JPH0811097B2 - Manufacturing method of titanium thermos - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for manufacturing a titanium thermos bottle that is lightweight and has excellent heat retention performance.

[Prior Art] At present, stainless steel thermos bottles are widely used. This product has the advantages that it has excellent heat retention performance, is not damaged, but is heavy and is inconvenient to carry. In addition, stainless steel has insufficient corrosion resistance and may be corroded when accommodating salt-containing food or drink.

For these reasons, a thermos bottle made of titanium or titanium alloy, which is lightweight, has high strength, and has high corrosion resistance, has been proposed.

In such a titanium thermos, in order to enhance the heat retention like a stainless steel thermos, the surface of the thermos inner or outer bottle facing the vacuum heat insulating layer is made of a metal with a low emissivity, such as copper or silver. It is necessary to form a plated layer to reduce heat transfer due to radiation.

[Problems to be Solved by the Invention]

However, when forming the vacuum insulation layer of the thermos,
Although vacuum evacuation is performed while heating to promote vacuum evacuation and degas from the metal, since the titanium and titanium alloys are metals with high chemical activity, the plating layer made of copper or silver is titanium during this heating. Alternatively, there is a problem that the heat insulation performance cannot be sufficiently enhanced because the plating layer disappears by reacting with the titanium alloy to form a diffusion alloy.

[Means for solving the problem]

In the present invention, before forming a radiation plating layer made of a metal having a low emissivity such as copper or silver, tin, antimony, aluminum, forming a barrier plating layer made of zirconium in advance, nickel, iron, copper,
The solution was to form a pretreatment plated layer of cobalt, chromium, etc. and heat treatment.

[Work]

The presence of the barrier plating layer or the pretreatment plating layer formed between the radiation plating layer and titanium or titanium alloy may cause the radiation plating layer to diffuse into titanium or titanium alloy even in the heat treatment during vacuum sealing. Suppressed.

 Hereinafter, a detailed description will be given with reference to the drawings.

First, the manufacturing method of the invention according to claim 1 will be described.

First, titanium or a titanium alloy material is molded into a bottomed cylinder to form an inner bottle 1 and an outer bottle as shown in FIG.
An exhaust hole 3 is formed at the bottom of the outer bottle 2. Then,
A barrier plating layer 4 is formed on the entire surface or a partial surface of one or both of the outer surface of the inner bottle 1 and the inner surface of the outer bottle 2, as shown in an enlarged manner in FIG. This barrier plating layer 4 is a group consisting of a metal having a small diffusion rate with respect to titanium or a titanium alloy at a heat treatment temperature during vacuum exhaust described later, that is, tin (Sn), antimony (Sb), aluminum (Al), zirconium (Zr). A plating layer made of a metal selected from
It is about 0 μm. The barrier plating layer 4 is formed by a method such as normal electroplating.

Then, as shown in FIG. 2, a radiation plating layer 5 is formed on the surface of the barrier plating layer 4. This radiation plating layer 5
Is a metal having at least an emissivity lower than that of titanium or a titanium alloy, that is, silver (Ag) or copper (Cu) and having a thickness of 1 to 30 μm. As the method for forming the radiation plating layer 5, chemical plating (electroless plating) is preferable for those made of silver, and ordinary electroplating is used for those made of copper.

Next, as shown in FIG. 1, the inner bottle 1 and the outer bottle 2 having such two-layered plated layers 4 and 5 are joined at their mouths to form a double structure. Welding means such as spot welding or TIG welding (argon welding) is used for joining.

Subsequently, a solid brazing material is placed around the exhaust hole 3 at the bottom of the outer bottle 2 of this double-structured bottle, and the solid brazing material 6 made of titanium or the like is placed on the solid brazing material in a vacuum furnace. Temperature 500
Vacuum evacuation is performed while heating at ˜800 ° C., the space between the inner and outer bottles is evacuated, the solid brazing material is melted, and the sealing plate 6 is brazed to the outer bottle 2 for vacuum puncturing. As the solid brazing material, Ag-Cu based, Cu-P based, Ag based, and Al based brazing materials are suitable. If the heating temperature during evacuation is less than 500 ° C, the gas adsorbed on the surface of the inner and outer bottles and the gas stored therein (especially hydrogen) cannot be sufficiently released, and a high degree of vacuum cannot be obtained. On the other hand, if the temperature exceeds 800 ° C., the diffusion of the barrier plating layer 4 into titanium or a titanium alloy becomes severe, the barrier plating layer 4 disappears, and the intended effect cannot be obtained.

