JPH0521713B2 - - Google Patents
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- Publication number
- JPH0521713B2 JPH0521713B2 JP61141174A JP14117486A JPH0521713B2 JP H0521713 B2 JPH0521713 B2 JP H0521713B2 JP 61141174 A JP61141174 A JP 61141174A JP 14117486 A JP14117486 A JP 14117486A JP H0521713 B2 JPH0521713 B2 JP H0521713B2
- Authority
- JP
- Japan
- Prior art keywords
- abrasive grains
- mol
- bond
- sio
- gel
- 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 - Fee Related
Links
- 239000006061 abrasive grain Substances 0.000 claims description 45
- 239000000203 mixture Substances 0.000 claims description 22
- 239000011521 glass Substances 0.000 claims description 13
- 238000000034 method Methods 0.000 claims description 13
- 239000000843 powder Substances 0.000 claims description 13
- 239000002994 raw material Substances 0.000 claims description 13
- 229910018072 Al 2 O 3 Inorganic materials 0.000 claims description 12
- 229910004298 SiO 2 Inorganic materials 0.000 claims description 10
- BOTDANWDWHJENH-UHFFFAOYSA-N Tetraethyl orthosilicate Chemical compound CCO[Si](OCC)(OCC)OCC BOTDANWDWHJENH-UHFFFAOYSA-N 0.000 claims description 8
- SMZOGRDCAXLAAR-UHFFFAOYSA-N aluminium isopropoxide Chemical compound [Al+3].CC(C)[O-].CC(C)[O-].CC(C)[O-] SMZOGRDCAXLAAR-UHFFFAOYSA-N 0.000 claims description 8
- BDERNNFJNOPAEC-UHFFFAOYSA-N propan-1-ol Chemical compound CCCO BDERNNFJNOPAEC-UHFFFAOYSA-N 0.000 claims description 8
- 150000004703 alkoxides Chemical class 0.000 claims description 6
- 238000006297 dehydration reaction Methods 0.000 claims description 6
- 238000004519 manufacturing process Methods 0.000 claims description 6
- 229910052751 metal Inorganic materials 0.000 claims description 6
- 239000002184 metal Substances 0.000 claims description 6
- 239000011247 coating layer Substances 0.000 claims description 4
- 238000010438 heat treatment Methods 0.000 claims description 4
- JILPJDVXYVTZDQ-UHFFFAOYSA-N lithium methoxide Chemical compound [Li+].[O-]C JILPJDVXYVTZDQ-UHFFFAOYSA-N 0.000 claims description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 4
- 229910018068 Li 2 O Inorganic materials 0.000 claims description 3
- 238000002156 mixing Methods 0.000 claims description 3
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims description 2
- 239000010942 ceramic carbide Substances 0.000 claims description 2
- 238000000465 moulding Methods 0.000 claims description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims 2
- 229910008556 Li2O—Al2O3—SiO2 Inorganic materials 0.000 claims 1
- 229910052681 coesite Inorganic materials 0.000 claims 1
- 229910052593 corundum Inorganic materials 0.000 claims 1
- 229910052906 cristobalite Inorganic materials 0.000 claims 1
- 239000000377 silicon dioxide Substances 0.000 claims 1
