JPH0834088B2 - Alloy plate for shed mask and shed mask - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a shadow mask used in a picture tube for a color television.

(Prior Art) A shadow mask used in a picture tube for color television has a function of projecting an accurate electron beam spot on a three-color fluorescent screen. Therefore, the relative position of the electron beam passage hole, the hole diameter and the hole shape directly affect the image quality, and a high degree of processing of the electron beam passage hole is required. Further, in order to prevent the generation of scattered electrons, it is necessary to perform a special process of chamfering the surface of the electron beam passage hole facing the fluorescent surface into a hemispherical shape. If these processing precisions are low, the image quality is deteriorated due to doming.

Conventionally, in the processing of such a shadow mask, elongated electron passing holes are formed in a shadow mask original plate by etching.

On the other hand, in recent years, a general demand for "fineness" of a television screen has increased, and a high-definition television system has been developed as a communication system. Therefore, also in the picture tube, from the viewpoint of improving the resolution, it is required to form a finer electron beam passage hole in the shadow mask. In addition, the problem of displacement of the electron beam passage hole due to thermal expansion of the shadow mask with high definition occurs.
The use of Ni-based amber alloy is being considered. However, under such circumstances, problems that have not been a problem in the past will be highlighted. As one of them, there is a defect that when the shadow mask original plate thinned by rolling is used to open fine electron beam passage holes by etching, the holes are not uniform. It was found that by aligning {100} planes on the surface of the shadow mask original plate, the hole shape becomes uniform, and Japanese Patent Application Nos. 57-147790 and 60-106024.
Japanese Patent Application No. 58-19085 and Japanese Patent Application No. 60-73847.

However, white unevenness was found in the shadow mask that was opened in the shadow mask original plate with the plate surface aligned on the {100} plane, and detailed measurements showed that the shape of the electron hole was an ideal similar shape, but It turned out that there are big and small.

(Problems to be Solved by the Invention) The present invention has been made to solve the above-mentioned conventional problems, and not only the shape of the electron holes but also the size thereof are extremely uniform, and as a result, a shadow mask without white unevenness is obtained. Is to provide.

[Structure of Invention]

(Means and Actions for Solving Problems) According to the study by the present inventors, it was found that the above-mentioned white unevenness was caused by the precipitation of α-Fe. Since α-Fe is inferior in corrosion resistance to amber alloy, the diameter of the electron hole becomes large at the location where α-Fe is localized. Therefore, it was found that the white unevenness was eliminated by suppressing the precipitation of α-Fe, and the present invention was created.

That is, in the present invention, the X-ray diffraction intensity on the plate surface of the Fe-Ni-based amber alloy plate is And a shadow mask formed by forming electron beam passage holes in the alloy plate. In the present invention, h is an index indicating the amount of α-Fe impurities mixed in the Fe-Ni amber alloy. That is, {111}, {220}, and {220} crystal planes are strongly observed when the Fe-Ni amber alloy is measured by X-ray diffraction, and the sum of the X-ray diffraction intensities of the three parties is the Fe-Ni amber alloy. Proportional to the abundance of. On the other hand, α-Fe {110}, {20
The sum of the diffraction intensities of the 0} crystal plane is proportional to the amount of α-Fe present. Therefore, The relationship is established. When h is less than 20, the amount of α-Fe present is large and white unevenness is likely to occur.

The shadow mask alloy plate of the present invention is manufactured as follows. In Fe-Ni alloys, Fe and Ni at 900 ° C and above
It is known that γ phase (fcc) is obtained regardless of the component ratio of. When the γ phase at 900 ° C or higher is cooled, the γ phase F
α-phase Fe and γ-phase Ni are precipitated in the e-Ni alloy. However, if the γ phase above 900 ° C is rapidly cooled, the crystal structure formed at 900 ° C can be maintained as it is at room temperature.
It is possible to obtain a Fe-Ni alloy having a uniform phase.

Therefore, the alloy sheet of the present invention can be obtained by performing heat treatment for quenching from a high temperature of 900 ° C. or higher during the manufacturing process such as ordinary forging, hot rolling, cold rolling and the like. This tempering heat treatment may be performed anywhere during the manufacturing process, for example, after hot forging and cold rolling, but it is preferably performed after hot rolling and before cold rolling. When the end temperature of hot rolling is 900 ° C. or higher, this heat treatment can be replaced by rapidly cooling the temperature after hot rolling.

