JP3232053B2 - Coating method of platinum material on refractory substrate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a coating method of a platinum material for coating a refractory substrate mainly used for glass industrial products with platinum or a platinum alloy.

[0002]

2. Description of the Related Art Conventionally, Mo, N
A refractory such as a heat-resistant metal such as an i-base alloy or a ceramic (for example, mullite) coated with a platinum upholstery may be used, or a refractory ceramic substrate as disclosed in JP-A-5-339082. And a noble metal or a noble metal alloy coated by thermal spraying.

[0003] In the case where the base material coated with the platinum upholstery is a refractory material such as ceramics, the platinum upholstery is wrinkled due to a difference in thermal expansion between the base material and the upholstery during use.
May have adverse effects on glassware. When the base material coated with the platinum upholstery is a heat-resistant metal such as a Mo-based or Ni-based alloy, a ceramic layer such as alumina is sprayed on the surface of the base material to prevent the diffusion of platinum and the base material. However, when joining the platinum upholstery, heat is applied to the alumina base near the weld to crack the seam to weld the seam, and the heat resistant metal base material and the platinum upholstery can be shut off. However, the base material and the upholstery material may come into contact with each other during use and diffuse with each other, or may cause a fatal defect such as generation of bubbles or the like in the molten glass due to an electrolytic action.

[0004] Further, in the latter JP-A-5-339082, a noble metal or a noble metal alloy is coated on a refractory ceramic substrate by a thermal spraying method. This sprayed film is a platinum alloy, and because it is porous, it may be made non-porous by shot peening, flame baking, mechanical polishing, etc., but even with these treatments, there are no fine holes on the surface. It is difficult to do. Therefore, in a long-time glass environment, the molten glass permeates through the holes in the sprayed film, causing a contact reaction between the refractory ceramic substrate and the glass, often causing problems such as generation of bubbles and coloring of the glass. Also,
When coating a platinum-based upholstery on a refractory ceramic base or the like, heat is applied to the refractory ceramic base near the welded portion of the seam of the upholstery, and the heat-resistant ceramic base may be deteriorated or have minute cracks.
When a product made of this refractory material is used in a glass product manufacturing process, there is a problem that cracks are enlarged and the life is shortened.

[0005]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a method for producing a coated platinum material which is swollen, wrinkled, peeled off, cracked, or soaked even in molten glass for a long time. It is an object of the present invention to provide a method for coating a refractory substrate with a platinum material without causing sludge and without invading the refractory substrate.

[0006]

According to the present invention, there is provided a method for coating a refractory base material with a platinum material by spraying platinum or a platinum alloy on a refractory such as ceramics by thermal spraying. Thereafter, the thermal sprayed layer of platinum or platinum alloy is coated with an upholstery of platinum or platinum alloy.
Still another method of coating a refractory substrate with a platinum material according to the present invention is to apply a ceramic to a surface of a refractory metal made of a refractory metal such as a Mo or Ni-based alloy by thermal spraying, and then apply platinum to the ceramic sprayed layer. Alternatively, a platinum alloy is applied by thermal spraying, and then the platinum or platinum alloy sprayed layer is coated with a platinum or platinum alloy upholstery.

As described above, according to the method for coating a refractory substrate with a platinum material according to the present invention, the refractory substrate and the sprayed layer of platinum or a platinum alloy are brought into close contact with each other by the anchor effect of the ceramic sprayed layer, and the platinum or platinum is sprayed. Since the sprayed layer of the alloy is substantially porous, the difference in thermal expansion can be absorbed. Furthermore, the outside of the sprayed layer of platinum or a platinum alloy is covered with an upholstery of platinum or a platinum alloy.At this time, the sprayed layer and the upholstery are integrated by performing vacuum and heat treatment, and the refractory base material and the upholstery of the upholstery are coated. Strong adhesion is obtained and no defects such as wrinkles are generated. Therefore, if this material is used, a product with a long life and a platinum material can be obtained as a good product for the glass industry. Also, when joining upholstery materials by welding, there is a sprayed layer of platinum or a platinum alloy on the outside of the ceramic sprayed layer, so the heat during welding is absorbed by the sprayed layer of platinum or platinum alloy, and the heat is applied to the ceramic sprayed layer. The heat conduction is reduced, and defects such as cracks do not occur. Further, since the thinning material of the platinum or platinum alloy used in the coating method of the present invention can be thinner than the conventional one, the welding bead at the seam can be reduced, and cracks can be formed on the refractory base material such as ceramics or the ceramic sprayed layer. And no adhesion to heat-resistant metals such as Mo and Ni-based alloys.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the method for coating a refractory substrate with a platinum material of the present invention and a conventional example will be described. First, a conventional example will be described.

<Conventional Example 1> A 0.3 mm-thick Mo substrate 1 having a diameter of 36 mm and a length of 950 mm shown in FIG.
After the alumina coating 2 is uniformly applied to the
An upholstery material 3 of 10% Pt-Rh was wound around the outer surface at 0 mm, and the seam was sealed by welding. Next, the flange 4 was placed on the upper part, and the joint 5 was brazed with Au-Ni 17.5% brazing material.
Next, this was put into an electric furnace 6 shown in FIG. 2, and the temperature was increased while evacuating through a vacuum evacuation tube 7 with a vacuum pump 8 to 1350 ° C. and a vacuum of 3 × 10 ⁻⁵ Torr. The pulling tube 7 was sealed and kept for 10 hours. After the furnace was cooled, the product was taken out, and then the blades 9 were welded as shown in FIG.