- 235000012239 silicon dioxide Nutrition 0.000 claims 1
- 229910052682 stishovite Inorganic materials 0.000 claims 1
- 229910052905 tridymite Inorganic materials 0.000 claims 1
- 229910001845 yogo sapphire Inorganic materials 0.000 claims 1
- 238000000227 grinding Methods 0.000 description 14
- 239000000243 solution Substances 0.000 description 9
- 229910003460 diamond Inorganic materials 0.000 description 5
- 239000010432 diamond Substances 0.000 description 5
- 239000007788 liquid Substances 0.000 description 5
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 4
- 239000011248 coating agent Substances 0.000 description 4
- 238000000576 coating method Methods 0.000 description 4
- 238000001816 cooling Methods 0.000 description 4
- 230000018044 dehydration Effects 0.000 description 4
- 239000010408 film Substances 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 239000002245 particle Substances 0.000 description 4
- 238000010304 firing Methods 0.000 description 3
- 238000001879 gelation Methods 0.000 description 3
- 238000006460 hydrolysis reaction Methods 0.000 description 3
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- 238000006482 condensation reaction Methods 0.000 description 2
- 108010025899 gelatin film Proteins 0.000 description 2
- 230000005484 gravity Effects 0.000 description 2
- 230000007062 hydrolysis Effects 0.000 description 2
- 239000010410 layer Substances 0.000 description 2
- 230000014759 maintenance of location Effects 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- 239000003921 oil Substances 0.000 description 2
- 238000003980 solgel method Methods 0.000 description 2
- 238000003756 stirring Methods 0.000 description 2
- 239000010409 thin film Substances 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 1
- 229910052582 BN Inorganic materials 0.000 description 1
- PZNSFCLAULLKQX-UHFFFAOYSA-N Boron nitride Chemical compound N#B PZNSFCLAULLKQX-UHFFFAOYSA-N 0.000 description 1
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 1
- 229910001060 Gray iron Inorganic materials 0.000 description 1
- 229910020489 SiO3 Inorganic materials 0.000 description 1
- 229910002808 Si–O–Si Inorganic materials 0.000 description 1
- 230000001476 alcoholic effect Effects 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 238000009833 condensation Methods 0.000 description 1
- 230000005494 condensation Effects 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000010685 fatty oil Substances 0.000 description 1
- 230000036571 hydration Effects 0.000 description 1
- 238000006703 hydration reaction Methods 0.000 description 1
- 230000001050 lubricating effect Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000002480 mineral oil Substances 0.000 description 1
- 235000010446 mineral oil Nutrition 0.000 description 1
- 239000011259 mixed solution Substances 0.000 description 1
