JPH0592285A - Manufacture of cao nozzle - Google Patents

Abstract

(57) [Summary] [Objective] To manufacture a CaO-based nozzle suitable as a nozzle for flowing out a molten metal of various high-activity, high-melting point metals or alloys thereof. [Structure] A CaO-based refractory material containing 40% by weight or more of CaO and the remainder substantially consisting of metal oxide is molded and fired into a nozzle shape, and then the tip is laser-processed to form the ejection hole 2. Form. [Effect] The CaO-based refractory material according to the present invention hardly contaminates a highly active metal or alloy molten metal, and the refractory material is less likely to be damaged by these molten metals. When the molten metal contains a deoxidizing element, it also has a refining action. Since CaO of the nozzle material is hydratable, conventional electrical discharge machining or ultrasonic machining using water is impossible, but laser machining can form ejection holes of a desired shape with extremely high precision.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a CaO-based nozzle, and more particularly to a method for manufacturing a CaO-based nozzle suitable as a nozzle for flowing out molten metal of various high-activity, high-melting point metals or alloys thereof.

[0002]

2. Description of the Related Art A nozzle for ejecting a molten metal is used in the production of amorphous metal. As a material for this nozzle, a SiO ₂ refractory material has been generally used. However, in recent years, as the demand for quenched ribbons of metals or alloys has expanded, or various amorphous alloys have diversified, or have become highly active and have a high melting point, the materials for these nozzles have changed from SiO ₂ refractory materials to Al ₂ O ₃
Series, ZrO ₂ series refractory materials, and further Si ₃ N ₄ and Si
It is shifting to non-oxide ceramics such as C, BN and BC.

[0003]

Problems to be Solved by the Invention However, Al
_{When using a 2} O ₃ -based or ZrO ₂ -based refractory material nozzle, there is a problem that the molten metal passing through the nozzle reacts with the refractory material in the nozzle, causing oxygen contamination and eroding the tip of the nozzle. As a result, the shape of the ejection hole changes, the molten metal is contaminated, and a high quality product cannot be obtained.

Further, a nozzle made of non-oxide ceramics such as Si ₃ N ₄ , SiC, BN and BC is expensive and easily cracked by thermal shock, and the problem of molten metal contamination is unavoidable.

[0005]

The method for producing a CaO-based nozzle of the present invention comprises forming a CaO-based refractory material containing 40% by weight or more of CaO and the balance substantially consisting of a metal oxide,
After firing to form a nozzle shape, the tip is subjected to laser processing to form an ejection hole.

[0006]

The CaO-based refractory material is extremely stable in a vacuum or an inert gas, has a small dissociation oxygen pressure, and can be used even at high temperatures. Moreover, it is inexpensive and has excellent thermal shock resistance.

In addition, containing 40% by weight or more of CaO,
The CaO-based refractory material, the balance of which is substantially metal oxide,
Even highly active metal or alloy melts are hardly contaminated, and the refractory material is less likely to be damaged by these melts. Further, when the molten metal contains a deoxidizing element, it also has a refining action.

[0008] When such a CaO refractory material is molded and fired into a nozzle shape to form an ejection hole at the tip, conventional water is used because CaO of the nozzle material is hydratable. Electric discharge machining and ultrasonic machining are not suitable. In the present invention, the laser processing can form the ejection hole having a desired shape at a desired position with extremely high accuracy.

[0009]

The present invention will be described in detail below with reference to the embodiments shown in the drawings.

In the following, "%" means "% by weight".

FIGS. 1 to 3 are views showing an example of a CaO nozzle manufactured by the method of the present invention.
(A) is sectional drawing of a front-end | tip part, (b) is a bottom view of (a) figure. 4A to 4C are bottom views showing examples of the shape of the ejection port.

A concrete example of the shape of the CaO-based nozzle 1 manufactured by the present invention is a circular ejection hole 2 as shown in FIG.
And those having square ejection holes 2 as shown in FIGS. Further, as the shape of the ejection holes, as shown in FIG. 4, various shapes such as a square shape (the same (a)) and a star shape (the same (b)) as well as a ring shape (the same (c)) can be cited. Be done.

