JPS5877564A - Coating method for surface - Google Patents

Abstract

PURPOSE:To form a coating layer with high heat resistance, corrosion resistance, stress corrosion resistance, etc. by adding a specified amount of a rare earth element to a metal for deposition to form an electrode wire and by causing the discharge explosion of the wire on a surface to be worked. CONSTITUTION:A rare earth element or misch metal is added to >=1 kind of metal or compound selected optionally from metals for deposition such as W, Mo and Ti, carbides and nitrides thereof by 0.1-20wt%, preferably 0.5-15wt% of the amount of the total composition, and an electrode wire of a prescribed shape is formed. The preferred rare earth element is Sc, Y, La, Ce, Pr, Nd or Sm. The electrode wire is placed between opposite electrodes, and by supplying a large electric current between the electrodes in the air or an inert atmosphere, the instantaneous line explosion of the wire is caused to deposit a coating layer on a surface to be worked by spraying.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a method of forming a coating layer or a diffused surface layer on a predetermined machined surface by causing a so-called discharge explosion by discharging a large amount of water between opposing electrodes. In particular, it relates to a method of breaking using clay filler alloy as a line for line military poles.

Conventionally, the coating layer caused by line explosion was treated in a prescribed manner f14! For example, 6jJ'-' (
As a method of coating J i metals such as tungsten, machete, molybdenum, etc. A wire is made of these carbides, and an electrode with a fixed length of opposing gap is provided at a predetermined location on the inner surface of the cylinder, and a wire is disposed between the electrodes, and a large-scale spark is instantaneously applied between the two electrodes. Iwa (φi, explode the discharge 6, make the ejected bath-imitating grains collide with the desired location on the inner surface of the goo) Then, the entire surface layer 1)!ij, -NF method is known.Also, copper, which produces conductivity and magnetism,
Cobalt alloy coatings are also known. Such a discharge explosion causes a specific metal to be thermally sprayed. The method must therefore be carried out under respective appropriate requirements depending on the applied materials and application conditions.

Now, the welded metal coating or metal diffusion layer is
Improved heat resistance and stronger abrasion resistance than the molten layer -1
It can increase corrosion resistance, improve stress corrosion resistance, improve hardness, and increase elasticity, and can also be achieved in cases where activation as a necessary catalyst or ease of discharge is required. It would be great if some or most of them could show remarkable effects. however,
It cannot be said that this will be easily achieved depending on the proposals made by the US residents.

In view of the above-mentioned current situation, the present invention aims to provide a method that can meet these expectations and can be used very effectively in practice. In order to achieve this object, the present invention is directed to metals used as electrode wires containing rare earth alloys, rare earth alloy bases and rare earth oxides, formation of laminated or diffused layers by discharge explosion of these metals, Furthermore, the atmosphere activity during formation of these layers is controlled to make the process more effective. Sufficient proposals have not been made regarding the formation of alloys based on such melts, layer metals and rare earth elements, and sprayed layers thereof.

Next, the present invention will be explained in detail. As a rare earth element, 1
Seven types can be listed. Of these, the present invention particularly focuses on scandium, yttrium, lanthanum, cerium,
Practical use of praseodymium, neodymium, samarium and mitschmetal. One or more elements arbitrarily selected from these are 01. An alloy containing a proportion in the range of ~20 wt% is produced by containing one or more arbitrarily selected metals to be welded, such as the above-mentioned tungsten, molybdenum, titanium, or carbides or nitrides thereof, Used as an electrode wire of a predetermined shape.

For the above range of 0.1-20 wt%, 20%
(3) If the above is contained, the activity will be sieved and oxidation will occur easily, and in this respect, 20% is the upper limit. Moreover, since no effect is observed below 0.1 IWt, this is the lower limit. Generally, it is preferably in the range of () 5 to 15 wt.
The range to be selected depends on the application and the allowable cost. b. As an alloy with molybdenum, the content of Mitsushi metal consisting of lanthanum, cerium, praseodymium, samarium, and neodymium is 5 to 10 wt.
%, the balance being molybdenum, was permeated and diffused into an electrode wire. Explosive thermal spraying formed the coating layer in an inert atmosphere. In this case, we were able to confirm that the electron emission characteristics required a lower discharge voltage compared to a layer coated with explosive thermal spraying using molybdenum wires, and that it was easier to discharge the rare earth element content. . Furthermore, a coating layer having remarkable heat resistance, corrosion resistance, and stress corrosion resistance was obtained.

The total of scandium, lanthanum, and cerium is 1.5~
Using an electrode wire containing 5 wt% of alloyed copper (4) with the remainder being copper, the diffused layer formed on the surface of the copper(4) alloy plate by line explosion thermal spraying in the atmosphere has a low discharge voltage. The results showed that the elasticity was improved and the frictional resistance could be controlled by varying the amount of rare earth.

