JPH0310165B2 - - Google Patents
Info
- Publication number
- JPH0310165B2 JPH0310165B2 JP58068053A JP6805383A JPH0310165B2 JP H0310165 B2 JPH0310165 B2 JP H0310165B2 JP 58068053 A JP58068053 A JP 58068053A JP 6805383 A JP6805383 A JP 6805383A JP H0310165 B2 JPH0310165 B2 JP H0310165B2
- Authority
- JP
- Japan
- Prior art keywords
- less
- alloy
- content
- intermetallic compounds
- present
- 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
- 229910045601 alloy Inorganic materials 0.000 claims description 12
- 239000000956 alloy Substances 0.000 claims description 12
- 239000000758 substrate Substances 0.000 claims description 11
- 239000012535 impurity Substances 0.000 claims description 9
- 229910052742 iron Inorganic materials 0.000 claims description 9
- 229910052804 chromium Inorganic materials 0.000 claims description 8
- 229910052802 copper Inorganic materials 0.000 claims description 8
- 229910052759 nickel Inorganic materials 0.000 claims description 7
- 229910052719 titanium Inorganic materials 0.000 claims description 7
- 229910052710 silicon Inorganic materials 0.000 claims description 6
- 229910052725 zinc Inorganic materials 0.000 claims description 3
- 229910000838 Al alloy Inorganic materials 0.000 description 16
- 229910000765 intermetallic Inorganic materials 0.000 description 14
- 230000000694 effects Effects 0.000 description 7
- 239000000463 material Substances 0.000 description 6
- 238000005498 polishing Methods 0.000 description 4
- 238000007670 refining Methods 0.000 description 3
- 230000007547 defect Effects 0.000 description 2
- 238000001914 filtration Methods 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 238000005096 rolling process Methods 0.000 description 2
- 230000003746 surface roughness Effects 0.000 description 2
- 229910018084 Al-Fe Inorganic materials 0.000 description 1
- 229910018134 Al-Mg Inorganic materials 0.000 description 1
- 229910018192 Al—Fe Inorganic materials 0.000 description 1
- 229910018191 Al—Fe—Si Inorganic materials 0.000 description 1
- 229910018467 Al—Mg Inorganic materials 0.000 description 1
- 229910018580 Al—Zr Inorganic materials 0.000 description 1
- KZBUYRJDOAKODT-UHFFFAOYSA-N Chlorine Chemical compound ClCl KZBUYRJDOAKODT-UHFFFAOYSA-N 0.000 description 1
- 238000005275 alloying Methods 0.000 description 1
- 238000000137 annealing Methods 0.000 description 1
- 239000010953 base metal Substances 0.000 description 1
- 238000005253 cladding Methods 0.000 description 1
- 238000009749 continuous casting Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 229910052748 manganese Inorganic materials 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000004080 punching Methods 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/62—Record carriers characterised by the selection of the material
- G11B5/73—Base layers, i.e. all non-magnetic layers lying under a lowermost magnetic recording layer, e.g. including any non-magnetic layer in between a first magnetic recording layer and either an underlying substrate or a soft magnetic underlayer
- G11B5/739—Magnetic recording media substrates
- G11B5/73911—Inorganic substrates
- G11B5/73917—Metallic substrates, i.e. elemental metal or metal alloy substrates
- G11B5/73919—Aluminium or titanium elemental or alloy substrates
Description
この発明は、高硬度および高強度を有し、かつ
素地中に金属間化合物が均一微細に存在し、さら
に非金属介在物がほとんど存在しない、特にこれ
らの特性が要求される磁気デイスクの基板として
用いた場合に、磁気デイスクの高記録密度化を可
能にするAl合金に関するものである。
従来、磁気デイスクとして、例えばAl合金製
基板の表面に磁気記録媒体の皮膜を形成したもの
が知られており、通常、前記基板としてはAA規
格5086Al合金（Mn：0.20〜0.70％、Mg：3.5〜
4.5％、Cr：0.05〜0.25％、Alおよび不可避不純
物：残り）が使用されている。
一方、近年、磁気デイスクの記憶容量の増大、
アクセス時間の短縮、１ビツト当りの価格の低
減、小型化、および軽量化に対する要求が強くな
されるようになつており、これらの要求を満足さ
せるためには、磁気デイスクの磁気記録の高密度
化が不可欠の要件である。
このような磁気記録の高密度化をはかるために
は、磁気記録媒体に欠陥がなく、かつその表面が
平滑で、しかも磁気記録媒体の膜厚が薄く均一で
あることが必要である。
しかし、磁気記録媒体を薄くした場合、基板の
素地に大きな金属間化合物や非金属介在物が存在
すると、これがビツト落（情報の一部が記録され
ない現象）などの欠陥の原因となることから、大
きな金属間化合物や非金属介在物の存在しない基
板が必要となるが、上記の5086Al合金において
は、溶湯過などにより非金属介在物が著しく低
減した状態にすることができるが、金属間化合物
が比較的大寸の状態で存在することから、磁気記
録媒体の薄膜化にも限度があるものである。
また、磁気デイスク表面の平滑さは、とりもな
おさず基板表面の平滑さによるものであり、した
がつて基板には鏡面仕上げが施されるが、上記の
5086Al合金は、これらの研磨を容易とするほど
の十分満足する硬さをもつものではない。
さらに、基板の強度が高いほど磁気デイスクの
小型化、軽量化、および薄肉化がはかれることに
なるが、同様に上記5086Al合金は、これらを実
現するのに十分な高強度をもつものではない。
そこで、本発明者等は、上述のような観点か
ら、高硬度および高強度を有し、非金属介在物が
存在しないことは勿論のこと、素地中に分布する
金属間化合物が微細な組織を有するAl合金を開
発すべく研究を行なつた結果、
Mn：0.1〜0.5％、
Mg：3.0〜5.0％、
Zn：0.5〜3.0％、
を含有し、さらに必要に応じて、
Zr：0.02〜0.5％、
を含有し、かつ不可避不純物としてのSi，Fe，
Cu，Cr，Ni、およびTiの含有量が、それぞれ、
Si：0.20％以下、
Fe：0.50％以下、
Cu：0.30％以下、
Cr：0.05％以下、
Ni：0.04％以下、
Ti：0.01％以下、
であり、残りがAlとその他の不可避不純物から
なる組成（以上重量％、以下％は重量％を示す）
を有するAl合金は、上記の特性をすべて兼ね備
え、したがつてこのAl合金を磁気デイスクの基
板として用いた場合には磁気デイスクにおける磁
気記録の高密度化が可能となるという知見を得た
のである。
この発明は、上記知見にもとづいてなされたも
のであつて、以下に成分組成範囲を上記の通りに
限定した理由を説明する。
(a) Mn
Mn成分には、不可避不純物たるFeおよびSiに
よつて形成されるAl−FeおよびAl−Fe−Siの金
属間化合物を微細化する作用があるが、その含有
量が0.1％未満では前記作用に所望の効果が得ら
れず、一方0.5％を越えて含有させると、Mn自体
が金属間化合物を形成する場合が生ずることか
ら、その含有量を0.1〜0.5％と定めた。
(b) Mg
Mg成分には、合金の硬さおよび強度を著しく
向上させる作用があるが、その含有量が3.0％未
満では所望の高硬度および高強度を確保すること
ができず、一方5.0％を越えて含有させると、圧
延加工が困難になると共に、大きなAl−Mg系の
金属間化合物が形成されるようになることから、
その含有量を3.0〜5.0％と定めた。
(c) Zn
Zn成分には、大きな金属間化合物を形成する
ことなしに、合金の硬さを向上させる作用がある
が、その含有量が0.5％未満では所望の硬さ向上
効果が得られず、一方3.0％を越えて含有させる
と、鋳造性および圧延加工性が劣化するようにな
ることから、その含有量を0.5〜3.0％と定めた。
(d) Zr
Zr成分には、合金の結晶粒および金属間化合
物を微細化する作用があるので必要に応じて含有
されるが、その含有量が0.02％未満では所望の微
細化効果が得られず、一方0.5％を越えて含有さ
せると、大きなAl−Zr系金属間化合物が形成さ
れるようになることから、その含有量を0.02〜
0.5％と定めた。
(e) 不可避不純物としてのSi，Fe，Cu，Cr，
Ni，およびTi
これらの成分には、いずれも金属間化合物を形
成する作用があり、しかもその含有量が下記の許
容値を越えると、いずれの場合も大きな金属間化
合物を形成するようになることから、それぞれ、
その含有量を、Si：0.20％以下、Fe：0.50％以
下、Cu：0.30％以下、Cr：0.05％以下、Ni：0.04
％以下、およびTi：0.01％以下と定めた。
つぎに、この発明のAl合金を実施例により具
体的に説明する。
実施例
市販の純度：99.7％以上を有するAl地金を溶解
し、これに合金元素を添加して、それぞれ第１表
に示される成分組成をもつたAl合金溶湯に調製
した後、塩素ガスを吹き込んで脱ガスし、沈静処
理を行ない、さらに非金属介在物を除去するため
に耐火物製フイルタにて過してから、直接冷却
This invention has high hardness and high strength, has intermetallic compounds uniformly and finely present in the base material, and has almost no nonmetallic inclusions, and is particularly suitable for use as a magnetic disk substrate that requires these characteristics. This invention relates to an Al alloy that enables high recording density of magnetic disks when used. Conventionally, magnetic disks have been known, for example, having a magnetic recording medium film formed on the surface of an Al alloy substrate, and the substrate is usually made of AA standard 5086 Al alloy (Mn: 0.20-0.70%, Mg: 3.5%). ~
4.5%, Cr: 0.05-0.25%, Al and unavoidable impurities: remainder) are used. On the other hand, in recent years, the storage capacity of magnetic disks has increased,
