JPH0257141B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a nozzle for producing rapidly solidified metal strips.

Recently, the production of rapidly solidified metals such as amorphous metal ribbons and high Si-containing magnetic material ribbons has been actively carried out.
Particularly, amorphous magnetic ribbons used as materials for transformers have been partially industrialized and are now commercially available.

Generally, to produce rapidly solidified metal ribbon, molten metal is jetted onto rotating rolls from a 0.2 mm to approximately 1 mm slit provided at the tip of a nozzle (Japanese Patent Laid-Open No. 53-53525). Public bulletin). By the way, since this nozzle requires high dimensional accuracy and surface accuracy of the slit, advanced technology is required for its manufacture. In addition, the material of the nozzle is required to have wear resistance, spall resistance, corrosion resistance, workability, etc., so we have repeatedly examined the selection of a material that satisfies all of these requirements.
There is still no definitive method for producing rapidly solidified metal ribbons over a long period of time by continuously processing the above-mentioned molten metal, and the method is still at the exploratory stage.

Currently, quartz is often used as a nozzle for producing rapidly solidified metal ribbons of amorphous metals weighing up to about 1 kg. The reason is that the nozzle is relatively easy to manufacture, but it is expensive. In addition, when aiming for mass production as mentioned above, in addition to price, corrosion resistance, abrasion resistance,
It is difficult to say that it is necessarily satisfactory in terms of thermal deformation (heat resistance), etc. On the other hand, with resistive materials other than quartz,
Al ₂ O ₃ , Si ₃ N ₄ , BN, etc. are considered to be effective. However, although these have almost satisfactory corrosion resistance in an inert gas atmosphere, they are insufficient in hot strength and spalling resistance. In addition, when processing slits, not only can ordinary machine tools be used, but even ultrasonic waves, lasers, etc. can be used.
In the case of ultrasonic waves, there are limits to the processing width and depth, and it takes a long time. Furthermore, in the case of a laser, a gradient remains in the depth direction due to the narrowing down of the beam. In any case, the machining accuracy is poor and a polishing finish is essential, and since the work is done in extremely small spaces, it requires an extremely high level of skill and time.

It is also known that nozzle wear and deterioration is represented by erosion and deterioration, and the rate of progress of these processes has an important relationship with the apparent porosity. Corrosion resistance also has an important relationship with wettability, and even if the apparent density is somewhat high, materials that are difficult to wet with molten metal will have less erosion loss and deterioration.

In view of this, the present invention seeks to provide a method for manufacturing a nozzle that has all of the above-mentioned characteristics.

That is, in the present invention, while rotating a template having at least one end a portion of length L with a rectangular cross section of thickness T and width W about a rotation axis parallel to the L direction, The present invention relates to a method for manufacturing a nozzle for rapidly solidifying metal production, which comprises depositing refractory powder on parallel surfaces using a plasma spraying method, and then removing the template.

Here, the shape and dimensions of the end of the template correspond to the shape and dimensions of the nozzle opening illustrated in FIG. Specifically, the thickness T of the template is the short side of the slit-shaped opening,
The width W of the template corresponds to the long side of the slit opening, and the length L of the parallel portion corresponds to the height of the slit. Further, the deposited thickness of the thermal spray material corresponds to the wall thickness t ₁ or t ₂ of the nozzle.

It is well known that in the so-called single-roll quenching method using a slit-shaped opening, the shape and size of the slit is an important factor governing casting stability and product quality (Japanese Patent Laid-Open No. 53525/1983).

In the present invention, the thickness T of the template is preferably 0.1 to 3 mm. The reason for this is that when the thickness exceeds 3 mm, the supply of molten metal exceeds the solidification rate. Moreover, if it is less than 0.1 mm, nozzle clogging will occur. Further, the length L of the template is preferably 1 to 50 mm. If it is less than 1 mm, the strength of the manufactured nozzle will be insufficient. On the other hand, if it exceeds 50 mm, the flow resistance of the molten metal becomes large and excessive ejection pressure is required, which is not preferable.
Note that there is no particular restriction on the width of the template. The width of the template determines the width of the rapidly solidified metal, but there is no theoretical limit to this.

Furthermore, the deposited thickness of the sprayed material controls the strength of the nozzle. The minimum required thickness varies depending on the material to be thermally sprayed, but in the case of Al ₂ O ₃ , Si ₃ N ₄ , and BN, if it is 1 mm or more, it maintains a strength sufficient for practical use. The upper limit of the deposited thickness is determined from the viewpoints of required strength and economical efficiency, but is preferably in the range of 2 mm to 10 mm.

The method of the present invention will be explained below with reference to the drawings.