The total of cerium, lanthanum, and samarium is 0.5~
The laminated layer formed on the surface of the aluminum-silicon alloy plate by line explosion thermal spraying in the atmosphere using a wire containing 3 wt% of the mixture with the remainder being titanium is heat resistant. It was observed that the corrosion resistance improved and the hardness increased.

1. Using a wire electrode formed by permeating and diffusing a mixture containing 0.5 to 1.0 wt% of Mitsushimetal, the remainder being titanium and titanium carbide. The laminated layer obtained by explosive spraying in the atmosphere was found to have uniformly increased hardness, improved abrasion resistance, and improved elasticity.

Using a sintered wire of a mixture of 9.5 to 1.0 wt% of Mitshu metal, 0.5 wt% of cerium oxide, and 30% of cobalt, and the balance being tungsten, the same method was used as above, but without changing the atmosphere. The laminated layer formed in an active gas has a low discharge voltage, improved hardness and wear resistance, and good corrosion resistance.

The laminated layer formed in an inert gas using an electrode wire made of an alloy containing 10 wt% of mitshu metal, 15 wt% of lanthanum and cerium oxide, and the remainder being molybdenum has a decrease in emitted 1 m pressure and hardness. , improved corrosion resistance, and increased elasticity. When the atmosphere was air, there were cases where the constant value was not stable.

In either case, the common results are that the laminated layers are dense, the discharge voltage decreases, the hardness increases, the elasticity increases, and corrosion resistance, heat resistance, and abrasion resistance are improved. The goal is to improve

Furthermore, it was found that the stress corrosion resistance increased when the coating layer was formed on both the stainless steel plate surface and the copper alloy plate surface.

As a 15i child derived from the results of these series of tests, the content of rare earth elements or Mitsushi metals is 20w
When t is 4 or more, the activity is low, and if line explosion thermal spraying is continued in an inert gas, the negative side due to oxidation becomes noticeable. It is clear from the above example that the addition of rare earth element oxides also brings about good results in modification, but even if the addition is less than 20%, it can be carried out in an inert gas depending on the application and if necessary. gives more stable results.

Depending on the added content of the rare earth element or metal, and the atmosphere in which the test is carried out, the results of the test will vary depending on the content. Results of alloying and
The difference in radical opening from the results obtained when a composite, for example a sintered body, is formed by permeation-diffusion treatment of the mixture is not so clear as to be particularly noticeable. This means that even if an alloy electrode wire is not used, it is sufficient to obtain an electrode wire that can easily hold the shape of the electrode wire and allow a discharge current to be explosively sprayed.

From a series of these studies, we have determined that properties such as wear resistance, which is affected by complex factors, as well as properties such as corrosion resistance, heat resistance, elasticity, and stress corrosion resistance, as well as the amount of rare earth elements or Mitsushi metal added, It is expected that by mixing rare earth element oxides and selecting the atmosphere, it will be possible to adjust and control (7).

As already explained, the present invention is #! Gold metal 01-2
The coating layer is extremely useful when electrode wires are formed by containing rare earth elements and Mitsushi metal within the range of 0w1%, and a thermally sprayed coating is formed by instantly passing a large explosion current between the electrodes. It shows a certain characteristic. The effect of lowering the discharge voltage, ie, facilitating wire explosion due to current carrying base. It also improves heat resistance, corrosion resistance, and stress corrosion resistance. Increases hardness. Increases elasticity. Improves wear resistance. It is expected that these can be controlled by adjusting the applied atmosphere and the needle containing the rare earth element.

Using Mitshumetal has the same effect.

The effect can also be improved by adding an appropriate amount of oxide.

Patent applicant: Inoue Japax Research Co., Ltd. 91st generation
Attorney Patent Attorney Nishi Naka -+9+
-355- ()

Claims (1)

[Claims] 1. An electrode wire is attached between opposing electrode wires, and a large current is passed between both electrodes to cause an instantaneous explosion so that the electrode wire metal is tangent to the workpiece surface to form a coating layer. In the product to be formed, the main component metal of the metal forming the coating j-, which is the E4L polar ray, is alloyed or mixed with a rare earth element or Mitsushi metal in the O1 to 20 wt group in the total composition. The electrode wires are formed and fixed between the electrodes, and a predetermined flow is applied to apply a coating layer or a diffusion coating layer to the surface to be machined by Ipolar explosion thermal spraying. surface coating method. 2. The surface coating according to claim 1, in which a suitable amount of these oxides is added to 0.1 to 20 wt% of the rare earth element or metal contained in the entire composition. Method. 3. The surface coating method according to claim 1, wherein the wire explosion of the electrode wire is performed in the atmosphere. 4. The surface coating method according to claim 1, wherein the wire explosion of the electrode wire is performed in an inert atmosphere.