JP3018798B2 - Manufacturing method of evaporation material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a Co-Ni-based alloy vapor deposition material used for producing a vapor deposition VTR tape or the like.

[0002]

2. Description of the Related Art Co-Ni alloys have recently been used particularly as magnetic recording materials for VTRs and the like because of their excellent magnetic properties, that is, coercive force and residual magnetic flux density.

[0003] The conventional vapor deposition method is 10 ^-5 to 10 ^-6 T.
It is performed in a vacuum chamber evacuated to about orr,
The deposition material in the crucible was heated to about 2000 ° C. with an electron beam, melted, evaporated, and deposited on a base film.

[0004] Here, the evaporation material must be replenished in an amount corresponding to the evaporation. About 10mmφ × 10
It was common to use a 30 mm so-called pellet-shaped material and drop it into a crucible melt.

[0005]

However, in the case of the above-mentioned supply method, the deposition conditions such as turbulence of the molten metal surface of the vapor deposition material, scattering of the molten metal, and non-uniform temperature distribution in the molten metal due to falling of the pellets are not sufficient. Become stable. These methods have a problem that a tape of a stable quality cannot be manufactured because the evaporation direction and the evaporation amount of the material become unstable.

As a countermeasure against such a problem, it is conceivable that a long wire material is used as the evaporating material, and the long wire material is continuously supplied into a crucible to stabilize the vapor deposition conditions and produce a highly reliable tape. In this case, there is an advantage that a long-time continuous vapor deposition operation can be performed, and therefore, it has been desired to use a Co—Ni alloy as a wire rod.

[0007] However, since the Co-Ni alloy is a difficult-to-work material, it is extremely difficult to lengthen it by wire drawing or the like. As disclosed in JP-A-59-64734, there is a method of improving the workability and toughness of a wire rod by adding Fe to a Co-Ni alloy. However, such a technique causes another problem such as lowering the excellent magnetic properties of the Co—Ni alloy. In addition, JP-A-3-
As disclosed in Japanese Patent Publication No. 236435, there is a technique for improving the toughness and the like by limiting impurities in an alloy. But,
Only by studying the alloy composition, it was not possible to sufficiently improve the workability such as drawing by this alone.

The present invention has been made in view of such a technical background, and is intended to obtain stable deposition conditions.
An object of the present invention is to provide a Co-Ni-based alloy vapor deposition material having excellent workability and toughness.

In order to achieve the above object, the method for producing a vapor deposition material of the present invention is characterized in that the transformation temperature from the hcp structure to the fcc structure is Tu (° C.) during the heating process, and the fcp
When the transformation temperature to the structure is Td (° C.), Ni is 10
After heating a Co alloy containing up to 30% by weight to a temperature of not less than Tu ° C., drawing is performed at a temperature of not less than Td and not more than Tu + 200 ° C. in a cooling process. Here, for the wire drawing method, forging, rolling, or wire drawing is preferable, and the working degree at that time is a cross-sectional reduction rate of 10%.
It is preferably at least 30%. Further, the cooling rate after the processing is preferably 0.1 ° C./sec or more.

[0010]

As described above, in the method of the present invention, Ni is added to 10 to 10%.
Although a Co alloy containing 30% by weight (hereinafter, all referred to by weight) is used, a Co alloy containing less than 10% or more than 30% of Ni has a coercive force exhibiting characteristics as a magnetic tape,
This is because the residual magnetic flux density does not show a good value.

Incidentally, such a Co alloy is usually
Although it has an hcp structure, if it is heated to a transformation temperature Tu or higher in a temperature rising process, the crystal structure of the alloy material is transformed into an fcc structure. The material, once in the fcc structure by heating, retains its crystal structure even if the temperature drops below Tu, and does not transform into the hcp structure until it becomes Td or less. For example, in a Co alloy containing 20% of Ni, Tu = 380 ° C. and Td = 200 ° C.
It is. Therefore, it is stable even at a temperature near Tu.
When the fcc structure is maintained and wire drawing is performed at a temperature of not less than Td and not more than Tu + 200 ° C. and a cross-sectional reduction rate of 10 to 30%, fc
Suppresses the transformation from c-structure to hcp-structure, resulting in an fcc-rich structure at room temperature.

However, when the cross-sectional reduction rate is 10% or less at a temperature of Tu + 200 ° C. or more, the hc is easily changed from the fcc structure to the hc at the time of cooling.
Since it can be transformed into a p-structure, the processing characteristics after cooling are not good. On the other hand, when the cross-sectional reduction rate exceeds 30%, the processing distortion remains even after cooling, and the characteristics are insufficient. Further, when the cooling rate after processing is as slow as less than 0.1 ° C./sec, the transformation from the fcc structure to the hcp structure is promoted, and excellent characteristics are not exhibited.

[0013] For the above reasons, as in the present invention, C
By processing the o-Ni alloy, it is possible to obtain a fcc-rich Co alloy having excellent cold workability. Therefore, processing such as cutting and drawing can be easily performed at room temperature, and a suitable evaporation material can be obtained.

