JPH0261826A - Production of ultra-specular surface disk - Google Patents
Production of ultra-specular surface diskInfo
- Publication number
- JPH0261826A JPH0261826A JP21317688A JP21317688A JPH0261826A JP H0261826 A JPH0261826 A JP H0261826A JP 21317688 A JP21317688 A JP 21317688A JP 21317688 A JP21317688 A JP 21317688A JP H0261826 A JPH0261826 A JP H0261826A
- Authority
- JP
- Japan
- Prior art keywords
- stock
- disk substrate
- ultra
- cutting
- alloy
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000004519 manufacturing process Methods 0.000 title claims description 6
- 239000000758 substrate Substances 0.000 claims abstract description 19
- 238000005520 cutting process Methods 0.000 claims abstract description 17
- 230000003746 surface roughness Effects 0.000 claims abstract description 14
- 229910000838 Al alloy Inorganic materials 0.000 claims abstract description 9
- 238000005266 casting Methods 0.000 claims abstract description 8
- 239000000463 material Substances 0.000 claims description 19
- 238000000034 method Methods 0.000 claims description 12
- 238000007711 solidification Methods 0.000 claims description 7
- 230000008023 solidification Effects 0.000 claims description 7
- 239000000203 mixture Substances 0.000 claims description 4
- 239000000498 cooling water Substances 0.000 abstract description 6
- 238000010438 heat treatment Methods 0.000 abstract description 4
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 abstract description 3
- 229910045601 alloy Inorganic materials 0.000 abstract description 3
- 239000000956 alloy Substances 0.000 abstract description 3
- 229910002804 graphite Inorganic materials 0.000 abstract description 3
- 239000010439 graphite Substances 0.000 abstract description 3
- 229910018134 Al-Mg Inorganic materials 0.000 abstract 1
- 229910018467 Al—Mg Inorganic materials 0.000 abstract 1
- 239000013078 crystal Substances 0.000 description 15
- 229910052751 metal Inorganic materials 0.000 description 7
- 239000002184 metal Substances 0.000 description 7
- 238000010586 diagram Methods 0.000 description 5
- 229910003460 diamond Inorganic materials 0.000 description 5
- 239000010432 diamond Substances 0.000 description 5
- 238000007796 conventional method Methods 0.000 description 4
- 238000005516 engineering process Methods 0.000 description 4
- 238000003860 storage Methods 0.000 description 4
- 229910000861 Mg alloy Inorganic materials 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 230000003287 optical effect Effects 0.000 description 2
- 238000005498 polishing Methods 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 235000002597 Solanum melongena Nutrition 0.000 description 1
- 244000061458 Solanum melongena Species 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 238000009749 continuous casting Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000005868 electrolysis reaction Methods 0.000 description 1
- 230000006870 function Effects 0.000 description 1
- 239000010410 layer Substances 0.000 description 1
- 238000003754 machining Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000007747 plating Methods 0.000 description 1
- 238000007517 polishing process Methods 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
Landscapes
- Manufacturing Of Magnetic Record Carriers (AREA)
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明は、情報記憶媒体として使用される磁気ディスク
、その他超鏡面を要する精密金型等の製造法に関する。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for manufacturing magnetic disks used as information storage media, precision molds, etc. that require a super mirror surface.
