JPH09125106A - Metal coated with granular material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a metal coated with a granular material capable of being machined to a metallic parts such as thin plate, fine wire and small article and large in the combination strength of a coated layer with a base metal. SOLUTION: This metal A coated with the granular material is constituted so that the surface of a heat resistance steel containing chromium and at least one kind of nickel, aluminum and yttrium, for example, a stainless steel wire 2 is coated with the coating layer 10 consisting of nickel-based alloy particles containing aluminum or a chromium-based alloy particles 4 containing the aluminum coated with ceramic particles 6. The stainless steel wire 2 coated with the coating layer 10 is subjected to a heat treatment at 1100-1300 deg.C in vacuum to weld the alloy particles 4 to the wire 2 and to combine the alloy particles 4 of the coating layer 10 and the ceramic particles 6 with each other. The average grain size of the ceramic particles 6 of the coating layer 10 is <=1μm and the particles contain at least the one kind of aluminum, silicon, magnesium, zirconium, barium and titanium.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a particulate matter-coated metal suitable for electric heating wires and the like, and more particularly to a particulate matter-coated metal having a large binding force of a coating layer to a metal as a base material.

[0002]

2. Description of the Related Art CVD, PVD, sol-gel, thermal spraying and the like are known as methods for applying a ceramic / metal composite coating on a metal surface.

However, CVD (chemical vapor depositi)
on) method, the materials of the base metal and the coating material are limited,
The PVD (physical vapor deposition) method has a weak bonding force or adhesion between the base metal and the coating material. Also in the sol-gel method, the bonding strength or adhesion between the base metal and the coating substance is weak, and it is difficult to form a thick coating layer having a layer thickness of more than 1 μm. In particular, since it is necessary to form fine irregularities on the surface of the base metal by means of shot blasting before binding the coating substance, it is necessary to form a coating layer on metal parts such as thin plates, fine wires and small items. Is very difficult.

Japanese Unexamined Patent Publication (Kokai) No. 5-287407 discloses, as a ceramic-based powder for metallurgy for coating the surface of a base metal such as a cutting tool, a nickel alloy on the surface of a relatively coarse ceramic powder such as silicon nitride or alumina. , Those which firmly adhere alloy powder such as cobalt alloy are disclosed, but this ceramic-based powder for metallurgy is not only different in structure and base metal coating method between ceramic-based powder and alloy powder, The mechanical strength is not sufficient and its use is limited.

[0005]

In view of the above-mentioned problems, the object of the present invention is that it is possible to process metal parts such as thin plates, fine wires and small articles, and the binding force of the coating layer to the base metal is large. To provide a metal coated with a particulate matter.

[0006]

In order to solve the above-mentioned problems, the structure of the present invention uses chromium as a particulate matter coating metal.
The surface of the heat-resistant steel containing (Cr) is covered with a coating layer consisting of nickel (Ni) -based alloy particles containing aluminum (Al) or chromium (Cr) -based alloy particles containing aluminum (Al) coated with ceramic particles. In addition, the heat resistant steel and the alloy particles are welded together.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, a mixed powder of a ceramic powder and an alloy powder having a uniform particle size distribution and an average particle size of 1 μm or less is adhered to the surface of a base metal with an organic solvent, and then in a vacuum. By heat treatment, a particulate matter-coated metal is obtained. By the heat treatment, the ceramic powder and the alloy powder are reduced by the carbon of the organic solvent and welded to the base metal.

In addition to chromium (Cr), nickel (N
A heat resistant steel containing at least one of i), aluminum (Al) and yttrium (Y), for example, stainless steel is selected. Aluminum (Al), silicon (S
i), magnesium (Mg), zirconium (Zr), barium (B
At least one of a) and titanium (Ti) is selected. Specifically, they are oxides such as Al ₂ O ₃ , SiO ₂ , MgO, ZrO ₂ , BaTiO ₃ , and TiO ₂ . As the alloy powder, nickel (Ni) -based alloy powder containing aluminum (Al) or chromium (Cr) -based alloy powder containing aluminum (Al), preferably Ni-Cr-Al alloy powder is selected.

[0009]

EXAMPLES As shown in FIGS. 1 and 2, a synthetic rubber adhesive composed of acrylic rubber, an organic solvent, isohexane gas, etc., was applied to the surface of a stainless steel wire 2 having a wire diameter of 0.2 mm as a base metal. It was applied by spraying. The surface of the adhesive applied to the surface of the stainless steel wire 2 has an average particle size of 5 to 5.
20 μm Ni-Cr-Al alloy powder 4 and average particle size of 0.3-
A 1.0 μm mixed powder of Al ₂ O ₃ , SiO ₂ , MgO, ZrO ₂ , BaTiO ₃ , TiO _{2 and the} like with the ceramic powder 6 was deposited. Next, the stainless steel wire 2 was heated in a vacuum at a temperature of 1100 to 1300 ° C. for about 2 hours to obtain a particulate matter-coated stainless steel wire A.

