JPS60244013A - Manufacture of magnetic material - Google Patents

Abstract

PURPOSE:To obtain a large type magnetic material target having no cavity and no crack by a method wherein a molten metal of magnetic material is poured into a two layer structural mold and a mold base consisting of a metal material, and the molten metal thereof is solidified to one direction from the mold base consisting of the metal material. CONSTITUTION:An inner mold 2 having a dead head 2b and formed according to a refractory is put ona large type metal mold base 1. An outer mold 3 manufactures of a metal is engaged on the outside part of the inner mold 2 to construct a mold of two layer construction. When a molten metal (m) consisting of a magnetic material is poured from the pouring gate thereof in the inner mold 2, the molten metal (m) of magnetic material is almost ignored by cooling from the lateral periphery, and cooling of the molten metal is advanced to be solidified only from the mold base 1 side manufactured of a metal on the base side. Accordingly, the molten metal of magnetic material to be cast in the mold is solidified to one direction from the base side without leaking outside, and casting of a large type ingot having no cavity can be attained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for producing a magnetic material for producing a sputtering target for forming a releasable metal thin film.

BACKGROUND TECHNOLOGY AND PROBLEMS Conventionally, sputtering targets for forming magnetic metal i1X films have been manufactured by pouring molten magnetic metal into a metal mold or refractory brick mold and casting it into a block shape. For materials that are prone to splintering, a riser was installed for casting.

However, with this manufacturing method, it is not possible to cast a magnetic material target block with a diameter of 150 mm or more, and materials such as sendust alloy, which are hard and brittle, tend to have coarse grains, and have large shrinkage during solidification, are simply It was difficult to cast a large block without cracking just by providing a riser.

OBJECTS OF THE INVENTION In view of the above, it is an object of the present invention to provide a method for producing a magnetic material that allows a large-sized magnetic material target without cracks or cracks to be obtained.

Summary of the Invention In order to achieve the above-mentioned object, the present invention has a two-layered mold with a fire-resistant heat insulating material for the inner mold and a metal material for the outer mold, and a mold base made of the metal material, in which molten metal of a magnetic material is poured. By solidifying this molten metal in one direction through a mold stand made of two metal materials to produce a magnetic material, it is possible to obtain a large magnetic material target without cracks or cracks. .

EXAMPLE An example of the present invention will be described below with reference to the drawings. First, as shown in the drawings, a large metal mold stand (1 ) is designed to the specified dimensions using a refractory material such as sintered alumina or graphite, and then pressed with a fire-retaining property (2a
) is placed on the inner mold. Then, a metal outer mold (3) made of a steel material such as mild steel or cast iron is fitted to the outside of this inner mold (2) to form a mold with a one-piece structure. In addition, the leakage of molten metal is prevented by the metal perforated mold (3).

A molten metal m of a magnetic material such as sendust alloy is poured into an inner mold (1. Pour hot water from the sprue. The molten metal m of the magnetic material 1 poured into the inner mold (2) in this way is cooled only from the metal mold base (11 side) on the bottom side, with almost no cooling from the lateral surroundings. As it progresses, it solidifies.

Therefore, the quality and volume of the metal mold stand (1) must be designed depending on the use of the molten metal.

For example, mold stand +11 is formed by tJil, 1500
The temperature when pouring the molten metal M of Sendas I and alloy at ℃ is 5
When cooling from 00 to 500℃, the amount of heat released is approximately 2.7
×10' cal/kg, and copper is
The absorbed heat when the temperature rises to 00°C is approximately 470 cal
/cld.

Therefore, if 10 kg of molten metal m is to be cast, the mold table f
The volume of copper forming il is 2.7X 10' X 10÷470ζ5745c+d
It would be a good idea to change the design accordingly.

Further, in order to prevent the cast ingot from cracking, it is desirable to leave the cast ingot in a vacuum or in a melting atmosphere for a long time, preferably about 10 hours.

This is magnetic! l - When pouring the milk material 1, the inside mold (2
) and the outer mold (3) into a circular, rectangular, or square shape, magnetic material ingots of various shapes, that is, targets can be obtained.

In addition to the materials mentioned above, the mold base (1) is made of aluminum and aluminum alloys, titanium and titanium alloys, or gold, etc. for the inner mold (
2) is sapphire, sintered zirconia, sintered magnesia,
Sintered molybdenum silicide, molybdenum nitride, boron nitride, silicon carbide, etc. may be used, and the outer mold (3) may be formed using a steel material such as stainless steel, nitrided steel, or high-hardness steel.

Note that if the mold base (1) is laid with fire-resistant bricks or the inner mold (2) is made of a fire-resistant hot material, there is a risk of ingot splintering or leakage.

As described above, in this example, the bottom side of the mold is made of a metal material that can sufficiently absorb the solidification heat of the molten magnetic material and the heat released during cooling.
In addition, the side and top surfaces are made of a heat insulating material with extremely low heat conductivity, and the top surface is coated with a metal material from the sides made of a fire-resistant heat insulating material, so that the molten metal of the magnetic material poured into the mold is exposed to the outside. It solidifies in one direction from the bottom side without leaking, making it possible to cast large, clean ingots with a diameter of 150 mm.
It is possible to manufacture a cougette for sputtering magnetic materials that exceeds the size of a seal.

Effects of the Invention As described above, according to the present invention, molten metal of a magnetic material is poured into a mold having a two-layer structure using a refractory heat insulating material for the inner mold and a metal material for the outer mold, and a mold base made of a metal material. Since this molten metal is solidified in one direction from a mold stand made of a metal material, it is possible to cast large ingots without any defects, and it is possible to reliably form targets for magnetic materials such as sendust sputtering, and the manufacturing yield is improved. This has the effect of improving sputtering efficiency by reliably forming a large target.

[Brief explanation of drawings]

The figure is a sectional view of an example of a mold applied to the present invention. In the figure, (1) is a mold stand, (2) is an inner mold, (2a) is a riser, and (3) is an outer mold.

Claims (1)

[Claims] A molten metal of a magnetic material is poured into a mold with a two-layer structure in which an inner mold is made of a refractory heat insulating material and an outer mold is made of a metal material, and a mold stand made of a metal material is used, and the molten metal of the magnetic material is poured into a mold made of the metal material. A method for manufacturing a magnetic material, characterized by solidifying it in one direction from a stand.