JP2790029B2 - Method for producing coated fused alumina particles - Google Patents
Method for producing coated fused alumina particlesInfo
- Publication number
- JP2790029B2 JP2790029B2 JP6013719A JP1371994A JP2790029B2 JP 2790029 B2 JP2790029 B2 JP 2790029B2 JP 6013719 A JP6013719 A JP 6013719A JP 1371994 A JP1371994 A JP 1371994A JP 2790029 B2 JP2790029 B2 JP 2790029B2
- Authority
- JP
- Japan
- Prior art keywords
- particles
- alumina
- fused alumina
- aluminum titanate
- abrasive
- 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 - Lifetime
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B08—CLEANING
- B08B—CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
- B08B15/00—Preventing escape of dirt or fumes from the area where they are produced; Collecting or removing dirt or fumes from that area
- B08B15/02—Preventing escape of dirt or fumes from the area where they are produced; Collecting or removing dirt or fumes from that area using chambers or hoods covering the area
- B08B15/023—Fume cabinets or cupboards, e.g. for laboratories
Landscapes
- Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
- Polishing Bodies And Polishing Tools (AREA)
- Compositions Of Oxide Ceramics (AREA)
- Inorganic Compounds Of Heavy Metals (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明はチタン酸アルミニウムで
表面が被覆された酸化チタン含有の電融アルミナ粒の製
造方法に関し、製造されたものは研削性能に優れた砥粒
や高強度で耐熱衝撃性の大きい耐火材などとして使用す
ることができる。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing fused alumina particles containing titanium oxide, the surface of which is coated with aluminum titanate. It can be used as a highly refractory material.
【０００２】[0002]
【従来の技術】人造研削材についてＪＩＳ Ｒ６１１１
−１９８７に規定されているようにバイヤー法で精製さ
れたアルミナを電気炉で溶融して造られたアルミナ質研
削材には、白色アルミナ研削材（ＷＡ）、淡紅色アルミ
ナ研削材（ＰＡ）、解砕型アルミナ研削材（ＨＡ）等が
ある。これらの砥粒の靭性はＨＡ＞ＰＡ＞ＷＡの順で高
くなっているが、工具鋼等の難削材には、未だ十分満足
すべき研削性能が得られているとは言い難いため、上記
電融アルミナ粒を熱処理することが試みられている。例
えば、特開昭５０−８０３０５では、アルミナ含有量が
９９．０％以上の白色電融アルミナ研削材（ＷＡ）を１
６００〜１８５０℃で３０分〜２時間加熱処理すること
が開示されている。これは電融アルミナのインゴットの
粉砕時に生じた欠陥や微細な傷及びクラックを高温下で
の原子の拡散や再配列によって欠陥を回復させたり、傷
を浅くしたり、また砥粒に含まれるＮａ2 Ｏを揮散させ
て強度を改善するものであって、ある一定の効果は認め
られるものの、本質的に研削材自体が改善されたとは言
い難い。また該公報には、ＴｉＯ2 、ＳｉＯ2 等がかな
り含まれる研削材、例えば褐色電融アルミナ研削材
（Ａ）では１０００〜１３００℃程度の温度で焼成する
とある程度ひび割れが消滅し、砥粒の圧壊強度を高める
ことが記載され、１４００℃以上に焼成するとかえって
強度が低下すると述べられている。2. Description of the Related Art Regarding artificial abrasives JIS R6111
-Alumina abrasives produced by melting an alumina purified by the Bayer method in an electric furnace as specified in 1987 include white alumina abrasives (WA), pink alumina abrasives (PA), There is a crushed alumina abrasive (HA). Although the toughness of these abrasive grains increases in the order of HA>PA> WA, it is difficult to say that a sufficiently satisfactory grinding performance has not yet been obtained for difficult-to-cut materials such as tool steel. Attempts have been made to heat treat fused alumina particles. For example, in Japanese Patent Application Laid-Open No. 50-80305, a white fused alumina abrasive (WA) having an alumina content of 99.0% or more
It is disclosed that heat treatment is performed at 600 to 1850 ° C. for 30 minutes to 2 hours. This is because defects and fine scratches and cracks generated during grinding of ingots of fused alumina can be recovered by atom diffusion and rearrangement under high temperature, the scratches can be made shallow, and Na contained in abrasive grains can be reduced. It is to improve the strength by volatilizing 2 O, and although a certain effect is recognized, it cannot be said that the abrasive itself has essentially been improved. Further, in this publication, when abrasives containing a considerable amount of TiO 2 , SiO 2, etc., for example, brown fused alumina abrasives (A), are burned at a temperature of about 1000 to 1300 ° C., cracks disappear to some extent and the abrasive grains are crushed. It is described that the strength is increased, and it is stated that firing at 1400 ° C. or more lowers the strength.
