JPH0116764B2 - - Google Patents
Info
- Publication number
- JPH0116764B2 JPH0116764B2 JP55146800A JP14680080A JPH0116764B2 JP H0116764 B2 JPH0116764 B2 JP H0116764B2 JP 55146800 A JP55146800 A JP 55146800A JP 14680080 A JP14680080 A JP 14680080A JP H0116764 B2 JPH0116764 B2 JP H0116764B2
- Authority
- JP
- Japan
- Prior art keywords
- silicon carbide
- fine powder
- carbide fine
- composite plating
- powder
- 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
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 claims description 113
- 238000007747 plating Methods 0.000 claims description 78
- 239000002131 composite material Substances 0.000 claims description 58
- 239000002245 particle Substances 0.000 claims description 48
- 239000000463 material Substances 0.000 claims description 36
- 239000000843 powder Substances 0.000 claims description 27
- 239000002253 acid Substances 0.000 claims description 26
- 239000007864 aqueous solution Substances 0.000 claims description 23
- 238000000034 method Methods 0.000 claims description 22
- 239000007788 liquid Substances 0.000 claims description 21
- 239000011159 matrix material Substances 0.000 claims description 20
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims description 14
- 239000000243 solution Substances 0.000 claims description 12
- 239000000725 suspension Substances 0.000 claims description 10
- 238000000926 separation method Methods 0.000 claims description 9
- 239000012535 impurity Substances 0.000 claims description 8
- 238000004519 manufacturing process Methods 0.000 claims description 8
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 claims description 7
- 229910052759 nickel Inorganic materials 0.000 claims description 7
- 239000002994 raw material Substances 0.000 claims description 5
- 238000010306 acid treatment Methods 0.000 claims 1
- DITXJPASYXFQAS-UHFFFAOYSA-N nickel;sulfamic acid Chemical compound [Ni].NS(O)(=O)=O DITXJPASYXFQAS-UHFFFAOYSA-N 0.000 claims 1
- 229910052751 metal Inorganic materials 0.000 description 16
- 239000002184 metal Substances 0.000 description 16
- 229910010271 silicon carbide Inorganic materials 0.000 description 15
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 description 12
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 8
- 239000000126 substance Substances 0.000 description 8
- 238000007654 immersion Methods 0.000 description 7
- 230000000704 physical effect Effects 0.000 description 7
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 6
- 230000000694 effects Effects 0.000 description 6
- 238000005299 abrasion Methods 0.000 description 5
- 230000007423 decrease Effects 0.000 description 5
- 239000010419 fine particle Substances 0.000 description 5
- 230000013011 mating Effects 0.000 description 5
- 239000006228 supernatant Substances 0.000 description 5
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 4
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 4
- 238000010438 heat treatment Methods 0.000 description 4
- KERTUBUCQCSNJU-UHFFFAOYSA-L nickel(2+);disulfamate Chemical compound [Ni+2].NS([O-])(=O)=O.NS([O-])(=O)=O KERTUBUCQCSNJU-UHFFFAOYSA-L 0.000 description 4
- 239000000377 silicon dioxide Substances 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 3
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 3
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 3
- 238000004220 aggregation Methods 0.000 description 3
- 230000002776 aggregation Effects 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 239000013078 crystal Substances 0.000 description 3
- 239000002270 dispersing agent Substances 0.000 description 3
- 229910021645 metal ion Inorganic materials 0.000 description 3
- 229910017604 nitric acid Inorganic materials 0.000 description 3
- 238000004062 sedimentation Methods 0.000 description 3
- 238000003756 stirring Methods 0.000 description 3
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 2
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 2
- QUSNBJAOOMFDIB-UHFFFAOYSA-N Ethylamine Chemical compound CCN QUSNBJAOOMFDIB-UHFFFAOYSA-N 0.000 description 2
- BAVYZALUXZFZLV-UHFFFAOYSA-N Methylamine Chemical compound NC BAVYZALUXZFZLV-UHFFFAOYSA-N 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 229910052804 chromium Inorganic materials 0.000 description 2
- 239000011651 chromium Substances 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- 238000002485 combustion reaction Methods 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 239000010949 copper Substances 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- 238000005461 lubrication Methods 0.000 description 2