As a result of observing the surface of the particulate matter-coated stainless steel wire A obtained by the present invention, the Ni-Cr-Al alloy powder 4 and the ceramic powder 6 for coating the surface of the stainless steel wire 2 are shown in FIG. As shown in No. 1, the particles adhered while maintaining the shape and particle size before coating. The coating particles 4 and 6 of the coating layer 10 of the stainless steel wire 2 do not overlap each other so much and form a uniform coating layer 10 dispersed in almost one layer, and the coating particles aggregate or burn. I couldn't see it tied up.

As shown in FIG. 4, the smaller the particle size of the ceramic particles coating the surface of the stainless steel wire 2 was, the more uniform the coating layer 10 was. That is, when the particle diameter of the ceramic particles 6 exceeds 1 μm, a portion of the surface of the stainless steel wire 2 which is not covered with the particulate matter occurs. As a result of the comparative test, it was found that when the particle diameter of the ceramic particles 6 covering the surface of the stainless steel wire 2 exceeds 1 μm, the ceramic particles 6 are less likely to adhere to the stainless steel wire 2. Further, it can be seen that when only Ni-Cr-Al alloy particles are used as the particulate matter for coating the surface of the stainless steel wire 2, the Ni-Cr-Al alloy particles are coagulated with each other.

As a result of observing and analyzing the cross section of the particulate matter-coated stainless steel wire A according to the present invention, as shown in FIG.
At the interface between the coated particles 4 and 6 and the stainless steel wire 2, the reaction layer 3 of the constituent elements of the coated particles 4 and 6 and the constituent element of the stainless steel wire 2 was observed. It is thought that this is because not only the Ni-Cr-Al alloy particles 4 but also the fine ceramic particles 6 were reduced in vacuum by carbon (C) contained in the organic solvent and reacted with the stainless steel wire 2 which is the base metal. To be

In order to evaluate the adhesion between the stainless steel wire 2 which is the base metal of the particulate matter-coated stainless steel wire A according to the present invention and the coating layer 10 or the coated particles 4 and 6, the particulate matter-coated stainless steel is used. A self-wrapping test was conducted on the wire A that was repeatedly heated and the wire that was not heated.
As a result of the test, when the particulate matter-coated stainless steel wire A according to the present invention was wound and when it was straightened after being wound, the coated particles 4 and 6 did not fall off. The coating layer 10 does not crack and the coating particles 4 and 6 do not fall off because the coating particles 4 and 6 and the stainless steel wire 2 are bonded to each other through the reaction layer 3 and the ceramic particles 6 do not sinter each other and are independent. As a result, it is considered that the thermal stress is relaxed.

Next, the particulate material according to the present invention using Ni-Cr-Al alloy particles and ceramic particles such as Al ₂ O ₃ , SiO ₂ , MgO, ZrO ₂ , BaTiO ₃ and TiO ₂ as the particulate material. With respect to the coated stainless steel wires A1, A5, A3, A4, A2 and the stainless steel wires B1 to B3 of the comparative example, a heat resistance strength test was performed to see the strength change after exposure to the atmosphere at a temperature of 1100 ° C. for 25 hours. FIG.
As shown in, the tensile strength of the particulate matter-coated stainless steel wires A1 to A5 according to the present invention was 300 MPa or more. On the other hand, the tensile strength of the uncoated stainless steel wire B1 is 1 hour of exposure, and the tensile strength of the stainless steel wire B2 coated with Al ₂ O ₃ by the sol-gel method is 10 hours of exposure, and only Ni-Cr-Al alloy is exposed. The tensile strength of the coated stainless steel wire B3 became unmeasurable after 10 hours of exposure.

Further, the particulate matter is Ni-Cr-Al alloy particles and Al is
Regarding the particulate-material-coated stainless steel wire A using ₂ O ₃ particles added in an amount of 5 wt% or more, the surface of the stainless steel wire 2 was oxidized after a heat resistance test in which it was exposed to the atmosphere at a temperature of 1100 ° C. for 25 hours. Analysis of the layers showed that chromium (C
r) and aluminum (Al) were detected. On the other hand, iron (Fe) and chromium (Cr) were detected in the oxide layer on the surface of the stainless steel wire 2 using only the Ni-Cr-Al alloy as the particulate matter.

According to the above heat resistance test, the stainless steel wire 2
As a particulate matter for coating the surface of Ni-Cr-Al alloy particles, if more than 5 wt% of Al ₂ O ₃ particles are added, the oxidation weight increase decreases as shown in Figs. It was found that the strength was also improved. Here, the oxidation weight increase PW is PW = 100, where W1 and W0 are the masses before and after the heat resistance test.
It is represented by (W1-W0) / W0. From the above-mentioned analysis and heat resistance strength test, when Al ₂ O ₃ particles are added to Ni—Cr—Al alloy particles as the particulate material of the coating layer 10, the heat resistance is improved by iron.
It is considered that the oxidation of (Fe) was suppressed.