【０００３】[0003]
【発明が解決しようとする課題】上記に記載されている
白色電融アルミナの１６００〜１８５０℃での熱処理
は、インゴット粉砕時に砥粒に生じた結晶の欠陥を回復
させたり、微細な傷やクラック先端を浅くして、応力の
集中を緩和することにより砥粒の強度や靭性を向上させ
ようとするものである。しかし、このような処理を行っ
ても、白色電融アルミナの特性が解砕型アルミナ（Ｈ
Ａ）の特性に近いものになるだけで、本質的な改善には
なっておらず、研削性能はそれほど改善されることには
ならない。また、非常に高温で熱処理するため、コスト
的等の問題がある。The above-described heat treatment of the fused white alumina at 1600 to 1850 ° C. recovers crystal defects generated in the abrasive grains during pulverization of the ingot, and removes fine scratches and cracks. The purpose of the present invention is to improve the strength and toughness of the abrasive grains by making the tip shallower to reduce the concentration of stress. However, even when such a treatment is performed, the characteristics of the white fused alumina can be changed to the crushed alumina (H
Only the characteristics of A) are obtained, but there is no substantial improvement, and the grinding performance is not so much improved. Further, since the heat treatment is performed at a very high temperature, there are problems such as cost.
【０００４】[0004]
【課題を解決するための手段】発明者は、より優れた研
削性能を持つ研削材または強度、耐熱性に優れた耐火材
を造る目的を達成すべき努力し、いろいろ検討した結
果、本発明を見出した。即ち、酸化チタンを含有する電
融アルミナ粒を１３００℃以上に加熱し、固溶している
チタンを析出させ該粒の表面にチタン酸アルミニウムを
生成させた後、１３００〜７５０℃の温度範囲を３００
℃／時間以上の速度で冷却することを特徴とするチタン
酸アルミニウム被覆電融アルミナ粒の製造方法を見出し
た。The inventors of the present invention have made efforts to achieve the object of producing a grinding material having better grinding performance or a refractory material having excellent strength and heat resistance. I found it. That is, the fused alumina particles containing titanium oxide are heated to 1300 ° C. or more to precipitate solid solution titanium and form aluminum titanate on the surface of the particles, and then the temperature range of 1300 to 750 ° C. 300
A method for producing fused aluminum particles coated with aluminum titanate, characterized in that the particles are cooled at a rate of at least ° C / hour.
【０００５】まず、酸化チタンを含有する電融アルミナ
について述べる。これは一般的な各種電融アルミナを造
る方法により製造する。即ち、アルミナとＴｉＯ2 とを
電気炉で電融すればよい。ＴｉＯ2 源としては酸化チタ
ン（ルチル型または／およびアナターゼ型）、チタンス
ラグ（ルチル鉱、チタン鉄鉱を電気炉中にて、木炭、コ
ークスで還元し、鉄を分離したものでＴｉＯ2 ≧８０wt
％）等が使用できる。アルミナ、例えばバイヤー法によ
るアルミナに上記のＴｉＯ2 源を添加し、アーク式等の
電気炉で溶融するか、ボーキサイトを電気炉でコークス
等の還元材と共に溶融強還元して得た、酸化チタン以外
の不純物が比較的少なく、アルミナ純度の高い電融アル
ミナを本発明の原料である酸化チタンを含有する電融ア
ルミナとして使用する。この前者が淡紅色アルミナ研削
材（ＰＡ）の造り方であり、後者が解砕型アルミナ研削
材（ＨＡ）の造り方に類するものである。First, fused alumina containing titanium oxide will be described. This is manufactured by a method for producing general fused alumina. That is, alumina and TiO 2 may be electromelted in an electric furnace. The TiO 2 source of titanium oxide (rutile and / or anatase form), titanium slag (rutile ore, the ilmenite in an electric furnace, charcoal, and reduced with cokes, TiO 2 ≧ 80 wt in that separation of the iron
%) Can be used. Other than titanium oxide obtained by adding the above TiO 2 source to alumina, for example, alumina by the Bayer method, and melting it in an electric furnace such as an arc type, or melting and reducing bauxite together with a reducing material such as coke in an electric furnace. The fused alumina having a relatively small amount of impurities and high alumina purity is used as the fused alumina containing titanium oxide which is a raw material of the present invention. The former is a method of producing a light red alumina abrasive (PA), and the latter is similar to a method of producing a crushed alumina abrasive (HA).
【０００６】電融アルミナに含まれる酸化チタンの量
は、ＴｉＯ2 換算で０．１〜１．５wt％が好ましい。酸
化チタンの量が０．１wt％未満では固溶状態から析出す
るチタンの量が少なく生成するチタン酸アルミニウムの
量も少なくなるため粒の表面全面に均一に被覆させるこ
とが難しく、１．５wt％を超えると析出する量が多くな
り生成するチタン酸アルミニウムの他に未反応の酸化チ
タンが残り、被覆膜の特性を劣化させることになるこ
と、また多量のチタンが離溶したあとの欠陥が多くなり
粒の特性を悪くすることになり好ましくない。安定して
粒の特性の向上が期待できる、より好ましい酸化チタン
の量は、ＴｉＯ2 換算で０．２〜１．０wt％である。[0006] The amount of titanium oxide contained in the fused alumina is, 0.1~1.5wt% in terms of TiO 2 is preferred. When the amount of titanium oxide is less than 0.1 wt%, the amount of titanium precipitated from the solid solution state is small and the amount of aluminum titanate generated is also small, so that it is difficult to uniformly coat the entire surface of the grain, and the amount is 1.5 wt%. If the amount exceeds, the amount of precipitation increases and unreacted titanium oxide remains in addition to the generated aluminum titanate, which deteriorates the characteristics of the coating film. It is not preferable because it increases the properties of the grains. Stable can be expected to improve the particle properties, the amount of more preferred titanium oxide is 0.2～1.0Wt% in terms of TiO 2.
