
- 230000035882 stress Effects 0.000 description 6
- 239000011248 coating agent Substances 0.000 description 5
- 238000000576 coating method Methods 0.000 description 5
- 239000000843 powder Substances 0.000 description 5
- 239000007921 spray Substances 0.000 description 5
- 229910010293 ceramic material Inorganic materials 0.000 description 4
- 230000007423 decrease Effects 0.000 description 4
- 238000011156 evaluation Methods 0.000 description 4
- 238000007750 plasma spraying Methods 0.000 description 4
- 238000007751 thermal spraying Methods 0.000 description 4
- 229910045601 alloy Inorganic materials 0.000 description 3
- 239000000956 alloy Substances 0.000 description 3
- 238000001035 drying Methods 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 239000002245 particle Substances 0.000 description 3
- 230000002093 peripheral effect Effects 0.000 description 3
- 239000010931 gold Substances 0.000 description 2
- 229910052737 gold Inorganic materials 0.000 description 2
- 230000001771 impaired effect Effects 0.000 description 2
- 230000003746 surface roughness Effects 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 229910000674 AJ alloy Inorganic materials 0.000 description 1
- 229910001018 Cast iron Inorganic materials 0.000 description 1
- 229910018106 Ni—C Inorganic materials 0.000 description 1
- 230000005856 abnormality Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 230000015271 coagulation Effects 0.000 description 1
- 238000005345 coagulation Methods 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 150000002343 gold Chemical class 0.000 description 1
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 1
- 238000003780 insertion Methods 0.000 description 1
- 230000037431 insertion Effects 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 230000000149 penetrating effect Effects 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 238000007711 solidification Methods 0.000 description 1
- 230000008023 solidification Effects 0.000 description 1
- 230000008646 thermal stress Effects 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Coating By Spraying Or Casting (AREA)
Abstract
Description
【発明の詳細な説明】
産業上の利用分野
この発明は自動車用エンジンのシリンダヘッドの排気ボ
ートライナーの如く、セラミック断熱層を内面に形成し
た中空部を有する部材の製造方法に関するものである。DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a method for manufacturing a member having a hollow portion with a ceramic heat insulating layer formed on the inner surface, such as an exhaust boat liner for a cylinder head of an automobile engine.
従来の技術
自動車用エンジンのシリンダヘッドの排気ポートは、燃
焼室内で燃焼した高温の排気ガスが流通する部分であり
、この排気ポートでの熱損失を少なくするため、排気ボ
ートの内面をセラミックで被覆して断熱効果を与えるこ
とが従来から知られている。Conventional technology The exhaust port of the cylinder head of an automobile engine is the part through which the high-temperature exhaust gas combusted in the combustion chamber flows.In order to reduce heat loss at this exhaust port, the inner surface of the exhaust boat is coated with ceramic. It has been known for a long time to provide a heat insulating effect.
排気ポートの内面にセラミックを主体とする断熱層が形
成されたシリンダヘッドを製造する方法としては、例え
ば実公平１−１１９６２号に示されているように、シリ
ンダヘッドを鋳造するにあたって、予め排気ボート用中
子の外周壁に、金属層およびセラミック層の２層からな
る断熱層を溶射しておき、この排気ポート用中子を用い
てシリンダヘッドを鋳造し、その後排気ボート用中子を
除去することによって排気ボートの内面にセラミック層
、金属層の２層構造の断熱層を有するシリンダヘッドを
得る技術が知られている。As a method of manufacturing a cylinder head in which a heat insulating layer mainly made of ceramic is formed on the inner surface of the exhaust port, for example, as shown in Utility Model Publication No. 1-11962, when casting the cylinder head, the exhaust port is A heat insulating layer consisting of two layers, a metal layer and a ceramic layer, is thermally sprayed on the outer peripheral wall of the exhaust port core, and a cylinder head is cast using this exhaust port core, after which the exhaust boat core is removed. A known technique is to obtain a cylinder head having a two-layer heat insulating layer including a ceramic layer and a metal layer on the inner surface of the exhaust boat.
そして、上述のような従来技術に準じてシリンダヘッド
の排気ポート用ライナーを製造する方法としては、例え
ば第２図、第３図に示すような方法が考えられている。As a method of manufacturing a liner for an exhaust port of a cylinder head according to the above-mentioned prior art, methods such as those shown in FIGS. 2 and 3, for example, have been considered.
すなわち、第２図、第３図において、排気ボート用の砂
中千１の外周面上にセラミック溶射層２を形成し、さら
にそのセラミック溶射層の外周面上にセラミックと排気
ボート用ライナーの本体材料である金属（例えばＡ／合
金）との中間の熱膨張率を有する金属、例えばＮｉ−Ｃ
ｒ−Ａ７合金からなる金属溶射層３を形成し、さらにそ
の全体を排気ポート用ライナーの本体材料である金属４
によって鋳包み、その後砂中子１を除去することによっ
て、内面にセラミック溶射層２を有しかつそのセラミッ
ク溶射層２と本体金属４との間に金属溶射層３を有する
排気ボート用ライナーを製造する。That is, in FIGS. 2 and 3, a ceramic sprayed layer 2 is formed on the outer peripheral surface of a sand bath 1 for an exhaust boat, and a ceramic and a main body of the exhaust boat liner are further formed on the outer peripheral surface of the ceramic sprayed layer. A metal with a coefficient of thermal expansion intermediate to that of the material metal (e.g. A/alloy), e.g. Ni-C
A metal sprayed layer 3 made of r-A7 alloy is formed, and the entire layer is coated with metal 4, which is the main body material of the exhaust port liner.
and then removing the sand core 1 to produce an exhaust boat liner having a ceramic sprayed layer 2 on the inner surface and a metal sprayed layer 3 between the ceramic sprayed layer 2 and the metal body 4. do.