（従来の技術）
前記種類のアルミニウム合金製磁気ディスクは、従来、
次の（１）〜（■）の工程により製造される。すなわち
、
（１）第５図（イ）のように該当組成のアルミニウム合
金溶湯（ａ）から連続鋳造により鋳塊素材働）を形成し
、
（Ｉｆ）この鋳塊素材［有］）の外表層は溶湯が鋳型（
Ｃ）表面に接して冷却される部分から凝固を開始し、い
わゆる柱状晶（ｄ）が鋳造方向に対し直角に発達した組
織になっているので、この偏析層を切削して除去し、
（Ｉ［［）このインゴット（ｅ）を第５図（ロ）のよう
に熱間で粗圧延し、
（ＩＶ）さらに第５図（ハ）のように熱間で仕上圧延し
て厚さ２〜３胴の薄板（ｆ）とし、（Ｖ）これを第５図
（ニ）のように打抜いて所望の形状精度の円板（（至）
とし、
（Ｖｌ）円板（６）のゆがみを除去するため高温下で矯
正を施し、
（■）矯正円板をダイヤモンドバイトによる切削を行っ
て超鏡面仕上げの磁気ディスク基板を得ている。(Prior Art) The above type of aluminum alloy magnetic disk has conventionally
It is manufactured by the following steps (1) to (■). That is, (1) Form an ingot material by continuous casting from a molten aluminum alloy (a) of the corresponding composition as shown in Figure 5 (a), and (If) form an ingot material (if) the outer surface layer of this ingot material. The molten metal is in the mold (
C) Solidification starts from the part that is in contact with the surface and is cooled, resulting in a structure in which so-called columnar crystals (d) are developed perpendicular to the casting direction, so this segregated layer is removed by cutting (I [[) This ingot (e) is hot roughly rolled as shown in Figure 5 (b), (IV) and further hot finished rolled as shown in Figure 5 (c) to a thickness of 2 to 3 mm. A thin plate (f) of the body is made, and (V) is punched out as shown in Fig. 5 (d) to form a disc with the desired shape accuracy ((to)
(Vl) The disc (6) is straightened at high temperature to remove distortion, and (■) The straightened disc is cut with a diamond cutting tool to obtain a magnetic disk substrate with an ultra-mirror finish.
（発明が解決しようとする問題点）
従来技術の磁気ディスク基板の製造法では、前記のよう
に多くの塑性変形工程を経由することにより結晶組織を
変形させて多方位結晶集合組織とした上で、最終工程の
ダイヤモンドバイトによる切削により超鏡面に仕上げて
いる。この場合、仕上表面には、第６図の写真に示すよ
うに、結晶粒界が明確に認められ、結晶粒界に段差が生
じ、段差の大きさは２／１００〜３／１００μｍに達す
る。そのため超鏡面仕上げに最大の注意を払っても、段
差より小さい表面粗さに到達させることは実際上できな
い。(Problems to be Solved by the Invention) In the conventional method of manufacturing a magnetic disk substrate, the crystal structure is deformed into a multi-oriented crystal texture by going through many plastic deformation steps as described above. The final step is cutting with a diamond cutting tool to create an ultra-mirror finish. In this case, as shown in the photograph of FIG. 6, grain boundaries are clearly recognized on the finished surface, and steps are formed at the grain boundaries, and the size of the steps reaches 2/100 to 3/100 μm. Therefore, even if maximum attention is paid to ultra-mirror finishing, it is practically impossible to achieve a surface roughness smaller than a step difference.
表面平滑度をさらに向上させることが必要な場合には、
さらにラッピング、ボリシング、電解を伴わせた研磨な
どを施すことが考えられるが、何れの方法によっても、
粒界をはさむ結晶粒に方位差があって各結晶粒の変形能
が異なるため、粒界段差の影響を受けないようにするこ
とができず、依然２／１００μｍ程度の段差が残り、表
面粗さをこの段差の高さ以下にすることば不可能に近＜
、０．０２μｍ Ｒｍａｘが到達できる限度であった
。If it is necessary to further improve the surface smoothness,
Furthermore, it is possible to perform lapping, borishing, polishing with electrolysis, etc., but with any method,
Because the crystal grains sandwiching grain boundaries have different orientations and the deformability of each grain differs, it is impossible to avoid the influence of the grain boundary step, and a step of about 2/100 μm still remains, resulting in surface roughness. It is almost impossible to reduce the height to below the height of this step.
, 0.02 μm Rmax was the limit that could be reached.
また単結晶を用いて加工すれば、粒界段差は生じなくな
るが機械的強度が低下し、コストも割高となる。また表
面コーティングにより平滑化を図ることが考えられるが
、通常用いられる非晶質メツキは耐熱性に欠け、さらに
硬度が高いために工具の摩耗が著しく形状精度が出にく
い。Further, if a single crystal is used for processing, grain boundary steps will not occur, but the mechanical strength will decrease and the cost will be relatively high. It is also possible to smooth the surface by coating it, but the commonly used amorphous plating lacks heat resistance, and its high hardness causes significant tool wear, making it difficult to achieve shape accuracy.
