JPS63140091A - Improvement of corrosion resistance in electroless ni-p plating substrate for magnetic disk - Google Patents
Improvement of corrosion resistance in electroless ni-p plating substrate for magnetic diskInfo
- Publication number
- JPS63140091A JPS63140091A JP28749786A JP28749786A JPS63140091A JP S63140091 A JPS63140091 A JP S63140091A JP 28749786 A JP28749786 A JP 28749786A JP 28749786 A JP28749786 A JP 28749786A JP S63140091 A JPS63140091 A JP S63140091A
- Authority
- JP
- Japan
- Prior art keywords
- electroless
- corrosion resistance
- substrate
- plating
- magnetic disk
- 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.)
- Granted
Links
- 239000000758 substrate Substances 0.000 title claims abstract description 31
- 238000007747 plating Methods 0.000 title claims abstract description 23
- 230000007797 corrosion Effects 0.000 title claims abstract description 18
- 238000005260 corrosion Methods 0.000 title claims abstract description 18
- 238000010438 heat treatment Methods 0.000 claims abstract description 19
- 229910018104 Ni-P Inorganic materials 0.000 claims abstract description 17
- 229910018536 Ni—P Inorganic materials 0.000 claims abstract description 17
- 229910000838 Al alloy Inorganic materials 0.000 claims abstract description 13
- 230000007704 transition Effects 0.000 claims abstract description 11
- 238000000034 method Methods 0.000 claims description 10
- 230000005415 magnetization Effects 0.000 claims description 9
- 230000006866 deterioration Effects 0.000 abstract 1
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 6
- 230000000694 effects Effects 0.000 description 3
- 238000000576 coating method Methods 0.000 description 2
- 230000004907 flux Effects 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 241000282693 Cercopithecidae Species 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 230000005389 magnetism Effects 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 230000003746 surface roughness Effects 0.000 description 1
- 238000004381 surface treatment Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C18/00—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating
- C23C18/16—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating by reduction or substitution, e.g. electroless plating
- C23C18/31—Coating with metals
- C23C18/32—Coating with nickel, cobalt or mixtures thereof with phosphorus or boron
- C23C18/34—Coating with nickel, cobalt or mixtures thereof with phosphorus or boron using reducing agents
- C23C18/36—Coating with nickel, cobalt or mixtures thereof with phosphorus or boron using reducing agents using hypophosphites
Landscapes
- Chemical & Material Sciences (AREA)
- General Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Magnetic Record Carriers (AREA)
- Manufacturing Of Magnetic Record Carriers (AREA)
- Chemically Coating (AREA)
- Preventing Corrosion Or Incrustation Of Metals (AREA)
Abstract
Description
（産業上の利用分野）
本発明は磁気ディスク用基盤の製造技術に係り、より詳
細には、アルミ合金基盤上に無電解Ｎｉ−Ｐメッキによ
り下地メッキ層を形成した磁気ディスク用基盤の耐食性
向上方法に関する。
（従来の技術及び解決しようとする問題点）一般に、磁
気ディスク用基盤としては、金属製ディスク基盤上に磁
性層を形成して製造されるが、記録密度の高密度化に伴
って磁気ディスク用基盤と磁気ヘッドとの間隔はますま
す小さくなり。
０．１μｍ程度まで狭くするよう要請されてきている。
そのため、基盤表面の欠陥はできるだけ小さく、かつ表