この方法において、セラミック溶射層２と本体金属４と
の間の金属溶射層３は、セラミック溶射層２と本体金属
４との間の熱膨張率の差による応力発生を緩和するとと
もに、鋳造時における本体金８１４の溶湯の濡れ性を改
善するために形成されている。In this method, the metal sprayed layer 3 between the ceramic sprayed layer 2 and the metal body 4 alleviates the stress generated due to the difference in thermal expansion coefficient between the ceramic sprayed layer 2 and the metal body 4, and also It is formed to improve the wettability of the molten metal of the main body gold 814.
発明が解決しようとする課題
セラミックによる断熱効果を高めるには、セラミック層
の厚みを大きくすることが必要であり、したがって前述
のように排気ボートの内面にセラミックを被覆した排気
ポート用ライナーにおいて、熱損失をより少なくするた
めにはセラミック層の厚みを可及的に大きくすることが
望ましい。例えば、排気ポートライナーの排気ガス温度
を３０℃上げるためには、バルク材のセラミックを用い
た場合で２．５〜３ＩＩＩ１程度、セラミック溶射の場
合でｌ，５〜２ ０ｍ程度（いずれもセラミックとして
Ｚｒ０２を用いた場合）の厚みでセラミック層を形成す
る必要があることが判明している。Problems to be Solved by the Invention In order to increase the heat insulation effect of ceramic, it is necessary to increase the thickness of the ceramic layer. In order to further reduce loss, it is desirable to increase the thickness of the ceramic layer as much as possible. For example, in order to raise the exhaust gas temperature of the exhaust port liner by 30°C, it is about 2.5 to 3III1 when using bulk ceramic material, and about 1,5 to 20 m when using ceramic spraying (in both cases, Zr02 is used as ceramic). It has been found that it is necessary to form a ceramic layer with a thickness of
しかしながら、中子として常用されている砂中子にセラ
ミック溶射を施した場合、膜厚ｌＩＩｌ１ｌ前後を境と
して被覆効率が急激に低下するため、ｌｎｉ＋を越える
厚内のセラミック溶射層を形戊すれば、セラミック材料
コストが嵩むとともに生産性も大幅に低下する問題があ
る。またセラミック溶射層を厚くする場合、溶射場内の
残留応力が大きくなって溶射層にクラックや剥離が生じ
やすくなる問題もある。However, when ceramic spraying is applied to a sand core, which is commonly used as a core, the coating efficiency decreases rapidly when the film thickness reaches around lIIl1l. However, there are problems in that the cost of ceramic materials increases and productivity also decreases significantly. In addition, when the ceramic sprayed layer is made thicker, residual stress within the spraying field becomes larger, which causes the problem that the sprayed layer is more likely to crack or peel.
具体的には、既に述べた第２図、第３図に示すような排
気ボート用ライナーの製造過程において、砂中子１に先
ずセラミック溶射層２を形成する際の溶射時間とセラミ
ック被覆厚みとの関係は第４図に示すようにあらわされ
ることが判明している。Specifically, in the process of manufacturing liners for exhaust boats as shown in FIGS. 2 and 3, which have already been described, the spraying time and ceramic coating thickness when first forming the ceramic spray layer 2 on the sand core 1 are determined. It has been found that the relationship is expressed as shown in FIG.
第４図から明らかなように、セラミック被覆厚みが大き
くなるほど被膜の形成が遅くなる。これは、溶射開始の
初期は下地に相当する母材（砂中子）の表面の凹凸に溶
射材が食い込んで溶射被膜が形或されるが、溶射被膜厚
みが大きくなるにしたがって母材の表面の凹凸の影響を
受けにくくなって表面粗さが小さくなり、溶射材の食い
込みが少なくなって溶射彼膜生成効率が低下するものと
考えられる。As is clear from FIG. 4, the thicker the ceramic coating, the slower the coating will form. This is because at the beginning of thermal spraying, the sprayed material bites into the unevenness of the surface of the base material (sand core), which forms the sprayed coating, but as the thickness of the sprayed coating increases, the surface of the base material It is thought that this makes the surface less susceptible to the effects of unevenness, reduces surface roughness, reduces the penetration of the sprayed material, and reduces the efficiency of sprayed film formation.