<Conventional example 2> A 1.3 mm thick Pt-Rh 10% upholstery 12 is wound around an outer peripheral surface of an alumina substrate 11 having a diameter of 95 mm and a length of 1000 mm shown in FIG.
The seams were sealed by welding. Next, the flange 13 was placed on the upper part, and the seam 14 was brazed with Au-Ni 17.5% brazing material. Next, this was put into the electric furnace 6 shown in FIG.
The temperature is increased while evacuating with a vacuum pump 8 through a vacuum evacuation tube 7 to 1350 ° C., 3 × 10 ⁻⁵ To.
After evacuating to rr, the evacuation tube 7 was sealed and kept for 10 hours. After cooling the furnace, the product was taken out to obtain a plunger 15.

<Example 1> As shown in FIG. 4, similarly to the conventional example 1, the surface of a Mo base material 1 having a diameter of 36 mm and a length of 950 mm is uniformly coated with an alumina coating 2 to a thickness of 0.3 mm. After that, a Pt-Rh 10% thermal sprayed layer 16 having a thickness of 0.3 mm was formed on the surface by a plasma arc method. This thermal spray layer 16 is substantially porous. Next, a Pt-Rh 10% upholstery 17 having a thickness of 0.8 mm is formed on the thermal spray layer 16.
And the seam was sealed by welding. Next, the flange 4 was placed on the upper part, and the joint 5 was brazed with Au-Ni 17.5% brazing material. Next, this was put into an electric furnace 6 shown in FIG. 2, and the temperature was increased while evacuating through a vacuum evacuation tube 7 with a vacuum pump 8 to 1350 ° C. and 3 × 10 ⁻⁵ Torr.
r, the vacuum evacuation tube 7 is sealed and
Hold for 0 hours. After the furnace was cooled, the product was taken out, and then the blades 9 were welded as shown in FIG.

Example 2 As shown in FIG. 5, a 0.3 mm thick Pt-Rh 10% by plasma arc method was applied to the outer peripheral surface of an alumina substrate 11 having a diameter of 95 mm as in the conventional example 2.
Was formed. This thermal spray layer 19 is substantially porous. Next, Pt-0.8 mm thick Pt-
An upholstery material 12 of Rh 10% was wound, and the seam was sealed by welding.
Next, the flange 13 is placed on the upper part, and the seam 14 is Au-
It was brazed with Ni17.5% brazing material. Next, this is shown in FIG.
And the temperature was increased while vacuum was evacuated by a vacuum pump 8 through a vacuum evacuation tube 7.
After applying a vacuum of 3 × 10 ⁻⁵ Torr at 50 ° C., the evacuation tube 7 was sealed and maintained for 10 hours. After cooling the furnace, the product was taken out to obtain a plunger 20.

<Evaluation 1> The stirrers of Conventional Example 1 and Example 1 were taken out after use at 1,400 ° C. for 720 hours in a glass melting apparatus and inspected. The stirrer of Conventional Example 1 had cracks at the weld seam. The stirrer of Example 1 was in a good condition without cracks.

<Evaluation 2> When the plungers of Conventional Example 2 and Example 2 were immersed in molten glass at 1400 ° C. for 720 hours using a glass melting apparatus and then taken out and inspected, the plunger 10 of the conventional example was converted to an alumina substrate 11 And 8mm Pt-
A gap was formed between the upholstery members 12 of Rh 10%, and several wrinkles occurred in the surface layer portion. However, the plunger of Example 2 did not show any wrinkles and was in an extremely good state.

As can be seen from the above description, according to the method for coating a refractory substrate with a platinum material of the present invention, even if the refractory substrate is in a molten glass for a long time, the refractory substrate is not affected by the molten glass. Also, the platinum material may bulge or wrinkle,
The resulting refractory material has a very long service life and at the same time a glass product made from it, because it can be coated without peeling, cracking or seepage of the molten glass. Quality is improved.

[Brief description of the drawings]

FIG. 1 is a view for explaining a stirrer manufacturing process by a conventional platinum material coating method.

FIG. 2 is a view showing an electric furnace used for manufacturing a stirrer.

FIG. 3 is a view for explaining a manufacturing process of a plunger by a conventional platinum material coating method.

FIG. 4 is a diagram for explaining a stirrer manufacturing process according to the platinum material coating method of the present invention.

FIG. 5 is a diagram for explaining a manufacturing process of a plunger according to the platinum material coating method of the present invention.

[Explanation of symbols]

 Reference Signs List 1 Mo base material 2 Alumina coating 11 Alumina base material 12 Pt-Rh 10% upholstery 16 Pt-Rh 10% sprayed layer 17 Pt-Rh 10% upholstery 18 Stirrer 19 Pt-Rh 10% sprayed layer 20 Plunger

Claims (5)

(57) [Claims] 1. A refractory material comprising applying platinum or a platinum alloy to a refractory such as ceramics by thermal spraying, and then coating the sprayed layer of the platinum or platinum alloy with an upholstery of platinum or platinum alloy. A method for coating a base material with a platinum material. 2. A ceramic is deposited on the surface of a refractory metal made of a heat-resistant metal such as a Mo or Ni-based alloy by thermal spraying, and then platinum or a platinum alloy is deposited on the ceramic sprayed layer by thermal spraying. A method for coating a refractory substrate with a platinum material, wherein the sprayed layer of platinum or a platinum alloy is coated with an upholstery of platinum or a platinum alloy. 3. The method for coating a refractory substrate with a platinum material according to claim 1, wherein the sprayed layer of platinum or a platinum alloy is substantially porous. 4. The method according to claim 1, wherein after coating the thermal spraying layer with the upholstery, the thermal spraying layer and the upholstery are integrated by performing a vacuum heating process. 5. A platinum product for the glass industry using a platinum-coated refractory substrate produced by the method according to claim 1.