【０００７】本発明では上記の電融アルミナを粉砕し、
除鉄したもの、あるいは所定の粒度に整粒した粒状のも
のを使用する。本発明は上記の酸化チタンを含有する電
融アルミナ粒を加熱処理を行なうが、それについて記
す。酸化チタン含有の電融アルミナ粒を匣鉢等の容器に
入れマッフル炉等の電気炉またはトルネル式連続焼成炉
で加熱するか、または当該粒を直接ロータリーキルン等
の焼成装置で加熱処理を行なう。In the present invention, the above fused alumina is pulverized,
Use iron-removed ones, or granular ones sized to a predetermined particle size. In the present invention, the fused alumina particles containing titanium oxide are subjected to a heat treatment, which will be described. The fused alumina particles containing titanium oxide are placed in a container such as a sagger and heated in an electric furnace such as a muffle furnace or a continuous tornel-type continuous firing furnace, or the particles are directly subjected to heat treatment in a firing device such as a rotary kiln.
【０００８】加熱処理の温度は、１３００℃以上で上限
は１７００℃以下の範囲が好ましい。より好ましくは、
１４００〜１６００℃である。１２００℃付近から電融
粒に固溶していたチタンの離溶が始まり、析出したチタ
ンは粒表面付近に移動し、アルミナと反応してチタン酸
アルミニウムを生成する。しかし、１３００℃以下では
非常に長時間を要し実用的ではない。より好ましくは１
４００℃以上で、この温度では離溶速度が速くなるため
長時間加熱することなく、固溶していたチタンが離溶析
出し、表面に移動し、アルミナと反応してチタン酸アル
ミニウムを生成する。温度が１７００℃を超えると粒同
士の焼結が起こり、焼成後に解砕することが必要にな
る。解砕を行うと粒の表面に形成されたチタン酸アルミ
ニウムの被覆層が壊されるため粒の強度が低くなる。粒
同士の焼結がなく解砕せずに用いることのできるより好
ましい温度は１６００℃以下である。加熱時の保持時間
は１４００℃では３０分以上保持することが好ましく、
１６００℃では１０分以上とすることが好ましい。The temperature of the heat treatment is preferably 1300 ° C. or higher and the upper limit is preferably 1700 ° C. or lower. More preferably,
1400-1600 ° C. At around 1200 ° C., the exsolution of titanium solid-dissolved in the electrofused particles starts, and the precipitated titanium moves to the vicinity of the particle surface and reacts with alumina to produce aluminum titanate. However, when the temperature is 1300 ° C. or lower, it takes a very long time, and is not practical. More preferably 1
Above 400 ° C., at this temperature, the exsolution rate is high, so that the solid-dissolved titanium is exfoliated and precipitated without heating for a long time, moves to the surface and reacts with alumina to produce aluminum titanate. . If the temperature exceeds 1700 ° C., sintering of the particles occurs, and it is necessary to disintegrate after firing. When crushing is performed, the coating layer of aluminum titanate formed on the surface of the grains is broken, so that the strength of the grains decreases. A more preferable temperature at which the particles can be used without sintering and without crushing is 1600 ° C. or less. The holding time at the time of heating is preferably held at 1400 ° C. for 30 minutes or more,
At 1600 ° C., the heating is preferably performed for 10 minutes or more.
【０００９】本発明でもう一つ重要な要件は、上記の加
熱処理後の冷却時のコントロールにある。即ち、１３０
０〜７５０℃の間を３００℃／時間以上の速さで急冷さ
せることにある。より好ましくは５００℃／時間以上で
ある。このように急冷させるのは粒表面に形成されたチ
タン酸アルミニウムが１３００〜７５０℃の間で分解を
起こすため、上記の程度以上の急冷が必要となる。Another important requirement of the present invention is control of cooling after the above heat treatment. That is, 130
Rapid cooling at a rate of 300 ° C./hour or more between 0 and 750 ° C. More preferably, the temperature is 500 ° C./hour or more. The rapid cooling in this manner requires the rapid cooling of the above degree or more because the aluminum titanate formed on the grain surface is decomposed between 1300 and 750 ° C.
【００１０】このようにして本発明により製造されたチ
タン酸アルミニウムで被覆された酸化チタン含有電融ア
ルミナについて述べる。電融アルミナ粒の表面が５〜１
５μｍの厚みのチタン酸アルミニウムの膜で被覆されて
おり、表面のチタン元素は総てチタン酸アルミニウムと
なっている。またＥＰＭＡによるチタンの存在分布を調
べたところ、チタンは粒表面部の他に粒内部にも存在し
ていた。加熱処理前の原料である酸化チタンを含有する
電融アルミナでは、酸化チタンはその６〜７割程度は、
Ｔｉ2 Ｏ3 の型でアルミナ（コランダム）に固溶してい
る。残りの酸化チタンは、粒界や気孔表面等にＴｉＯ2
として、あるいはＳｉＯ2 、Ｎａ2 Ｏ等の不純物との化
合物または／およびガラスとして存在している。本発明
により加熱処理すると上記の前者のように固溶している
酸化チタンが離溶してアルミナと反応してチタン酸アル
ミニウムを生成する。上記の後者のようにＳｉＯ2 、Ｎ
ａ2 Ｏ等の不純物との化合物、ガラスとして存在する酸
化チタンはチタン酸アルミニウムの生成には関与しない
と思われる。The fused alumina containing titanium oxide coated with aluminum titanate thus produced according to the present invention will be described. The surface of the fused alumina particles is 5-1
It is covered with a film of aluminum titanate having a thickness of 5 μm, and all the titanium elements on the surface are aluminum titanate. When the distribution of titanium present was examined by EPMA, titanium was present inside the grain as well as on the grain surface. In fused alumina containing titanium oxide, which is a raw material before heat treatment, about 60 to 70% of titanium oxide is
It is a type of Ti 2 O 3 and is dissolved in alumina (corundum). The remaining titanium oxide is TiO 2 on the grain boundaries and pore surfaces.
