JPS6051545B2 - Method for manufacturing hydrogen storage materials - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a hydrogen storage material, which can speed up the cooling rate after solidification, reduce contamination with impurities, and produce a uniform material with less segregation of material composition. It is an object of the present invention to provide a method for manufacturing a hydrogen storage material, particularly a hydrogen storage material made of a Ti-Fe alloy.

Currently, hydrogen storage materials include Ti-Fe alloys, and rare earth metals such as Zr9Mo, Nb, and La9Ce are added to these alloys and melted in vacuum to produce hydrogen storage materials made of Ti-Fe alloys. ing. That is, the so-called TIG melting method, which uses a tungsten electrode on a water-cooled copper hearth and is manufactured on a small scale in a vacuum or argon atmosphere, is free from contamination from the crucible.
Moreover, since the alloy is rapidly cooled, its components are uniform, there is no segregation, and the hydrogen storage properties (hydrogen storage, hysteresis, Pradot properties, etc.) are good. However, in the method of melting using a crucible in a high-frequency induction furnace, which is known as a large-scale melting method, contamination due to the reaction between the crucible and the material cannot be avoided. The method of melting with hydrogen has the disadvantage that the cooling rate is very slow, and therefore the hydrogen storage material is not uniform and segregated, and its hydrogen storage properties are also poor. By adopting the structure described in the claims of the present invention, the product can be rapidly cooled without forming large lumps, and therefore a hydrogen storage material with a uniform composition without segregation of the product can be obtained. I was able to get it. Figures 1 to 4
The drawings show an example of an apparatus used to carry out the invention, and the invention will now be described based on these drawings.

A water-cooled copper crucible 2 is installed inside the vacuum tank 1,
A consumable arc electrode (hereinafter simply referred to as electrode) 3 made of a metal rod of Fe and Ti is suspended from above the crucible 2 . As shown in FIGS. 2 and 3, the electrode used in the above-mentioned process consists of a plurality of Fe rods 5 arranged around the outer periphery of a Ti rod 4 according to the composition of Ti and Fe as the hydrogen storage material. It is attached to surround one rod 4.

Further, the water-cooled copper crucible 2 mentioned above has a copper liner 6 attached to the inside of the crucible 2 as shown in FIG. 4, and a gap 7 through which water can conduct is formed at the outer periphery and lower part of the bottom surface of the copper liner 6. It is.

In the above device, the electrode 3 is connected to the pneumatic cylinder 8.
At the same time, the inside of the vacuum tank 1 is depressurized and evacuated to 6 to 8 x 10-3T0rr'-, and then a DC voltage is applied to the electrode 3 and the water-cooled copper crucible 2 to create an arc. Electric discharge is generated to dissolve the electrode 3 into the water-cooled copper crucible 2.

At the same time, water is introduced into the void 7 of the water-cooled copper crucible 2. Therefore, the very thin part of the electrode 3 melted in the water-cooled copper crucible 2 that is in contact with the copper liner 6 is rapidly solidified by water cooling, and a thin skull (30T thick) is formed on the inner surface of the copper liner 6.
1 Tm or less), the molten content inside the skull can be maintained as having a uniform composition. After a predetermined weight has been melted through the above operations, the undissolved portion of the electrode 3 is pulled up by the pneumatic cylinder 8, and then the water-cooled copper crucible 2 is tilted by operating the handle 9. The molten portion 3 is poured into a graphite funnel 10, and the molten portion 3 is poured onto a copper plate mold 12 fixed on a dispersion rotary table 11 which is rotating at a speed that does not allow the alloy to scatter. After cooling, the skull adhering to the water-cooled copper crucible 2, the deposits on the graphite funnel 10, and the plate-shaped ingot 1 in the copper plate-shaped mold 12 are taken out.

As described above, in the present invention, by forming a skull on the inner surface of the crucible 2, the composition of the molten metal in the water-cooled copper crucible 2 can be maintained uniform, and the composition of the molten metal in the water-cooled copper crucible 2 can be maintained uniform. Since the molten metal is cast in the graphite funnel 10 and copper plate-shaped mold 12, the product is rapidly cooled without forming large lumps as in the conventional method, and the composition can be made uniform.

Further, although the vacuum tank 1 is set to a vacuum in the above-mentioned operation, it is not limited to a vacuum, but can be set to an inert gas atmosphere such as argon or helium, and accordingly, H, MO or various rare earth metals, etc. can be added as appropriate. together with Ti, Zr
Furthermore, since the water-cooled copper crucible 2 is used, there is no contamination caused by reactions with crucible materials as in conventional crucibles. Furthermore, the present invention can use conventionally used vacuum heating equipment, and can be manufactured using almost the same operations as conventional vacuum heating methods. It has the advantage that it can be manufactured without requiring any equipment or means.

In addition, in the illustrated example, the electrode is consumed to produce a hydrogen storage material, but the method is not limited to this, and is not limited to non-consumable electrode arc heating, plasma arc heating, plasma electron beam heating, or electron beam heating. Of course, various heating methods such as beam heating can be employed.

Example Using the apparatus and members shown in FIGS. 1 to 4, Fe, T
The atomic ratio of i, Zr and Nb is 0.94:0.96:0
．． 04:0.04 (weight ratio 49.6:43.4:3.5
:3.5) A hydrogen storage material made of a T1-Fe-based alloy was manufactured.

The dissolution conditions and yield in this case are as follows. Melting weight 203.5k9 Melting conditions Arc current 10KA Arc voltage 42V (D.C) Pressure 6-8×10-3T0rr Melting time 31 minutes Product weight Copper plate mold 137.5
k9 skull 61.3kg graphite funnel part
2.4k, and the composition of the obtained product is as shown in the table below.

As described above, the hydrogen storage properties (hydrogen storage amount, hysteresis, plateau property, etc.) of the product obtained by the present invention are determined by the so-called TIG melting method, which is manufactured on a water-cooled copper hearth using a tungsten electrode in an argon gas atmosphere. It can be made to have properties that are as good as, if not better than, those of the agglomerated sample.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of an example of the device used in the present invention, Fig. 2 is a side view showing an example of an electrode, Fig. 3 is a sectional view taken along the line ■-■ in Fig. 2, and Fig. 4 is a water-cooled copper crucible. FIG. 1: Vacuum tank, 2: Water-cooled copper crucible, 3: Consumable/type arc electrode, 10: Graphite funnel, 12: Copper plate mold.

Claims (1)

[Claims] 1. A raw material for a hydrogen storage material is melted in a water-cooled copper crucible in a vacuum or an inert gas atmosphere to form a skull on the inner wall surface of the water-cooled copper crucible, and the molten material inside the skull is melted in the vacuum or inert gas atmosphere. A method for producing a hydrogen storage material, which comprises tilting a water-cooled copper crucible in an active gas atmosphere, injecting the crucible into a plate-shaped copper mold and rapidly cooling it, and then collecting the skull and the product inside the plate-shaped copper mold.