面粗度もできるだけ小さいことが要求される等、基盤の
平滑度が重要な特性となっている。
一方、磁気ディスクは、データの長期ファイリング用と
して使用されるものであるため、保存中に基盤の腐食に
よりふくれや生成物等が僅ずかでも発生すると、ヘッド
クラッシュの発生、記録の消失などによって記録媒体と
して用をなさなくなることから、基盤の耐食性が重要な
因子の１つとなっている。
これらの要請を考慮し、最近では、磁気ディスク用基盤
として、非磁性で、高速回転に耐える剛性を有し、優れ
た耐食性と良好な加工性を（（ｉｔえている等の観点か
ら、アルミ合金に無電解Ｎｉ−Ｐメッキを施して下地メ
ッキ層を形成した基盤が使われ始めてきている。
ところで、上記無電解Ｎｉ−Ｐメッキによる下地Ｎｉ−
Ｐ皮膜の耐食性の評価方法の１つとして。
この下地メッキを施したアルミ合金基盤を塩酸溶液中に
一定時間浸漬する方法がある。この方法によれば、耐食
性が悪い場合にはＮｉ−Ｐメッキ皮膜表面にふくれが発
生し、著しい場合にはアルミ素地を完全に溶かし、Ｎｉ
−Ｐメッキ皮膜が脱落することになる。
しかし、この耐食性の問題は従来より指摘されていなが
ら、これまでの無電解Ｎｉ−Ｐメッキアルミ合金基盤は
必ずしも耐食性が良好とは云えず。
そのため、様々な耐食性向上方法が試みられてはいるが
、有効な解決手段がないのが現状である。
本発明は、かＮる状況に鑑みてなされたものであって、
アルミ合金基盤上に無電解Ｎｉ−Ｐメッキによって下地
メッキ層を形成した磁気ディスク用基盤の耐食性、特に
耐酸性を向上し得る新規な方法を提供することを目的と
するものである。
（問題点を解決するための手段）
上記目的を達成するため、本発明者は、無電解Ｎｉ−Ｐ
メッキアルミ合金基盤に種々の表面処理、熱処理等を施
す実験研究を重ねた結果、その原理は必ずしも明らかで
はないが、該メッキ基盤を特定条件で熱処理することに
より可能であることを見い出したものである。
すなわち、本発明に係る磁気ディスク用無電解Ｎｉ−Ｐ
メッキ基盤の耐食性向上方法は、アルミ合金基盤上に無
電解Ｎｉ−Ｐメッキを施した後、該基盤を少なくとも１
回以上の頻度で１００℃以上、該メッキ層の磁化転移温
度未満の温度に加熱することを特徴とするものである。
以下に本発明を実施例に基づいて詳述する。
本発明法が対象とする磁気ディスク用基盤は、従来と同
様にして、アルミ合金基盤を製造し、無電解Ｎｉ−Ｐメ
ッキを施したものであり、特に製造条件、メッキ条件等
々は制限されない。
無電解Ｎｉ−Ｐメッキ処理後に加熱するに際しては、加
熱温度は１００’Ｃ以上必要であるが、しかし、該メッ
キ層の磁化転移温度未満の温度、望ましくは１５０〜２
５０℃とし、かつ該温度で少なくとも１回以上加熱する
。なお、１００℃未満では耐食性改善の効果が少なく、
また磁化転移温度以上に加熱すると下地Ｎｉ−Ｐメッキ
皮膜に構成変化が起こるので、磁化転移温度以上での加
熱は避けなければならない。すなわち、磁気ディスク用
下地として用いられる無電解Ｎｉ−Ｐ皮膜は、通常メッ
キのまＮの状態ではアモルファスのため非磁性を保って
いるが、磁気転移温度以上に加熱すると急激に結晶化が
進んで磁性を帯び、磁気ディスク用の下地基盤として用
いることができなくなるためである。
なお、本発明における磁化転移温度とは、その温度で特
定時間加熱した後の残留磁束密度（Ｂｒ）が２ガウス以
下となる温度と定義されるもので、Ｎｉ−Ｐの成膜速度
のコントロール等によってＰ濃度を高くすれば磁化転移
温度を高めることが可能である０通常の条件での無電解
Ｎｉ−Ｐメッキ皮膜の磁化転移温度は概ね２６０℃程度
であるが、本発明における加熱温度は高いほど望ましい
ので。
２６０℃以上の磁化転移温度となるような条件でメッキ
するのが望ましい。
また、１回の加熱時間は加熱温度により異なり、高温側
では１０分以上で良いが、品質の安定性、作業性等を考
慮すると３０〜６０分が適当である。
勿論、上記加熱条件によっては、加熱を２回以上繰り返
しても同様の効果が得られる。
次に本発明の実施例を示す。
（実施例）
５インチサイズのアルミ合金サブストレート上に無電解
Ｎｉ−ＰメッキによりＮｉ−Ｐ皮膜（磁化転移温度２６
０”Ｃ）を形成した基盤を試料とし。
恒温槽を用いて大気中で第１表に示す温度で６０分間加
熱した。
次いで、加熱後の試料について耐塩酸試験を実施した。
試験は、３５℃±１℃の温度に加熱した５％濃度の塩酸
溶液に２４時間浸漬して行い、試験後の試料の表面外観
の変化を調べた。また、振動試料型磁力計を用いて帯磁
性を測定し、加熱による影響を調べた。これらの結果は
第１表に併記する。
同表よりわかるように、無電解Ｎｉ−Ｐメッキアルミ合
金基盤に加熱処理をしない従来例（Ｎα１）では試料全
面にふくれが発生したが、加熱温度を高めることにより
ふくれの数は少なくなり（＆２）、適切な加熱処理をし
た本発明例（Ｎα３〜５）はいずれも全くふくれが発生
せず、しかも帯磁性も良好な結果を示した。なお、加熱
温度が高すぎるとふくれ発生は認められないものの、帯
磁性の点で悪化した（比較例＆６．７）。(Industrial Application Field) The present invention relates to a manufacturing technology for a magnetic disk substrate, and more specifically, to improve the corrosion resistance of a magnetic disk substrate in which a base plating layer is formed by electroless Ni-P plating on an aluminum alloy substrate. Regarding the method. (Prior art and problems to be solved) Generally, magnetic disk substrates are manufactured by forming a magnetic layer on a metal disk substrate. The distance between the base and the magnetic head is becoming smaller and smaller. There have been requests to narrow it down to about 0.1 μm. Therefore, the smoothness of the substrate is an important characteristic, such as requiring that the defects on the substrate surface be as small as possible and that the surface roughness be as small as possible. On the other hand, magnetic disks are used for long-term filing of data, so if even a slight amount of blisters or products occur due to corrosion