There are increasing demands for shorter access times, lower prices per bit, smaller size, and lighter weight.In order to meet these demands, it is necessary to increase the density of magnetic recording in magnetic disks. is an essential requirement. In order to achieve such high density magnetic recording, it is necessary that the magnetic recording medium be free from defects, have a smooth surface, and have a thin and uniform film thickness. However, when making a magnetic recording medium thinner, if large intermetallic compounds or nonmetallic inclusions are present in the base material of the substrate, this can cause defects such as bit dropout (a phenomenon in which some information is not recorded). A substrate without large intermetallic compounds or non-metallic inclusions is required, but in the 5086Al alloy mentioned above, non-metallic inclusions can be significantly reduced by molten metal filtration, etc. Since the magnetic recording medium exists in a relatively large size, there is a limit to how thin the magnetic recording medium can be made. Furthermore, the smoothness of the magnetic disk surface is primarily due to the smoothness of the substrate surface, and therefore the substrate is given a mirror finish, but the above
5086Al alloy does not have sufficient hardness to facilitate these polishing operations. Furthermore, the higher the strength of the substrate, the smaller, lighter, and thinner the magnetic disk will be, but the 5086Al alloy does not have a sufficiently high strength to achieve these goals. Therefore, from the above-mentioned viewpoints, the present inventors have determined that the material has high hardness and strength, is free from non-metallic inclusions, and has a fine structure in which the intermetallic compounds distributed in the material have a fine structure. As a result of conducting research to develop an Al alloy containing Mn: 0.1 to 0.5%, Mg: 3.0 to 5.0%, Zn: 0.5 to 3.0%, and further containing Zr: 0.02 to 0.5 as necessary. %, and contains Si, Fe, as unavoidable impurities.
The content of Cu, Cr, Ni, and Ti is, respectively, Si: 0.20% or less, Fe: 0.50% or less, Cu: 0.30% or less, Cr: 0.05% or less, Ni: 0.04% or less, Ti: 0.01% or less. , with the remainder consisting of Al and other unavoidable impurities (the above weight percent, the below weight percent)
The researchers discovered that an Al alloy with a . This invention was made based on the above knowledge, and the reason why the component composition range was limited as described above will be explained below. (a) Mn The Mn component has the effect of refining Al-Fe and Al-Fe-Si intermetallic compounds formed by Fe and Si, which are unavoidable impurities, but its content is less than 0.1%. However, if the content exceeds 0.5%, Mn itself may form an intermetallic compound, so the content was set at 0.1 to 0.5%. (b) Mg The Mg component has the effect of significantly improving the hardness and strength of the alloy, but if its content is less than 3.0%, the desired high hardness and strength cannot be achieved; If the content exceeds 100%, rolling becomes difficult and large Al-Mg-based intermetallic compounds are formed.
Its content was set at 3.0-5.0%. (c) Zn The Zn component has the effect of improving the hardness of the alloy without forming large intermetallic compounds, but if its content is less than 0.5%, the desired hardness improvement effect cannot be obtained. On the other hand, if the content exceeds 3.0%, the castability and rolling workability deteriorate, so the content was set at 0.5 to 3.0%. (d) Zr The Zr component has the effect of refining the crystal grains and intermetallic compounds of the alloy, so it is included as necessary, but if its content is less than 0.02%, the desired refining effect cannot be obtained. On the other hand, if the content exceeds 0.5%, large Al-Zr based intermetallic compounds will be formed, so the content should be reduced from 0.02 to 0.5%.