According to such a manufacturing method, at the time of heating during vacuum evacuation, a part of the barrier plating layer 4 diffuses into titanium or a titanium alloy, but since the diffusion rate is low, it does not completely diffuse and remains. The radiation plating layer 5 is prevented from diffusing into titanium or a titanium alloy.

Next, another example of the manufacturing method according to claim 1 will be described.

In the manufacturing method of this example, as shown in FIG. 3, a nickel plating layer 7 is formed on the whole or a part of the outer surface of the inner bottle 1 or the inner surface of the outer bottle 2, and a barrier plating layer 4 is formed thereon. Further, after the radiation plating layer 5 is formed, the mouth portions are joined in the same manner as in the previous example, and then the material is evacuated while heating in a vacuum furnace. The nickel plating layer 7 in this example is for preventing poor adhesion between the titanium or titanium alloy of the base material and the barrier plating layer 4, and its thickness is 0.1 to 20 μm.
It is about m. The presence of the nickel plating layer 7 enhances the adhesion of the barrier plating layer 4 and the radiation plating layer 5 to the base material, and prevents the barrier plating layer 4 and the radiation plating layer 5 from peeling during manufacturing. The nickel plating layer 7 is completely diffused with the barrier plating layer 4 and titanium or titanium alloy during heating during vacuum exhaust, but the components of the barrier plating layer 4 remain thick, so that the same effect as the above example can be obtained. .

According to the manufacturing method of claim 2, as shown in FIG. 4, first, the pretreatment plating layer 8 is formed on the entire surface or a partial surface of either or both of the outer surface of the inner bottle 1 and the inner surface of the outer bottle 2.
To form. The pretreatment plated layer 8 is selected from the group consisting of metals having a large diffusivity with respect to titanium or titanium alloy, that is, nickel (Ni), iron (Fe), copper (Cu), cobalt (Co), and chromium (Cr). The thickness of one metal is 0.1 to 20 μm. In order to form the pretreatment plated layer 8, a method such as chemical plating can be adopted as necessary in addition to the usual electroplating.

Then, the inner bottle 1 or the outer bottle 2 on which the pretreatment plated layer 8 is formed is placed in a vacuum heating furnace, and under vacuum (about 10 ⁻³ Torr is sufficient) at a temperature of 400 to 800 ° C. By heating for 60 minutes, the pretreatment plated layer 8 is diffused in titanium or titanium alloy of the base material to form a diffusion alloy layer. If the temperature during this heat treatment is less than 400 ° C, the pretreatment plated layer 8 will not sufficiently diffuse, and if it exceeds 800 ° C, the diffusion will proceed too much and the diffusion alloy layer on the surface will be thin, resulting in the intended purpose. Cannot be reached.

Then, the inner bottle 1 or the outer bottle 2 after this heat treatment is completed.
After forming the radiation plating layer 5 made of silver or copper similar to the above example on the diffusion alloy layer of No. 1, the inner bottle 1 and the outer bottle 2 are joined at their mouths to form a double structure, and further vacuum The outer bottle 2 is sealed with a sealing plate 6 while being evacuated in a heating furnace and heated at 500 to 800 ° C. If the heating temperature here is less than 500 ° C, the surface adsorbed gas or the occluded gas cannot be sufficiently degassed, and if it exceeds 800 ° C, the diffusion of the radiation plating layer 5 increases even if the diffusion alloy layer exists. There is a risk of loss.

In this manufacturing method, the pretreatment plating layer 8 is formed in advance, the heat treatment is performed to form the diffusion alloy layer, and then the radiation plating layer 5 is formed. Occasionally, the radiation plating layer 5 is prevented from diffusing into titanium or a titanium alloy of the base material by the presence of the diffusion alloy layer.