of the base during storage, it may cause head crashes, loss of records, etc. The corrosion resistance of the substrate is one of the important factors since it becomes useless as a recording medium. Taking these demands into account, aluminum alloys have recently been developed as substrates for magnetic disks, which are non-magnetic, have the rigidity to withstand high-speed rotation, have excellent corrosion resistance, and have good workability. Substrates with a base plating layer formed by electroless Ni-P plating have begun to be used.
As one method for evaluating the corrosion resistance of P coatings. There is a method of immersing the aluminum alloy substrate coated with this base plating in a hydrochloric acid solution for a certain period of time. According to this method, if the corrosion resistance is poor, blistering will occur on the surface of the Ni-P plating film, and if it is severe, the aluminum base will be completely dissolved, and the Ni
-The P plating film will fall off. However, although this problem of corrosion resistance has been pointed out in the past, conventional electroless Ni-P plated aluminum alloy substrates cannot necessarily be said to have good corrosion resistance. Therefore, although various methods for improving corrosion resistance have been attempted, there is currently no effective solution. The present invention was made in view of the situation, and
The object of the present invention is to provide a new method for improving the corrosion resistance, particularly the acid resistance, of a magnetic disk substrate in which a base plating layer is formed by electroless Ni--P plating on an aluminum alloy substrate. (Means for Solving the Problems) In order to achieve the above object, the present inventor has developed an electroless Ni-P
As a result of repeated experimental research on applying various surface treatments, heat treatments, etc. to plated aluminum alloy substrates, we have discovered that although the principles are not necessarily clear, it is possible to do this by heat treating the plated substrate under specific conditions. be. That is, the electroless Ni-P for magnetic disk according to the present invention
A method for improving the corrosion resistance of a plated substrate includes applying electroless Ni-P plating on an aluminum alloy substrate, and then coating the substrate with at least one
The method is characterized in that the plated layer is heated to a temperature of 100° C. or higher and lower than the magnetization transition temperature of the plated layer at least once. The present invention will be explained in detail below based on examples. The magnetic disk substrate to which the method of the present invention is applied is an aluminum alloy substrate manufactured and subjected to electroless Ni--P plating in the same manner as conventional methods, and there are no particular restrictions on manufacturing conditions, plating conditions, etc. When heating after electroless Ni-P plating, the heating temperature needs to be 100'C or higher, but the temperature is lower than the magnetization transition temperature of the plating layer, preferably 150~200C.