また、溶射層形成時には、溶射直後の溶射粒子の凝固に
伴なって残留応力が発生するが、溶射披膜が厚くなるに
したがってこの残留応力が累積されて大きくなり、その
残留応力によって母材である中子砂からセラミック溶射
層が引き剥されたり、溶射層にクラックが生じたりする
ようになる。このようにしてセラミック溶射層にクラッ
クが生じた場合には、第２図、第３図に示すようにセラ
ミック溶射層２上に金属溶射層３を形成しても、そのク
ラックは金属溶射では埋められず、そのため金属溶射層
３の外側に本体金属４を鋳包む際に、金属溶湯がクラッ
ク中に差し込まれてしまい、セラミック溶射層の内面（
したがって砂中子１を除去した後の中空部内面）まで本
体金属４の一部が露呈してしまうことになって、断熱効
果が損なわれてしまう。In addition, when forming a sprayed layer, residual stress is generated as the sprayed particles solidify immediately after spraying, but as the sprayed film becomes thicker, this residual stress accumulates and becomes larger. The ceramic sprayed layer may peel off from some core sands or cracks may appear in the sprayed layer. If a crack occurs in the ceramic sprayed layer in this way, even if a metal sprayed layer 3 is formed on the ceramic sprayed layer 2 as shown in FIGS. 2 and 3, the crack will be filled with metal spraying. Therefore, when casting the main body metal 4 on the outside of the metal sprayed layer 3, the molten metal is inserted into the crack, and the inner surface of the ceramic sprayed layer (
Therefore, part of the metal body 4 is exposed to the inner surface of the hollow part after the sand core 1 is removed, and the heat insulation effect is impaired.
この発明は以上の事情を背景としてなされたもので、排
気ポート用ライナーの如く、内面に断熱セラミック被覆
層を有する中空部材を製造するにあたって、その断熱セ
ラミック被覆層の厚みを大きくしても、材料コストが嵩
んだり生産性が低下したりすることがなくしかも断熱セ
ラミック被覆層にクラックが生じたり剥離が生じたりす
ることかない方法を提供することを目的とするものであ
る。This invention was made against the background of the above circumstances, and when manufacturing a hollow member having a heat insulating ceramic coating layer on the inner surface, such as a liner for an exhaust port, even if the thickness of the heat insulating ceramic coating layer is increased, the material It is an object of the present invention to provide a method that does not increase costs or reduce productivity, and does not cause cracks or peeling of the heat-insulating ceramic coating layer.
課題を解決するための手段
前述のような課題を解決するため、この発明の断熱セラ
ミック被覆層を有する中空部材の製造方法では、中子表
面に厚さ Ｉｍａ＋以下のセラミック溶一射層を形成し
た後、そのセラミック溶射層の表面にセラミックスラリ
ーを塗布して乾燥させ、これによりセラミック溶射層と
スラリー乾燥セラミック層との２層からなる断熱セラミ
ック被覆層を形成し、その後その断熱セラミック被覆層
の表面に金属溶射層を形成し、次いで中子を鋳型内に設
置して中空部材の本体となる金属の溶湯を注湯し、前記
金属溶射層の外側を前記金属により鋳包んだ後、中子を
除去することとしている。Means for Solving the Problems In order to solve the above-mentioned problems, in the method of manufacturing a hollow member having a heat insulating ceramic coating layer of the present invention, a ceramic spray layer having a thickness of Ima+ or less is formed on the surface of the core. After that, a ceramic slurry is applied to the surface of the ceramic sprayed layer and dried, thereby forming a heat insulating ceramic coating layer consisting of two layers, the ceramic sprayed layer and the slurry-dried ceramic layer, and then the surface of the heat insulating ceramic coating layer is A metal spray layer is formed on the core, and then the core is placed in a mold, and molten metal that will become the main body of the hollow member is poured in. After the outside of the metal spray layer is covered with the metal, the core is We are planning to remove it.
作 用
この発明の方法では、中子の表面に厚みｌｎｍ以下の比
較的薄いセラミック溶射層が形成され、さらにそのセラ
ミック溶射層の上にセラミックスラリーを所要の厚みで
塗布して乾燥させたスラリー乾燥セラミック層が形成さ
れて、これらのセラミック溶射層とスラリー乾燥セラミ
ック層との２層によって断熱セラミック被覆層が形成さ
れる。そしてこの断熱セラミック被覆層上に金属溶射層
を形成した後、排気ボート用ライナーの如き目的とする
中空部材の本体材料となる金属の溶湯によって鋳包み、
その後中子を除去すれば、鋳包み金属からなる中空部材
本体の中空部内面に金属溶射層を介して断熱セラミック
被覆層を有する中空部材を得ることができる。Function: In the method of the present invention, a relatively thin ceramic sprayed layer with a thickness of 1 nm or less is formed on the surface of the core, and a slurry drying process is performed in which a ceramic slurry is applied to a desired thickness on the ceramic sprayed layer and dried. Ceramic layers are formed, and the two layers, the ceramic sprayed layer and the slurry dried ceramic layer, form a thermally insulating ceramic coating layer. After forming a metal sprayed layer on this heat insulating ceramic coating layer, it is cast in with molten metal that will become the main body material of the intended hollow member such as a liner for an exhaust boat.
If the core is then removed, it is possible to obtain a hollow member having a heat insulating ceramic coating layer on the inner surface of the hollow part of the hollow member main body made of cast-in metal via a metal sprayed layer.
ここで、断熱セラミック被覆層は、前述のように厚み
ｌ＋ｍ以下の比較的薄いセラミック溶射層と、その上の
スラリー乾燥セラミック層とで構威されるから、充分な
断熱効果を確保するために断熱セラミック被覆層の全体
厚みを大きくしたい場合も、セラミックスラリーの塗布
厚みを大きくしてスラリー乾燥セラミック層の厚みを大
きくすれば良い。Here, the heat insulating ceramic coating layer has a thickness as described above.