- 150000007522 mineralic acids Chemical class 0.000 description 2
- 239000000047 product Substances 0.000 description 2
- 238000010298 pulverizing process Methods 0.000 description 2
- 238000000746 purification Methods 0.000 description 2
- 238000001878 scanning electron micrograph Methods 0.000 description 2
- 238000005406 washing Methods 0.000 description 2
- 229910001018 Cast iron Inorganic materials 0.000 description 1
- AVXURJPOCDRRFD-UHFFFAOYSA-N Hydroxylamine Chemical compound ON AVXURJPOCDRRFD-UHFFFAOYSA-N 0.000 description 1
- 229910021586 Nickel(II) chloride Inorganic materials 0.000 description 1
- BPQQTUXANYXVAA-UHFFFAOYSA-N Orthosilicate Chemical compound [O-][Si]([O-])([O-])[O-] BPQQTUXANYXVAA-UHFFFAOYSA-N 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- 230000002159 abnormal effect Effects 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 150000001412 amines Chemical class 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- 235000011114 ammonium hydroxide Nutrition 0.000 description 1
- 230000003466 anti-cipated effect Effects 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- KGBXLFKZBHKPEV-UHFFFAOYSA-N boric acid Chemical compound OB(O)O KGBXLFKZBHKPEV-UHFFFAOYSA-N 0.000 description 1
- 239000004327 boric acid Substances 0.000 description 1
- AXCZMVOFGPJBDE-UHFFFAOYSA-L calcium dihydroxide Chemical compound [OH-].[OH-].[Ca+2] AXCZMVOFGPJBDE-UHFFFAOYSA-L 0.000 description 1
- 239000000920 calcium hydroxide Substances 0.000 description 1
- 229910001861 calcium hydroxide Inorganic materials 0.000 description 1
- -1 carbide Substances 0.000 description 1
- 239000011362 coarse particle Substances 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 239000010432 diamond Substances 0.000 description 1
- 229910003460 diamond Inorganic materials 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 239000012153 distilled water Substances 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 238000007772 electroless plating Methods 0.000 description 1
- 239000003792 electrolyte Substances 0.000 description 1
- 239000008151 electrolyte solution Substances 0.000 description 1
- 238000010828 elution Methods 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 238000005755 formation reaction Methods 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 238000000227 grinding Methods 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 239000010687 lubricating oil Substances 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- QMMRZOWCJAIUJA-UHFFFAOYSA-L nickel dichloride Chemical compound Cl[Ni]Cl QMMRZOWCJAIUJA-UHFFFAOYSA-L 0.000 description 1
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 description 1
- RVTZCBVAJQQJTK-UHFFFAOYSA-N oxygen(2-);zirconium(4+) Chemical compound [O-2].[O-2].[Zr+4] RVTZCBVAJQQJTK-UHFFFAOYSA-N 0.000 description 1
- 238000005554 pickling Methods 0.000 description 1
- 238000005498 polishing Methods 0.000 description 1
- 239000002861 polymer material Substances 0.000 description 1
- 230000002250 progressing effect Effects 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 238000004904 shortening Methods 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 238000005728 strengthening Methods 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
- UONOETXJSWQNOL-UHFFFAOYSA-N tungsten carbide Chemical compound [W+]#[C-] UONOETXJSWQNOL-UHFFFAOYSA-N 0.000 description 1
- 229910001928 zirconium oxide Inorganic materials 0.000 description 1
Description
本発明は分散性に優れた高純度炭化珪素微粉末
とその製造方法ならびに前記微粉末を使用する複
合メツキ方法に関する。
近年、金属を不溶性の共析物質例えば酸化物、
炭化物、ダイヤモンドあるいは金属性物質のよう
な無機質の微粉末とともに電着し、耐摩耗性、耐
食性、耐熱性、あるいは耐衝撃性に優れた被覆膜
を形成する技術が開発され、例えばロケツトエン
ジンの燃焼室、内燃機関のピストンリングあるい
はシリンダ内壁面等の摺動部への複合メツキ技術
が実用化されている。
例えば、特公昭36−3806号公報に電解液中に炭
化珪素、酸化アルミニウム、炭化タングステンあ
るいは酸化ジルコニウム等の粉末状物質を懸濁さ
せ、被メツキ物からなる陰極と陽極との間に適当
な電流を印加し、被メツキ物表面に前記粉末状物
質を沈降させながら複合メツキする方法が開示さ
れている。
最近では、耐摩耗性に優れた被覆膜を得ること
を目的としてニツケルマトリツクス中に炭化珪素
粉末を共析させる複合メツキが盛んに行なわれて
いる。しかしながら、炭化珪素粉末は一般的に凝
集し易い特性を有するため、従来各種の分散剤を
使用する複合メツキ方法が報告されている。
例えば、特開昭50−62136号公報に共析物質の
分散剤としてケイ酸アルミナをメツキ液に添加す
ることにより、複合メツキ層における共析物質の
分散性を改良する方法が開示されている。
特開昭52−135837号公報にメツキ液中にメツキ
液より比重のわずかに大きな高分子材料よりなる
分散促進材料を混入して複合メツキ層における共
析物質を均一に共析できる複合メツキ液が開示さ
れている。
さらに、特開昭52−88549号公報には微細な炭
化珪素粉末を共析させた複合メツキでは、摺動材
料として使用した場合炭化珪素の微粒子が剥落し
たり、ニツケルマトリツクス内へ埋没したりして
複合メツキ層の耐摩耗性が低下するため、共析物
質としての炭化珪素は平均粒子径3.5〜20μの範囲
内が適していると記載されており、平均粒子径が
1μｍ以下の極めて微細な粒子よりなる炭化珪素
微粉末を共析物質として使用することは好ましく
ないと記載されている。
したがつて、従来知られた前記諸公報記載の複
合メツキ方法において使用されている炭化珪素粉
末はいずれも平均粒径が2μｍ以上の比較的粗粒
であつた。
以上従来知られた炭化珪素粉末を共析させる複
合メツキ方法においては炭化珪素微粉末を共析物
質として使用することには種々の欠点があつた。
本発明は、前記種々の欠点を除去、改善した分
