JPH0364444A - Wire for forming surface film - Google Patents

Abstract

PURPOSE:To obtain the wire forming a film having excellent characteristics of tight adhesion with a base metal, wear resistance, heat resistance, corrosion resistance, etc., by incorporating an aluminum base metal as a matrix with hard grains. CONSTITUTION:The wire is formed by incorporating an Al or Al alloy matrix with >=50vol% hard grains constituted of ceramics, intermetallic compounds, cermet, metals or the like and having >=500Hv hardness of themselves. The wire is stuck onto the surface of a base metal by adopting thermal-spraying and cladding by welding, by which a film having excellent characteristics of wear resistance, heat resistance, corrosion resistance, etc., can efficiently be formed. As for the above hard grains, in the case of <=500Hv hardness, wear resistance can not be obtd., and in the case of >50vol% incorporation, the homogeneous dispersion of the hard grains into the matrix of the film is made difficult and the matrix is reduced, so that the conformability of the film with the base metal is deteriorated.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to a material for forming a surface film, and more particularly, it mainly involves melting a wire by thermal spraying and attaching it to the surface of a base material to improve wear resistance and heat resistance. This invention relates to a wire suitable for forming a coating with excellent properties such as corrosion resistance.

(Prior art and problems to be solved) Conventionally, there are surface treatment methods that form films with various characteristics on the surface of a base material, which is a metal material, to impart properties different from those of the base material. Depending on the material of the base material, various methods such as ion implantation, surface hardening, hard plating, nitriding, sparse penetration plating, overlaying, thermal spraying, etc. are selected and adopted as appropriate.

For example, when aluminum or its alloy is used as the base material to take advantage of its light weight, the method for hardening its surface-1 is to use different materials such as W-based, Nj-based, Co-based, and S.
There is a method of forming a thin film by overlaying, thermal spraying, etc. using -Fe-based materials. For example, regarding the method by overlaying, JP-A-58-179569, JP-A-58-21529j, JP-A-115676, etc., and the method by thermal spraying, JP-A-54-7012, JP-A-54. -701
No. 3 and No. 63-4051.

However, thin film materials have a different coefficient of thermal expansion than aluminum materials,
There were problems such as poor adhesion, the need for many expensive materials, large differences in specific gravity, and the tendency to segregate during thin film formation, particularly during overlaying, making it impossible to obtain homogeneity.

In addition, attempts have been made to make such thin films into multilayer films and layer them in order of the thermal expansion coefficient of the base material to alleviate the difference in thermal expansion coefficient with the base material, but in addition to the above problems, the process is There were problems such as complexity.

On the other hand, in order to obtain a film with a thickness on the order of millimeters, there is a method of attaching ceramics to the surface of the aluminum material.
Most of the methods involve scattering ceramics on a base material in advance and then melting the ceramics using an arc, laser, etc., which is often impractical.

The present invention was made in view of the above circumstances, and
It is an object of the present invention to provide a material for forming a surface film that can efficiently, simply, and stably form a film that has excellent adhesion to a base material and has desired properties such as abrasion resistance, heat resistance, and corrosion resistance. This is the purpose.

(Means for Solving the Problems) In order to achieve the above object, the present inventors first conducted intensive research to find out the cause of the above problems when thermal spraying and overlaying are employed as coating formation methods. As a result, in the conventional surface treatment method by overlaying or thermal spraying, hard particles are supplied as they are, that is, in the form of particles or powder, to the surface of the base material and melted to form a film. It turns out that there is a problem with the expansion rate.

Therefore, although hard particles are used, the present invention has been made as a result of further research on ways to minimize the difference in thermal expansion coefficient with the base material.

That is, the present invention is made of ceramics, intermetallic compounds, cermets, metals, etc., and has a hardness Hv of 5.
The gist of the present invention is a wire for forming a surface film, characterized in that hard particles having a number of 00 or more are contained in aluminum or aluminum alloy 71 to linox in an amount of 50 vol % or less.

The present invention will be explained in more detail below.

(Function) As mentioned above, in the past, the material of the base material and the material of the film to be formed were generally selected almost independently, and a film made of different materials was formed on the surface of the base material. So,
Considering that the base material to be coated is mainly aluminum or aluminum alloy, a matrix made of aluminum or aluminum 11 alloy, which is the same type as this, is coated, and at that time, predetermined hard particles are contained in the matrix. By doing so, it is possible to obtain a film with excellent adhesion even at high temperatures.

The hard particles can be made of various materials such as ceramics, intermetallic compounds, and cermet 1-1 metals.
These are A O,,7,r, Cr,]゛l,V,T
a, SJ, W, Nb, Cu, Ni, Co, Fc and Nj
It can be included as a compound or metal having at least one element selected from the group consisting of as a base element. For example, examples of ceramics include alumina, titania, and alumina titania. Composite powder, nitride,
Examples of erosides include Cr3C2, TiC, B4C, W
C, ZrC, T"B2, M o 132, ZrB2, T
iN, 7. Examples include rTj, composite powders thereof, and the like. Of course, it goes without saying that it is not limited to only these.

In addition, when selecting these hard particles, it is preferable to select them in relation to the material of the base material. That is, if a material having a specific gravity as close as possible to that of the base material is selected, segregation during film formation can be significantly reduced, and the homogeneity of the film can be ensured. For example, when the base material is aluminum, the specific gravity of the aluminium 11 is 2.
7, those that have a specific gravity of 2.7±2'lU degrees, such as Sj, AQ201, SiC, Si
Select 3N4, B4C, CBN, BN-TiB2, etc.

Pay particular attention to this when overlaying.

Of course, it goes without saying that the material of the hard particles can be selected depending on the characteristics of the film to be formed. For example, when the purpose is to harden aluminum using thermal spraying, WC, MO, ZrO2, TiC, TiN, Cr3
C,, Cr, ZrO2-Y2O2, WC-Ni-Cr
, WC-Co, MgO, TiC-Ni, NbC, etc. may be selected.

However, hard particles have their own hardness Hv (Knoop hardness)
has Hv≧500, and it is necessary to contain it in the matrix in an amount of 50ν01% or less. Although it depends on the material of the hard particles, it is usually 20 to 50 vol%. Hardness Hv is 5
If the particle size is lower than 0.00, wear resistance, which is the main coating property, cannot be obtained. Moreover, if the content exceeds 50 vol%, it becomes difficult to homogeneously disperse the hard particles in the matrix of the coating, or there are problems such as poor staining with the base material because the matrix decreases.

Furthermore, such hard particles have a diameter of 5
It is recommended that the size be less than 00μ■1. If the size is larger than 500 μm, it becomes difficult to uniformly disperse the hard particles in the matrix. but,
If it is too fine, it will be easy to melt during thermal spraying and the yield of the thermal sprayed film will be difficult, so it is desirable that the thickness is 1 μm or more. In addition, it is preferable for the shape to have no sharp protrusions (eg, spherical shape) from the viewpoint of manufacturing.

The form of the wire made of a hard matrix and hard particles is not particularly limited, but it may be a solid wire in which hard particles are dispersed in a matrix, or a composite wire in which the matrix is used as a hoop and hard particles are filled inside. There are various aspects. Solid wires are made into billets or slabs by powder metallurgy, in which 71-Rix powder and hard particles are mixed and solidified, or by molten metal forging, in which a preform of hard particles is impregnated with a matrix melt under pressure. The wire is then formed into a wire, or the wire is obtained by hydrostatic extrusion. In the case of composite wire, the cross-sectional shape is a hoop filled with hard particles, but in some cases,
A heat generating agent or a heat insulating agent (Mg, aluminum powder, REM type, etc.) can also be filled. By filling the film with a heating agent, the effect of preheating or keeping warm after film formation can be obtained, and the adhesion can be improved. Note that in order to obtain a heat retention effect, it is also possible to cover the surface with a slag agent after film formation.

The wire of the present invention is melted by thermal spraying, overlaying, etc. to form a film with desired thickness and characteristics on the surface of the base material. As the thermal spraying method, various thermal spraying methods such as arc thermal spraying, high frequency thermal spraying, gas thermal spraying, plasma thermal spraying, etc. are possible. Plasma spraying with high spray velocity is recommended.

The film can have a variety of thicknesses, and can be uniformly formed from a micron order to a millimeter order thick film.

(Example) Next, examples of the present invention will be shown.

In order to eliminate this problem, pure aluminum was used as the ear base (matrix), and a wire containing particles of the size and amount shown in the construction table was prepared.The wire type is a solid wire with particles dispersed in it. There were two types of wires: a wire and a composite wire in which particles were filled in a hoop made of a wire base.Next, these wires were used to perform gas spraying to coat the surface of the aluminum base material (A5083) as shown in Table 1. A film of the thickness shown was formed.

A wear resistance test was conducted on the obtained film under the following conditions, and the amount of wear was measured. The results are also listed in Table 1.

<Wear resistance test conditions> Test method: Okura test method Final load: 3 kgf Wear rate: 1.36 m/see Wear distance: 100 m From Table 1, invention examples No. 1 to No. 9 all have a small amount of wear. It can be seen that the film has excellent wear resistance regardless of the film thickness.

11 Loss 41) iii □□ ;; - The construction drawing shows the relationship between the final load and the amount of wear for the thermal spray coating obtained using the wire in the case of test Nn 3.

From the same figure, the thermal spray coating obtained with the wire of Invention Example No. 3 shows less wear than that of FC25 cast iron, regardless of the final load, and has stable and excellent wear resistance (long lifespan). etc.).

In addition, large pores are generated in the thermal spray coating obtained with a wire (solid wire) made only of 5183, and the amount of wear is large.

Figure 2 is a micrograph showing a cross section of the thermal sprayed coating and base material obtained in the example of the present invention, in which SiC particles are
It can be seen that the sprayed film is homogeneously (densely) dispersed in the linox, has small and small pores, and is of high quality.

(Effects of the Invention) As described in detail below, the material for forming a surface film according to the present invention is a wire having aluminum or an aluminum alloy as a matrix and hard particles contained in the matrix, so that it has excellent wear resistance, A homogeneous film with desired properties such as heat resistance and corrosion resistance can be obtained, and it has excellent adhesion to the base material even at high temperatures. Furthermore, since it uses surface treatment methods such as thermal spraying and overlaying, it is excellent in terms of efficiency, simplicity, ease of work, and ease of controlling the coating, and the overall cost can be reduced.

[Brief explanation of drawings]

Fig. 1 is a diagram showing the relationship between the amount of wear and final load for the thermal sprayed coating, and Fig. 2 is a micrograph (X100) showing the particle structure of a cross section between the thermal sprayed coating and the base material.

Claims (4)

[Claims] (1) A surface characterized by containing hard particles made of ceramics, intermetallic compounds, cermets, metals, etc. and having a hardness Hv of 500 or more in an aluminum or aluminum alloy matrix in an amount of 50 vol% or less Wire for film formation. (2) The wire according to claim 1, wherein the hard particles have a diameter of 500 μm or less. (3) The hard particles include Al, Zr, Cr, Ti,
Using a compound or metal whose base element is at least one selected from the group consisting of V, Ta, Si, W, Nb, Cu, Ni, Co, Fe, and Ni, and the main element of the base material to be coated. 3. The wire according to claim 1, wherein the matrix is made of the same element as . (4) The wire is either a solid wire in which hard particles are dispersed in an aluminum or aluminum alloy matrix, or a composite wire in which the hard particles are filled in an aluminum or aluminum alloy sheath metal serving as a matrix. The wire according to item 1, 2 or 3.