JPS6013574Y2 - Nozzle for spouting molten metal - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of a molten metal jet nozzle used when manufacturing a ribbon from molten metal by a known liquid quenching method.

Traditionally, amorphous or microcrystalline metal ribbons have been produced using the so-called liquid quenching method, in which molten metal is jetted from a nozzle onto a cooling roll rotating at high speed to rapidly solidify it. Manufacturing methods are known.

By the way, one of the important factors that must be taken into consideration when manufacturing a metal ribbon using the above manufacturing method is the distance between the nozzle and the cooling roll, and usually this distance is 0.3 to 0.
．． It is set to about 8W1.

The reason for setting such a narrow interval is that as shown in Fig. 1, the molten metal 2 spouted from the nozzle 1 has a large surface tension, so as soon as it is jetted from the nozzle 1, it is immediately constricted and contracted. This is because if the distance between the first tip and the cooling roll is large, the shape of the manufactured metal ribbon will become unstable and desired properties cannot be obtained.

In particular, commonly used alumina, sapphire,
In the case of nozzles made of oxide-based refractories such as quartz or nitride-based refractories such as silicon nitride and boron nitride, the material has poor wettability (atomic bonding) with molten metal, so the As shown in the figure, the molten metal 2 ejected from the tip of the nozzle 1 does not spread beyond the slit width, but immediately squeezes and contracts to reach the surface of the cooling roll 3. As shown in the figure, even if the inner corner of the tip of the nozzle 1 is rounded or sloped (not shown), the molten metal 2 will not eject along the shape.
Since the liquid is ejected with the same original width, the above-mentioned tendency cannot be improved, and therefore, the nozzle tip and the cooling port must be set at a narrow interval as described above.

However, setting the minute spacing of 0.3 to 0.8 ym is not only very difficult to adjust, but also requires the tip of the nozzle, which has a large volume and a large heat capacity at high temperatures, to approach the cooling surface of the cooling roll. Therefore, it cannot be expected to delay the growth of the rapidly solidified layer that grows from the cooling surface and further improve the rapid cooling effect.

Further, there are drawbacks such as damage to the nozzle tip due to slag generated from the molten metal or solidified deposits on the surface of the cooling roll.

In order to eliminate the above-mentioned drawbacks of the conventional technology, the present invention uses a conventional oxide-based or oxide-based refractory for the main body of the nozzle, which has low erosion loss against molten metal, and uses a carbide-based refractory such as SiC for the tip of the nozzle. It is characterized by being formed as an integral object.

In other words, the carbide refractory has a more significant reaction with molten metal than the conventionally used oxide or nitride refractories, and therefore suffers from greater erosion loss due to the molten metal.If the entire nozzle is made of carbide refractory, Conventionally, this material was not used due to the difficulty of maintaining the slit shape, but when considered from the viewpoint of wettability with the molten metal, it has very good wettability. As shown in FIG. 5, for example, the nozzle tip 5 within a range of about 2 to 10 degrees from the tip surface is made of carbide-based refractory, and the nozzle body 4 is made of oxide-based or nitride-based refractory as before. It is formed in one piece.

By forming the structure as described above, even if there is a corner inside the nozzle tip 5 shown in FIG. 4, the molten metal 2 spouted out has good wettability with the nozzle material, so it tends to wet the nozzle end surface side as well. The nozzle tip 5 expands beyond the slit width, and in order to further increase this expansion, the nozzle tip 5
If the inside is rounded, it will spread further along the rounded shape, so in order to suppress the shrinkage of the molten metal 2 and obtain the same width of the molten metal on the surface of the cooling roll 3, the steps shown in FIG. The distance between the nozzle tip 5 and the cooling roll 3 can be made wider than in the conventional case shown in FIG.

Next, an embodiment according to the present invention will be explained in comparison with a conventional one.

A molten metal with a composition of 18 at% Co, 18 at% Ni, 10 at% Zr, and the balance Fe and impurities is rotated at a circumferential speed of 59 m/sec using a nozzle made of silicon nitride (Si3N4) as before. When spraying on the outer circumference of a single cooling roll with a slit shape of 0.5 x 50 m, when the distance between the nozzle and the cooling roll was 0.7 m+++, an amorphous metal ribbon with a width of 5 (ha) was obtained. However, when the spacing was set to 1.2, the particles did not become amorphous and were scattered as thin metal particles that were extremely brittle and had irregular dimensions and shapes.

In contrast, only the tip of the nozzle according to the present invention is made of silicon carbide (
When SiC) was used instead, even if the distance between the nozzle tip and the cooling roll was set to 1.5, the obtained metal ribbon was amorphous and the width was constant at 5.

As described above, in this invention, only the nozzle tip is made of carbide refractory, which suppresses the shrinkage of the molten metal, and the setting accuracy of the distance between the nozzle tip and the cooling roll is greatly relaxed, making adjustment very easy. In addition, since the distance can be increased, the quenching effect of the molten metal is improved, and nozzle damage due to slag or solidified deposits is also prevented.

Note that nozzle melting damage is alleviated by the nozzle main body, which has less melting damage, so there is no problem.

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[Brief explanation of the drawing]

FIG. 1 is a perspective view for explaining how molten metal is ejected from a nozzle, and FIGS. 2 and 3 are longitudinal cross-sectional views for explaining how molten metal is ejected from a conventional nozzle, respectively.
FIGS. 4 and 5 are longitudinal cross-sectional views for explaining the state of molten metal ejection from the nozzle of the present invention, respectively. 1: Nozzle, 2: Molten metal, 3: Cooling roll, 4: Nozzle body, 5: Nozzle tip.

Claims (1)

[Scope of utility model registration request] When manufacturing a metal ribbon by spouting molten metal from a nozzle onto a cooling roll rotating at high speed and rapidly solidifying it, the main body of the nozzle is made of an oxide-based or nitride-based refractory, and the tip of the nozzle is made of SiC. A nozzle for spouting molten metal characterized by being integrally formed with a carbide-based refractory.