散性に優れた高純度炭化珪素微粉末とその製造方
法ならびに前記微粉末を使用する複合メツキ方法
を提供することを目的とするものであり、特許請
求の範囲記載の炭化珪素微粉末とその製造方法な
らびにこの微粉末を使用する複合メツキ方法を提
供することによつて前記目的を達成することがで
きる。
次に本発明を詳細に説明する。
本発明者らは複合メツキの共析物質として従来
好ましくないとされていた極めて微細な粒子より
なる炭化珪素微粉末について研究した結果、次に
述べるような機構が存在しているという結論に到
達した。
即ち、従来一般に市販されている炭化珪素粉末
の殆どは合成時あるいは粉砕時において混入する
不純物を塩酸、硫酸、フツ化水素酸あるいは硝酸
等の無機酸の水溶液に浸漬することによつて洗浄
除去したものである。例えば、α型結晶よりなる
炭化珪素粉末はアチエソン型電気炉で合成された
塊状の生成物を粉砕分級することによつて製造さ
れる。このような塊状のα型結晶よりなる炭化珪
素の如く硬い材料を微粉砕することは極めて困難
であるばかりでなく、粉砕中に不純物が混入する
ため通常塩酸あるいは硫酸の水溶液に浸漬する精
製処理が施される。また不純物として遊離シリカ
や遊離珪素を含有している場合には通常フツ化水
素酸あるいはフツ化水素酸と硝酸の混酸に浸漬す
ることによつて前記不純物が除去されている。し
かしながら、前記無機酸は通常の水洗処理では炭
化珪素粉末より充分に除去されることが難かし
く、このようにして製造された炭化珪素粉末の粒
子表面には前記酸成分が付着しているため粉末の
PH値は極めて低く、かつ凝集性が強い。特に1μ
ｍ以下の如き超微粉末においては凝集性が著し
く、メツキ液中に懸濁させた場合でも従来の分散
剤では単一粒子までほぐして懸濁させることは困
難で、炭化珪素微粉末は凝集した粒子の状態で懸
濁される。このようなメツキ液を使用すると共析
物質である炭化珪素微粉末は凝集した粒子のまま
マトリツクス金属中に共析し、第１図ａに示す如
き構造となるため炭化珪素微粉末の粒子とマトリ
ツクス金属との接着面積が小さく、表面に露出し
た粒子は剥落し易い欠点を有するし、また分散性
も不均一となるため複合メツキ膜の硬度や耐摩耗
性を向上させる効果がなかつた。
前述の如く、PH値が低く、粒子表面に酸成分が
多量に付着している炭化珪素微粉末を複合メツキ
の共析物質として使用した場合、メツキ液中に単
一粒子にまでほぐして懸濁させることが極めて困
難で、炭化珪素微粉末が凝集した粒子のままマト
リツクス金属中に共析されるために複合メツキ膜
の物性を著しく劣化させることは知られていなか
つた。さらに、極めて微細な炭化珪素微粉末のPH
値を調整したり、粒子表面に付着している酸成分
を除去することは工業上極めて困難で従来実施さ
れず、PH値が中性に近く、かつ残留酸成分含有量
の少ない炭化珪素微粉末が複合メツキの共析物質
として適していることは知られなかつた。
本発明者らは炭化珪素微粉末のPH値を調整し、
残留酸成分を除去して複合メツキの共析物質とし
て使用した結果、従来共析物質として良好である
とは推測だにされなかつた炭化珪素微粉末が共析
物質として極めて優れており、しかも比較的粗粒
の炭化珪素粉末に比較して複合メツキ膜の物性を
著しく向上させるおどろくべき効果を有している
ことを発見した。
本発明の炭化珪素微粉末は従来複合メツキの共
析物質として使用されていた炭化珪素粉末と比較
して、極めて微細であり、かつ酸洗処理されてい
るにもかかわらず液中分散性特にスルフアミン酸
ニツケル浴中での分散性に極めて優れているた
め、従来の炭化珪素粉末では得ることのできなか
つた硬度、耐摩耗性等の優れた複合メツキ膜を得
ることができる。
本発明の炭化珪素微粉末が複合メツキの共析物
質として優れている理由は、
(1) 粒径が非常に微細な超微粉であり、比表面積
が非常に大きいため、マトリツクス金属との接
着面積が大きく剥落し難い。
(2) 炭化珪素微粉末は硬い材料であり、しかも第
１図ｂに示す如く単一粒子の状態でマトリツク
ス金属中に共析されるため、粒子が凝集した状
態で共析したもののように小さな応力によつて
壊れることがない。
(3) 超微粉がマトリツクス金属中に均一に分散す
るため、応力が局所的に集中することがない。
(4) 共析物質が超微粉でしかもマトリツクス金属
中に均一に分散するため、メツキ層表面は平滑
性に優れ、相手材を異常摩耗させることがな
い。
本発明の高純度炭化珪素微粉末において、その
PH値は4.5〜8.0の範囲であることが必要である。
前記PH値を4.5〜8.0の範囲内に限定する理由は、
粉末のPH値が4.5より低いとメツキ液中における
分散性が悪く、単一粒子にまで分散させることが
極めて困難であるし、一方PH値が8.0より高い場
合には粉末中に含有される塩基性物が共電着しメ
ツキ膜の特性を劣化させるからである。
前記PH値が4.5より低い場合には炭化珪素微粉
末がメツキ液中に分散し難い原因は、粒子表面に
付着している電解質が極端に酸性側となつている
ため、メツキ液中に投入しても粒子表面における
水分子の配位が生ぜず、電気二重層を形成しない
からであると考えられる。
また、本発明によれば、炭化珪素微粉末中に含
有される酸成分量を0.3重量％以下とすることが
必要である。前記炭化珪素微粉末中に含有される
酸成分は炭化珪素微粉末の表面に比較的強固に付
着しており、前記酸成分量が0.3重量％よりも多
い炭化珪素微粉末を共析物質として使用すると、
酸成分はメツキ膜中に共電着され、マトリツクス
金属と粉末粒子との接着強度を劣化させるため、
共析物質として使用しても、複合メツキ膜の硬度
や耐摩耗性を向上させる効果が極めて小さいから
である。
本発明によれば、炭化珪素微粉末の比表面積が
５m2／ｇ以上、平均粒子径が1μｍ以下であるこ
とが好ましい。前記炭化珪素微粉末の比表面積が
５m2／ｇより小さいとマトリツクス金属との接着
面積が小さく接着強度が弱いため、摺動材料等に
使用した場合に剥落し易いと、一方平均粒子径が
1μｍより大きいと摺動材料等に使用した場合相
手材との接触点が減少し相手材の接触点における
剪断応力が大きくなるため相手材の摩耗量が増大
するからである。
本発明によれば炭化珪素粉末は粒子の長径／短
径比の平均値（以下、平均粒径比で表す。）が1.1
〜1.7の範囲内であることが有利である。前記平
均粒径比が1.7より大きい粒子形状を有する炭化
珪素粉末を摺動材料に共析物質として複合メツキ
すると使用時において表面に露出している各粒子
にかかる面圧が不均一となり相手材に深い傷を発
生させたり、著しく摩耗したりするため、共析物
質として使用する場合には厳重な粒度管理を必要
とする等の欠点を有するし、一方前記平均粒径比
が1.1より小さい範囲であれば非常に好ましいと
考えられるが、このような形状の微粉末を得るこ
とは非常に困難で、例え製造できたとしても極め
て高価となり、実用的でないと考えられるからで
ある。
本発明によれば、炭化珪素微粉末原料を塩基性
水溶液に浸漬した後、固液分離操作を施す必要が
ある。炭化珪素微粉末を塩基性水溶液に浸漬した
後、固液分離操作を施す理由は、炭化珪素微粉末
の粒子表面に付着しており、特に水洗では除去す
ることの極めて困難な不純物、即ち酸洗時に付着
した残留酸成分を塩基性水溶液に浸漬することに
よつて塩基性水溶液に溶出させ、さらに固液分離
することによつて前記溶出した酸成分を効率的に
除去するためである。
しかしながら、従来微粉末の固液分離操作は極
めて困難であることが知られており、特に分散性
を向上させた微粉末の固液分離操作を工業的に実
施することは設備的にも経済的にも極めて困難で
あるため、分散性を向上させた微粉末の懸濁液よ
り微粉末を分散性を維持したまま固液分離するこ
とは当業者の間では実施されなかつた。したがつ
て、前記の如き処理を施された炭化珪素微粉末が
複合メツキの共析物質として極めて顕著な複合メ
ツキ膜の強化作用を有することは従来予想だにさ
れなかつたことである。
本発明によれば、前記基塩性水溶液の規定度を
少なくとも0.01Nとすることが好ましい。前記塩
基性水溶液の規定度が0.01Nより低いと炭化珪素
微粉末に含有されている残留酸成分の浸漬液中へ
の溶出量が少なくなり残留酸成分の除去効率が極
めて低いからである。一方、前記塩基性水溶液の
規定度が余り高い場合には逆に塩基性成分が炭化
珪素微粉末に付着し、むしろ炭化珪素微粉末の不
純物含有量が増加するため、塩基性水溶液の規定
度は1N以下とすることが有利である。
前記塩基性水溶液に炭化珪素微粉末を浸漬する
割合は25ｇ／〜200ｇ／の範囲内とすること
が有利である。前記割合が200ｇ／より多いと
残留酸成分の除去効率が低く、しかも固液分離操
作が困難であるし、一方25ｇ／より少ないと設
備あたりの処理量が極めて少なく効率的でないか
らである。
前記塩基性水溶液としては、例えばアンモニ
ア、水酸化ナトリウム、水酸化カリウム、水酸化
カルシウム等の無機塩基性物質あるいはヒドロキ
シルアミン、メチルアミン、エチルアミン等の有
機アミン類の水溶液を使用することができるが、
なかでもアンモニアの水溶液が最も好ましい。そ
の理由は必要とされる量より過剰に添加しても加
熱することによつて容易に過剰分を気化せしめて
除去することができ、炭化珪素微粉末の粒子表面
に付着したりして残存し悪影響を及ぼすことが極
めて少ないからである。
本発明によれば、炭化珪素微粉末の塩基性水溶
液による懸濁液を80℃以上に加熱することが好ま
しい。その理由は、炭化珪素微粉末の粒子表面に
付着している残留酸成分を速やかに溶出でき、工
程に要する時間を短縮できる利点を有するからで
ある。
なお、本発明における固液分離は炭化珪素微粉
を沈降させて上澄み液を排除する方法によること
が有利である。
前記炭化珪素微粉末は先に本発明者らが出願し
た特願昭54−146389号公報記載の主としてβ型結
晶よりなる炭化珪素の製造方法によつて製造され
るβ型炭化珪素微粉末を有利に使用することがで
きる。
なお、前記の如き方法で得られた生成物には
SiC化反応にあずからなかつた未反応炭素や未反
応シリカが含有されているため、これらを除去精
製することによつて炭化珪素純度が向上する。例
えば未反応シリカはフツ化水素酸あるいはフツ化
水素酸と硝酸の混酸に浸漬し洗浄除去される。こ
のようにして精製された炭化珪素微粉末は極めて
活性な炭化珪素の表面が露出されるため、複合メ
ツキの共析物質として使用するとマトリツクス金
属との接着性が良好であり、複合メツキ膜の物性