一方、第７図の経年傾向図に示されるように、磁気ディ
スクの面記憶密度（ＫＢ／ｉｎ”）は、第８図のように
、ディスク（ｉ）の表面粗さを小さくして磁気ヘッド（
Ｍ）を近接させ浮上高さ（Ｈ）を減少させるのに伴って
増加する傾向にあることが認められるので、面記憶密度
の向上を実現するには、前記の従来技術の多結晶材を用
いて鏡面加工を施した場合の到達限界を超えて表面粗さ
を向上させることが要望される。本発明はこれを可能に
する技術を提供することを目的とする。On the other hand, as shown in the secular trend chart in Figure 7, the areal storage density (KB/in'') of the magnetic disk is increased by decreasing the surface roughness of the disk (i) as shown in Figure 8. (
It is recognized that there is a tendency to increase as the flying height (H) is reduced by bringing M) closer to each other, so in order to improve the areal memory density, it is necessary to use the polycrystalline material of the prior art described above. It is desired to improve the surface roughness beyond the limit achieved by mirror finishing. The present invention aims to provide technology that makes this possible.
（問題点を解決するための手段）
前記目的を達成するため、本発明においては、磁気ディ
スクが一定しない結晶方位を有する多結晶組織材からつ
くられる場合に結晶粒界に生ずる段差が鏡面加工表面粗
さに対して持つ限界的影響を軽減するため、加工手段の
工夫に依存しないで加工素材そのものにつき結晶方位が
一方向に揃うようにする。そのため、溶湯から一方向凝
固組織を有する鋳造素材をつくり、これに結晶方位を変
える塑性加工を加えることをしないで、直接に切出して
結晶方位をそのままに保つ、た所定形状精度を有する素
板をつくり、これに鏡面切削加工を施して磁気ディスク
製品とする。(Means for Solving the Problems) In order to achieve the above object, in the present invention, when a magnetic disk is made from a polycrystalline material having an inconsistent crystal orientation, the step that occurs at the grain boundary is reduced to a mirror-finished surface. In order to reduce the marginal influence on roughness, the crystal orientation of the processed material itself is aligned in one direction, regardless of the ingenuity of the processing means. Therefore, we create a cast material with a unidirectional solidification structure from the molten metal, and then directly cut it without applying plastic working to change the crystal orientation to keep the crystal orientation as it is. This is then subjected to a mirror cutting process to create a magnetic disk product.
すなわち、本発明の超鏡面ディスクの製造法は、次の３
工程からなり、（１）所定組成のアルミニウム合金溶湯
から一方向凝固組織を有する鋳造素材を作成し、（ＩＩ
）この鋳造素材から切出し加工により所定の形状精度を
有する基板をつくり、（Ｉ［［）該素材に超鏡面切削加
工を施して仕上げる、ことを特徴とする。That is, the method for manufacturing a super-mirrored disk of the present invention includes the following three steps.
The process consists of (1) creating a cast material having a unidirectional solidification structure from a molten aluminum alloy of a predetermined composition, and (II)
) A substrate having a predetermined shape accuracy is made by cutting from this cast material, and the material is finished by performing ultra-mirror cutting.
本発明によれば、一方向凝固組織をそのまま有するアル
ミニウム合金からなり、その表面粗さが０．０２μｍ
Ｒｍａｘ以下の程度に小さい磁気ディスク基板が得られ
る。According to the present invention, the aluminum alloy is made of an aluminum alloy that has a unidirectional solidification structure as it is, and its surface roughness is 0.02 μm.
A magnetic disk substrate as small as Rmax or less can be obtained.
（作 用）
本発明方法によれば、結晶粒界の段差の影響が少なくな
ることにより表面粗さが０．０２μｍ Ｒｍａｘ以下の
小さいディスク基板を製造でき、従来よりも高性能で記
憶密度の高い磁気ディスクが製造できる。(Function) According to the method of the present invention, it is possible to manufacture a small disk substrate with a surface roughness of 0.02 μm Rmax or less by reducing the influence of steps at grain boundaries, and it has higher performance and storage density than conventional methods. Magnetic disks can be manufactured.
一方向凝固組織を用いるので、例えばダイヤモンドバイ
トによる切削のみで２／１００μｍ Ｒｍａｘ以下の超
々鏡面が得られる。そのため従来技術では特殊な研磨を
必要としたものが不要になる。Since a unidirectionally solidified structure is used, an ultra-super mirror surface of 2/100 μm Rmax or less can be obtained only by cutting with a diamond cutting tool, for example. This eliminates the need for special polishing in the prior art.