Or as a compound with impurities such as SiO 2 and Na 2 O and / or as glass. When heat treatment is performed according to the present invention, the solid oxide titanium oxide is dissolved as described above and reacts with alumina to produce aluminum titanate. SiO 2 , N
It is considered that a compound with impurities such as a 2 O and titanium oxide present as glass do not participate in the production of aluminum titanate.
【００１１】本発明に使用することができる原料の「酸
化チタンを含有する電融アルミナ」にはＴｉの他にＣ
ｒ、Ｓｉ、Ｎａ、Ｆｅが含まれてもよい。これらの元素
のうちのＣｒは、アルミナに全量固溶するため、粒を強
化する元素として用いられており３wt％程度までは硬度
や強度を僅かに向上させる効果がある。しかし、一旦固
溶したＣｒは、その後の加熱によっても変化しないため
本発明の効果や作用には影響を及ぼさない。Ｔｉ、Ｃｒ
以外の不純物量は、それぞれの酸化物換算として総量
１．５wt％以下が好ましい。１．５wt％を超えると得ら
れる被覆電融アルミナ粒の硬度が低く、研削材特性が劣
るので好ましくない。The raw material “fused alumina containing titanium oxide” which can be used in the present invention includes, in addition to Ti, C
r, Si, Na, and Fe may be included. Since all of these elements, Cr, form a solid solution with alumina, they are used as elements for strengthening grains, and have an effect of slightly improving hardness and strength up to about 3% by weight. However, once dissolved, Cr does not change even by subsequent heating, and thus does not affect the effects and functions of the present invention. Ti, Cr
The amount of impurities other than the above is preferably 1.5 wt% or less in total as oxides. If the content exceeds 1.5% by weight, the hardness of the coated fused alumina particles obtained is low, and the properties of the abrasive are inferior.
【００１２】本発明により得られたチタン酸アルミニウ
ム被覆電融アルミナ粒は、未被覆電融アルミナより硬度
が高くなり、荷重５００ｇでのマイクロビッカース硬度
測定で２１００ｋｇ／ｍｍ2 以上となる。前述のように
１３００℃以上で熱処理した後、所定の条件で急冷し、
室温まで冷却し、目的とする粒度に再度篩い分け等で整
粒し、目的の粒度をもつ研削材、耐火材料等を得ること
ができる。The hardness of the fused alumina particles coated with aluminum titanate obtained according to the present invention is higher than that of the uncoated fused alumina, and is 2100 kg / mm 2 or more as measured by micro Vickers hardness under a load of 500 g. After heat treatment at 1300 ° C. or higher as described above, quenched under predetermined conditions,
The mixture is cooled to room temperature, sieved again to a desired particle size by sieving or the like, and an abrasive having a desired particle size, a refractory material or the like can be obtained.
【００１３】[0013]
【実施例】以下に実施例および比較例にて本発明を詳説
する。 実施例１ 酸化チタンをＴｉＯ2 換算で０．３０wt％含有する解砕
型電融アルミナ研削材（昭和電工（株）製ＳＡ）の＃６
０粒度のものを５００ｇアルミナ坩堝に入れ、マッフル
炉内で１４００℃まで７時間で昇温し、１４００℃にて
２時間保持し、加熱を停止し炉内で放冷した。このとき
の１３００〜７５０℃への冷却時間は１時間で、この温
度範囲の冷却速度は５５０℃／時間であった。室温まで
冷却後、３５０〜２１０μｍの篩網で整粒し、粒同士が
固着して粗くなった粒や微細粒を取り除き＃６０のアル
ミナ研削材に相当する粒を得た。このようにして得られ
た粒の密度は３．９６ｇ／ｃｍ3 で、粒子の荷重５００
ｇでのマイクロビッカース硬度は２１８０ｋｇ／ｍｍ2
であった。また得られた粒をＸ線回折装置を用いて粒表
面に生成した物質の定性分析を行った結果、チタン酸ア
ルミニウムの生成が確認された。The present invention will be described in detail below with reference to examples and comparative examples. # Solutions砕型fused alumina abrasive containing 0.30 wt% Example 1 Titanium oxide in terms of TiO 2 (Showa Denko KK SA) 6
500 g of 0-granular particles were put into an alumina crucible, heated in a muffle furnace to 1400 ° C. in 7 hours, kept at 1400 ° C. for 2 hours, stopped heating, and allowed to cool in the furnace. At this time, the cooling time to 1300 to 750 ° C. was 1 hour, and the cooling rate in this temperature range was 550 ° C./hour. After cooling to room temperature, the particles were sized with a sieve screen of 350 to 210 μm to remove coarse particles and fine particles which adhered to each other to obtain particles corresponding to # 60 alumina abrasive. The density of the particles thus obtained is 3.96 g / cm 3 and the particle load is 500
micro Vickers hardness in grams is 2180 kg / mm 2
Met. The obtained particles were subjected to a qualitative analysis of a substance formed on the surface of the particles using an X-ray diffractometer. As a result, formation of aluminum titanate was confirmed.