を向上させる効果が極めて顕著である。
次に前述の如き分散性に優れた高純度炭化珪素
微粉末を使用する複合メツキ方法について述べ
る。
本発明によれば、ニツケルマトリツクス中に炭
化珪素微粉末を共析させた複合メツキ膜のメツキ
方法において、PH値が4.5〜8.0の範囲内で、かつ
酸成分含有量が0.3重量％以下の分散性に優れた
高純度炭化珪素微粉末が共析物質として使用され
る。前記共析物質としての炭化珪素微粉末は目的
とするマトリツクス金属の金属イオンを含有する
メツキ液例えばスルフアミン酸ニツケル浴に70〜
250ｇ／の割合で添加され、超音波撹拌させな
がら被メツキ物を陰極とし電圧を印加して複合メ
ツキされる。浴のPH値は5.0〜6.5の範囲内が好ま
しく、浴温は50〜70℃の範囲内、電流密度は10〜
30A／ｄm2の範囲内とすることが有利である。前
記浴のPH値が5.0〜6.5の範囲内であることが好ま
しい理由は、PH値が5.0より低いとメツキ液中に
おいて炭化珪素微粉末が凝集し易いし、一方6.5
より高い場合には陽極からの金属イオンの溶出速
度が低くメツキ液中における金属イオン濃度が減
少するため、メツキ効率が低下するからである。
また複合メツキ膜の炭化珪素微粉末含有率として
は２〜15重量％の範囲内とすることが有利であ
る。その理由は炭化珪素微粉末の含有率が２重量
％より少ないと複合メツキ膜の硬度や耐摩耗性を
向上させる効果が低く、一方15重量％より多いと
炭化珪素微粉末の均一分散性が損なわれ炭化珪素
微粉末が剥落したり、メツキ膜が剥離し易くなり
複合メツキ膜の物性が低下するからである。
複合メツキのマトリツクス金属としては前述の
ニツケルの他にクロムあるいは銅を使用すること
もできる。
なお、本発明の炭化珪素微粉末は無電解メツキ
法の共析物質としても優れた特性を有している。
以下に、本発明を実施例について説明する。
実施例 １
前記特願昭54−146389号公報記載の主としてβ
型結晶よりなる炭化珪素の製造方法により、SiC
化反応させ、空気気流中で500℃に加熱して遊離
炭素を除去した後フツ化水素酸に浸漬して遊離シ
リカを除去精製し、さらに粒度分級することによ
つてβ型炭化珪素微粉末（PH値：3.2、残留酸成
分含有量：0.41重量％、比表面積：10.1m2／ｇ、
平均粒子径：0.33μｍ、平均粒径比：1.42、α型
炭化珪素含有率：3.5重量％）を製造した。
前記β型炭化珪素微粉末を0.17Nのアンモニア
水溶液に懸濁液濃度が7.7重量％となるよう添加
し懸濁させた。前記懸濁液を90℃迄加熱した後β
型炭化珪素微粉末を沈降させて上澄み液を除去
し、約120℃の温度で乾燥した。上澄み液を除去
した後の懸濁液濃度は約24重量％であつた。得ら
れたβ型炭化珪素微粉末のPH値は5.8、残留酸成
分含有量は0.12重量％であつた。
なお、粉末のPH値はJIS−Ｒ−6129に従つて測
定した。
上記β型炭化珪素微粉末１ｇをスルフアミン酸
ニツケル浴（スルフアミン酸ニツケル：480ｇ／
、塩化ニツケル：15ｇ／、ホウ酸：30ｇ／
）200ml中に投入し、20分間超音波撹拌した後、
島津自動粒度測定器を使用し粒子の沈降状況を観
察することによつて分散性を調べた。この測定方
法によれば、沈降速度が遅いほど分散性が良好で
あるといえる。
第２図に示した結果よりわかるように、本実施
例の処理を施したβ型炭化珪素微粉末は、処理を
施していないβ型炭化珪素微粉末に比較して沈降
速度が極めて遅く、殆ど単一粒子の沈降が進行し
ているだけであり、凝集による見掛けの粒子粗大
化は殆ど生成しないことがわかる。
さらに、本実施例の処理を施したβ型炭化珪素
微粉末をスルフアミン酸ニツケル浴に150ｇ／
の割合で添加し、鋼板を陰極とし陽極にニツケル
を使用し、メツキ液を超音波撹拌しながら180分
間複合メツキを行つた。メツキ条件は浴温60℃、
浴のPH値5.8、両極間距離８cm、電流密度20A／
ｄm2とした。なおメツキ液のPH値はアンモニア水
を使用して調整した。
得られた複合メツキ膜中のβ型炭化珪素微粉末
含有量は5.5重量％であり、第３図の走査型電子
顕微鏡写真（1500倍）に示す如く、β型炭化珪素
微粉末が複合メツキ膜中に極めて均一に分散して
いることがわかる。
複合メツキ膜の硬度および耐摩耗性は複合メツ
キを施した後最終的に＃1500の研磨紙で研磨を行
つたものと、さらに400℃のアルゴンガス気流中
で４時間熱処理したものについて調べ、第１表に
示した。硬度はマイクロビツカース硬度計を使用
し、荷重500Kg、保持時間５秒で測定した。耐摩
耗性は大越式迅速摩耗試験機を用いてその摩耗量
で表わした。回転円板は鋳鉄（FC−35）を用い、
潤滑油（モービル＃20）滴下注油潤滑方式、摩擦
速度1.96ｍ／秒、最高荷重18.8Kg／cm2および摩擦
距離600ｍで行つた。
The present invention relates to a high-purity silicon carbide fine powder with excellent dispersibility, a method for producing the same, and a composite plating method using the fine powder. In recent years, metal-insoluble eutectoids such as oxides,
A technology has been developed to form a coating film with excellent wear resistance, corrosion resistance, heat resistance, or impact resistance by electrodepositing together with inorganic fine powder such as carbide, diamond, or metallic substances. Composite plating technology has been put into practical use for sliding parts such as combustion chambers, piston rings of internal combustion engines, and cylinder inner walls. For example, in Japanese Patent Publication No. 36-3806, powdered substances such as silicon carbide, aluminum oxide, tungsten carbide, or zirconium oxide are suspended in an electrolytic solution, and an appropriate current is applied between the cathode and anode consisting of the material to be plated. A method for composite plating is disclosed in which the powdery substance is deposited on the surface of the object to be plated by applying the powder. Recently, composite plating in which silicon carbide powder is eutectoided into a nickel matrix has been widely used in order to obtain a coating film with excellent wear resistance. However, since silicon carbide powder generally has the property of being easily agglomerated, composite plating methods using various dispersants have been reported. For example, JP-A-50-62136 discloses a method of improving the dispersibility of the eutectoid in a composite plating layer by adding alumina silicate to the plating solution as a dispersant for the eutectoid. JP-A No. 52-135837 discloses a composite plating liquid that can uniformly eutectoid eutectoid substances in a composite plating layer by mixing a dispersion promoting material made of a polymer material with a specific gravity slightly higher than that of the plating liquid into the plating liquid. Disclosed. Furthermore, Japanese Patent Application Laid-Open No. 52-88549 discloses that in composite plating made of eutectoid fine silicon carbide powder, when used as a sliding material, the fine particles of silicon carbide may fall off or become embedded in the nickel matrix. It is stated that the average particle size of silicon carbide as a eutectoid substance is suitable in the range of 3.5 to 20μ, because the wear resistance of the composite plating layer decreases.