FIG. 1 is an explanatory diagram showing the external appearance of a nozzle manufactured by the method of the present invention, where 1 is a nozzle main body, and 2 is a slit-shaped opening provided on the lower surface thereof. Also, the second
The figure shows an example of the method of the invention, where 4 is a template whose end is equal to the slit size of the nozzle. This template is connected to a rotary drive device 10 and is rotatable. Reference numeral 6 denotes a plasma spraying device for thermally spraying refractory powder 9 onto the template 4, and is capable of reciprocating in a direction perpendicular to the rotational direction of the template 4. 7 is a refractory powder supply pipe provided in the apparatus, and 8 is an electrode. To manufacture a nozzle by the method of the present invention, first, a template 4 having an outer diameter equal to the slit size of the nozzle to be manufactured is connected to a rotary drive device 10. This template 4 can be easily removed after molding if, for example, graphite or copper is used. Further, a plasma spraying device 6 is arranged on the side surface of the template 4, and the plasma spraying device 6 sprays Al ₂ O ₃ ,
A refractory powder 9 such as Si ₃ N ₄ or BN is sprayed onto the template. At this time, the template 4 is rotating and the plasma spraying device 6 is reciprocating in a direction perpendicular to the rotation direction of the template 4, so the sprayed refractory powder 9 is evenly welded and deposited on the template 4. The nozzle is then molded.
When the desired wall thickness is reached, the spraying is stopped and the template 4
A nozzle of the desired size can be obtained by pulling it out of the molded refractory, or removing it by burning or melting it.

Next, examples of the present invention will be shown.

Example 1 A nozzle for producing rapidly solidified metal was manufactured using the apparatus shown in FIG. The refractory powder 9 used is Al ₂ O ₃
(100 metsushiyu). While supplying this powder 9 from the powder supply pipe 7 of the plasma spraying device 6 at a rate of 5 kg/hr, the plasma spraying device 6 is connected to the template 4 (minimum thickness: 0.6 mm, width: 25 mm, length: 50 mm). The steel plate) is moved back and forth along the length direction at a speed of 1 cm/sec,
Thermal spraying was carried out while rotating the template 4 at 5 rpm.
The resulting nozzle has both end faces slightly polished, and has superior dimensional and surface accuracy than nozzles conventionally manufactured by sintering, and has high-temperature strength (1500
℃) is about 3 times higher. Also actually Fe ₇₈
When 3 kg of an alloy of -Si ₁₀ -B ₁₂ (at.

Example 2 A nozzle was also manufactured by the method shown in FIG. First, an ice-coolable mold (for example, made of copper) 3 having an inner diameter equal to the outer diameter of the desired nozzle and a graphite template 4 equal to the nozzle slit dimension are placed on a rotary table 5 that can move in the X, Y, and Z directions. did. Furthermore, a plasma spraying device 6 is arranged above the mold, and from the powder supply pipe 7 of the device 6,
Si ₃ N ₄ (150 mesh) was thermally sprayed into the mold 3 while being supplied at a rate of 8 kg/hr. At this time, mold 3
The sprayed refractory powder rotates sequentially in the X and Y directions at 3 rpm, and also moves in the Z direction so as to maintain a constant distance between the tip of the plasma spraying device 6 and the sprayed material deposition surface 11. Deposits uniformly within the mold,
A nozzle is formed. When the desired shape was reached, the thermal spraying was stopped, the graphite template 4 was pulled out, and the molded nozzle was taken out of the mold, resulting in a nozzle with dimensions that did not require finishing. The performance of the obtained nozzle was similar to that of Example 1. In addition,
During thermal spraying, the mold 3 is moved and rotated in the X and Y directions in order to faithfully spray the mold along the inside of the mold, and if only a cylindrical nozzle is to be obtained, only rotation is sufficient.
Furthermore, instead of rotating the mold, the plasma spray device 6 may be moved along the inner wall of the mold, or the mold and the plasma spray device may be moved in opposite directions. The movement in the Z direction is to maintain a constant distance between the deposited refractory and the thermal spraying device. Furthermore, if the graphite template 4 cannot be pulled out, it may be burned in an electric furnace or gas burner. If the method of Example 2 is adopted, the outer shape of the nozzle can be controlled to any shape.

As explained above, according to the present invention, it is possible to easily manufacture a nozzle with excellent dimensional accuracy and excellent wear resistance, corrosion resistance, spall resistance, etc., and its effects are extremely large.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a nozzle manufactured by the method of the present invention, and FIGS. 2 and 3 are explanatory views showing examples of the method of the present invention. 1: Nozzle, 2: Slit-shaped opening, 3: Water-coolable mold, 4: Template plate, 5: Movable rotary table, 6: Plasma spraying device, 7: Refractory powder supply pipe, 8: Electrode, 9: Refractory powder, 10: Rotary drive device, 1
1: Thermal spray material deposition surface.

Claims (1)

[Claims] 1. While rotating a template having at least one end a portion of length L with a rectangular cross section of thickness T and width W around a rotation axis parallel to the L direction, on a surface parallel to the rotation axis of the template. 1. A method for manufacturing a nozzle for rapidly solidifying metal manufacturing, comprising depositing refractory powder on a metal plate using a plasma spraying method, and then removing the template.