【００１４】当該粒の靭性は、ＪＩＳ Ｒ１２６８−１
９７５人造研削材の靭性の試験方法（ボールミル法）に
準拠したＣ係数として定義される方法によって測定し
た。即ち、試料約２５０ｇをＪＩＳ Ｒ６００１−１９
８７に規定される標準篩を用いてロータップ試験機によ
って１０分間篩い分ける。３段目の篩に留まった試料の
全量を更に１０分間篩い分け、再び３段目の篩に留まっ
た試料１００ｇを供試試料とする。この試料をＪＩＳ
Ｒ６１２８−１９７５に規定される方法でボールミル粉
砕する。粉砕試料を標準篩を用いて５分間篩い分け、４
段目の篩に留まった試料の重量をＲ（ｘ）とする。ま
た、標準試料としてＪＩＳ Ｒ６１２８−１９７５に規
定される黒色炭化けい素質研削材の＃６０を用いて同様
の操作を行い、ボールミル粉砕後４段目に留まった試料
の重量をＲ（ｓ）とし、次式によりＣ係数を算出する。 Ｃ係数＝ｌｏｇ（１００／Ｒ（ｘ））／ｌｏｇ（１００
／Ｒ（ｓ）） この値が小さい程高靭性となるが、実施例１の被覆電融
アルミナ粒のＣ係数は、０．７５であった。The toughness of the grains is determined according to JIS R1268-1.
It was measured by a method defined as a C coefficient according to a test method (ball mill method) of a 975 artificial abrasive. That is, about 250 g of a sample is weighed according to JIS R6001-19.
Sieve for 10 minutes with a low tap tester using a standard sieve specified in # 87. The total amount of the sample remaining on the third-stage sieve is sieved for another 10 minutes, and 100 g of the sample remaining on the third-stage sieve is used as a test sample. This sample is JIS
Ball milling is performed according to the method specified in R6128-1975. The ground sample is sieved for 5 minutes using a standard sieve, 4
Let R (x) be the weight of the sample remaining on the sieve of the stage. The same operation was performed using # 60 black silicon carbide abrasive stipulated in JIS R6128-1975 as a standard sample, and the weight of the sample remaining at the fourth stage after ball milling was defined as R (s), The C coefficient is calculated by the following equation. C coefficient = log (100 / R (x)) / log (100
/ R (s)) The smaller this value, the higher the toughness, but the C coefficient of the coated fused alumina particles of Example 1 was 0.75.
【００１５】実施例２ 加熱温度と保持時間を１５００℃で１時間とし、１３０
０〜７５０℃の間の冷却速度を２２００℃／時間とする
以外は、実施例１と同様にして被覆粒を得た。このよう
にして得た粒の密度は３．９８ｇ／ｃｍ3 で、粒子の荷
重５００ｇでのマイクロビッカース硬度は２１７０ｋｇ
／ｍｍ2 であり、Ｃ係数は０．７３であった。また得ら
れた粒をＸ線回折装置を用いて粒子表面に生成した物質
の定性分析を行った結果、チタン酸アルミニウムが確認
された。Example 2 The heating temperature and the holding time were set at 1500 ° C. for 1 hour,
Coated particles were obtained in the same manner as in Example 1, except that the cooling rate between 0 and 750 ° C was 2200 ° C / hour. The density of the particles thus obtained is 3.98 g / cm 3 , and the micro Vickers hardness under a load of 500 g of the particles is 2170 kg.
/ Mm 2 and the C coefficient was 0.73. The particles obtained were subjected to a qualitative analysis of a substance formed on the surface of the particles using an X-ray diffractometer. As a result, aluminum titanate was confirmed.
【００１６】実施例３ 加熱温度を１６００℃とし保持時間を３０分とする以外
は、実施例１と同様にして被覆粒を得た。この粒の密度
は３．９８ｇ／ｃｍ3 で、粒子の荷重５００ｇでのマイ
クロビッカース硬度は２１９０ｋｇ／ｍｍ2 であり、Ｃ
係数は０．７０であった。また得られた粒をＸ線回折装
置を用いて粒子表面に生成した物質の定性分析を行った
結果、チタン酸アルミニウムが確認された。Example 3 Coated particles were obtained in the same manner as in Example 1 except that the heating temperature was 1600 ° C. and the holding time was 30 minutes. The density of the particles is 3.98 g / cm 3 , the micro Vickers hardness at a load of 500 g of the particles is 2190 kg / mm 2 ,
The coefficient was 0.70. The particles obtained were subjected to a qualitative analysis of a substance formed on the surface of the particles using an X-ray diffractometer. As a result, aluminum titanate was confirmed.