It is stated that it is not preferable to use silicon carbide fine powder consisting of extremely fine particles of 1 μm or less as a eutectoid material. Therefore, all of the silicon carbide powders used in the conventionally known composite plating methods described in the above-mentioned publications had relatively coarse particles with an average particle size of 2 μm or more. As described above, in the conventionally known composite plating method of eutectoiding silicon carbide powder, there are various disadvantages in using fine silicon carbide powder as the eutectoid material. The object of the present invention is to provide a high-purity silicon carbide fine powder with excellent dispersibility that eliminates and improves the various drawbacks described above, a method for producing the same, and a composite plating method using the fine powder, The above object can be achieved by providing a silicon carbide fine powder, a method for producing the same, and a composite plating method using this fine powder as described in the claims. Next, the present invention will be explained in detail. The present inventors studied silicon carbide fine powder consisting of extremely fine particles, which had been considered undesirable as a eutectoid material for composite plating, and came to the conclusion that the following mechanism exists. . In other words, impurities mixed in in most commercially available silicon carbide powders during synthesis or pulverization are removed by immersion in an aqueous solution of an inorganic acid such as hydrochloric acid, sulfuric acid, hydrofluoric acid, or nitric acid. It is something. For example, silicon carbide powder consisting of α-type crystals is produced by crushing and classifying a lumpy product synthesized in an Acheson-type electric furnace. Not only is it extremely difficult to pulverize a hard material such as silicon carbide, which is made of lumpy α-type crystals, but also impurities are mixed in during the pulverization process, so the purification treatment usually involves immersion in an aqueous solution of hydrochloric acid or sulfuric acid. administered. In addition, when free silica or free silicon is contained as an impurity, the impurity is usually removed by immersion in hydrofluoric acid or a mixed acid of hydrofluoric acid and nitric acid. However, the inorganic acid is more difficult to remove than the silicon carbide powder by ordinary water washing treatment, and the acid component is attached to the particle surface of the silicon carbide powder produced in this way. of
The pH value is extremely low and the aggregation property is strong. Especially 1μ
Ultrafine powders with a particle diameter of less than m have a remarkable aggregation property, and even when suspended in a plating liquid, it is difficult to loosen and suspend them into single particles using conventional dispersants, and silicon carbide fine powders tend to aggregate. Suspended in the form of particles. When such a plating solution is used, the silicon carbide fine powder, which is a eutectoid substance, eutectoids into the matrix metal as agglomerated particles, resulting in a structure as shown in Figure 1a, so that the silicon carbide fine powder particles and the matrix are mixed together. The adhesion area with the metal is small and the particles exposed on the surface tend to peel off easily, and the dispersibility is non-uniform, so it is not effective in improving the hardness and abrasion resistance of the composite plating film. As mentioned above, when silicon carbide fine powder, which has a low pH value and has a large amount of acid components attached to the particle surface, is used as a eutectoid material for composite plating, it is loosened into single particles and suspended in the plating solution. It was not known that the physical properties of the composite plating film would be significantly deteriorated because the fine silicon carbide powder would be co-deposited into the matrix metal as agglomerated particles. Furthermore, the pH of extremely fine silicon carbide powder is
It is industrially extremely difficult to adjust the value or remove acid components attached to the particle surface, and this has not been done in the past, resulting in silicon carbide fine powder with a pH value close to neutrality and a low residual acid component content. It was not known that this compound was suitable as a eutectoid material for composite plating. The present inventors adjusted the PH value of silicon carbide fine powder,
As a result of removing the residual acid component and using it as a eutectoid material for composite plating, we found that fine silicon carbide powder, which had not been previously thought to be good as a eutectoid material, was extremely excellent as a eutectoid material, and moreover, compared to It has been discovered that this method has the surprising effect of significantly improving the physical properties of composite plating films compared to coarse-grained silicon carbide powder. The silicon carbide fine powder of the present invention is extremely fine compared to the silicon carbide powder conventionally used as a eutectoid material for composite plating, and has good dispersibility in liquid even though it has been pickled. Since it has extremely excellent dispersibility in a nickel acid bath, it is possible to obtain a composite plating film with excellent hardness, wear resistance, etc. that could not be obtained with conventional silicon carbide powder. The reasons why the silicon carbide fine powder of the present invention is excellent as a eutectoid material for composite plating are as follows: (1) It is an ultra-fine powder with a very fine particle size and a very large specific surface area, so the adhesion area with the matrix metal is small. is difficult to peel off. (2) Silicon carbide fine powder is a hard material, and as shown in Figure 1b, it is eutectoid in the matrix metal in the form of a single particle. Will not break due to stress. (3) Because the ultrafine powder is uniformly dispersed in the matrix metal, there is no local concentration of stress. (4) Since the eutectoid is an ultrafine powder and is uniformly dispersed in the matrix metal, the plating layer surface has excellent smoothness and does not cause abnormal wear of the mating material. In the high purity silicon carbide fine powder of the present invention, the
The PH value must be in the range of 4.5 to 8.0.
The reason for limiting the PH value to within the range of 4.5 to 8.0 is
If the PH value of the powder is lower than 4.5, the dispersibility in the plating liquid is poor and it is extremely difficult to disperse it into single particles.On the other hand, if the PH value is higher than 8.0, the base contained in the powder is This is because the electrolytic materials are co-electrodeposited and deteriorate the properties of the plating film. When the PH value is lower than 4.5, the reason why fine silicon carbide powder is difficult to disperse in the plating solution is that the electrolyte attached to the particle surface is extremely acidic. This is thought to be due to the fact that no coordination of water molecules occurs on the particle surface even when the particles are heated, and an electric double layer is not formed. Further, according to the present invention, it is necessary that the amount of acid component contained in the silicon carbide fine powder is 0.3% by weight or less. The acid component contained in the silicon carbide fine powder adheres relatively firmly to the surface of the silicon carbide fine powder, and the silicon carbide fine powder containing more than 0.3% by weight of the acid component is used as the eutectoid material. Then,
The acid component is co-electrodeposited into the plating film and deteriorates the adhesive strength between the matrix metal and the powder particles.
This is because even when used as a eutectoid, the effect of improving the hardness and wear resistance of the composite plating film is extremely small. According to the present invention, it is preferable that the silicon carbide fine powder has a specific surface area of 5 m 2 /g or more and an average particle diameter of 1 μm or less. If the specific surface area of the silicon carbide fine powder is less than 5 m 2 /g, the adhesion area with the matrix metal is small and the adhesion strength is weak, so if it is used for sliding materials etc., it will easily peel off, and on the other hand, the average particle size will be
This is because if the diameter is larger than 1 μm, when used as a sliding material, the number of contact points with the mating material decreases and the shear stress at the contact points of the mating material increases, resulting in an increase in the amount of wear of the mating material. According to the present invention, the silicon carbide powder has an average length/breadth ratio of particles (hereinafter expressed as average particle size ratio) of 1.1.