In manufacturing the CaO-based nozzle of the present invention, first, a CaO-based refractory material containing 40% or more of CaO and the balance substantially consisting of metal oxide is prepared.

The CaO raw material of this calcia refractory material is a refractory material mainly composed of CaO, such as calcia (Ca
O), CaO-enriched dolomite and the like. C
As aO, electrofused calcia is particularly dense, and even when it comes into contact with a highly active metal or alloy melt, contamination with the melt is small and suitable.

Such CaO refractory material is
The higher the content, the more thermodynamically stable it is, and the higher the temperature, the higher the temperature at which it can be used. Therefore, the CaO content of the CaO-based refractory material is preferably 80% or more, particularly 90% or more.

In the present invention, when the CaO quality nozzle is manufactured with such a CaO quality refractory material, the C
There is no limitation on the shape, size, hole diameter, etc. of the aO quality nozzle, and it may be exactly the same as the conventional nozzle, and is selected according to the purpose of use.

The CaO-based refractory material used as a raw material is, for example, a powder of a calcia-based raw material such as electro-fused calcia having a predetermined particle size and, if necessary, a high-melting metal oxide such as ZrO ₂ , MgO or Y ₂ O _3. It is prepared by mixing the materials and other additives for improving the characteristics at an appropriate ratio. This raw material is molded and fired in the shape of a nozzle after adding an appropriate binder if necessary.

A non-aqueous binder is used as this binder. The non-aqueous binder may be either liquid or solid. As a liquid type, alcohol (monohydric or polyhydric alcohol) in which anhydrous calcium chloride or gum arabic is dissolved, oleic acid dissolved in toluene, oleic acid dissolved in alcohol, oil It is preferable to use oleic acid dissolved in carbon dioxide, beeswax dissolved in carbon tetrachloride, or isobutyl acetate, but it does not digest calcia, such as mineral oils such as tar and pitch, animal oils, vegetable oils, etc. Any non-aqueous liquid can be used.

As the solid binder, polyethylene, polypropylene, cellulose acetate, acrylic resin, thermoplastic resin such as polyvinyl alcohol, thermosetting resin such as novolac, paraffin and the like can be preferably used. Other substances that give the can also be used.

As the molding method, various methods such as mold molding, slip casting, rubber pressing, injection molding, warm pressing, stamping and the like are used. Other,
A molded body may be prepared by mixing with a non-aqueous solvent such as n-hexane to form a slurry, and then pouring the mixture into a mold.

The molded body or the stamped nozzle body is dried if necessary, and then calcined preferably at a temperature lower than the main-baking temperature, and then main-baked and sintered. The firing temperature is 1100 ° C. or higher, especially 1300 to 18
A temperature of about 00 ° C is suitable.

Of course, in the present invention, a method such as hot pressing may be adopted for molding and firing.

In the present invention, when the ejection hole is formed in the tip portion of the nozzle body thus obtained, since CaO of the nozzle material is hydratable, conventional electric discharge machining using water or super Sonic processing is not suitable. Therefore, in the present invention, laser processing (C
O ₂ laser processing) is adopted. As a result, 0.3-
It is possible to form a jet hole having a desired shape with a diameter of about 1.0 mm with extremely high accuracy.

The CaO-based refractory material produced by the present invention is generally digestible and may be damaged by absorbing moisture in the atmosphere. Therefore, it is necessary to store the obtained nozzle in a vacuum or at a high temperature, but by vacuum packaging in a vinyl bag or the like, it can be favorably stored for more than half a year in a normal atmosphere.

The CaO-based nozzle manufactured according to the present invention has a high melting point metal and a high activity metal such as Sc, Y, L.
a, lanthanoid elements such as Ce and Pr having atomic numbers 58 to 71, Ti, Zr, Hf, V, Nb, Ta, Cr and M
o, W, Mn, Mg, Al, Tc, Re, Ru, Os,
It is very suitable for flowing out the molten metal of Co, Ni, Rh, Pd, Ir, Pt or an alloy containing one or more of these elements.