（実施例）
以下、本発明を第１〜４図を参照し実施例に即して詳細
に説明する。(Example) Hereinafter, the present invention will be described in detail based on an example with reference to FIGS. 1 to 4.
（１）第１工程
磁気ディスク基板のアルミニウム合金としては、Ｍｇ
４．１％、Ｆｅ Ｏ，５％、Ｓｉ Ｏ，４％、Ｍｎ Ｏ
，２％、ＺｎＯ，２５％、Ｃｒ０．０５％、残りＡｊ２
のＡ ｆｆ−Ｍｇ合金を使用する。これは従来技術で第
６図の結晶組織のもとに粒界段差を生じたものである。(1) As the aluminum alloy for the first step magnetic disk substrate, Mg
4.1%, FeO, 5%, SiO, 4%, MnO
,2%, ZnO, 25%, Cr0.05%, remainder Aj2
A ff-Mg alloy is used. This is because grain boundary steps are created in the conventional technique based on the crystal structure shown in FIG.
この溶湯を第１図の横形の鋳型（１）の黒鉛内面の抵抗
加熱方式のヒータ（２）を有する高さ５薗、幅１００ｍ
ｍの型孔（３）内にその開口側をホルダ（４）で閉じて
注入し、その加熱温度を７５０°Ｃに維持し、ホルダ（
４）に冷却水バイブ（５）を通じて冷却水を循環させ、
その側から冷却して凝固を開始させながら鋳型（１）と
ホルダ（４）とを相対的に０．５ｍｍ／分の相対速度で
横方向に離隔移動させることにより溶湯をホルダ（４）
から一方向に凝固させることを継続しながらホルダ（４
）により鋳型（１）から鋳塊として引抜き、全長にわた
り一方向凝固組織の鋳造素材を得た。得られた素材は集
合組織エッチビット法により調べた結果、はぼ＜１００
＞に結晶粒が成長していることを確認した。This molten metal is then placed in the horizontal mold (1) shown in Figure 1, which has a graphite inner surface and a resistance heating type heater (2).
The opening side of the mold hole (3) is closed with a holder (4), and the heating temperature is maintained at 750°C.
4) circulate the cooling water through the cooling water vibrator (5),
The molten metal is transferred to the holder (4) by moving the mold (1) and the holder (4) apart laterally at a relative speed of 0.5 mm/min while cooling and starting solidification from that side.
Holder (4) while continuing to solidify in one direction from
) was pulled out as an ingot from the mold (1) to obtain a cast material with a unidirectionally solidified structure over the entire length. The obtained material was examined by the texture etch bit method, and it was found that the texture was <100
It was confirmed that crystal grains were growing.
（ＩＩ）第２工程
得られた鋳造素材に粗切削加工を施して厚さ４胴、径９
５胴の所定の形状精度を有する円板状の素材を製作した
。(II) Second step The obtained casting material is roughly cut to a thickness of 4 mm and a diameter of 9 mm.
A disk-shaped material with a predetermined shape accuracy of 5 cylinders was manufactured.
（ＩＩＩ）第３工程
この素板の表面をダイヤモンドバイトを用い４４８ ｍ
／分の切削速度で鏡面加工を行って仕上げ、磁気ディス
ク基板を製作した。(III) Third step The surface of this blank plate was cut by 448 m using a diamond tool.
A magnetic disk substrate was manufactured by performing mirror finishing at a cutting speed of /min.
（ＩＶ）ディスク基板の組織及び表面粗さ得られたディ
スク基板の表面粗さをタリサーフ、クリステツブで測定
したが、粒界段差は測定できないほど小さいものであっ
た。そこで、光学式粗さ計を用いて測定した。その結果
を第２図に示す。粒界段差は図中記入のように約８ｎｍ
（０，００８μｍ）で、従来技術の到達限界の２／１０
０μｍより顕著に小さい、第２図中のＧ、Ｂ、は結晶粒
界の位置を示す。第３図の写真は第２図と同じ測定個所
の結晶組織を示し、ＧＢは対応する。(IV) Structure and surface roughness of disk substrate The surface roughness of the obtained disk substrate was measured using Talysurf and Cristeb, but the grain boundary step was so small that it could not be measured. Therefore, an optical roughness meter was used to measure the roughness. The results are shown in FIG. The grain boundary step is approximately 8 nm as shown in the figure.