Advantageously, it is within the range ~1.7. If silicon carbide powder having a particle shape with an average particle size ratio of more than 1.7 is composite plated as a eutectoid material on a sliding material, the surface pressure applied to each particle exposed on the surface during use will be uneven, causing damage to the mating material. Since it causes deep scratches and significant abrasion, it has disadvantages such as requiring strict particle size control when used as a eutectoid. On the other hand, if the average particle size ratio is less than 1.1, Although it would be very desirable to have such a powder, it would be extremely difficult to obtain a fine powder with such a shape, and even if it could be produced, it would be extremely expensive and impractical. According to the present invention, it is necessary to perform a solid-liquid separation operation after immersing the silicon carbide fine powder raw material in a basic aqueous solution. The reason for performing a solid-liquid separation operation after immersing fine silicon carbide powder in a basic aqueous solution is to remove impurities that adhere to the particle surface of fine silicon carbide powder and are extremely difficult to remove with water washing, that is, pickling. This is to efficiently remove the residual acid component that has adhered to the base by immersing it in the basic aqueous solution and eluting it into the basic aqueous solution, and then performing solid-liquid separation. However, it is known that conventional solid-liquid separation operations for fine powders are extremely difficult, and it is not economical in terms of equipment to carry out industrial solid-liquid separation operations for fine powders with improved dispersibility. However, it has not been possible for those skilled in the art to perform solid-liquid separation of fine powder from a suspension of fine powder with improved dispersibility while maintaining its dispersibility. Therefore, it has not been previously anticipated that the silicon carbide fine powder subjected to the above-mentioned treatment has an extremely significant strengthening effect on the composite plating film as a eutectoid material in the composite plating. According to the invention, the normality of the basic aqueous solution is preferably at least 0.01N. This is because if the normality of the basic aqueous solution is lower than 0.01N, the amount of residual acid components contained in the fine silicon carbide powder eluted into the immersion liquid will be small, and the removal efficiency of the residual acid components will be extremely low. On the other hand, if the normality of the basic aqueous solution is too high, the basic component will adhere to the silicon carbide fine powder, and the impurity content of the silicon carbide fine powder will increase, so the normality of the basic aqueous solution will be It is advantageous to set it to 1N or less. It is advantageous that the proportion of silicon carbide fine powder immersed in the basic aqueous solution is within the range of 25 g/-200 g/. If the ratio is more than 200g/, the removal efficiency of residual acid components is low and solid-liquid separation operation is difficult, while if it is less than 25g/, the amount of treatment per equipment is extremely small and not efficient. As the basic aqueous solution, for example, an aqueous solution of an inorganic basic substance such as ammonia, sodium hydroxide, potassium hydroxide, calcium hydroxide, etc. or an organic amine such as hydroxylamine, methylamine, ethylamine, etc. can be used.
Among these, an ammonia aqueous solution is most preferred. The reason for this is that even if the amount is added in excess of the required amount, the excess can be easily vaporized and removed by heating, and it will not remain by adhering to the particle surface of the silicon carbide fine powder. This is because there are very few negative effects. According to the present invention, it is preferable to heat the suspension of fine silicon carbide powder in a basic aqueous solution to 80° C. or higher. The reason for this is that the residual acid component adhering to the particle surface of the silicon carbide fine powder can be quickly eluted, which has the advantage of shortening the time required for the process. Note that it is advantageous for the solid-liquid separation in the present invention to be carried out by a method in which fine silicon carbide powder is precipitated and a supernatant liquid is removed. The silicon carbide fine powder is advantageously a β-type silicon carbide fine powder manufactured by the method for manufacturing silicon carbide mainly composed of β-type crystals described in Japanese Patent Application No. 146389/1989 previously filed by the present inventors. It can be used for. In addition, the products obtained by the above method include
Since unreacted carbon and unreacted silica that have not taken part in the SiC formation reaction are contained, the purity of silicon carbide is improved by removing and refining these. For example, unreacted silica is removed by immersion in hydrofluoric acid or a mixed acid of hydrofluoric acid and nitric acid. Since the silicon carbide fine powder purified in this way exposes the extremely active surface of silicon carbide, when used as a eutectoid material for composite plating, it has good adhesion with the matrix metal, and the physical properties of the composite plating film. The effect of improving this is extremely significant. Next, a composite plating method using high-purity silicon carbide fine powder with excellent dispersibility as described above will be described. According to the present invention, in the method of plating a composite plating film in which silicon carbide fine powder is eutectoided in a nickel matrix, the PH value is within the range of 4.5 to 8.0 and the acid component content is 0.3% by weight or less. High-purity silicon carbide fine powder with excellent dispersibility is used as the eutectoid material. The silicon carbide fine powder as the eutectoid substance is added to a plating solution, such as a nickel sulfamate bath, containing metal ions of the desired matrix metal for 70 to 70 minutes.
It is added at a rate of 250 g/kg, and composite plating is performed by applying a voltage using the object to be plated as a cathode while stirring it ultrasonically. The PH value of the bath is preferably within the range of 5.0 to 6.5, the bath temperature is within the range of 50 to 70°C, and the current density is 10 to 6.5.
A range of 30 A/dm 2 is advantageous. The reason why the pH value of the bath is preferably within the range of 5.0 to 6.5 is that if the pH value is lower than 5.0, silicon carbide fine powder tends to aggregate in the plating solution;
This is because if it is higher, the elution rate of metal ions from the anode will be low and the metal ion concentration in the plating solution will decrease, resulting in a decrease in plating efficiency.
Further, it is advantageous that the content of silicon carbide fine powder in the composite plating film is within the range of 2 to 15% by weight. The reason is that if the content of silicon carbide fine powder is less than 2% by weight, the effect of improving the hardness and wear resistance of the composite plating film will be low, while if it is more than 15% by weight, the uniform dispersibility of silicon carbide fine powder will be impaired. This is because the fine silicon carbide powder will peel off or the plating film will easily peel off, resulting in a decrease in the physical properties of the composite plating film. In addition to the above-mentioned nickel, chromium or copper can also be used as the matrix metal of the composite plating. The silicon carbide fine powder of the present invention also has excellent properties as a eutectoid material for electroless plating. The present invention will be described below with reference to Examples. Example 1 Mainly β described in the above-mentioned Japanese Patent Application No. 146389/1989
SiC
After heating to 500°C in an air stream to remove free carbon, immersion in hydrofluoric acid to remove free silica and purification, and further particle size classification to obtain β-type silicon carbide fine powder ( PH value: 3.2, residual acid component content: 0.41% by weight, specific surface area: 10.1m 2 /g,
Average particle size: 0.33 μm, average particle size ratio: 1.42, α-type silicon carbide content: 3.5% by weight). The β-type silicon carbide fine powder was added and suspended in a 0.17N ammonia aqueous solution so that the suspension concentration was 7.7% by weight. After heating the suspension to 90°C, β
The molded silicon carbide fine powder was allowed to settle, the supernatant liquid was removed, and it was dried at a temperature of about 120°C. The suspension concentration after removing the supernatant was approximately 24% by weight. The obtained β-type silicon carbide fine powder had a pH value of 5.8 and a residual acid component content of 0.12% by weight. Note that the PH value of the powder was measured according to JIS-R-6129. 1 g of the above β-type silicon carbide fine powder was added to a nickel sulfamate bath (nickel sulfamate: 480 g/
, Nickel chloride: 15g/, Boric acid: 30g/
) After pouring into 200ml and stirring ultrasonically for 20 minutes,
Dispersibility was investigated by observing the sedimentation of particles using a Shimadzu automatic particle size analyzer. According to this measurement method, it can be said that the slower the sedimentation rate, the better the dispersibility. As can be seen from the results shown in FIG. 2, the β-type silicon carbide fine powder treated in this example had an extremely slow settling rate compared to the untreated β-type silicon carbide fine powder, and almost It can be seen that only the sedimentation of single particles is progressing, and there is almost no apparent coarsening of particles due to aggregation. Furthermore, 150 g of β-type silicon carbide fine powder treated in this example was added to a nickel sulfamate bath.
Using the steel plate as the cathode and nickel as the anode, composite plating was performed for 180 minutes while stirring the plating solution ultrasonically. The plating conditions were a bath temperature of 60°C.