50° C., and heated at least once at that temperature. Note that below 100°C, the effect of improving corrosion resistance is small;
Furthermore, heating above the magnetization transition temperature causes a change in the structure of the underlying Ni--P plating film, so heating above the magnetization transition temperature must be avoided. In other words, the electroless Ni-P film used as a base for magnetic disks is usually amorphous and nonmagnetic in the unplated N state, but when heated above the magnetic transition temperature, it rapidly crystallizes. This is because it becomes magnetic and cannot be used as an underlying base for magnetic disks. The magnetization transition temperature in the present invention is defined as the temperature at which the residual magnetic flux density (Br) becomes 2 Gauss or less after heating at that temperature for a specific time. It is possible to raise the magnetization transition temperature by increasing the P concentration according to Because it's so desirable. It is desirable to perform plating under conditions that result in a magnetization transition temperature of 260° C. or higher. Further, the heating time for one time varies depending on the heating temperature, and may be 10 minutes or more on the high temperature side, but 30 to 60 minutes is appropriate in consideration of quality stability, workability, etc. Of course, depending on the above heating conditions, the same effect can be obtained even if heating is repeated two or more times. Next, examples of the present invention will be shown. (Example) A Ni-P film (magnetic transition temperature 26
0"C) was used as a sample. It was heated for 60 minutes in the air at the temperature shown in Table 1 using a constant temperature bath. Next, a hydrochloric acid resistance test was conducted on the sample after heating. The samples were immersed in a 5% hydrochloric acid solution heated to a temperature of ±1°C for 24 hours, and changes in the surface appearance of the samples after the test were investigated. Magnetism was also measured using a vibrating sample magnetometer. The effects of heating were investigated.These results are also listed in Table 1.As can be seen from the table, in the conventional example (Nα1) in which the electroless Ni-P plated aluminum alloy substrate was not heat-treated, the entire surface of the sample was Although blistering occurred, the number of blisters decreased by increasing the heating temperature (&2), and in all of the examples of the present invention (Nα3 to 5) that were subjected to appropriate heat treatment, no blistering occurred at all, and there was no magnetic susceptibility. Good results were shown. Note that if the heating temperature was too high, although no blistering was observed, the magnetization deteriorated (Comparative Example & 6.7).
第１表
申傘 ０：残留磁束密度（Ｂｒ）が２ガウス以下Δ：
〃 が加熱時間が３０分未満の場合、２ガ
ウス以下を満足する
Ｘ： 〃 が２ガウス以上（発明の効果）
以上説明したように、本発明によれば、磁気ディスク用
下地Ｎｉ−Ｐメッキアルミ合金基盤を所定の温度で加熱
処理するので、下地Ｎｉ−Ｐメッキ皮膜にふくれ、脱落
等が全く起こらず、皮膜特性を損なうことなく、極めて
優れた耐食性を付与することができる。したがって、磁
気ディスクを長期使用しても基盤の平滑度を維持でき、
ヘッドクラッシュ、記録の消失等を防止可能となる。Table 1: Monkey umbrella 0: Residual magnetic flux density (Br) is 2 Gauss or less Δ:
〃 satisfies 2 Gauss or less when the heating time is less than 30 minutes: Since the alloy base is heat-treated at a predetermined temperature, the underlying Ni-P plating film does not blister or fall off at all, and extremely excellent corrosion resistance can be imparted without impairing the film properties. Therefore, even if the magnetic disk is used for a long time, the smoothness of the base can be maintained.
Head crashes, loss of records, etc. can be prevented.