The Fe-Ni-based amber alloy used in the present invention is typically an alloy of Ni of 30 to 50 wt% balance Fe centered at 36Ni-Fe, but Cr, Co, etc. may be added if necessary.

When manufacturing a shadow mask, electron beam passage holes are formed, but in order to provide holes with uniform shapes,
It is preferable that the crystal planes of the alloy plate are aligned.
Specifically, the Fe-Ni amber alloy has {200} crystal faces and {1}
The degree to which the 11} crystal planes are more assembled than the {220} crystal planes is the {200} diffraction intensity is I _{200} , the {111} diffraction intensity is I _{111} , and the {220} diffraction intensity is I. _{Let {220}} be defined as g = (I _{200} + I _{111} ) / I _{220} , and it is sufficient if this g value is 2 or more. That is,
It is preferable to reduce the degree of aggregation of {220} crystal planes in which the shapes of the holes are non-uniform.

In addition, the plate surface has a {100} surface of 35% or more, preferably 40%
The above-mentioned groups are better in terms of etching properties, etc. V _φ : Volume ratio of crystal grains _φ : The angle formed by the direction perpendicular to the plate surface and the <100> direction of the crystal grains is 0.35 or more, preferably 0.4 or more.

In order to obtain an alloy plate for a shadow mask in which {100} planes are aggregated in this manner, an alloy ingot is generally ingot-cast, forged, and hot-rolled. % Or more, and then heat-treated at a temperature exceeding the recrystallization temperature. Aggregates on {110} crystal planes by strong work rolling, and {1} by heat treatment above recrystallization temperature.
Rotate to the {00} crystal plane and {100} crystal planes gather. Further, if necessary, cold rolling may be performed under conditions of a rolling rate of 25% or less without rotating the crystal plane to improve the accuracy of the plate thickness.

Furthermore, by making the plane (A) with more {100} crystal planes in the opposite side of the electron beam incident side,
The sectional shape of the electron beam passage hole is large on the side of the surface (A), which is suitable as a hole. Therefore, when a = I _{200} / I _{220} , it is desirable to make the surface having a large value of a the opposite side to the electron beam incident side.

(Example) Example-1 36% Ni-Fe amber alloy was melted as a target composition to obtain a plurality of 5 ton ingots. This was heated at 1200 ° C. for 4 hours and then forged to have dimensions of 160 ^t × 625 ^w × 6000 ^l . Then 1
It heated at 100 degreeC for 4 hours, and performed hot rolling. After that, water was cooled after being kept at 1100 ° C in a continuous heat treatment furnace (heat treatment). After that, 90% cold rolling and 900 ° C. recrystallization annealing were performed, and flattening was performed with a 4% skin pass to obtain a shadow mask original plate. When electron beam passage holes were opened in this original plate by a photo-etching method, uniform electron beam passage holes were obtained over the entire surface of the shadow mask.

FIG. 1 is an X-ray diffraction diagram of the shadow mask alloy plate of this example. When X-ray diffraction was performed on the entire surface of the shadow mask, it was found that the same 36% Ni-Fe {111},
The peaks of {200} and {220} were shown.

 The h value was 101.5 and there was no white unevenness.

FIG. 2 is an example of X-ray diffraction of a shadow mask when heat treatment for refining was not performed. In this case, most of the surface of the shadow mask is typical as shown in FIG. 1, but the peaks of α-Fe {110}, {200} and Ni {220} are observed as shown in FIG. was there. The h value was 15.8, which coincided with the white spots of white unevenness.

Example 2 36% Ni—Fe alloy plates for shadow masks having various h values were manufactured under different manufacturing conditions, and the occurrence of white unevenness was investigated when a shadow mask was manufactured using this alloy plate.

In X-ray diffraction, CuKα 50kV 100mA 2θ = 40 to 80 ° Further, better holes could be formed when the larger a value was set on the side opposite to the electron beam incident surface.

〔The invention's effect〕

As described above, according to the present invention, a shadow mask without white unevenness can be obtained, which is very effective.

[Brief description of drawings]

FIG. 1 is an X-ray diffraction diagram of an example of the present invention, and FIG. 2 is an X-ray diffraction diagram of a comparative example.

Claims (2)

[Claims] 1. X on the plate surface of an Fe-Ni-based amber alloy plate
The line diffraction integrated intensity is An alloy plate for a shadow mask, which satisfies the relationship of. 2. X on the plate surface of an Fe-Ni amber alloy plate
The line diffraction integrated intensity is A shadow mask, characterized in that an electron beam passage hole is provided in an alloy plate for a shadow mask satisfying the above relationship.