It was set at 0.5%. (e) Si, Fe, Cu, Cr as inevitable impurities,
Ni, Ti These components all have the effect of forming intermetallic compounds, and if their content exceeds the allowable value below, large intermetallic compounds will be formed in either case. From, respectively,
The content is Si: 0.20% or less, Fe: 0.50% or less, Cu: 0.30% or less, Cr: 0.05% or less, Ni: 0.04
% or less, and Ti: 0.01% or less. Next, the Al alloy of the present invention will be specifically explained using examples. Example A commercially available Al base metal having a purity of 99.7% or more is melted, alloying elements are added to it to prepare a molten Al alloy having the composition shown in Table 1, and then chlorine gas is added. Blow to degas, settle, pass through a refractory filter to remove non-metallic inclusions, and then cool directly.
【表】
連続鋳造法にて幅：1000mm×長さ：2500mm×厚
さ：600mmの寸法をもつた鋳塊とし、ついで、こ
の鋳塊に500〜540℃の範囲内の温度に12時間保持
後放冷の熱処理を施した後、この鋳塊の上下両面
を厚さ15mmに亘つて面削して厚さ：570mmの鋳塊
とした状態で、500℃に加熱して熱間圧延を施し
て板厚：５mmの熱延板とし、引続いて、この熱延
板に冷間圧延を施して板厚：２mmの冷延板とし、
さらにこの冷延板より直径：200mmの円板をプレ
スにて打抜くことによつて、本発明Al合金１〜
９および従来の5086Al合金の円板をそれぞれ製
造した。
つぎに、この結果得られた本発明Al合金１〜
９および5086Al合金の円板に、350℃の温度に２
時間保持の加圧焼鈍を施した後、荒研磨を行な
い、さらにバフ研磨を施して、その表面を鏡面仕
上げした。なお、研磨代は0.2mmであつた。それ
ぞれの円板に要したバフ研磨時間を測定すると共
に、鏡面仕上げ面の表面粗さを測定し、また鏡面
仕上げ面における金属間化合物の最大寸法を測[Table] An ingot with the dimensions of width: 1000 mm x length: 2500 mm x thickness: 600 mm is made using the continuous casting method, and then the ingot is kept at a temperature within the range of 500 to 540 °C for 12 hours. After heat treatment by allowing the ingot to cool, the top and bottom sides of this ingot were faceted to a thickness of 15 mm to obtain an ingot with a thickness of 570 mm.The ingot was then heated to 500℃ and hot rolled. A hot-rolled plate with a plate thickness of 5 mm, and then cold-rolled on this hot-rolled plate to produce a cold-rolled plate with a plate thickness of 2 mm,
Furthermore, by punching out a disk with a diameter of 200 mm from this cold-rolled sheet using a press, Al alloys 1 to 1 of the present invention
9 and conventional 5086Al alloy discs were manufactured, respectively. Next, the resulting Al alloys of the present invention 1~
9 and 5086Al alloy disks at a temperature of 350℃.
After time-hold pressure annealing, rough polishing and buff polishing were performed to give the surface a mirror finish. Note that the polishing allowance was 0.2 mm. In addition to measuring the buffing time required for each disk, the surface roughness of the mirror-finished surface was also measured, and the maximum dimension of the intermetallic compound on the mirror-finished surface was measured.
【表】
定した。さらに、上記本発明Al合金１〜９およ
び5086Al合金について、機械的性質も測定した。
これらの測定結果を第２表に示した。
第２表に示される結果から、本発明Al合金１
〜９は、いずれも従来の5086Al合金に比して、
高強度および高硬度を有し、このことはより短か
いバフ研磨時間で表面粗さのより良好な鏡面に仕
上げることができることからも明らかであり、ま
た素地中に存在する非金属介在物のサイズも著し
く小さいものである。
なお、この発明のAl合金は、例えば上記の
5086Al合金等と市販のAl合金とのクラツド材と
して用いてもよく、この場合磁気記録媒体の皮膜
が形成されるのは、この発明のAl合金の表面上
であることは勿論である。
上述のように、この発明のAl合金は、高硬度
をもつので、これを磁気デイスクの基板として用
いる場合には、比較的短かいバフ研磨時間で、表
面をきわめてすぐれた鏡面に仕上げることができ
るばかりでなく、素地中に存在する金属間化合物
が微細にして均一であり、しかも非金属介在物が
溶湯過などの手段により除去されているので、
磁気記録媒体の膜厚を薄くすることができること
から、磁気記録の高密度化をはかることができ、
さらに高強度を有するので、磁気デイスクの小型
化および軽量化が可能となるなど工業上有用な特
性を有するのである。[Table] Established. Furthermore, mechanical properties were also measured for the above-mentioned Al alloys 1 to 9 of the present invention and 5086 Al alloy.
