JPS58217651A - Preparation of material for storing hydrogen - Google Patents

Abstract

PURPOSE:To prepare an alloy for storing hydrogen free from componential segregation, having a uniform composition and excellent in characteristics, in preparing the alloy for storing hydrogen, by a method wherein a consumable electrode comprising alloy compositional components is melted in a vacuum furnace and the melted one is cast into a rotary casting mold made of copper to be quenched therein. CONSTITUTION:In preparing a Ti-Fe alloy as an alloy for storing hydrogen, a water cooled copper crucible 2 is placed in a vacuum tank 1 and a consumable electode 3 formed by attaching plural Fe rods with a small diameter around a Ti rod is fallen thereinto while arc discharge is carried out between the electrode 3 and the copper crucible 2 to melt the electrode and Ti-Fe alloy melt is formed in the crucible 2. This molten alloy is cast into a slowly rotating plate shaped casting mold 2 made of copper through a graphite funnel 10 to be qunched therein. The Ti-Fe alloy is directly solidified in a uniform compositional state at the time of melting by quenching to obtain a Ti-Fe alloy free from componential segregation, having uniform composition and exellent in hydrogen storing characteristics.

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 furthermore Zr, Mo, Nb, La, and C.
A hydrogen storage material made of a Ti-Fe alloy is manufactured by adding rare earth metals such as e and melting them in a vacuum. In other words, products manufactured by so-called TIG melting, which uses a tungsten electrode on a water-cooled copper hearth and is manufactured on a small scale in a vacuum or argon atmosphere, are free from contamination from the crucible, and because the alloy is rapidly cooled, the components are It is uniform, has no segregation, and has good hydrogen storage properties (hydrogen storage, hysteresis, plateau, etc.). 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 is unavoidable. The method of melting in a furnace has the drawback that the cooling rate is very slow, so the hydrogen storage material is not uniform and segregated, and the hydrogen storage properties are also poor.

By adopting the structure described in the claims, the present invention can rapidly cool a product without forming large lumps, and therefore obtain a hydrogen storage material with a uniform composition and less segregation of the product. was completed.

1 to 9 show an example of an apparatus used to carry out the present invention. Next, the present invention will be explained based on these drawings. A water-cooled copper crucible 2 is installed in a vacuum tank 1, and a consumable arc electrode (hereinafter simply referred to as an electrode) 3 made of metal rods of Fe and Ti is attached to the water-cooled copper crucible 2.
is suspended from the top of crucible 2.

As shown in FIGS. 2 and 3, the electrodes used in the above are arranged so that a plurality of Fe rods 5 are arranged around the outer periphery of the Ti rod 4 in accordance with the composition of Ti and Fe as the hydrogen storage material. It is attached to surround the rod 4.

Furthermore, as shown in FIG. 9, the water-cooled copper crucible 2 described above has a copper liner 6 attached to the inside of the crucible 2, 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 something.

In the above device, the electrode 3 is connected to the pneumatic cylinder 8.
The electrode 3 is lowered and inserted into the water-cooled copper crucible 2, and the inside of the vacuum tank 1 is depressurized to 0-3 To'rr, and then a DC voltage is applied to the electrode 3 and the water-cooled copper crucible 2. An arc discharge is generated and the electrode 3 is placed in a water-cooled copper crucible 2.
dissolve inward. 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 (within a thickness of 30 WR) is formed on the inner surface of the copper liner 6. Because of this, the molten zone inside the skull can be kept uniform in composition.

After melting a predetermined weight through the above operations, the pneumatic cylinder 8 pulls up the remaining portion of the melt on the electrode 3, and then the water-cooled copper crucible 2 is tilted by operating the nozzle 9, and the melt inside the water-cooled copper crucible 2 is The molten portion is poured into a graphite funnel 10, and then the molten portion is poured onto a copper plate-shaped mold 12 fixed on a dispersion rotary table 11 which is rotating at a speed that does not cause the alloy to scatter, and is cooled. After cooling, the skull adhering to the water-cooled copper crucible 2, the deposits on the graphite funnel 10, and the plate-shaped ingot 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 molten metal in the water-cooled copper crucible 2 can be kept uniform. A graphite funnel 10 and a copper plate mold 12
Since the product is cast within the mold, it 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 kept in a vacuum state in the above-mentioned operation, it is not limited to vacuum and can be in an inert gas atmosphere such as argon or helium.
Or various rare earth metals etc. can be added and Ti
, Zr, or rare earth metals, and since the water-cooled copper crucible 2 is used, there is no contamination due to reaction with the crucible material as in conventional methods.

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 two devices.

Further, in the illustrated example, the electrode is consumed to produce a hydrogen storage material, but the present invention is not limited to this, and non-consumable electrode arc heating can be used.

Of course, various heating methods such as plasma arc heating, plasma electron beam heating, or electron beam heating can be employed.

Example Using the apparatus and members shown in FIGS. 1 to 9, Fe,
The atomic ratio of Ti, Zr and Nb is 0.9'l:o
, q O: o, o 11. : o, og (weight ratio 99 fish:'l 3.'l: 3.!; : 3. left) Ti
A hydrogen storage material made of a -Fe-based alloy was manufactured.

The dissolution conditions and yield in this case are as follows.

Dissolved weight aθ3. ! 9 Melting conditions Arc current /θKA Arc voltage Il, 2V (D, C) Pressure Otsu, vg X / (1)-3
Torr melting time: 37 minutes Product weight: Copper plate mold / 37.3 kg skull
B/, 3 to 9 Graphite funnel part K, G kg The composition of the obtained product is as shown in the following table.

The elemental storage properties (hydrogen storage capacity, hysteresis, plateau properties, etc.) are superior to those produced by agglomeration using the TIG melting method on a water-cooled copper hearth using a tungsten electrode in an argon gas atmosphere. It can be made to have certain characteristics.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of an example of the device used in the present invention, Fig. Ω is a side view showing an example of an electrode, and Fig. 3 is a sectional view showing an example of the electrode.
III line sectional view, Figure 9 is a sectional view of a water-cooled copper crucible''Q
be. 1: Vacuum tank, 2: Water-cooled copper crucible, 3: Consumable arc electrode, 10: Graphite funnel, 12: Copper plate mold. Patent applicant: Japan Heavy and Chemical Industry Co., Ltd.
Japan Vacuum Technology Co., Ltd. Vacuum Metallurgy Co., Ltd. Agent: Osamu Ichikawa, Japan Heavy Chemical Industry Co., Ltd. (2 persons other than C) Agent: Rikichi Ichikawa (Continued from page 1) 0 Inventor: Seiichi Kashu To Inse District, Chiba Prefecture 053-233 in Machachi Yachimata @Applicant Japan Vacuum Technology Co., Ltd. 2500 Hagizono, Chigasaki City ■Applicant Vacuum Metallurgy Co., Ltd. 516 Yokota, Sammu-cho, Sammu-gun, Chiba Prefecture

Claims (1)

[Claims] 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 a vacuum or inert gas atmosphere. A method for producing a hydrogen storage material, which comprises tilting a water-cooled copper crucible in a gas atmosphere, injecting it into a copper plate-shaped mold, rapidly cooling it, and then collecting the skull and the product inside the copper plate-shaped mold.