It consists of a relatively thin ceramic sprayed layer of less than l+m and a slurry-dried ceramic layer on top of it, so even if you want to increase the overall thickness of the heat-insulating ceramic coating layer to ensure sufficient insulation effect, the ceramic slurry The thickness of the slurry-dried ceramic layer can be increased by increasing the coating thickness of the slurry.
したがってセラミック溶射層は ｌｗ以下の薄いままで
良いから、従来技術のようにセラミック溶射層の厚みを
増すことによってセラミック溶射層にクラックが発生し
たり、母材（中子）から剥離したりすることを有効に防
止できる。なおスラリー乾燥セラミック層の形或は、溶
射層の場合のような溶射粒子の凝固を伴なわないから、
残留応力の発生はほとんどなく、したがってその厚みを
大きくしても残留応力によるクラックや剥離の発生を招
くことはない。Therefore, since the ceramic sprayed layer can be kept as thin as lw or less, increasing the thickness of the ceramic sprayed layer as in the conventional technology will prevent the ceramic sprayed layer from cracking or peeling off from the base material (core). can be effectively prevented. Furthermore, because the form of the slurry-dried ceramic layer does not involve coagulation of sprayed particles as in the case of a thermally sprayed layer,
Almost no residual stress is generated, so even if the thickness is increased, cracks or peeling due to residual stress will not occur.
またスラリー乾燥セラミック層は、セラミックスラリー
の塗布および乾燥によって形成されるため、その厚みが
増しても材料歩留りはほぼ１ ０ ０ ９６で、しかも
その厚みを増しても生産性が低下することはな＜、シた
がって材料コスト、生産性ともに従来技術の場合よりも
各段に良好となる。Furthermore, since the slurry-dried ceramic layer is formed by applying and drying a ceramic slurry, the material yield is approximately 10096 even when the thickness increases, and productivity does not decrease even when the thickness increases. Therefore, both material cost and productivity are much better than in the case of the prior art.
ここで、セラミック溶射層の厚みが１閣を越えれば、従
来技術と同様にクラック発生の問題や生産性の低下等の
問題が生じるから、セラミック溶射層の厚みは Ｉｎｎ
以下に限定した。Here, if the thickness of the ceramic sprayed layer exceeds 1 inch, problems such as crack generation and decreased productivity will occur as in the conventional technology, so the thickness of the ceramic sprayed layer should be set at Inn.
Limited to the following.
なお、セラミック溶射層を形成せずに、直接中子表面に
セラミックスラリーを塗布した場合には、スラリー自体
が水溶性もしくは有機性のため、スラリー塗布時あるい
は鋳造時にセラミック分を含む水分が中子の砂の中に浸
透し、そのため中子砂を除去する際に砂が落ちにくく、
また砂とスラリーのセラミックとが混合した部分が脱落
したりして、製品のセラミック層内面の表面粗さが著し
く大きくなってしまい、そのため内側のセラミック層に
クラックが発生しやすくなってその耐久性が低下するお
それがある。これに対し、この発明の方法では中子表面
に一旦セラミック溶射層を形成しておき、その上にセラ
ミックスラリーを塗布しているため、セラミック溶射層
がスラリーに対する遮蔽層として機能して、スラリー塗
布時や鋳造時においてスラリーの水分がセラミックとと
もに中子に浸透することが有効に防止され、そのため中
子妙の除去を容易に行なうことができるとともに、製品
の内面性状を良好に維持することができる。Note that if ceramic slurry is applied directly to the core surface without forming a ceramic spray layer, the slurry itself is water-soluble or organic, so water containing ceramic components will be absorbed into the core during slurry application or casting. The sand penetrates into the core sand, making it difficult for the sand to fall off when removing the core sand.
In addition, the mixed part of the sand and ceramic in the slurry may fall off, which significantly increases the surface roughness of the inner surface of the ceramic layer of the product, making the inner ceramic layer more likely to crack and reduce its durability. may decrease. On the other hand, in the method of the present invention, a ceramic sprayed layer is first formed on the surface of the core, and then the ceramic slurry is applied on top of the ceramic sprayed layer, so the ceramic sprayed layer functions as a shielding layer against the slurry and the slurry is coated. This effectively prevents the moisture in the slurry from penetrating into the core together with the ceramic during casting and casting, making it possible to easily remove the core and maintain good internal properties of the product. .
なおまた、セラミック溶射層およびスラリー乾燥セラミ
ック層からなる断熱セラミック被覆層の外周上に形成さ
れる金属溶射層は、本体金属の鋳造時において本体金属
溶湯の濡れ性を良好にして、断熱セラミック被覆層の耐
剥離強度を高める作用を果たす。またこの金屑溶射層の
溶射材として、セラミックと本体金属の中間の熱膨張率
を有する金属を選択して用いれば、断熱セラミック披覆
層と本体金属の熱膨張差を緩和して、熱応力の発生を小
さくする作用も得ることができる。Furthermore, the metal sprayed layer formed on the outer periphery of the heat insulating ceramic coating layer consisting of the ceramic sprayed layer and the slurry dried ceramic layer improves the wettability of the molten metal of the main body during casting of the main body metal, so that the heat insulating ceramic coating layer It has the effect of increasing the peeling resistance of. In addition, if a metal with a coefficient of thermal expansion between that of the ceramic and the main body metal is selected as the spraying material for the metal scrap spraying layer, the difference in thermal expansion between the heat-insulating ceramic covering layer and the main body metal can be alleviated, and thermal stress can be reduced. It is also possible to obtain the effect of reducing the occurrence of.