(0,008 μm), which is 2/10 of the limit achieved by conventional technology.
G and B in FIG. 2, which are significantly smaller than 0 μm, indicate the positions of grain boundaries. The photograph in FIG. 3 shows the crystal structure at the same measurement location as in FIG. 2, and GB corresponds.
第２図は第３図の矢印の方向にスキャンして得たもので
ある。また得られた基板の表面粗さは０．０１０〜０．
０２０ μｍ Ｒｍａｘの範囲に入り、従来技術の限界
を超えていることが確認された。FIG. 2 was obtained by scanning in the direction of the arrow in FIG. 3. Moreover, the surface roughness of the obtained substrate was 0.010 to 0.0.
It was confirmed that it fell within the range of 0.020 μm Rmax and exceeded the limits of the conventional technology.
（Ｖ）変形例
前記第１工程は特公昭５５−４６２６５号記載の方法に
準じても実施することができる。第４図において上記と
同じ組成のＡ １−Ｍｇ合金の溶湯をタンデイツシュ（
６）からそれに接続した溶湯の凝固温度とほぼ同じ温度
に加熱した水平鋳型（７）の高さ５Ｍ、幅５０ｍｍの黒
鉛の型孔に注ぎ、−力比口側の板表面にノズル（８）か
ら冷却水を噴霧することにより一方向凝固させながら鋳
造素材をダミーバー（９）、ピーンチロールｑωにより
引抜いてゆくことにより一方向凝固鋳造素材をつくる。(V) Modification The first step can also be carried out according to the method described in Japanese Patent Publication No. 55-46265. In Fig. 4, a molten metal of A1-Mg alloy having the same composition as above is poured into a tundish (
6) into a graphite mold hole with a height of 5M and a width of 50mm in a horizontal mold (7) heated to approximately the same temperature as the solidification temperature of the molten metal connected to it, and a nozzle (8) on the plate surface on the -force ratio mouth side. A unidirectionally solidified casting material is produced by unidirectionally solidifying the casting material by spraying cooling water thereon and pulling it out using a dummy bar (9) and a pinch roll qω.
鋳型の型孔の全外周にヒータ（１１）を設けて全体を６
６０°Ｃに保温している。合金溶湯温度は６９０°Ｃで
あり、出口側での冷却水は１．５４２／分で供給し、引
抜速度を４０柵／分とした。この条件により、得られた
鋳造素材は組織調査の結果、一方向凝固組織となり、結
晶粒の成長方向はほぼ＜１００＞であることを確認した
。A heater (11) is provided around the entire outer periphery of the mold hole, and the entire mold is heated to 6.
It is kept warm at 60°C. The temperature of the molten alloy was 690°C, the cooling water on the outlet side was supplied at a rate of 1.542/min, and the drawing speed was 40 bars/min. Under these conditions, the resulting cast material was found to have a unidirectionally solidified structure, and the crystal grain growth direction was approximately <100>.
第２工程および第３工程を前記と同様な条件で実施した
結果、得られた厚さ４胴、径４５＠ｍのディスク基板は
、表面粗さは０．０１８ μｍ Ｒｍａｘで、粒界段差
は５〜１０ｎｍの範囲であった。As a result of performing the second and third steps under the same conditions as above, the obtained disk substrate with a thickness of 4 cylinders and a diameter of 45@m has a surface roughness of 0.018 μm Rmax and a grain boundary step. It was in the range of 5 to 10 nm.
（発明の効果）
本発明方法によると、従来技術に較べて少ない工程で表
面粗さの小さい面記憶密度を高くすることのできるディ
スク基板を得ることができ、しかもその超鏡面加工はダ
イヤモンド工具切削加工で足り特殊な研磨工程の付加を
要しない等の効果を得ることができる。(Effects of the Invention) According to the method of the present invention, a disk substrate with a small surface roughness and a high areal memory density can be obtained with fewer steps than the conventional technique, and its ultra-mirror finishing can be achieved by cutting with a diamond tool. Effects such as machining is sufficient and no special polishing process is required.