【００１７】実施例４ 酸化チタンをＴｉＯ2 換算で０．３０wt％含有する淡紅
色電融アルミナ研削材（昭和電工（株）製ＰＷ）を実施
例１と同様に加熱処理して被覆粒を得た。この粒の密度
は３．９８ｇ／ｃｍ3 で、粒子の荷重５００ｇでのマイ
クロビッカース硬度は２１６０ｋｇ／ｍｍ2 であり、Ｃ
係数は０．７６であった。また得られた粒をＸ線回折装
置を用いて粒子表面に生成した物質の定性分析を行った
結果、チタン酸アルミニウムが確認された。Example 4 A reddish-colored fused alumina abrasive (PW manufactured by Showa Denko KK) containing 0.30% by weight of titanium oxide in terms of TiO 2 was heated in the same manner as in Example 1 to obtain coated particles. Was. The density of the particles is 3.98 g / cm 3 , the micro Vickers hardness at a load of 500 g of the particles is 2160 kg / mm 2 ,
The coefficient was 0.76. The particles obtained were subjected to a qualitative analysis of a substance formed on the surface of the particles using an X-ray diffractometer. As a result, aluminum titanate was confirmed.
【００１８】実施例５ バイヤー法アルミナに酸化チタンを０．７wt％添加しア
ーク炉で溶融後、粉砕整粒して得た＃６０の粒を保持時
間を１時間とした以外は実施例１と同様に加熱処理して
粒を得た。この粒の密度は３．９８ｇ／ｃｍ3 で、粒子
の荷重５００ｇでのマイクロビッカース硬度は２１３０
ｋｇ／ｍｍ2 であり、Ｃ係数は０．６８であった。また
得られた粒をＸ線回折装置を用いて粒子表面に生成した
物質の定性分析を行った結果、チタン酸アルミニウムが
確認された。一方、加熱処理前の粒の密度は３．９７ｇ
／ｃｍ3 で、粒子の荷重５００ｇでのマイクロビッカー
ス硬度は２０１０ｋｇ／ｍｍ2 であり、Ｃ係数は１．１
３であった。またＸ線回折装置を用いて粒子表面部分を
定性分析した結果、チタン酸アルミニウムは検出されな
かった。Example 5 The procedure of Example 1 was repeated except that 0.7 wt% of titanium oxide was added to the Bayer method alumina, and the resulting mixture was melted in an arc furnace and pulverized and sized. Similarly, heat treatment was performed to obtain grains. The particles have a density of 3.98 g / cm 3 and a micro Vickers hardness at a load of 500 g of the particles of 2130.
kg / mm 2 and the C coefficient was 0.68. The particles obtained were subjected to a qualitative analysis of a substance formed on the surface of the particles using an X-ray diffractometer. As a result, aluminum titanate was confirmed. On the other hand, the grain density before the heat treatment was 3.97 g.
/ Cm 3 , the micro Vickers hardness at a load of 500 g of the particles is 2010 kg / mm 2 , and the C coefficient is 1.1.
It was 3. As a result of qualitative analysis of the particle surface portion using an X-ray diffractometer, no aluminum titanate was detected.
【００１９】比較例１〜３ 昭和電工（株）製白色電融アルミナ研削材ＷＡ、単結晶
電融アルミナ研削材ＳＡおよび淡紅色電融アルミナ研削
材ＰＷのそれぞれの＃６０の密度、マイクロビッカース
硬度、Ｃ係数を求め、比較例１〜３とした。その結果を
表１に示す。また、これらの砥粒のＸ線回折による定性
分析では、何れの砥粒からもチタン酸アルミニウムは検
出されなかった。Comparative Examples 1 to 3 Density of # 60, micro Vickers hardness of each of white fused alumina abrasive WA, single crystal fused alumina abrasive SA and light red fused alumina abrasive PW manufactured by Showa Denko KK , And C coefficient were determined, and Comparative Examples 1 to 3 were obtained. Table 1 shows the results. Further, in the qualitative analysis of these abrasive grains by X-ray diffraction, aluminum titanate was not detected from any of the abrasive grains.
【００２０】[0020]
【表１】 [Table 1]
【００２１】比較例４ 特開昭５０−８０３０５の追試の目的で、比較例１と同
じ＃６０のＷＡ研削材５００ｇをアルミナ坩堝に入れ、
マッフル炉で１７００℃まで７時間で昇温し、３０分間
保持した後加熱を停止し、炉内で自然放冷した。室温ま
で冷却後実施例１と同様に篩い分け＃６０の研削材相当
の粒を得た。この粒の密度は３．９８ｇ／ｃｍ3 で、粒
子の荷重５００ｇでのマイクロビッカース硬度は２０６
０ｋｇ／ｍｍ2 であり、Ｃ係数は０．９７であった。ま
たＸ線回折装置による解析では、加熱処理後にβ−アル
ミナ相の回折ピーク強度の減少がみられたが、その他の
変化は認められなかった。Comparative Example 4 For the purpose of a supplementary test in Japanese Patent Application Laid-Open No. 50-80305, 500 g of the same # 60 WA abrasive as in Comparative Example 1 was placed in an alumina crucible.
The temperature was raised to 1700 ° C. for 7 hours in a muffle furnace, kept for 30 minutes, stopped heating, and allowed to cool naturally in the furnace. After cooling to room temperature, grains equivalent to abrasives of # 60 sieved were obtained in the same manner as in Example 1. The particle has a density of 3.98 g / cm 3 and a micro Vickers hardness at a load of 500 g of the particles of 206.
It was 0 kg / mm 2 and the C coefficient was 0.97. Further, analysis by an X-ray diffractometer revealed that the diffraction peak intensity of the β-alumina phase decreased after the heat treatment, but no other change was observed.
【００２２】比較例５ 実施例１と同じＳＡ研削材を、加熱温度と時間を１２５
０℃で５時間とした以外は、実施例１と同様にして＃６
０の粒を得た。この粒の密度は３．９５ｇ／ｃｍ3 で、
粒子の荷重５００ｇでのマイクロビッカース硬度は２０
７０ｋｇ／ｍｍ2 であり、Ｃ係数は０．８８であった。
また得られた粒をＸ線回折装置を用いて粒子表面に生成
した物質の定性分析を行った結果、チタン酸アルミニウ
ムは確認されなかった。Comparative Example 5 The same SA abrasive material as in Example 1 was heated at a heating temperature and for 125
# 6 in the same manner as in Example 1 except that the temperature was changed to 0 ° C. for 5 hours.
0 grains were obtained. The density of these grains is 3.95 g / cm 3 ,
The micro Vickers hardness at a load of 500 g of the particles is 20.
It was 70 kg / mm 2 and the C coefficient was 0.88.
Further, as a result of qualitative analysis of a substance formed on the particle surface of the obtained particle using an X-ray diffractometer, aluminum titanate was not confirmed.
【００２３】比較例６ 実施例１で、１３００〜７５０℃の間の冷却速度を５０
℃／時間とした以外は実施例１と同様にして粒を得た。
この粒の密度は３．９８ｇ／ｃｍ3 で、粒子の荷重５０
０ｇでのマイクロビッカース硬度は２１９０ｋｇ／ｍｍ
2 であり、Ｃ係数は０．７３であった。また得られた粒
をＸ線回折装置を用いて粒子表面に生成した物質の定性
分析を行った結果、ルチル型の酸化チタンと極少量のチ
タン酸アルミニウムが確認された。COMPARATIVE EXAMPLE 6 In Example 1, the cooling rate between 1300 and 750.degree.
Grains were obtained in the same manner as in Example 1 except that the temperature was changed to ° C./hour.
The density of the particles is 3.98 g / cm 3 and the particle load is 50
Micro Vickers hardness at 0 g is 2190 kg / mm
2 , and the C coefficient was 0.73. The obtained particles were subjected to a qualitative analysis of a substance formed on the surface of the particles using an X-ray diffractometer. As a result, rutile-type titanium oxide and a very small amount of aluminum titanate were confirmed.
【００２４】実施例６〜１０および比較例７〜１２ 実施例１〜５および比較例１〜６の＃６０の研削材相当
の粒１００重量部に対して、それぞれ、レジノイド砥石
用ボンドとして乾燥フェノール（昭和高分子製ＢＲＰ−
５４２８）を１０．７重量部、液状フェノール（昭和高
分子製ＢＲＬ−２０４）３．６重量部、更にフィラーと
して氷晶石（４４μｍＦ）９．８重量部をミキサーで混
合した。混合後、プレス成形し、砥粒率４６％の成形体
を作製した。これを１２０℃で５時間乾燥した後、１８
０℃で１５時間焼成した。このようにしてＪＩＳ Ｒ６
２１２規定の結合度Ｋのレジノイド砥石を作製した。砥
石の寸法は、すべて外形２００ｍｍφ×厚み１９ｍｍ×
内径５０．８ｍｍφである。Examples 6 to 10 and Comparative Examples 7 to 12 For 100 parts by weight of grains equivalent to # 60 abrasive in Examples 1 to 5 and Comparative Examples 1 to 6, dry phenol was used as a bond for a resinoid grindstone. (Showa Polymer BRP-
5428), 3.6 parts by weight of liquid phenol (BRL-204 manufactured by Showa Polymer), and 9.8 parts by weight of cryolite (44 μmF) as a filler were mixed by a mixer. After mixing, press molding was performed to produce a molded body having an abrasive grain ratio of 46%. After drying this at 120 ° C. for 5 hours, 18
Firing at 0 ° C. for 15 hours. Thus, JIS R6
A resinoid grindstone having a 212 degree bond K was prepared. The dimensions of the whetstone are all 200mmφ x 19mm x
The inner diameter is 50.8 mmφ.
【００２５】実施例１１〜１５および比較例１３〜１８ 実施例６〜１０および比較例７〜１２のレジノイド砥石
につき下記の試験条件で研削を行い、研削性能を評価し
た。Examples 11 to 15 and Comparative Examples 13 to 18 The resinoid grindstones of Examples 6 to 10 and Comparative Examples 7 to 12 were ground under the following test conditions to evaluate the grinding performance.
【００２６】試験条件 研削機械 ：（株）岡本工作機械製作所 平面研削
盤 ＰＳＧ−５２ＤＸ（３．７ｋｗ） 研削方式 ：プランジ研削 ダウンカット 被削材 ：ＳＵＪ−２（ＨRC６０）、１００ｍｍ
長×５０ｍｍ高×１０ｍｍ厚 砥石周速度 ：１８００ｍ／min テーブル速度 ： ２０ｍ／min 切り込み寸法 ：１５μｍ／pass 総切り込み寸法：５ｍｍ 研削幅 ：１０ｍｍ 研削油 ：ノリタケクール Ｋ−８２Ｂ（水溶性
研削油）８０倍液 ドレス条件 ：単石ダイアモンドドレッサー 切り込み：２０μｍ／pass その結果、研削比、最大消費電力値（無負荷電力を除い
た値）および面粗さにつき表２に示す値を得た。[0026] Test Conditions Grinding machines: manufactured) Okamoto Machine Tool Works surface grinding machine PSG-52DX (3.7kw) Grinding method: plunge grinding down cut Workpiece: SUJ-2 (H RC 60 ), 100mm
Length × 50mm height × 10mm thickness Grinding wheel peripheral speed: 1800m / min Table speed: 20m / min Cutting depth: 15μm / pass Total cutting dimension: 5mm Grinding width: 10mm Grinding oil: Noritake Cool K-82B (water-soluble grinding oil) 80 Double solution Dressing condition: single stone diamond dresser Depth of cut: 20 μm / pass As a result, the values shown in Table 2 were obtained for the grinding ratio, maximum power consumption value (value excluding no-load power), and surface roughness.
【００２７】[0027]
【表２】 [Table 2]
【００２８】表２からわかるように、本発明の方法によ
るアルミナ粒を研削材として使用した場合、研削比は市
販の白色電融アルミナ研削材の約２．５倍程度、市販の
単結晶質電融アルミナ研削材の１．８倍程度高い性能を
示す値を得た。また研削比が高いのにもかかわらず、最
大消費電力値は比較例に比べて低い値を示しており、更
に被削材の研削面の面粗さも比較例に比べて小さい傾向
にあった。As can be seen from Table 2, when the alumina particles according to the method of the present invention are used as the abrasive, the grinding ratio is about 2.5 times that of the commercially available white fused alumina abrasive, and the commercially available single-crystalline A value showing about 1.8 times higher performance than the fused alumina abrasive was obtained. In addition, despite the high grinding ratio, the maximum power consumption value was lower than that of the comparative example, and the surface roughness of the ground surface of the workpiece tended to be smaller than that of the comparative example.
【００２９】[0029]
【発明の効果】本発明のチタン酸アルミニウムで被覆さ
れた酸化チタン含有電融アルミナ粒の製法により、従来
の研削材に比べて硬度、靭性に優れ、また研削性能にも
優れた研削材を得ることができる。According to the method of the present invention for producing fused alumina particles containing titanium oxide coated with aluminum titanate, a grinding material having excellent hardness, toughness and grinding performance as compared with conventional grinding materials can be obtained. be able to.
───────────────────────────────────────────────────── フロントページの続き (58)調査した分野(Int.Cl.6，ＤＢ名) C01F 7/02 B24D 3/00 320 C09K 3/14 550──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. 6 , DB name) C01F 7/02 B24D 3/00 320 C09K 3/14 550
Claims (1)
１３００℃以上に加熱し、固溶しているチタンを析出さ
せ該粒の表面にチタン酸アルミニウムを生成させた後、
１３００〜７５０℃の温度範囲を３００℃／時間以上の
速度で冷却することを特徴とするチタン酸アルミニウム
被覆電融アルミナ粒の製造方法。1. An electrofused alumina particle containing titanium oxide is heated to 1300 ° C. or more to precipitate solid solution titanium and form aluminum titanate on the surface of the particle.
A method for producing aluminum titanate-coated fused alumina particles, characterized in that a temperature range of 1300 to 750 ° C is cooled at a rate of 300 ° C / hour or more.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6013719A JP2790029B2 (en) | 1994-02-07 | 1994-02-07 | Method for producing coated fused alumina particles |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6013719A JP2790029B2 (en) | 1994-02-07 | 1994-02-07 | Method for producing coated fused alumina particles |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH07215717A JPH07215717A (en) | 1995-08-15 |
| JP2790029B2 true JP2790029B2 (en) | 1998-08-27 |
Family
ID=11841059
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6013719A Expired - Lifetime JP2790029B2 (en) | 1994-02-07 | 1994-02-07 | Method for producing coated fused alumina particles |
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| Country | Link |
|---|---|
| JP (1) | JP2790029B2 (en) |
Families Citing this family (5)
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| DE102013111006B4 (en) * | 2013-10-04 | 2015-10-22 | Center For Abrasives And Refractories Research & Development C.A.R.R.D. Gmbh | Porous alumina-based polycrystalline Al 2 O 3 bodies with increased toughness |
| KR102184303B1 (en) | 2016-06-28 | 2020-11-30 | 쇼와 덴코 가부시키가이샤 | Electro-melted alumina particles, manufacturing method of electro-melted alumina particles, grinding stone and polishing paper |
| WO2019123833A1 (en) | 2017-12-19 | 2019-06-27 | 昭和電工株式会社 | Fused alumina grains, method for producing fused alumina grains, grindstone, and coated abrasive |
| CN108046772A (en) * | 2017-12-20 | 2018-05-18 | 山东磊宝锆业科技股份有限公司 | The production method of fused alumina/titanium oxide composite material |
| CN110241458A (en) * | 2019-05-24 | 2019-09-17 | 淅川正弘单晶刚玉厂 | The production method of canescence single alundum |
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1994
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