- 238000006116 polymerization reaction Methods 0.000 description 1
- 230000035939 shock Effects 0.000 description 1
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- 238000007613 slurry method Methods 0.000 description 1
- 238000007711 solidification Methods 0.000 description 1
- 230000008023 solidification Effects 0.000 description 1
- 239000004575 stone Substances 0.000 description 1
- 230000003685 thermal hair damage Effects 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B24—GRINDING; POLISHING
- B24D—TOOLS FOR GRINDING, BUFFING OR SHARPENING
- B24D3/00—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents
- B24D3/02—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents the constituent being used as bonding agent
- B24D3/04—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents the constituent being used as bonding agent and being essentially inorganic
- B24D3/14—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents the constituent being used as bonding agent and being essentially inorganic ceramic, i.e. vitrified bondings
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Ceramic Engineering (AREA)
- Inorganic Chemistry (AREA)
- Mechanical Engineering (AREA)
- Polishing Bodies And Polishing Tools (AREA)
- Compositions Of Oxide Ceramics (AREA)
Description
〔産業上の利用分野〕
この発明はセラミツク質超硬砥粒砥石の製造方
法に関するものである。
〔従来の技術〕
従来、ビトリフアイドボンド砥石は、特に超硬
砥粒がダイヤモンドであるときは、空気中650℃
付近から熱的損傷を受けるため900℃以下におけ
る熱安定性しか望めず、砥粒結合に適用するビト
リフアイドボンドは軟化温度と低いガラス組成の
選択となる。その結果熱膨脹係数の小さい〔たと
えば（2.5〜3.0）×10-6／℃、室温〜400℃〕砥粒
に対して、熱膨脹係数の大きいビトリフアイドボ
ンドは溶融冷却後に砥粒周辺における収縮量を増
し、砥粒を支持する強度が弱化することから、砥
石強度、砥石性能は低下してしまう。通常の研削
砥石の製造方法には、ビトリフアイドボンドの原
料粉末を粉末状態のままで砥粒と混合する乾式法
と、液体中に砥粒とボンド原料粉末とを分散混合
する湿式法（泥漿鋳込法とも呼ばれる）とがある
が、いずれの方法も成形後乾燥を終えた砥石中の
ビトリフアイドボンド原料粒子は800〜1300℃の
焼成によつて一旦溶融し、その後冷却固化してガ
ラス化したボンドによつて砥粒が接着支持される
ことになるので、砥粒とボンドとの特に熱膨脹係
数における相対関係は砥石特性を決定数するうえ
できわめて重要な因子となる。
〔発明が解決しようとする問題点〕
以上述べたように従来の技術におけるビトリフ
アイドボンド砥石については、特に超硬砥粒がダ
イヤモンドのときは、ボンド材料を900℃以下の
低温で焼成する必要があることから、ビトリフア
イドボンドは融点の低いものを選択しなければな
らず、その結果ボンドの膨脹係数の小さい超硬砥
粒と膨脹係数の大きいボンドの間に焼成冷却後収
縮差を生じ砥粒保持力は非常に弱くなり、砥石寿
命も極端に短くなるという問題点があつた。
〔問題点を解決するための手段〕
上記問題点を解決するために、この発明は最終
ガラス組成における酸化物組成がAl2O35〜20モ
ル、SiO280〜95モル％となるように、アルミニ
ウムイソプロポキシドおよびエチルシリケートを
プロパノールに溶解してゾル状態の混合金属アル
コキシドを調製し、これを超硬砥粒表面に付着さ
せ加水分解させてゲル状のAl2O3−SiO2系ガラス
化被覆層を有する超硬砥粒とし、別途、最終ガラ
ス組成における酸化物組成がLi2O5〜10モル％、
Al2O310〜15モル％、SiO275〜85モル％となるよ
うに、リチウムメトキシド、アルミニウムイソプ
ロポキシドおよびエチルシリケートをプロパノー
ルに溶解してゾル状態の混合物を調製しさらに加
水した後ゲル化させ、これを粉砕したLi2O−
Al2O3SiO2系ボンド原料粉末と前記ガラス化被覆
層を有する超硬砥粒とを混合し成形し、次いで加
熱脱水反応により結合させるという手段を採用し
たものである。以下その詳細を述べる。
まず、この発明における超硬砥粒とは、ダイ
ヤモンド、アルミナ、炭化珪素（SiC）、立方晶
窒化ホウ素（CBN）等からなる硬度のきわめて
高い砥石用粒子であり、その粒度は通常砥石に使
用される大きさのものであればよく、特に限定さ
れるものではない。
つぎにこのような超硬砥粒の表面に被覆する
Al2O3−SiO2系ガラス薄膜はゾル・ゲル法に基づ
いてガラスとなる組成に配合された金属アルコキ
シドのアルコール溶液から生成される。すなわ
ち、金属アルコキシドのアルコール溶液が、ゾル