Bath PH value 5.8, distance between poles 8cm, current density 20A/
dm2 . Note that the PH value of the Metsuki solution was adjusted using ammonia water. The content of β-type silicon carbide fine powder in the composite plating film obtained was 5.5% by weight, and as shown in the scanning electron micrograph (1500x magnification) in Figure 3, the β-type silicon carbide fine powder was present in the composite plating film. It can be seen that the particles are extremely uniformly dispersed. The hardness and abrasion resistance of the composite plating film were investigated by applying composite plating and finally polishing it with #1500 abrasive paper, and then heat-treating it in an argon gas stream at 400℃ for 4 hours. It is shown in Table 1. Hardness was measured using a Micro-Vickers hardness meter under a load of 500 kg and a holding time of 5 seconds. Wear resistance was expressed by the amount of wear using an Okoshi type rapid wear tester. The rotating disc is made of cast iron (FC-35),
The lubrication was carried out using a dripping lubrication method using lubricating oil (Mobil #20), a friction speed of 1.96 m/sec, a maximum load of 18.8 Kg/cm 2 and a friction distance of 600 m.
【表】【table】
【表】
比較例 １
実施例１に記載したβ型炭化珪素微粉末であつ
て、アンモニア水溶液に浸漬する処理を施してい
ないβ型炭化珪素微粉末25ｇを蒸留水300ml中に
投入し、５分間煮沸した後過する処理を４回繰
返し、約120℃の温度で乾燥した。得られたβ型
炭化珪素微粉末のPH値は4.1、残留酸成分含有量
は0.38重量％であつた。液中分散性については実
施例１と同様にして測定し第２図に示したが、こ
のような処理では本発明の目的としている如き分
散性の良好な炭化珪素微粉末を得ることが困難で
あることがわかる。
実施例２、比較例２
実施例１に記載したβ型炭化珪素微粉末を使用
し、アンモニア水溶液の規定度、懸濁液の濃度等
の条件を変えて粉末の処理を行つた。得られたβ
型炭化珪素微粉末の物性は第１表に、液中分散性
については実施例１と同様にして測定し代表的な
ものを第２図に示した。
さらに、上記の如くして得られたβ型炭化珪素
微粉末を共析物質として実施例１と同様の方法で
複合メツキ膜を得た。得られた複合メツキ膜の硬
度および耐摩耗性については実施例１と同様の方
法で調べ結果は第１表に示した。
実施例 ３
市販のα型炭化珪素粉末（GC＃6000）を鉄製
ボールミルで粉砕し、10％塩酸水溶液に浸漬する
ことによつて粉砕時に混入した鉄分を除去して粒
度分級したα型炭化珪素微粉末（PH値：3.8、残
留酸成分含有量：0.36重量％、比表面積：10.5
m2／ｇ、平均粒子径：0.34μｍ、平均粒径比：
1.9）を製造した。
前記α型炭化珪素微粉末を0.23Nのアンモニア
水溶液に懸濁液濃度が9.1重量％となるよう添加
し懸濁させた。前記懸濁液を85℃迄加熱した後α
型炭化珪素微粉末を沈降させて上澄み液を除去し
約130℃の温度で乾燥した。上澄み液を除去した
後の懸濁液濃度は約28重量％であつた。得られた
粉末のPH値は6.2、残留酸成分含有量は0.11重量
％であつた。得られたα型炭化珪素微粉末の分散
性については実施例１と同様にして測定したとこ
ろ極めて良好であつた。
実施例４、比較例３
実施例１によつて得られたβ型炭化珪素微粉末
を共析物質として使用し、実施例１と同様の方法
ではあるが、メツキ液中へのβ型炭化珪素微粉末
の添加量、浴のPH値を変化させて複合メツキを行
つた。得られた複合メツキ膜のβ型炭化珪素微粉
末含有量およびその他の物性については実施例１
と同様の方法で調べ、結果は第２表に示した。[Table] Comparative Example 1 25 g of the β-type silicon carbide fine powder described in Example 1, which had not been subjected to immersion treatment in an ammonia aqueous solution, was put into 300 ml of distilled water, and then soaked for 5 minutes. The process of boiling and filtering was repeated four times, followed by drying at a temperature of about 120°C. The resulting β-type silicon carbide fine powder had a PH value of 4.1 and a residual acid component content of 0.38% by weight. The dispersibility in liquid was measured in the same manner as in Example 1 and is shown in FIG. 2, but it is difficult to obtain fine silicon carbide powder with good dispersibility as the object of the present invention with such treatment. I understand that there is something. Example 2, Comparative Example 2 Using the β-type silicon carbide fine powder described in Example 1, the powder was processed by changing conditions such as the normality of the ammonia aqueous solution and the concentration of the suspension. The obtained β
The physical properties of the type silicon carbide fine powder are shown in Table 1, and the dispersibility in liquid was measured in the same manner as in Example 1, and typical results are shown in FIG. Furthermore, a composite plating film was obtained in the same manner as in Example 1 using the β-type silicon carbide fine powder obtained as described above as a eutectoid substance. The hardness and abrasion resistance of the resulting composite plating film were investigated using the same method as in Example 1, and the results are shown in Table 1. Example 3 A commercially available α-type silicon carbide powder (GC#6000) was ground in an iron ball mill, and iron mixed in during the grinding was removed by immersing it in a 10% aqueous hydrochloric acid solution, and the particle size was classified into α-type silicon carbide fine particles. Powder (PH value: 3.8, residual acid content: 0.36% by weight, specific surface area: 10.5
m 2 /g, average particle size: 0.34 μm, average particle size ratio:
1.9) was manufactured. The α-type silicon carbide fine powder was added and suspended in a 0.23N ammonia aqueous solution so that the suspension concentration was 9.1% by weight. After heating the suspension to 85°C, α
The type silicon carbide fine powder was precipitated, the supernatant liquid was removed, and it was dried at a temperature of about 130°C. The suspension concentration after removing the supernatant was approximately 28% by weight. The resulting powder had a PH value of 6.2 and a residual acid component content of 0.11% by weight. The dispersibility of the obtained α-type silicon carbide fine powder was measured in the same manner as in Example 1 and was found to be extremely good. Example 4, Comparative Example 3 The β-type silicon carbide fine powder obtained in Example 1 was used as the eutectoid material, and the β-type silicon carbide was added to the plating solution in the same manner as in Example 1. Composite plating was performed by changing the amount of fine powder added and the pH value of the bath. Regarding the content of β-type silicon carbide fine powder and other physical properties of the obtained composite plating film, see Example 1.
The results are shown in Table 2.
【表】
実施例 ５
実施例１によつて得られたβ型炭化珪素微粉末
を共析物質として使用し、クロムおよび銅のいず
れかをマトリツクス金属として複合メツキを行つ
た。これらの複合メツキ膜の物性を実施例１を同
様の方法で調べた結果、上記のいずれの複合メツ
キ膜も硬度および耐摩耗性が著しく向上している
ことがわかつた。
以上説明した如く、本発明の炭化珪素微粉末は
分散性が極めて良好であり、複合メツキの共析物
質として最適の炭化珪素微粉末であり、さらに耐
摩耗性に極めて優れた複合メツキ膜を形成するの
に使用することができ、工業上極めて有用なもの
である。[Table] Example 5 Composite plating was performed using the β-type silicon carbide fine powder obtained in Example 1 as a eutectoid material and using either chromium or copper as a matrix metal. The physical properties of these composite plating films were examined in the same manner as in Example 1, and it was found that the hardness and abrasion resistance of all of the above composite plating films were significantly improved. As explained above, the silicon carbide fine powder of the present invention has extremely good dispersibility, is the most suitable silicon carbide fine powder as a eutectoid material for composite plating, and also forms a composite plating film with extremely excellent wear resistance. It is extremely useful industrially.