[0014]

Embodiments of the present invention will be described below. (Example 1) Co alloy wire rod containing 20% Ni (Tu = 3
(80 ° C., Td = 200 ° C.) to a predetermined temperature, and in the subsequent natural cooling process, wire drawing was performed at a cross-sectional reduction rate of 14%. Table 1 shows the mechanical properties at room temperature after processing. However, the processing temperature in the table indicates a temperature immediately before processing, and as a standard of mechanical properties, elongation and reduction of 20% or more are good (the same applies to each of the following examples). .

[0015]

[Table 1]

[0016] As shown in the table, after heating once to Tu or more, processing was performed at a temperature of Td or more and Tu + 200 ° C or less.
It was confirmed that IB and IC were superior to other comparative examples in mechanical properties.

Next, the same alloy wire is heated to 1000 ° C., and the sectional reduction rate is reduced by 14% in the subsequent forced cooling process.
The mechanical characteristics of the case where the wire drawing process was performed were examined. Table 2 shows the results.

[0018]

[Table 2]

In this test, all the samples are once heated to Td or higher, but the temperatures during the subsequent processing are different. Here, the processing temperature is Tu
It was confirmed that each comparative example exceeding + 200 ° C. was inferior in mechanical properties as compared with the example.

Further, an alloy containing 10% or 30% of Ni was similarly heated once to 1000 ° C., and in the subsequent cooling process, wire drawing was performed to reduce the area by 14%, and mechanical properties were examined. . The results at that time are shown in the graph of FIG. When the elongation and the reduction are both 20% or more, the symbol is ○, and when it is less than 20%, the symbol is X. As shown in FIG.
It was confirmed that good mechanical properties were obtained by processing at + 200 ° C. or lower.

(Example 2) A Co alloy wire rod containing 15% of Ni was heated to a predetermined temperature, and was subjected to wire drawing with a cross-sectional reduction rate of 14% in the subsequent cooling process. The processing temperature is 400 ° C. for all samples. Table 3 shows the mechanical properties at room temperature after processing.

[0022]

[Table 3]

As shown in the table, there is no difference in mechanical properties depending on the heating temperature. However, since all of them were processed in the cooling process, the elongation and the reduction were all good at 20% or more. .

Example 3 A Co alloy wire rod containing 20% of Ni was subjected to wire drawing at a heating temperature of 600.degree. C. and a cooling temperature of 400.degree. Then, mechanical properties at room temperature after processing were examined. Table 4 shows the results.

[0025]

[Table 4]

As shown in the table, samples IV-A,
B, G and H all had insufficient mechanical properties,
The one that has been processed with a cross-section reduction rate of 10 to 30%
It was confirmed that good results were obtained at both apertures of 20% or more.

Further, C containing 10 or 30% of Ni
The o-alloy was processed under the same conditions, and the mechanical properties were examined. Table 5 shows the results.

[0028]

[Table 5]

As shown in the same table, Ni was 10 or 30%
It was confirmed that the contained Co alloy wire also exhibited excellent ductility by wire drawing with a reduction in area of 10 to 30%.

(Example 4) Further, a Co alloy wire containing 20% of Ni was heated to a temperature of 600 ° C, and the working temperature in the subsequent cooling process was set to 400 ° C to reduce the cross-sectional area by 14%.
Wire drawing process. Then, cooling was performed while changing the cooling rate after processing for each sample, and the mechanical properties of the obtained wire at room temperature were investigated. Table 6 shows the results.

[0031]

[Table 6]

As shown in the table, it was confirmed that good mechanical properties were obtained when the cooling rate after processing was 0.1 ° C./sec or more.

[0033]

As described above, the Co—Ni alloy material treated by the method of the present invention has excellent ductility after processing,
Processing such as cutting and drawing at room temperature becomes easy. Therefore,
Since a Co—Ni alloy, which is generally a difficult-to-process material, can be easily formed into a wire, using this as a vapor deposition material is extremely useful for stabilizing the vapor deposition conditions in VTR tape production and the like, and for long-term continuous operation.

[Brief description of the drawings]

FIG. 1 is a graph showing the quality of mechanical properties at different processing temperatures for Co alloys having different Ni contents.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI C22F 1/00 660 C22F 1/00 660C 661 661D 691 691B 692 692A G11B 5/85 G11B 5/85 A H01F 10/16 H01F 10 / 16 (56) References JP-A-60-46355 (JP, A) JP-A-5-311405 (JP, A) JP-A-6-108188 (JP, A) JP-A-6-299277 (JP, A) JP-B-28-4207 (JP, B1) (58) Fields investigated (Int. Cl. ⁷ , DB name) C22F 1/10 B21C 1/00 B21C 9/00 G11B 5/85 H01F 10/16

Claims (1)

(57) [Claims] 1. When the transformation temperature from the hcp structure to the fcc structure is Tu (° C.) during the temperature rise process, and the transformation temperature from the fcc structure to the hcp structure is Td (° C.) during the temperature decrease process, Ni is 10 to 30 ° C. after a Co alloy containing by weight% was heated above Tu ° C., Td or in the cooling process, and drawing processing in Tu + 200 ° C. below the temperature,
The cooling rate after processing is 0.1 ℃ / sec or more
Method of producing a vapor deposition material.