状態からゲル状態へ移行する過程を経て超硬砥粒
の表面に不完全脱水の水和ゲルを生成させるが、
たとえばAl2O3−SiO2系ガラスの組成はAl2O35〜
20モル％、SiO280〜95モル％であることが望ま
しく、このような組成のガラスが得られるように
アルミニウムイソプロポキシド〔Al（ｉ−
C3H7O3〕とエチルシリケート〔Si（C2H5O）4〕と
をプロパノール〔C3H7OH）に溶解させて得られ
る混合溶液を加水分解させ、超硬砥粒の表面に水
和ゲルの被膜を形成させるのである。この加水分
解反応を促進し、ゲル化速度を高めて均一反応と
するために反応系に少量の塩酸を添加するとよ
い。ここで超硬砥粒の表面に均一なガラス化被膜
層を確実に得るために、ゾルからゲルへの過程で
溶液濃度が約0.1〜0.3ポイズ（ｇ／cm・sec）にな
つた時点で超硬砥粒を加え、充分撹拌分散した後
静置することが望ましく、砥粒が沈降してから溶
液と砥粒とを分離し、溶液で表面を被覆された砥
粒を大気中で２〜６日間放置すると、表面に不完
全脱水状態のゲル被膜が形成される。なお、溶液
で表面を被覆された砥粒を大気中で放置する日数
が７日以上に長くなると、溶液の加水分解および
脱水重合が進み、加熱時における金属アルコキシ
ドの蒸発量は減少し、その結果として砥粒表面を
被覆したゲル層と後述するゲル化ボンドとの間で
の縮合反応が弱いものとなり砥粒保持力を低下を
招くことになる。
さらに、この発明において、前記の被覆された
砥粒を結合する結合材すなわりビトリフアイドボ
ンドも、前記同様のゾル・ゲル法によつて、低膨
脹性のLi2O−Al2O3−SiO2系ガラスとなる組成た
とえばLi2O5〜10モル％、Al2O310〜15モル％、
SiO375〜85％の組成を有する混合金属アルコキ
シドの溶液から生成される。すなわち、リチウム
メトキシド〔LiOCH3〕、アルミニウムイソプロ
ポキシド〔Al（ｉ−C3H7O〕3およびエチルシルケ
ート〔Si（C2H5O）4〕をプロパノールに溶解し、
均一反応と加水分解速度を促進させるために水を
加えて大気中で約１週間放置する。ゲル化反応の
進行した溶液は100〜200℃、２〜４時間加熱し脱
水した後、不完全脱水状態で粉砕する。粉砕は水
和固化の程度によつて平均粒径10〜40μｍの程度
まで可能であり、得られた粉末をボンドの原料と
する。
前記水和ゲルで被覆した超硬砥粒と上記の不完
全脱水ゲルのボンド原料粉末とを所定の比率で調
合し、冷間圧縮した後、成形体を取り出し加熱す
るか、または熱間圧縮した後冷却すれば所望の砥
石が得られる。
〔作用〕
この発明の不完全脱水状態のゲルである砥粒表
面の被膜もまたボンド原料粉末も、混合、成形、
加熱などの工程を経て完全脱水し強固なガラス質
となる過程で、砥粒表面被膜の水酸基とボンド原
料粉末中の水酸基との間で脱水縮合が起こり、≡
Si−Ｏ−Si≡、＝Al−Ｏ−Al＝、−もしくは≡Si
−Ｏ−Al＝などの結合によつて砥粒はボンドに
よつて強固に保持される結果、研削能力に優れ、
砥石摩耗量が少なく、研削比の大きい優れた砥石
が得らるれるものと考えられる。
〔実施例〕
Al2O3−SiO2系ガラス被膜の酸化物組成
15Al2O3・85SiO2に対応するようにアルミニウム
イソプロポキシド35重量部を３〜５倍量のプロパ
ノールに溶解し、さらにエチルシリケート100重
量部を加え撹拌しながら80〜90℃、２時間加熱す
る。この混合液に対してゲル化促進のため濃度35
重量％の塩酸１〜２重量部を加えた。このような
混合液の粘度がゾルからゲルに移行する過程にお
いて、約0.1〜0.3ポイズになつた時点で超硬砥粒
としてダイヤモンド砥粒（米国ゼネラル・エレク
トリツク社製：マンメードダイヤモンドMBG−
、メツシユグレード200／230）を混合液中に投
入し撹拌分散させた後静置し、沈降した砥粒を分
離し、混合液膜で被覆された砥粒を大気中で約５
日間放置し、砥粒表面にゲル被膜を形成させた。
一方、ボンドの酸化物組成8Li2O・12Al2O3・
80SiO2に対応するようアルミニウムイソプロポ
キシド30重量部、リチウムメトキシド４重量部お
よびエチルシリケート100重量部をプロパノール
120重量部に溶解し、さらに水85重量部を加えて
７日間大気中に放置してゲル化させた。このゲル
化物質を200℃、２時間加熱して脱水し、平均粒
径130μｍに粉砕したボンドの原料粉末とした。
このようにして作られた表面に不完全脱水状態
のゲル被膜を有する砥粒と不完全脱水状態のボン
ドの原料であるゲル粉末とを充分に混合して、所
定の形状寸法を成形し、加熱温度800℃から冷却
温度800℃の間窒素ガス雰囲気下にある電気炉に
よつて毎分２℃の昇温速度のもとに1000℃まで加
熱し、同温度に２時間保持して冷却した。なお、
砥粒とボンド原料粉末との配合に際しては、焼成
後の砥石が容積割合で砥粒率50％、結合材率18
％、気孔率32％となるように生砥石の嵩比重を予
め算出しておき、この嵩比重にもとづいてボンド
原料の配合割合および成形圧力を定めた（以下こ
れを本発明品と呼ぶ）。
得られた本発明品の結合度はロツクウエル硬度
計のＨスケールによるRH硬度で表わし、また、
砥石性能の測定は、被削材にねずみ鋳鉄品
（FC20、厚さHRC7）を用い、回転（406rpm）す
るリング状加工物（外径45mm、内径22mm）の端面
に各形砥石（10mm×３mm）を押し付けて、砥石に
振動（毎分1140回）と振幅（両側で2.1mm）を与
え、加工油（硫化脂肪油５部と鉱油95部との混合
油）を注油しながら、プランジカツト平面超仕上
げ方法に基づいて実施した。なお、この際の砥石
圧力は15Kg・ｆ／cm2、加工時間は２分であつた。
試験片７個からなる群の測定結果を表にまとめ
た。表中の研削比は研削量を砥石損耗量で除した
値である。
[Industrial Field of Application] This invention relates to a method for manufacturing a ceramic carbide abrasive grindstone. [Prior art] Conventionally, vitrified bonded grinding wheels have been used in the air at 650°C, especially when the carbide abrasive grains are diamond.
Since it is subject to thermal damage from nearby sources, thermal stability can only be expected at temperatures below 900°C, and vitrified bond, which is used to bond abrasive grains, has a softening temperature and a low glass composition. As a result, compared to abrasive grains with a small coefficient of thermal expansion (for example, (2.5 to 3.0) × 10 -6 /℃, room temperature to 400℃), vitrified bond, which has a large coefficient of thermal expansion, reduces the amount of shrinkage around the abrasive grains after melting and cooling. As the strength to support the abrasive grains increases, the strength of the whetstone and the performance of the whetstone deteriorate. Conventional manufacturing methods for grinding wheels include a dry method in which the raw material powder of vitrified bond is mixed with abrasive grains in a powder state, and a wet method (slurry method) in which the abrasive grains and bond raw material powder are dispersed and mixed in a liquid. In both methods, the vitrified bond raw material particles in the whetstone that have been dried after forming are melted by firing at 800 to 1300℃, and then cooled and solidified to form glass. Since the abrasive grains are adhesively supported by the bond, the relative relationship between the abrasive grains and the bond, particularly in terms of coefficient of thermal expansion, is an extremely important factor in determining the characteristics of the abrasive wheel. [Problems to be solved by the invention] As mentioned above, with regard to conventional vitrified bond grinding wheels, especially when the carbide abrasive grains are diamond, it is necessary to sinter the bond material at a low temperature of 900°C or less. Therefore, it is necessary to select a vitrified bond with a low melting point, which results in a difference in shrinkage after firing and cooling between the cemented carbide abrasive grains with a small expansion coefficient of the bond and the bond with a large expansion coefficient. There were problems in that the abrasive grain retention became very weak and the life of the grinding wheel was extremely short. [Means for Solving the Problems] In order to solve the above problems, the present invention is such that the oxide composition in the final glass composition is 5 to 20 mol% of Al 2 O 3 and 80 to 95 mol% of SiO 2 . , aluminum isopropoxide and ethyl silicate are dissolved in propanol to prepare a sol-state mixed metal alkoxide, which is attached to the surface of the carbide abrasive grain and hydrolyzed to form a gel-like Al 2 O 3 −SiO 2 glass. The carbide abrasive grains have a chemical coating layer, and the oxide composition in the final glass composition is Li 2 O 5 to 10 mol%,
After preparing a sol-state mixture by dissolving lithium methoxide, aluminum isopropoxide, and ethyl silicate in propanol to have Al 2 O 3 10 to 15 mol % and SiO 2 75 to 85 mol %, and further adding water. Li 2 O−, which was gelled and crushed
This method employs a method in which Al 2 O 3 SiO 2 -based bond raw material powder and the cemented carbide abrasive grains having the vitrified coating layer are mixed and molded, and then bonded by heating and dehydration reaction. The details will be described below. First, the carbide abrasive grains in this invention are extremely hard particles for grinding wheels made of diamond, alumina, silicon carbide (SiC), cubic boron nitride (CBN), etc. It is not particularly limited, as long as it is of a size that can be used. Next, coat the surface of such carbide abrasive grains.
Al 2 O 3 -SiO 2 -based glass thin films are produced from alcoholic solutions of metal alkoxides formulated to form glass based on the sol-gel method. In other words, an alcohol solution of a metal alkoxide generates a partially dehydrated hydrated gel on the surface of the carbide abrasive grains through a process of transitioning from a sol state to a gel state.
For example, the composition of Al 2 O 3 −SiO 2 glass is Al 2 O 3 5 ~
It is desirable that the content is 20 mol% and SiO 2 80 to 95 mol%.Aluminum isopropoxide [Al(i-
A mixed solution obtained by dissolving C 3 H 7 O 3 ] and ethyl silicate [Si(C 2 H 5 O) 4 ] in propanol [C 3 H 7 OH) is hydrolyzed, and the surface of the carbide abrasive is to form a film of hydrated gel. It is recommended to add a small amount of hydrochloric acid to the reaction system in order to accelerate this hydrolysis reaction, increase the gelation rate, and make the reaction uniform. In order to reliably obtain a uniform vitrified film layer on the surface of the carbide abrasive grains, in the process from sol to gel, when the solution concentration reaches approximately 0.1 to 0.3 poise (g/cm・sec), It is desirable to add hard abrasive grains, sufficiently stir and disperse, and then leave to stand. After the abrasive grains have settled, the solution and abrasive grains are separated, and the abrasive grains whose surfaces are coated with the solution are placed in the atmosphere for 2 to 6 hours. If left for several days, a partially dehydrated gel film will be formed on the surface. Note that if the abrasive grains whose surfaces are coated with the solution are left in the atmosphere for more than 7 days, the solution will undergo hydrolysis and dehydration polymerization, and the amount of metal alkoxide evaporated during heating will decrease. As a result, the condensation reaction between the gel layer covering the surface of the abrasive grains and the gelled bond described later becomes weak, resulting in a decrease in abrasive grain retention. Furthermore, in the present invention, the binding material or vitrified bond for binding the coated abrasive grains is also made of low-expansion Li 2 O-Al 2 O 3 by the same sol-gel method as described above. -Composition of SiO 2 glass, for example, Li 2 O 5 to 10 mol%, Al 2 O 3 10 to 15 mol%,
It is produced from a solution of mixed metal alkoxides with a composition of 75-85% SiO3 . That is, lithium methoxide [LiOCH 3 ], aluminum isopropoxide [Al(i-C 3 H 7 O] 3 and ethyl silicate [Si(C 2 H 5 O) 4 ] are dissolved in propanol,
Water is added and left in the atmosphere for about a week to promote homogeneous reaction and hydrolysis rate. The solution in which the gelation reaction has proceeded is heated at 100 to 200°C for 2 to 4 hours to dehydrate it, and then pulverized in an incompletely dehydrated state. The powder can be pulverized to an average particle diameter of 10 to 40 μm depending on the degree of hydration and solidification, and the resulting powder is used as a raw material for bond. The cemented carbide abrasive grains coated with the hydrated gel and the bond raw material powder of the incompletely dehydrated gel are mixed in a predetermined ratio, cold compressed, and then the compact is taken out and heated or hot compressed. After cooling, the desired grindstone can be obtained. [Function] The film on the surface of the abrasive grain, which is a gel in an incompletely dehydrated state, and the bond raw material powder of this invention are mixed, molded,
In the process of complete dehydration through processes such as heating and becoming a strong glass, dehydration condensation occurs between the hydroxyl groups on the abrasive grain surface coating and the hydroxyl groups in the bond raw material powder, and ≡
Si-O-Si≡, =Al-O-Al=, - or ≡Si
-O-Al=, etc., the abrasive grains are firmly held by the bond, resulting in excellent grinding ability.
It is thought that an excellent grindstone with a small amount of grinding wheel wear and a high grinding ratio can be obtained. [Example] Oxide composition of Al 2 O 3 -SiO 2 glass coating
35 parts by weight of aluminum isopropoxide was dissolved in 3 to 5 times the amount of propanol to correspond to 15Al 2 O 3 85SiO 2 , and 100 parts by weight of ethyl silicate was added and heated at 80 to 90°C for 2 hours while stirring. do. Concentration 35 was added to this mixture to promote gelation.
1-2 parts by weight of hydrochloric acid were added. In the process where the viscosity of the mixed liquid changes from sol to gel, when the viscosity of the liquid mixture reaches approximately 0.1 to 0.3 poise, diamond abrasive grains (manufactured by General Electric Company, USA: Manmade Diamond MBG-) are used as carbide abrasive grains.
, mesh grade 200/230) was added to the mixed liquid, stirred and dispersed, and left to stand, the settled abrasive grains were separated, and the abrasive grains coated with the mixed liquid film were placed in the atmosphere for about 50 minutes.
A gel film was formed on the surface of the abrasive grains. On the other hand, the oxide composition of the bond is 8Li 2 O・12Al 2 O 3・
80SiO2 , 30 parts by weight of aluminum isopropoxide, 4 parts by weight of lithium methoxide and 100 parts by weight of ethyl silicate were added to propanol.
The mixture was dissolved in 120 parts by weight, 85 parts by weight of water was added, and the mixture was allowed to stand in the air for 7 days to form a gel. This gelled substance was heated at 200° C. for 2 hours to dehydrate it, and was ground to an average particle size of 130 μm to obtain a bond raw material powder. The abrasive grains, which have a partially dehydrated gel coating on their surfaces, and the partially dehydrated gel powder, which is the raw material for the bond, are thoroughly mixed, molded into a predetermined shape, and heated. From a temperature of 800°C to a cooling temperature of 800°C, the material was heated to 1000°C at a temperature increase rate of 2°C per minute in an electric furnace under a nitrogen gas atmosphere, and was kept at the same temperature for 2 hours to cool. In addition,
When blending the abrasive grains and the bond raw material powder, the volume ratio of the abrasive stone after firing is 50% and the binder ratio is 18%.
%, and the bulk specific gravity of the green grindstone was calculated in advance so as to have a porosity of 32%, and based on this bulk specific gravity, the blending ratio of the bond raw material and the molding pressure were determined (hereinafter referred to as the product of the present invention). The degree of bonding of the obtained product of the present invention is expressed by the RH hardness on the H scale of the Rockwell hardness tester, and
The grindstone performance was measured using a gray cast iron product (FC20, thickness H R C7) as the work material, and each type of grindstone (10 mm x 3 mm) to apply vibrations (1140 times per minute) and amplitude (2.1 mm on both sides) to the grinding wheel, and while lubricating the grinding oil (mixed oil of 5 parts sulfurized fatty oil and 95 parts mineral oil), plunge cut. It was carried out based on the plane superfinishing method. The grindstone pressure at this time was 15 kg·f/cm 2 and the processing time was 2 minutes.
The measurement results for a group of seven test pieces are summarized in a table. The grinding ratio in the table is the value obtained by dividing the amount of grinding by the amount of wear on the grinding wheel.
この発明のセラミツク質超硬砥粒砥石の製造方
法は、以上述べたように、その製造工程におい
て、砥粒表面の被覆ゲルおよびゲル化ボンドをそ
れぞれ所定の組成で別個に調製して、水酸基同士
の脱水縮合反応または焼結によつて、砥粒をボン
ドに強固に保持させるようにする。このため、最
終的にガラス質となる砥粒表面の薄膜およびボン
ドが、低膨張性、耐熱性、熱衝撃抵抗性、化学的
耐久性に優れ、砥粒支持力および砥粒間結合力も
大きくなり、研削性、研削比が大きく、砥石寿命
において従来品よりも遥に卓越した性能を発揮で
きる砥石を製造できるという利点がある。
As described above, in the manufacturing method of the ceramic cemented carbide abrasive grindstone of the present invention, in the manufacturing process, the coating gel and the gelled bond on the surface of the abrasive grains are separately prepared with predetermined compositions, and the hydroxyl groups are bonded to each other. The abrasive grains are firmly held in the bond by the dehydration condensation reaction or sintering. For this reason, the thin film and bond on the surface of the abrasive grain, which will eventually become glassy, have low expansion, heat resistance, thermal shock resistance, and chemical durability, and the abrasive grain supporting capacity and bonding force between abrasive grains are also large. It has the advantage of being able to manufacture a whetstone that has high grindability and grinding ratio, and can exhibit far superior performance over conventional products over the life of the whetstone.