The results of these measurements are shown in Table 2. From the results shown in Table 2, the present invention Al alloy 1
-9 are all compared to the conventional 5086Al alloy,
It has high strength and hardness, which is clear from the fact that it can be finished to a mirror surface with better surface roughness in a shorter buffing time, and the size of nonmetallic inclusions present in the base material is also extremely small. Note that the Al alloy of the present invention can be used, for example, as described above.
It may also be used as a cladding material between a 5086Al alloy or the like and a commercially available Al alloy, and in this case, it goes without saying that the film of the magnetic recording medium is formed on the surface of the Al alloy of the present invention. As mentioned above, the Al alloy of the present invention has high hardness, so when it is used as a substrate for a magnetic disk, the surface can be finished to an excellent mirror finish with a relatively short buffing time. Not only that, the intermetallic compounds present in the matrix are fine and uniform, and non-metallic inclusions are removed by means such as molten metal filtration.
Since the film thickness of the magnetic recording medium can be made thinner, it is possible to increase the density of magnetic recording.
Furthermore, since it has high strength, it has industrially useful properties such as making it possible to make magnetic disks smaller and lighter.
Claims (1)
成（以上重量％）を有し、かつ不可避不純物とし
てのSi，Fe，Cu，Cr，Ni，およびTiの含有量
が、同じく重量％で、 Si：0.20％以下、 Fe：0.50％以下、 Cu：0.30％以下、 Cr：0.05％以下、 Ni：0.04％以下、 Ti：0.01％以下、 であることを特徴とする磁気デイスク基板用Al
合金。 ２ Mn：0.1〜0.5％、 Mg：3.0〜5.0％、 Zn：0.5〜3.0％、 を含有し、さらに、 Zr：0.02〜0.5％、 を含有し、残りがAlと不可避不純物からなる組
成（以上重量％）を有し、かつ不可避不純物とし
てのSi，Fe，Cu，Cr，Ni，およびTiの含有量
が、同じく重量％で、 Si：0.20％以下、 Fe：0.50％以下、 Cu：0.30％以下、 Cr：0.05％以下、 Ni：0.04％以下、 Ti：0.01％以下、 であることを特徴とする磁気デイスク基板用Al
合金。[Scope of Claims] 1 Contains Mn: 0.1 to 0.5%, Mg: 3.0 to 5.0%, Zn: 0.5 to 3.0%, and the remainder is Al and unavoidable impurities (weight %), And the content of Si, Fe, Cu, Cr, Ni, and Ti as unavoidable impurities is the same in weight%: Si: 0.20% or less, Fe: 0.50% or less, Cu: 0.30% or less, Cr: 0.05% or less. , Ni: 0.04% or less, Ti: 0.01% or less, Al for magnetic disk substrates
alloy. 2 Contains Mn: 0.1 to 0.5%, Mg: 3.0 to 5.0%, Zn: 0.5 to 3.0%, and further contains Zr: 0.02 to 0.5%, with the remainder consisting of Al and inevitable impurities (the above weight%), and the content of Si, Fe, Cu, Cr, Ni, and Ti as unavoidable impurities is the same weight%, Si: 0.20% or less, Fe: 0.50% or less, Cu: 0.30%. Al for magnetic disk substrate characterized by: Cr: 0.05% or less, Ni: 0.04% or less, Ti: 0.01% or less.
alloy.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58068053A JPS59193540A (en) | 1983-04-18 | 1983-04-18 | Al alloy for substrate of magnetic disk |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58068053A JPS59193540A (en) | 1983-04-18 | 1983-04-18 | Al alloy for substrate of magnetic disk |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS59193540A JPS59193540A (en) | 1984-11-02 |
| JPH0310165B2 true JPH0310165B2 (en) | 1991-02-13 |
Family
ID=13362648
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP58068053A Granted JPS59193540A (en) | 1983-04-18 | 1983-04-18 | Al alloy for substrate of magnetic disk |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS59193540A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61199046A (en) * | 1985-02-28 | 1986-09-03 | Showa Alum Corp | Aluminum alloy material for photosensitive drum of electrophotographic copying machine |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS56105846A (en) * | 1980-01-28 | 1981-08-22 | Kobe Steel Ltd | Production of al base alloy plate for magnetic disc |
| JPS5866789A (en) * | 1981-10-16 | 1983-04-21 | Hitachi Ltd | Heat accumulator |
-
1983
- 1983-04-18 JP JP58068053A patent/JPS59193540A/en active Granted
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS56105846A (en) * | 1980-01-28 | 1981-08-22 | Kobe Steel Ltd | Production of al base alloy plate for magnetic disc |
| JPS5866789A (en) * | 1981-10-16 | 1983-04-21 | Hitachi Ltd | Heat accumulator |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS59193540A (en) | 1984-11-02 |
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