第１図は本発明方法の第１工程の実施状況を示す装置の
縦断側面図、第２図は本発明方法によって得たディスク
基板の光学式粗さ計による測定結果を示す図表、第３図
はその表面の結晶組織写真図、第４図は本発明方法の第
１工程の変形実施状況を示す装置の縦断側面図、第５図
（イ）は従来技術の第１工程の略示図、第５図（ロ）は
その第３工程の略示図、第５図（ハ）はその第４工程の
略示図、第５図（ニ）はその第５工程の略示図、第６図
は従来技術による磁気ディスク基板の結晶組織写真図、
第７図は従末技術の磁気ディスク基板の面記憶密度およ
び浮上高さの経年傾向図、第８図はその浮上高さを示す
図である。
（１）・・・鋳型、（２）・・・ヒータ、（３）・・・
型孔、（４）・・・ホルダ、（５）・・・冷却水パイプ
、（６）・・・タンデイツシュ、（７）・・・鋳型、（
８）・・・ノズル、（９）・・・ダミーバー、００）・
・・ピンチロール、（Ｉ卜・・ヒータ、（ａ）・・・溶
湯、（ｂ）・・・鋳塊素材、（Ｃ）・・・鋳型、（ｄ）
・・・柱状晶、（ｅ）・・・インゴット、（ｆ）・・・
薄板、（縛・・・円板、（Ｍ）・・・磁気ヘッド、（Ｈ
）・・・浮上高さ、（ｉ）・・・ディスク。
茄３図
蔀６ン１Fig. 1 is a longitudinal cross-sectional side view of an apparatus showing the implementation status of the first step of the method of the present invention, Fig. 2 is a chart showing the measurement results of a disk substrate obtained by the method of the present invention using an optical roughness meter, and Fig. 3 4 is a longitudinal cross-sectional side view of the device showing a modified state of implementation of the first step of the method of the present invention, and FIG. 5 (a) is a schematic diagram of the first step of the prior art. FIG. 5(b) is a schematic diagram of the third step, FIG. 5(c) is a schematic diagram of the fourth step, FIG. 5(d) is a schematic diagram of the fifth step, and FIG. The figure is a photographic diagram of the crystal structure of a magnetic disk substrate according to the conventional technology.
FIG. 7 is a graph showing trends over time in areal storage density and flying height of magnetic disk substrates according to the prior art, and FIG. 8 is a graph showing the flying height. (1)...Mold, (2)...Heater, (3)...
Mold hole, (4)...Holder, (5)...Cooling water pipe, (6)...Tandish, (7)...Mold, (
8)... Nozzle, (9)... Dummy bar, 00)
...pinch roll, (I.. heater, (a) ... molten metal, (b) ... ingot material, (C) ... mold, (d)
... Columnar crystal, (e) ... Ingot, (f) ...
Thin plate, (bound...disk, (M)...magnetic head, (H
)... Flying height, (i)... Disk. 3 eggplants 6 in 1
Claims (1)
有する鋳造素材を作成し、この鋳造素材から切出し加工
により所定の形状精度を有する素板をつくり、該素板に
超鏡面切削加工を施して仕上げることからなる３工程に
より、表面粗さが０．０２μｍＲ＿ｍ＿ａ＿ｘより小さ
いディスク基板を製造することを特徴とする超鏡面ディ
スクの製造法。A casting material having a unidirectional solidification structure is created from a molten aluminum alloy of a predetermined composition, a blank plate having a predetermined shape accuracy is made by cutting from the casting blank, and the blank plate is finished by performing ultra-mirror cutting. A method for manufacturing a super-mirrored disk, characterized in that a disk substrate having a surface roughness of less than 0.02 μmR_m_a_x is manufactured through three steps consisting of the following steps.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP21317688A JPH0261826A (en) | 1988-08-26 | 1988-08-26 | Production of ultra-specular surface disk |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP21317688A JPH0261826A (en) | 1988-08-26 | 1988-08-26 | Production of ultra-specular surface disk |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0261826A true JPH0261826A (en) | 1990-03-01 |
Family
ID=16634803
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP21317688A Pending JPH0261826A (en) | 1988-08-26 | 1988-08-26 | Production of ultra-specular surface disk |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0261826A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5248662A (en) * | 1991-01-31 | 1993-09-28 | Sumitomo Electric Industries | Laser ablation method of preparing oxide superconducting films on elongated substrates |
-
1988
- 1988-08-26 JP JP21317688A patent/JPH0261826A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5248662A (en) * | 1991-01-31 | 1993-09-28 | Sumitomo Electric Industries | Laser ablation method of preparing oxide superconducting films on elongated substrates |
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