第１図ａは、共析物質を凝集した粒子のままマ
トリツクス金属中に複合メツキされている複合メ
ツキ膜の断面を示す模式図、第１図ｂは、共析物
質が単一粒子に分散してマトリツクス金属中に複
合メツキされている複合メツキ膜の断面を示す模
式図、第２図は、スルフアミン酸ニツケル浴中に
おける炭化珪素微粉末の沈降状況と時間の関係を
示す図、第３図は、実施例１で得た複合メツキ膜
中における炭化珪素微粉末の共析状態を観察した
走査型電子顕微鏡写真である。
１……被メツキ物、２……マトリツクス金属、
３……凝集した状態の炭化珪素微粉末、４……単
一粒子の炭化珪素微粉末。
Figure 1a is a schematic diagram showing a cross section of a composite plating film in which the eutectoid material is composite-plated into a matrix metal as agglomerated particles, and Figure 1b is a cross-sectional view in which the eutectoid material is dispersed into single particles. Fig. 2 is a schematic diagram showing the cross section of a composite plating film that is composite plated in a matrix metal. , is a scanning electron micrograph showing the eutectoid state of silicon carbide fine powder in the composite plating film obtained in Example 1. 1... object to be plated, 2... matrix metal,
3...Silicon carbide fine powder in an agglomerated state, 4...Single particle silicon carbide fine powder.
Claims (1)
ｍ以下の粉末であつて、PH値が4.5〜8.0の範囲内
にあり、かつ酸成分含有量が0.3重量％以下であ
る分散性に優れた高純度炭化珪素微粉末。 ２ 酸処理によつて不純物を溶出除去した炭化珪
素微粉末原料を、塩基性水溶液に浸漬して溶出さ
せ、ひきつづき固液分離操作を施すことにより、
不純物を除去し、これによつて比表面積が５m2／
ｇ以上、平均粒子径が1μｍ以下、PH値が4.5〜8.0
の範囲内にあり、かつ酸成分含有量が0.3重量％
以下である微粉末を得ることを特徴とする分散性
に優れた高純度炭化珪素微粉末の製造方法。 ３ 前記炭化珪素微粉末原料を0.01N以上の塩基
性水溶液に浸漬する特許請求の範囲第２項に記載
の製造方法。 ４ 前記炭化珪素微粉末原料を0.01N以上のアン
モニア水溶液に浸漬する特許請求の範囲第２ある
いは３項のいずれか１つに記載の製造方法。 ５ 炭化珪素微粉末原料を塩基性水溶液に浸漬さ
せてなる懸濁液を80℃以上に加熱する特許請求の
範囲第２〜４項のいずれか１つに記載の製造方
法。 ６ ニツケルマトリツクス中に炭化珪素微粉末を
共析させてなる複合メツキ膜のメツキ方法におい
て、比表面積が５m2／ｇ以上、平均粒子径が1μ
ｍ以下、PH値が4.5〜8.0の範囲内にあり、かつ酸
成分含有量が0.3重量％以下である分散性に優れ
た高純度炭化珪素微粉末を、共析物質として使用
することを特徴とする複合メツキ方法。 ７ メツキ液としてスルフアミン酸ニツケル浴を
使用し、浴のPH値を5.0〜6.5の範囲内とすること
を特徴とする特許請求の範囲第６項に記載の複合
メツキ方法。[Claims] 1. Specific surface area is 5 m 2 /g or more, average particle diameter is 1 μ
A high-purity silicon carbide fine powder with excellent dispersibility, which has a pH value in the range of 4.5 to 8.0, and an acid component content of 0.3% by weight or less. 2. By immersing the silicon carbide fine powder raw material from which impurities have been eluted and removed by acid treatment in a basic aqueous solution and eluting it, and subsequently performing a solid-liquid separation operation,
Impurities are removed, thereby reducing the specific surface area to 5 m 2 /
g or more, average particle diameter 1 μm or less, PH value 4.5 to 8.0
is within the range of , and the acid component content is 0.3% by weight.
A method for producing a high-purity silicon carbide fine powder with excellent dispersibility, characterized by obtaining a fine powder having the following properties. 3. The manufacturing method according to claim 2, wherein the silicon carbide fine powder raw material is immersed in a basic aqueous solution of 0.01N or more. 4. The manufacturing method according to claim 2 or 3, wherein the silicon carbide fine powder raw material is immersed in an ammonia aqueous solution of 0.01N or more. 5. The manufacturing method according to any one of claims 2 to 4, wherein a suspension obtained by immersing a silicon carbide fine powder raw material in a basic aqueous solution is heated to 80°C or higher. 6 In a plating method for a composite plating film formed by eutectoiding silicon carbide fine powder in a nickel matrix, the specific surface area is 5 m 2 /g or more and the average particle diameter is 1 μm.
m or less, a PH value within the range of 4.5 to 8.0, and an acid component content of 0.3% by weight or less, high-purity silicon carbide fine powder with excellent dispersibility is used as the eutectoid material. Composite plating method. 7. The composite plating method according to claim 6, characterized in that a nickel sulfamic acid bath is used as the plating solution, and the pH value of the bath is within the range of 5.0 to 6.5.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP55146800A JPS5771812A (en) | 1980-10-22 | 1980-10-22 | Fine powder of high-purity silicon carbide with high dispersibility, its production and composite plating therwith |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP55146800A JPS5771812A (en) | 1980-10-22 | 1980-10-22 | Fine powder of high-purity silicon carbide with high dispersibility, its production and composite plating therwith |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5771812A JPS5771812A (en) | 1982-05-04 |
| JPH0116764B2 true JPH0116764B2 (en) | 1989-03-27 |
Family
ID=15415809
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP55146800A Granted JPS5771812A (en) | 1980-10-22 | 1980-10-22 | Fine powder of high-purity silicon carbide with high dispersibility, its production and composite plating therwith |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5771812A (en) |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61149499A (en) * | 1984-12-25 | 1986-07-08 | Suzuki Motor Co Ltd | Dispersion-plated film |
| JPS62107098A (en) * | 1985-11-05 | 1987-05-18 | Teikoku Piston Ring Co Ltd | Plated composite ni-p alloy film having superior wear resistance |
| JPH01131100A (en) * | 1987-11-12 | 1989-05-23 | Toyota Motor Corp | Production of silicon carbide whisker |
| JPH05148690A (en) * | 1991-11-27 | 1993-06-15 | C Uyemura & Co Ltd | Composite plating method, composite material for composite plating and composite plated film |
| US5342502A (en) * | 1992-08-31 | 1994-08-30 | Industrial Technology Research Institute | Method of preparing silicon carbide particles dispersed in an electrolytic bath for composite electroplating of metals |
| JP2009179726A (en) * | 2008-01-31 | 2009-08-13 | Tkx:Kk | Manufacturing method of silicon carbide powder for grinding/polishing, and silicon carbide powder for grinding/polishing, and slurry for grinding/polishing |
| JP4862013B2 (en) * | 2008-06-05 | 2012-01-25 | 本田技研工業株式会社 | Composite plating method |
| CN101913605B (en) * | 2010-07-14 | 2012-02-22 | 平顶山易成新材料股份有限公司 | Method for separating silicon carbide from silicon carbide micro-powder graded byproducts |
| CN105621415B (en) * | 2016-03-21 | 2017-11-07 | 平顶山市国邦新材料有限公司 | A kind of silicon carbide slurry settles homogenization system |
-
1980
- 1980-10-22 JP JP55146800A patent/JPS5771812A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5771812A (en) | 1982-05-04 |
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