実 施 例
［実施例］
シリンダヘッドの排気ポート用ライナーを製造した実施
例を、第１図に従って説明する。Example [Example] An example in which a liner for an exhaust port of a cylinder head was manufactured will be described with reference to FIG.
中子１としては、第２図に示したと同様な形状でかつ直
径２０ｍｍ，長さ ２ ０ ０ ｆｆｌ＋ｓの砂中子を
、レジン含有率１．５％±０．０５％のシェル砂にて作
或した。As the core 1, a sand core having a shape similar to that shown in Fig. 2 and having a diameter of 20 mm and a length of 200 ffl+s was made of shell sand with a resin content of 1.5% ± 0.05%. There was.
その中子１の外周上に、セラミック溶射材としてＺｒ０
２−ｇｖｊ％Ｙ２０３粉末（粉末粒度１０〜４４一一）
を用いてプラズマ溶射を行なって、膜厚０．５閣のセラ
ミック溶射層２を形或した。この時のプラズマ溶射条件
は、Ｎ２流量４０ｊ’／＊、Ｈ ２流量７．５Ａ’／Ｉ
Ｉｌｂ，電流５００Ａ，電圧７０Ｖ１粉末供給量６０ｇ
／分とした。次いでセラミック溶射層２の表面に、セラ
ミックスラリーとしてＡＩ２０３系のスラリ−（粘度５
０ＧＯｃｐ）をスプレーにて厚さ ２ｌｗＩｌになるま
で塗布し、その後炉中で５０℃×１ｈ『加熱して乾燥さ
せ、さらに炉中で１５０℃Ｘ Ｉｈｒ加熱して乾燥さ
せ、スラリー乾燥セラミック層５を形成した。したがっ
てこの状態でセラミック溶射層２とスラリー乾燥セラミ
ック層５との２層構造の断熱セラミック被覆層６が形成
されたことになる。On the outer periphery of the core 1, Zr0 is applied as a ceramic spraying material.
2-gvj% Y203 powder (powder particle size 10-44-11)
A ceramic sprayed layer 2 having a film thickness of 0.5 mm was formed by plasma spraying using a . The plasma spraying conditions at this time were N2 flow rate 40j'/*, H2 flow rate 7.5A'/I
Ilb, current 500A, voltage 70V1 powder supply amount 60g
/ minute. Next, an AI203-based slurry (viscosity 5
0GOcp) was applied by spraying to a thickness of 2lwIl, and then heated and dried in an oven at 50°C for 1h. Formed. Therefore, in this state, a heat insulating ceramic coating layer 6 having a two-layer structure of the ceramic sprayed layer 2 and the slurry dried ceramic layer 5 was formed.
次いで金属溶射材として９５Ｗ１％（ ８０ｗｔ％Ｎｉ
−２０ｖｌ９６ Ｃ ｒ ） ５ｖｌ％ＡＩ合金粉
末を用いて、前述のセラミック溶射と同様な溶射条件で
、プラズマ溶射を行ない、０．０５＋＋＋ｎ厚の金属溶
射層３を形或した。Next, 95W1% (80wt%Ni) was used as a metal spraying material.
-20vl96Cr) 5vl% AI alloy powder was subjected to plasma spraying under the same spraying conditions as the ceramic spraying described above to form a metal sprayed layer 3 with a thickness of 0.05+++n.
このようにして外周面上に各層が形成された中子をシリ
ンダヘッドの排気ボート用ライナー鋳造用の鋳型内に設
置し、本体金属４として川Ｓ ＡＣ２Ｂのアルミニウム
合金の溶湯を用いて鋳包み、凝固後に鋳型から取出し、
中子砂を除去して、排気ポート用ライナーを得た。The core with each layer formed on the outer circumferential surface in this way is placed in a mold for casting a liner for an exhaust boat of a cylinder head, and is cast using molten aluminum alloy of Kawa S AC2B as the main body metal 4. After solidification, remove from the mold,
The core sand was removed to obtain a liner for an exhaust port.