In particular, when the CaO-based nozzle manufactured according to the present invention is used for a molten metal containing a deoxidizing element such as Al, Si, Zr and Ti, excellent deoxidation, desulfurization, denitrification and denitration are achieved. The refining effect of inclusions is obtained, which is extremely advantageous.

Next, specific production examples of the present invention, production examples of nozzles, and corrosion resistance test examples will be described.

Example 1 [0028] A main raw material was obtained by crushing and classifying electrofused calcia (CaO purity 98%) to 0.2 mm or less, and 3% by weight of heavy oil pitch was added to this, which was heated to 150 ° C and mixed well. After that, it was die-molded.

The molded body was calcined at 650 ° C. for 3 hours and then sintered at 1350 ° C. for 2 hours to sinter it. Then, the tip of the nozzle was perforated by a CO ₂ pulse laser. The composition of the sintered body thus obtained is as shown in Table 1, and its shape and dimensions are as shown in FIG.

To this nozzle, 50 g of an alloy having the following composition was charged, heated and held for 5 minutes, and then sprayed with Ar to observe the nozzle and analyze oxygen in the molten metal. The results are shown in Table 2.

No. 1 Co-60% Zr alloy No. 2 Ag-30% Cu-40% Ti alloy No. 3 Cu-50% Ti alloy No. 4 Cu-40% Nb alloy Comparative Example 1 Table 1 The molten metal in the nozzle was immersed in the same manner as in Example 1 except that the SiO ₂ refractory nozzle having the composition (the shape and dimensions were the same as those used in Example 1) was used.
The oxygen analysis results are shown in Table 2.

The appearance observation results of the nozzles of Example 1 and Comparative Example 1 are as follows. Example Nozzles: No damage or the like occurs.

Comparative Example Nozzle: Nozzle hole is eroded 2 to
In addition to spreading to a hole with a diameter of about 3 mm, countless cracks are introduced in the melted portion and cannot be reused. In particular, the experiment of the comparative example could not be performed on the No. 4 molten metal due to damage to the nozzle.

[0034]

[Table 1]

[0035]

[Table 2]

[0036]

As is apparent from the above examples, according to the present invention, it is extremely stable and can be satisfactorily used at high temperatures. Even when it is used for flowing out a molten metal having a high melting point and high activity, there is little contamination from the nozzle to the molten metal. Therefore, the nozzle is hardly eroded and damaged by the molten metal. Excellent thermal shock resistance. It is possible to manufacture a high-characteristic nozzle having advantages such as the above with high accuracy and high production efficiency. The nozzle obtained in the present invention enables the production of quenched ribbons and amorphous alloys having various alloy compositions, and the present invention is industrially very useful.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a CaO quality nozzle manufactured by the present invention, FIG. 1 (a) is a cross-sectional view of a tip portion,
(B) The figure is a bottom view.

FIG. 2 is a view showing another example of the CaO-based nozzle manufactured by the present invention, FIG. 2 (a) is a cross-sectional view of the tip portion,
(B) The figure is a bottom view.

FIG. 3 is a view showing another example of the CaO-based nozzle manufactured according to the present invention, wherein FIG. 3 (a) is a sectional view of the tip portion,
(B) The figure is a bottom view.

4 (a) to 4 (c) are bottom views of nozzles each showing an example of the shape of an ejection hole that can be adopted in the nozzle manufactured according to the present invention.

5 (a) and 5 (b) are Example 1 and Comparative Example 1.
It is a figure which shows the nozzle used by (a) is sectional drawing,
(B) is a bottom view.

[Explanation of symbols]

 1 nozzle 2 ejection hole

Claims (1)

[Claims] 1. A jetting hole is formed by molding a CaO-based refractory material containing 40% by weight or more of CaO and the remainder being substantially metal oxide, firing it into a nozzle shape, and then laser machining the tip. A method of manufacturing a CaO-based nozzle, which comprises: