JPS61219425A - Flat straightening method for aluminum plate material - Google Patents

Abstract

PURPOSE:To obtain the Al plate material having precise flatness by heating numerous stacked Al materials and by pinching them between the heated upper and lower bolsters. CONSTITUTION:The upper and lower bolsters 3, 4 of the main body 1 of pressure press are heated to refining temp. by heating heaters 5, 6. An Al plate material 11 is subjected to heat conduction heating with pressing slightly by pinching via aluminum spacer 12 that numerous Al plate materials 11 are stacked on this bolsters 3, 4. The heaters 9, 10 for heating the side face are actuated if necessary. With this straightening method, a sufficient flatness is obtd. and useful plate for a magnetic disc is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This is a method for straightening the flatness of an aluminum plate material that requires flatness, such as a magnetic disk.

Conventional technology The conventional method for straightening the flatness of aluminum plates is as follows:
As shown in Figure 2, a large number of stacked aluminum plates 1
1 between the aluminum spacers 12 and 12, and if necessary, sandwich the aluminum spacers in the middle between the bottom plate 13 and the weight 14, and hold it with a weight of about 200 to 500 kg , a method of softening by heating is adopted.

In the conventional method described above, if aluminum spacers are inserted in multiple layers in the middle of an aluminum plate, the flatness of the aluminum plate improves, but productivity decreases. Further, it takes a long processing time, for example, 5 hours for heating and 5 hours for cooling in the furnace, and has the disadvantage of high softening cost. Moreover, the flatness of the treated aluminum plate material cannot be said to be sufficient.

Means for solving illumination points The present invention is a method for flattening aluminum plates, which is characterized by heating a large number of stacked aluminum plates and squeezing them between heated upper and lower bolsters of a pressure press. be.

The heating temperature of aluminum plate material is the refining temperature (H24250
A suitable material is O material (350°C), which is placed between the bolsters that have been heated to the tempering temperature and kept under pressure for about 2 minutes. It is something to do.

The strength of the load varies depending on the size of the aluminum plate to be processed, but is preferably in the range of 0.8 to 1.2 kg/mm2 per surface. Surface pressure J is 1.2kg/m
If it exceeds m2, the product's dimensional tolerance will be exceeded due to changes in the outer and inner diameter dimensions, so it is necessary to create a cumulative period that takes into account the dimensional changes in advance, which causes difficulties in dimensional control.

Further, if the surface pressure is lower than 0.8 kg/mm2, the flatness of the aluminum plate material is not good due to springback due to residual stress.

To heat an aluminum plate, the plate is placed between heated upper and lower bolsters and heated by heat conduction from above and below, or by a combination of heating from the sides. In either case, if there is a gap between the plates, the heating time will be longer, so it is better to apply pressure to the extent that the plates are in close contact with each other.

Further, the aluminum plate material may be heated separately in a heating furnace.

An example of the embodiment will be described based on the drawings. FIG. 1 is a front view of an apparatus suitable for carrying out the present invention, in which 1 is a pressure press body, 2 is a heat insulating material, and 3 is a bolster. 14 is a lower bolster; 15 is a heater for heating the bolster; and 6 is a heater for heating the bolster. 7 is a ram, 8 is a cylinder, and side heaters 9 and 10 are installed as appropriate.

Heater 5.6 is used to heat Ni Bolster 3 and Lower Bolster 4 to the tempering temperature.
A stack of 50 donut-shaped aluminum plates 11 with an outer diameter of 360 mm and an inner diameter of 167 mm is sandwiched between aluminum spacers 12, and the aluminum plates 11 are heated by thermal conduction while being lightly pressurized, and then heated to 78,000 k.
g (1, Okq/mm2) (r) Apply the load for about 2 minutes or I
``It's J.

Although the side heating heater is not operated in this embodiment, it is operated as appropriate depending on the type and quantity of the aluminum plate material 11.

Effect of "L" The flatness of the aluminum plate treated according to the above example was 0.06 mm. On the other hand, using the conventional method shown in Figure 2, heating was performed in a batch furnace, and the temperature was 200 kQ.
When a load of (0,0025kQ/mm2) was applied (), the flatness was 0.14, regardless of the length of processing time.
It was mm.

As described above, according to the present invention, an aluminum plate having much more precise flatness than the conventional method can be obtained. Such a plate material is useful, for example, as a magnetic disk.

[Brief explanation of drawings]

FIG. 1 is a front view showing an example of an apparatus suitable for carrying out the present invention, and FIG. 2 is a front view showing a conventional method. 1... Pressure press body 2... Insulation material 3... Upper bolster 4... Lower bolster 5, 6... Heater γ... Ram 8... Cylinder 9.10...・Side heating heater 11... Aluminum plate material 12... Aluminum spacer 13... Bottom plate 14... Weight fang) Figure 13 Shij

Claims (1)

[Claims] A method for flattening aluminum plates, which comprises heating a large number of stacked aluminum plates and squeezing them between heated upper and lower bolsters of a pressure press.