［比較例１］
前記実施例と同様な中子を作製し、その中子表面に、実
施例と同じセラミック溶射材を用いて実施例と同じ条件
でプラズマ溶射を行ない、厚さ ３閣のセラミック溶射
層を形成した。このとき、セラミック溶射層には一部ク
ラックが生じ、また一部はセラミック溶射層の剥離によ
り中子の砂肌が露出した部分が生じていることが観察さ
れた。次いでセラミックスラリーの塗布を行なわずにセ
ラミック溶射層の表面に直接金属溶射を施した。この金
属溶射の溶射材、溶射条件、厚みは実施例と同様とした
。その後実施例と同様に鋳型内に配置してアルミニウム
合金により鋳包み、中子砂を除去して排気ポート用ライ
ナーを得た。[Comparative Example 1] A core similar to that in the above example was produced, and the surface of the core was subjected to plasma spraying using the same ceramic spraying material as in the example under the same conditions as in the example to obtain a ceramic with a thickness of 3 mm. A sprayed layer was formed. At this time, it was observed that cracks were formed in some parts of the ceramic sprayed layer, and in some parts, the sandy surface of the core was exposed due to peeling of the ceramic sprayed layer. Next, metal spraying was applied directly to the surface of the ceramic sprayed layer without applying the ceramic slurry. The spraying material, spraying conditions, and thickness for this metal spraying were the same as in the example. Thereafter, it was placed in a mold and cast in an aluminum alloy in the same manner as in the example, and the core sand was removed to obtain a liner for an exhaust port.
［比較例２］
前記実施例と同様な中子を作製し、セラミック溶射を行
なわずに、中子表面に直接セラミックスラリーを厚さ
３師にスプレー塗布した。このときのセラミックスラリ
ーとしては実施例と同様なものを用いた。その後、実施
例と同様にして金属溶射を施した。この金屑溶射の溶射
材、溶射条件、厚さは実施例と同様である。その後、実
施例と同様に鋳型内に配置してアルミニウム合金により
鋳包み、中子砂を除去して排気ボート用ライナーを得た
。[Comparative Example 2] A core similar to that of the above example was produced, and ceramic slurry was directly applied to the core surface to a thickness without ceramic spraying.
Sprayed on 3 areas. As the ceramic slurry at this time, the same one as in the example was used. Thereafter, metal spraying was performed in the same manner as in the example. The spraying material, spraying conditions, and thickness of this gold scrap spraying are the same as in the example. Thereafter, it was placed in a mold and cast in an aluminum alloy in the same manner as in the example, and the core sand was removed to obtain a liner for an exhaust boat.
［性能評価１］
前述のような実施例および比較例１．２により得られた
各排気ボート用ライナーについて調べたところ、比較例
１のものでは、セラミック溶射層のクラックがさらに拡
大して、そのクラックにアルミニウム合金溶湯が充填さ
れていることが判明した。また比較例２のものでは、中
子砂を除去する際に砂が落ちに＜＜、また一部では砂と
セラミック（スラリーの成分）とが混じってともに脱落
したため、内面の表面に著しい凹凸が生じていた。[Performance Evaluation 1] When we investigated the exhaust boat liners obtained in Examples and Comparative Examples 1 and 2 as described above, we found that in Comparative Example 1, the cracks in the ceramic sprayed layer further expanded and It was discovered that the crack was filled with molten aluminum alloy. In addition, in Comparative Example 2, the sand fell off when the core sand was removed, and in some cases, the sand and ceramic (component of the slurry) were mixed and fell off together, resulting in significant unevenness on the inner surface. was occurring.
これに対し実施例のものでは何ら異常が認められなかっ
た。In contrast, no abnormality was observed in the samples of Examples.
［性能評価２コ
前記実施例および比較例１．２の排気ポート用ライナー
をそれぞれ４個ずつ用意し、また内面にセラミック被覆
を施していない排気ポート用ライナーを４個用意し、そ
れぞれ別の４気筒シリンヘッドに組込み、実機エンジン
によって５０００＋ｐｍ連続高速運転試験を施して、排
気ガス温度を測定した。[Performance evaluation 2 types] Four exhaust port liners of the above embodiment and comparative example 1.2 were prepared, four exhaust port liners whose inner surfaces were not coated with ceramic were prepared, and four different exhaust port liners were prepared. It was installed in a cylinder cylinder head and subjected to a continuous high-speed operation test of 5000+ pm using an actual engine, and the exhaust gas temperature was measured.
その結果、比較例１のライナーを用いた場合は、セラミ
ック被覆なしのライナーを用いた場合と比較して、排気
ガス温度が２５〜３０℃上昇していたのに対し、実施例
のライナーを用いた場合は４５〜５０℃上昇しているこ
とが判明した。このことは、前述の性能評価１で述べた
ように、比較例１のライナーでは断熱セラミック被覆層
のクラックにライナー本体材料のアルミニウム合金が充
填されていたため、断熱効果が低下していたのに対し、
実施例のライナーではこのようなことがなく、充分な断
熱効果が得られたためと考えられる。一方、比較例２の
ライナーを用いた場合、排気ガス温度は実施例のライナ
ーを用いた場合と同等であったが、排気ボート出口から
砂状のセラミック粉末が出て、触媒に悪影響を及ぼして
いるこ・とが判明した。これは、ライナー内面のセラミ
ック層の表面の大きな凹凸が、運転試験中に排気ガスに
よってエロージョン的に除去されたものと推定される。As a result, when the liner of Comparative Example 1 was used, the exhaust gas temperature was 25 to 30°C higher than when the liner without ceramic coating was used, whereas when the liner of Example 1 was used, It was found that the temperature increased by 45 to 50°C. This is because, as mentioned in Performance Evaluation 1 above, in the liner of Comparative Example 1, the cracks in the heat-insulating ceramic coating layer were filled with the aluminum alloy of the liner body material, so the heat-insulating effect was reduced. ,
This is thought to be because the liner of the example did not have such a problem, and a sufficient heat insulation effect was obtained. On the other hand, when the liner of Comparative Example 2 was used, the exhaust gas temperature was the same as when the liner of Example was used, but sand-like ceramic powder came out from the exhaust boat outlet and had a negative effect on the catalyst. It turned out that there was. This is presumably because the large irregularities on the surface of the ceramic layer on the inner surface of the liner were eroded away by the exhaust gas during the driving test.
［性能評価３］
３閤厚のセラミック被覆層を溶射のみによって形成した
場合（比較例１）と、溶射およびスラリー塗布・乾燥に
よって合計３間厚のセラミック被覆層を形成した場合（
実施例）とについて、セラミック被覆層形成に要する合
計時間を調べたところ、実施例の場合は比較例１の場合
の １／２の時間で足りることが判明した。[Performance evaluation 3] A case in which a ceramic coating layer with a thickness of 3 layers was formed only by thermal spraying (Comparative Example 1), and a case in which a ceramic coating layer with a total thickness of 3 layers was formed by thermal spraying, slurry application, and drying (
When the total time required for forming the ceramic coating layer was investigated for Example 1, it was found that 1/2 the time required for Comparative Example 1 was sufficient for Example.
［その他の実施例］
前述の実施例では、セラミックスラリーのセラミック材
料としてＡＩ２０３系のものを用いたが、このほかの酸
化物系セラミック、例えばＺｒ０２系、Ｓｉ０２系、Ｓ
ｉＺｒ０４系、Ｔ ｉ Ｏ ２系、Ｆｅ２０３系、Ｃｕ
Ｏ系等の各種セラミックを、単独または複合して使用し
ても良い。またセラミック溶射材としても、前記実施例
のＺｒ０２系のほか、上記と同様の各種の酸化物系セラ
ミックを単独または複合して用いることができる。[Other Examples] In the above-described examples, AI203-based ceramic material was used as the ceramic material for the ceramic slurry, but other oxide-based ceramics such as Zr02-based, Si02-based, S
iZr04 series, T i O 2 series, Fe203 series, Cu
Various ceramics such as O-based ceramics may be used alone or in combination. Further, as the ceramic spraying material, in addition to the Zr02 type of the above embodiment, various oxide type ceramics similar to those mentioned above can be used alone or in combination.
さらに、鋳造される金属本体材料として実施例ではアル
ミニウム合金を用いているが、鋳鉄等、他の金属を用い
て鋳包んだ場合にも同様の効果が得られることは勿論で
ある。Furthermore, although an aluminum alloy is used in the embodiment as the metal body material to be cast, it goes without saying that similar effects can be obtained when other metals such as cast iron are used.
そしてまた、金属溶射層に用いる金属も、実施例のＮｉ
−Ｃｒ−ＡＪ合金に限定されないことは勿論であり、要
はセラミックと外側の鋳造金属に応じて選択すれば良い
。Furthermore, the metal used for the metal sprayed layer is Ni in the example.
Of course, it is not limited to the -Cr-AJ alloy, and the key point is to select it depending on the ceramic and the outer cast metal.
また、実施例では目的とする中空部材として、シリンダ
ヘッドの排気ポート用ライナーを製造する場合について
説明したが、シリンダヘッドの吸気ボート用ライナーを
製造する場合、あるいはボート用ライナーを別部材とせ
ずにシリンダヘッド自体を一体に製造する場合、さらに
はターボチャージャーのハウジングを製造する場合等に
も適用でき、要は内面を断熱する必要のある金属製中空
部材の製造には全て適用可能である。In addition, in the example, a case was explained in which a liner for an exhaust port of a cylinder head was manufactured as the target hollow member. It can be applied to the case where the cylinder head itself is manufactured in one piece, and even when the housing of a turbocharger is manufactured, and in short, it is applicable to all the manufacture of metal hollow members whose inner surfaces need to be insulated.
なおこの発明の方法は、砂中子を用いた場合に最も大き
な効果を発揮するが、砂以外の中子を用いた場合にも適
用することは可能である。Although the method of this invention exhibits the greatest effect when using a sand core, it can also be applied when using a core other than sand.
発明の効果
この発明の方法によれば、充分な断熱効果を得るために
厚い断熱セラミック被覆層を形或する場合でも断熱セラ
ミック被覆層にクラックが発生したり、断熱セラミック
被覆層の一部に剥離が生じたりすることを有効に防止で
き、そのためクラックや剥離部分への本体鋳造金属の差
し込みにより断熱効果が損なわれることなく、優れた断
熱効果を発揮させることができる。またこの発明の方法
では、厚い断熱セラミック被覆層の全体を溶射によって
形戊する場合と比較して格段に生産性が良好であり、ま
た材料歩留りも高く、したがってコスト低減を図ること
ができる。さらに、特に中子として砂中子を用いた場合
でも、セラミックスラリーと中子砂との親和性がセラミ
ック溶射層によって遮断されるため、中子砂の完全な除
去が困難となったり、内面性状が悪化することもない。Effects of the Invention According to the method of the present invention, even when a thick heat-insulating ceramic coating layer is formed to obtain a sufficient heat-insulating effect, cracks may occur in the heat-insulating ceramic coating layer or parts of the heat-insulating ceramic coating layer may peel off. Therefore, the insulation effect is not impaired due to insertion of the main body cast metal into cracks or peeled parts, and excellent insulation effects can be exhibited. Furthermore, the method of the present invention has much better productivity than the case where the entire thick heat-insulating ceramic coating layer is formed by thermal spraying, and the material yield is also high, so that costs can be reduced. Furthermore, even when a sand core is used as the core, the affinity between the ceramic slurry and the core sand is blocked by the ceramic sprayed layer, making it difficult to completely remove the core sand and causing the inner surface properties to deteriorate. It doesn't get worse.