Next, another example of the manufacturing method according to claim 2 will be described. In the manufacturing method of this example, as shown in FIG. 5, a pretreatment plated layer 8 is formed, and this is heat treated to form a diffusion alloy layer, then a nickel plated layer 9 is formed thereon, and radiation is further applied. The plating layer 5 is formed. The nickel plating layer 9 is used to enhance the adhesion between the radiation plating layer 5 and the base titanium or titanium alloy diffusion alloy layer, and has a thickness of about 0.1 to 20 μm. This nickel plating layer 9 is heated during vacuum sealing in a later step,
Part of it diffuses into titanium or titanium alloy,
Due to the presence of the diffusion alloy layer in which the pretreatment plating layer 9 is diffused,
The degree is slight and prevents diffusion of the radiation plating layer 5 together with the diffusion alloy layer.

It should be noted that, as the example of the vacuum sealing, the sealing by the sealing plate in the vacuum furnace was adopted and explained, but it is needless to say that the sealing by the chip tube in the atmosphere may be performed.

〔The invention's effect〕

As described above, the invention according to claim 1 has a double structure in which an inner bottle and an outer bottle made of titanium or a titanium alloy are joined at their mouths to form a double structure, and between the inner bottle and the outer bottle. When manufacturing a titanium thermos by evacuating the void, a part or all of the surface facing the void of one or both of the inner bottle and the outer bottle, tin, antimony, aluminum, zirconium Form a barrier plating layer consisting of one kind of metal selected from the group, and then form a radiation plating layer consisting of either silver or copper on this barrier plating layer, and at the temperature of 500-800 ℃ The gap between the bottle and the bottle is evacuated and sealed, and the invention according to claim 2 has a double structure in which an inner bottle and an outer bottle made of titanium or a titanium alloy are joined at their mouths. Make sure that the space between these inner and outer bottles is true. When manufacturing a vacuumed titanium thermos bottle, nickel or iron, copper, cobalt or chromium is formed on a part or all of the surface of the inner bottle and / or outer bottle facing the void. Form a pretreatment plating layer consisting of one kind of metal selected from the group, then heat-treat this, and then form a radiation plating layer consisting of either silver or copper, and apply it at a temperature of 500-800 ℃ The space between the bottle and the inner bottle is evacuated and sealed. Therefore, it is prevented by the diffusion alloy layer from the barrier plating layer or the pretreatment plating layer that the radiation plating layer is diffused and disappears in titanium or titanium alloy due to heating during vacuum sealing of the inner bottle and the outer bottle. It Therefore, according to this manufacturing method, it is possible to manufacture a titanium thermos bottle having a radiation plating layer and excellent in heat retention.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing an example of a titanium thermos bottle according to the present invention, and FIGS. 2 to 5 are schematic cross-sectional views showing the arrangement state of each plating layer in the manufacturing method of the present invention. 1 ... inner bottle, 2 ... outer bottle, 4 ... barrier plating layer, 5 ... radiation plating layer, 8 ... pretreatment plating layer.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shoji Hida 1-16-7 Nishishimbashi, Minato-ku, Tokyo Within Nihon Oxygen Co., Ltd. (72) Inventor Shigeru Tsuchiya 1-16-7 Nishishinbashi, Minato-ku, Tokyo No. Japan Oxide Co., Ltd.

Claims (2)

[Claims] 1. A titanium thermos bottle in which an inner bottle and an outer bottle made of titanium or a titanium alloy are joined at their mouths to form a double structure, and the space between the inner bottle and the outer bottle is evacuated. When manufacturing, one or more metals selected from the group consisting of tin, antimony, aluminum and zirconium on a part or all of the surface of the inner bottle and / or outer bottle facing the voids. A barrier plating layer consisting of, and then forming a radiation plating layer consisting of either silver or copper on this barrier plating layer, and evacuating and sealing the gap between the outer and inner bottles at a temperature of 500 to 800 ° C. A method for manufacturing a titanium thermos, characterized by comprising: 2. A titanium thermos bottle in which an inner bottle and an outer bottle made of titanium or a titanium alloy are joined at their mouths to form a double structure, and the space between the inner bottle and the outer bottle is evacuated. When manufacturing, a part or all of the surface of the inner bottle and the outer bottle facing one or both of the voids, nickel, iron,
A pretreatment plating layer made of one kind of metal selected from the group consisting of copper, cobalt and chromium is formed, and then this is heat treated, and then a radiation plating layer made of either silver or copper is formed. A method for manufacturing a titanium thermos bottle, characterized in that the space between the outer bottle and the inner bottle is evacuated and sealed at a temperature of up to 800 ° C.