Claims (1)
Al2O35〜20モル％、SiO280〜95モル％となるよ
うに、アルミニウムイソプロポキシドおよびエチ
ルシリケートをプロパノールに溶解してゾル状態
の混合金属アルコキシドを調製し、これを超硬砥
粒表面に付着させ加水分解させてゲル状のAl2O3
−SiO2系ガラス化被覆層を有する超硬砥粒とし、
別途、最終ガラス組成における酸化物組成が
Li2O5〜10モル％、Al2O310〜15モル％、SiO275
〜85モル％となるように、リチウムメトキシド、
アルミニウムイソプロポキシドおよびエチルシリ
ケートをプロパノールに溶解してゾル状態の混合
物を調製しさらに加水した後ゲル化させ、これを
粉砕したLi2O−Al2O3SiO2系ボンド原料粉末と前
記ガラス化被覆層を有する超硬砥粒とを混合し成
形し、次いで加熱脱水反応により結合させること
から成るセラミツク質超硬砥粒砥石の製造方法。1 The oxide composition in the final glass composition is
A mixed metal alkoxide in a sol state is prepared by dissolving aluminum isopropoxide and ethyl silicate in propanol so that Al2O3 is 5 to 20 mol% and SiO2 is 80 to 95 mol%. Al 2 O 3 is attached to the grain surface and hydrolyzed to form a gel.
- Carbide abrasive grains with a SiO 2- based vitrified coating layer,
Separately, the oxide composition in the final glass composition is
Li 2 O 5-10 mol%, Al 2 O 3 10-15 mol%, SiO 2 75
Lithium methoxide, to be ~85 mol%
Aluminum isopropoxide and ethyl silicate are dissolved in propanol to prepare a sol mixture, which is further added with water and then gelled, which is then ground into a Li 2 O−Al 2 O 3 SiO 2 bond raw material powder and the vitrified mixture. 1. A method for manufacturing a ceramic carbide abrasive grindstone, which comprises mixing and molding carbide abrasive grains having a coating layer, and then bonding them through a heating dehydration reaction.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61141174A JPS62297070A (en) | 1986-06-16 | 1986-06-16 | Ceramic superhard grinding grain grindstone and manufacture thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61141174A JPS62297070A (en) | 1986-06-16 | 1986-06-16 | Ceramic superhard grinding grain grindstone and manufacture thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS62297070A JPS62297070A (en) | 1987-12-24 |
| JPH0521713B2 true JPH0521713B2 (en) | 1993-03-25 |
Family
ID=15285863
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61141174A Granted JPS62297070A (en) | 1986-06-16 | 1986-06-16 | Ceramic superhard grinding grain grindstone and manufacture thereof |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS62297070A (en) |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4997461A (en) * | 1989-09-11 | 1991-03-05 | Norton Company | Nitrified bonded sol gel sintered aluminous abrasive bodies |
| US5007943A (en) * | 1989-11-03 | 1991-04-16 | Norton Company | Sol-gel process alumina abrasive grain blends in coated abrasive material |
| US5178644A (en) * | 1992-01-23 | 1993-01-12 | Cincinnati Milacron Inc. | Method for making vitreous bonded abrasive article and article made by the method |
| US6609963B2 (en) | 2001-08-21 | 2003-08-26 | Saint-Gobain Abrasives, Inc. | Vitrified superabrasive tool and method of manufacture |
| JP5458459B2 (en) * | 2008-07-02 | 2014-04-02 | 株式会社ノリタケカンパニーリミテド | Superabrasive grindstone, abrasive coating agent, method for producing superabrasive grain for vitrified grindstone, and method for producing abrasive coat agent |
| JP2013154441A (en) * | 2012-01-31 | 2013-08-15 | Jtekt Corp | Vitrified bond grindstone manufacturing method and vitrified bond grindstone |
| JP5953775B2 (en) * | 2012-01-31 | 2016-07-20 | 株式会社ジェイテクト | Vitrified bond grinding wheel manufacturing method |
| CN106607770B (en) * | 2015-10-27 | 2018-08-17 | 南京诺之瑞思商贸有限公司 | A kind of preparation method of microcrystal fused alumina Ceramic mill disc |
| CN106392909B (en) * | 2016-08-30 | 2018-10-26 | 湖北东方玉扬电子科技有限公司 | Brake block grinding machine high speed grinding disc and preparation method thereof |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5013992A (en) * | 1973-06-08 | 1975-02-13 | ||
| JPS50131193A (en) * | 1974-04-04 | 1975-10-17 |
-
1986
- 1986-06-16 JP JP61141174A patent/JPS62297070A/en active Granted
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5013992A (en) * | 1973-06-08 | 1975-02-13 | ||
| JPS50131193A (en) * | 1974-04-04 | 1975-10-17 |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS62297070A (en) | 1987-12-24 |
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