第１図はこの発明の実施例の方法を中子の横断面位置で
段階的に示す略解図、第２図は従来の技術の一例によっ
て内面に断熱セラミック波ｙＩＲを有する排気ポート用
ライナーを製造するにあたって、ライナー本体材料鋳造
後で中子除去前の状態を示す斜視図、第３図は第２図の
■−■線における横断面図、第４図はセラミック溶射時
間とセラミック被覆厚さとの関係を示すグラフである。
１・・・中子、 ２・・・セラミック溶射層、 ３・・
・金属溶射層、 ４・・・本体金属、 ５・・・スラ
リー乾燥セラミック層、 ６・・・断熱セラミック被覆
層。FIG. 1 is a schematic diagram showing step by step the cross-sectional position of the core according to the method of the embodiment of the present invention, and FIG. 2 is an example of manufacturing an exhaust port liner having heat insulating ceramic waves yIR on the inner surface by an example of the conventional technique. Fig. 3 is a cross-sectional view taken along the line ■-■ in Fig. 2, and Fig. 4 shows the relationship between ceramic spraying time and ceramic coating thickness. It is a graph showing a relationship. 1... Core, 2... Ceramic sprayed layer, 3...
・Metal sprayed layer, 4... Body metal, 5... Slurry dry ceramic layer, 6... Heat insulating ceramic coating layer.
Claims (1)
た後、そのセラミック溶射層の表面にセラミックスラリ
ーを塗布して乾燥させ、これによりセラミック溶射層と
スラリー乾燥セラミック層との２層からなる断熱セラミ
ック被覆層を形成し、その後その断熱セラミック被覆層
の表面に金属溶射層を形成し、次いで中子を鋳型内に設
置して中空部材の本体となる金属の溶湯を注湯し、前記
金属溶射層の外側を前記金属により鋳包んだ後、中子を
除去することを特徴とする断熱セラミック被覆層を内面
に有する中空部材の製造方法。After forming a ceramic sprayed layer with a thickness of 1 mm or less on the surface of the core, a ceramic slurry is applied to the surface of the ceramic sprayed layer and dried, thereby creating a thermal insulation layer consisting of two layers: the ceramic sprayed layer and the slurry-dried ceramic layer. A ceramic coating layer is formed, and then a metal spraying layer is formed on the surface of the heat-insulating ceramic coating layer, and then the core is placed in a mold and molten metal that will become the body of the hollow member is poured, and the metal spraying is performed. A method for producing a hollow member having a heat insulating ceramic coating layer on the inner surface, the method comprising: removing the core after casting the outer side of the layer with the metal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23098789A JPH03106553A (en) | 1989-09-06 | 1989-09-06 | Manufacture of hollow member having heat insulating ceramic covering layer on inside surface |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23098789A JPH03106553A (en) | 1989-09-06 | 1989-09-06 | Manufacture of hollow member having heat insulating ceramic covering layer on inside surface |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH03106553A true JPH03106553A (en) | 1991-05-07 |
Family
ID=16916458
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP23098789A Pending JPH03106553A (en) | 1989-09-06 | 1989-09-06 | Manufacture of hollow member having heat insulating ceramic covering layer on inside surface |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH03106553A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2328979A (en) * | 1997-09-04 | 1999-03-10 | Daimler Benz Ag | Exhaust pipe, duct or manifold with heat insulating layer for i.c. engine with a catalytic converter |
| JP2009257218A (en) * | 2008-04-17 | 2009-11-05 | Toyota Motor Corp | Cylinder block and cylinder block manufacturing method |
| CN113151655A (en) * | 2020-12-03 | 2021-07-23 | 深圳市万泽航空科技有限责任公司 | Heat treatment method and heat treatment device for high-temperature alloy casting |
-
1989
- 1989-09-06 JP JP23098789A patent/JPH03106553A/en active Pending
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2328979A (en) * | 1997-09-04 | 1999-03-10 | Daimler Benz Ag | Exhaust pipe, duct or manifold with heat insulating layer for i.c. engine with a catalytic converter |
| GB2328979B (en) * | 1997-09-04 | 1999-10-20 | Daimler Benz Ag | Exhaust pipe for an internal combustion engine having a catalytic converter |
| US6284332B1 (en) | 1997-09-04 | 2001-09-04 | Daimlerchrysler Ag | Exhaust line of an exhaust system equipped with a catalytic converter for an internal combustion engine |
| JP2009257218A (en) * | 2008-04-17 | 2009-11-05 | Toyota Motor Corp | Cylinder block and cylinder block manufacturing method |
| CN113151655A (en) * | 2020-12-03 | 2021-07-23 | 深圳市万泽航空科技有限责任公司 | Heat treatment method and heat treatment device for high-temperature alloy casting |
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