Claims (1)
該基盤を少なくとも１回以上の頻度で１００℃以上、該
メッキ層の磁化転移温度未満の温度に加熱することを特
徴とする磁気ディスク用無電解Ｎｉ−Ｐメッキ基盤の耐
食性向上方法。After applying electroless Ni-P plating on the aluminum alloy substrate,
A method for improving corrosion resistance of an electroless Ni-P plated substrate for a magnetic disk, comprising heating the substrate at least once to a temperature of 100° C. or higher and lower than the magnetization transition temperature of the plated layer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP28749786A JPS63140091A (en) | 1986-12-02 | 1986-12-02 | Improvement of corrosion resistance in electroless ni-p plating substrate for magnetic disk |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP28749786A JPS63140091A (en) | 1986-12-02 | 1986-12-02 | Improvement of corrosion resistance in electroless ni-p plating substrate for magnetic disk |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63140091A true JPS63140091A (en) | 1988-06-11 |
| JPH0159359B2 JPH0159359B2 (en) | 1989-12-15 |
Family
ID=17718108
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP28749786A Granted JPS63140091A (en) | 1986-12-02 | 1986-12-02 | Improvement of corrosion resistance in electroless ni-p plating substrate for magnetic disk |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS63140091A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5302434A (en) * | 1992-08-07 | 1994-04-12 | International Business Machines Corporation | Magnetic recording disk for contact recording |
| US5307223A (en) * | 1992-08-07 | 1994-04-26 | International Business Machines Corporation | Magnetic recording disk file for contact recording |
Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB870060A (en) * | 1956-08-08 | 1961-06-07 | Pechiney Prod Chimiques Sa | Improvements in or relating to the plating of metallic surfaces |
| JPS53133407A (en) * | 1977-04-27 | 1978-11-21 | Hitachi Ltd | Manufacture of high recording density magnetic disc |
| JPS54145335A (en) * | 1978-05-02 | 1979-11-13 | Kobe Steel Ltd | Surface reforming of metal molding |
| JPS59177726A (en) * | 1983-03-28 | 1984-10-08 | Toshiba Corp | Vertical magnetic disc recording medium |
| JPS60224127A (en) * | 1984-04-20 | 1985-11-08 | Tokico Ltd | Manufacture of magnetic disk |
| JPS60261022A (en) * | 1984-06-07 | 1985-12-24 | C Uyemura & Co Ltd | Magnetic recording medium |
| JPS6196522A (en) * | 1984-10-18 | 1986-05-15 | Seiko Epson Corp | Manufacture of magnetic recording body |
| JPS61204831A (en) * | 1985-03-06 | 1986-09-10 | Sony Corp | Magnetic disk |
| JPS61210521A (en) * | 1985-03-15 | 1986-09-18 | Sony Corp | Production of magnetic disk |
| JPS61224118A (en) * | 1985-03-29 | 1986-10-04 | Hitachi Metals Ltd | Magnetic disc |
| JPS61224139A (en) * | 1985-03-29 | 1986-10-04 | Hitachi Metals Ltd | Production of magnetic recording medium |
| JPS61246380A (en) * | 1985-04-23 | 1986-11-01 | Nec Corp | Production of magnetic disk substrate |
-
1986
- 1986-12-02 JP JP28749786A patent/JPS63140091A/en active Granted
Patent Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB870060A (en) * | 1956-08-08 | 1961-06-07 | Pechiney Prod Chimiques Sa | Improvements in or relating to the plating of metallic surfaces |
| JPS53133407A (en) * | 1977-04-27 | 1978-11-21 | Hitachi Ltd | Manufacture of high recording density magnetic disc |
| JPS54145335A (en) * | 1978-05-02 | 1979-11-13 | Kobe Steel Ltd | Surface reforming of metal molding |
| JPS59177726A (en) * | 1983-03-28 | 1984-10-08 | Toshiba Corp | Vertical magnetic disc recording medium |
| JPS60224127A (en) * | 1984-04-20 | 1985-11-08 | Tokico Ltd | Manufacture of magnetic disk |
| JPS60261022A (en) * | 1984-06-07 | 1985-12-24 | C Uyemura & Co Ltd | Magnetic recording medium |
| JPS6196522A (en) * | 1984-10-18 | 1986-05-15 | Seiko Epson Corp | Manufacture of magnetic recording body |
| JPS61204831A (en) * | 1985-03-06 | 1986-09-10 | Sony Corp | Magnetic disk |
| JPS61210521A (en) * | 1985-03-15 | 1986-09-18 | Sony Corp | Production of magnetic disk |
| JPS61224118A (en) * | 1985-03-29 | 1986-10-04 | Hitachi Metals Ltd | Magnetic disc |
| JPS61224139A (en) * | 1985-03-29 | 1986-10-04 | Hitachi Metals Ltd | Production of magnetic recording medium |
| JPS61246380A (en) * | 1985-04-23 | 1986-11-01 | Nec Corp | Production of magnetic disk substrate |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5302434A (en) * | 1992-08-07 | 1994-04-12 | International Business Machines Corporation | Magnetic recording disk for contact recording |
| US5307223A (en) * | 1992-08-07 | 1994-04-26 | International Business Machines Corporation | Magnetic recording disk file for contact recording |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0159359B2 (en) | 1989-12-15 |
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