JPS60110852A - Heat treatment of disk for magnetic disk - Google Patents

Abstract

PURPOSE:To prevent cracking during anodic oxidation and film formation when a magnetic Al disk is manufactured, by carrying out strain relief heat treatment at the highest temp. in the manufacturing process or above. CONSTITUTION:An Al plate is heat-treated, refined, mechanically worked, and subjected to strain relief annealing to relieve the working strain. At this time, the strain relief heat treatment temp. is set at the highest temp. in a process for manufacturing a magnetic disk or above. The grains can be conditioned during the strain relief annealing, so a disk for a magnetic disk preventing cracking due to a change of the grains anodic oxidation, sputtering and gamma-convertion is obtd.

Description

[Detailed Description of the Invention] [Sentence 11 of the Invention; Field J "Hardness and sharpness" relates to a strain relief annealing VC that can be applied to a 14f 4 degree disc V coating.

[Prior art]

A rough outline of the manufacturing process of a commercial recording wax disc using aluminum (hereinafter abbreviated as aluminum) as a base material.

The "annealing" and "strain relief annealing" performed in the process shown in the figure are for tempering after rolling and removing strain during machining. Aluminum crystal grains become coarser as the heating temperature increases, and once the crystal grains have grown larger, the original size VC will not return to its original size. Since it is desirable that the thickness of the trough is smaller, the temperature of the valley annealing is set at around 220° C. for TEA [for example, "strain relief annealing"] depending on the purpose.

When strain relief is performed at this annealing temperature, the temperature is sufficient to remove strain, and the effect of strain relief annealing increases.

＃、When the net temperature increases, the crystal grains become fine. 9. Since the mechanical properties are also compromised, the conventional temperature conditions for annealing are reasonable for strain relief work.

By the way, the substrate V thus manufactured was subjected to alumite processing and coated with a magnetic film (sputtering).

Based on the history of R conversion of magnetic films, cracks often occur on the film surface when a magnetic disk is obtained through a defeating process (not shown). When I chased the prisoner to death, I found that the substrate was in the oxidation process, and the temperature up to the smitter process was about 300 degrees Celsius. As a result, the crystal grains in the substrate become coarser, which causes movement between the grains.

It was found that stress was generated in the alumite group and the sputter 1 layer, causing cracks in the film surface.

[Summary of the invention]

This invention was made to resolve such problems (
/, ), as the heating temperature of the aluminum material increases tC, the crystal grains gradually increase in size to 111, and the temperature of the maximum 15 crystals added during the magnetic disk manufacturing process and ItiJ, etc.

Strain relief annealing is performed at a temperature higher than that to eliminate any change in the crystal grains after strain relief annealing, and then sigma backforming is performed to reduce the movement of crystal grains.

TL for No1 Izumi! h'JI? r: It is something that is prevented from occurring.

[Mitsuru 1 taro v) ha brother Akira] That's all about this invention! Example 1 Full drawing t I'll explain to you 1st brother 〇 The structure of the magnetic disk disk is all aluminum pressure treated and heat treated as an aluminum plate and tempered 0 The aluminum plate is machined 9 Machining distortion occurs due to machining In order to eliminate the distortion caused by machining, strain relief annealing is performed to eliminate the distortion caused by machining. The temperature required for strain relief annealing is approximately 220°C, and at this temperature, crystal grains have fine orientation points. Conventionally, V-processing was carried out like this, but in this precedent, r
A heating jar with a temperature of about 300℃,'! 2. When performing the oxidation process (not shown), heating is also required at approximately 300°C, so by setting the annealing temperature to the same or higher temperature, it is possible to This is based on the fact that the crystal grains do not change above and below F by +1 degrees. In other words, the further the temperature increases, the thicker the crystal grains become, and the crystal grains do not change when the temperature rises or falls below that temperature.
By setting these crystal grains, it is possible to prevent distortion due to changes in crystal grains from occurring during alumite and snow ivy, and later during r-kakoki.

In addition, in the oxidation process (not shown) or R Kakoki, za
The temperature is generally ~350°C, and good performance cannot be achieved at temperatures higher than this (/J temperature).

In addition, the annealing after pressing is not enough, but it is annealing to remove distortion! 7
It goes without saying that even if you jump 15 degrees in advance with a pitch of 164 degrees, the same effect will be obtained by 1;t.

[96 light effect] In this way, by annealing at the highest temperature or higher temperature during the process, the crystal grains Changes in tkoyo/S stop 6 raw materials are removed, anodized, and -
There is no one factor that causes cracks in the sputtered film with the image quality film.

As described above, in the 6 cases where the tc magnetic disk is manufactured, the peak characteristic j
Creating cracks or cracks in the underlying alumite will cause signal errors, and one of the causes of this is processing with a constant crystal grain, which eliminates fine defects. In that sense, a great effect can be obtained.

[Brief explanation of the drawing]

The figure is a diagram showing a magnetic disk manufacturing process for explaining the present invention. Agent Masuo Oiwa

Claims (1)

[Claims] 1. In the manufacturing process of a magnetic disk using aluminum as a base material, the strain 14y, the heat treatment temperature r, and the maximum yA expansion in the magnetic disk manufacturing process are equivalent to or higher than that. Do you mean temperature? Heat treatment force method for magnetic disks with l'pm. 2. Heat treatment of disks for magnetic disks, which is characterized by a temperature equal to or higher than the highest temperature in the disk manufacturing process after pre-heating and tempering after the pressing process. Method.