Further, the specific resistance of the surface of the particulate matter-coated stainless steel wire A obtained by the present invention at room temperature is about 20.
It was found that the resistivity of the surface of the particulate matter-coated stainless steel wire A using MgO as the particulate matter was about 10 MΩ · cm even at a temperature of 1000 ° C.

Next, as shown in FIG. 3, Ni-Cr-Al alloy particles 4 as the particulate matter, Al ₂ O ₃ , SiO ₂ , MgO, ZrO ₂ and Ba.
The sol-gel coating was performed on the particulate material-coated stainless steel wire A using each of the TiO ₃ and TiO ₂ ceramic powder 6 by using a coating solution prepared from a commercially available metal alkoxide on the surface of the coating layer 10. The conditions of the sol-gel coating are such that the particulate matter-coated stainless steel wire A is immersed in the coating solution, the particulate matter-coated stainless steel wire A is pulled up, hydrolyzed, and heat-treated in the atmosphere at a temperature of 600 ° C. The coating film was easily peeled off on the stainless steel wire not coated with the particulate matter as a comparative example, whereas the particulate matter-coated stainless steel wire A according to the present invention has a thickness of 1 to 2 μm. The coating film 12 did not peel off. It is considered that this is because the adhesion strength of the coating film 12 is increased by the anchor effect of the ceramic particles 6 attached to the surface.

[0019]

As described above, according to the present invention, after the mixed powder of the ceramic powder and the alloy powder is adhered to the surface of the base metal using the adhesive such as the synthetic rubber, the heat treatment is performed in vacuum. With this, it is possible to process base metal parts such as thin plates, thin wires, and small articles, and a particulate matter-coated metal having a large binding force of the coating layer to the base metal can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically showing a particulate matter-coated metal according to the present invention.

FIG. 2 is a cross-sectional view showing an enlarged main part of the particulate matter-coated metal.

FIG. 3 is a cross-sectional view schematically showing the particulate matter-coated metal shown in FIG. 1 having a surface coated with a coating film.

FIG. 4 is a diagram showing the relationship between the particle size of the particulate matter and the coating layer in the particulate matter-coated metal according to the present invention.

FIG. 5 is a diagram showing the results of a heat resistance test of a particulate matter-coated metal according to the present invention and a comparative example.

FIG. 6 is a graph showing the relationship between the amount of Al ₂ O ₃ added to the particulate matter and the tensile strength in the particulate matter-coated metal according to the present invention.

FIG. 7 is a diagram showing the relationship between the amount of Al ₂ O ₃ added and the amount of increased oxidation with respect to the particulate matter in the particulate matter-coated metal according to the present invention.

[Explanation of symbols]

A: Metal coated with particulate matter 2: Heat-resistant steel (stainless steel wire) 3: Reaction layer 4: Alloy particles 6: Ceramic particles 10: Coating layer 12: Coating film

Claims (6)

[Claims] 1. A nickel (Ni) -based alloy particle containing aluminum (Al) or a chromium (Cr) -based alloy particle containing aluminum (Al), wherein the surface of a heat-resistant steel containing chromium (Cr) is coated with ceramic particles. A particulate matter-coated metal, which is covered with a coating layer made of, and the alloy particles are welded to the heat-resistant steel. 2. The heat resistant steel is nickel (N) in addition to chromium (Cr).
The particulate matter-coated metal according to claim 1, comprising at least one of i), aluminum (Al), and yttrium (Y). 3. The alloy particles of the coating layer are bonded to each other, the ceramic particles of the coating layer are independent without sintering, and adhere to the surface of the alloy particles and the heat-resistant steel. 2. The particulate matter-coated metal according to any one of 1 and 2. 4. The particulate matter-coated metal according to claim 1, wherein the ceramic particles in the coating layer have an average particle size of 1 μm or less. 5. The ceramic particles of the coating layer are at least one of aluminum (Al), silicon (Si), magnesium (Mg), zirconium (Zr), barium (Ba), and titanium (Ti).
The particulate matter-coated metal according to any one of claims 1 and 2, which contains seeds and is contained in the coating layer in an amount of 5 wt% or more. 6. A nickel (Ni) -based alloy particle containing aluminum (Al) or a chromium (Cr) -based alloy particle containing aluminum (Al), wherein the surface of a heat-resistant steel containing chromium (Cr) is coated with ceramic particles. A particulate material-coated metal characterized in that the heat-resistant steel and the alloy particles are welded together, and the surface of the coating layer is covered with a dense ceramic coating.