JPS6230886A - Formation of alloy layer - Google Patents

Abstract

PURPOSE:To simply form an alloy layer on the surface of a base material such as Ni or Al at a low cost by mixing a soln. of an org. high molecular compound with metallic powder, applying the mixture to the surface of the base material and heating it to vanish the compound by thermal decomposition. CONSTITUTION:A soln. or a colloidal dispersion of an org. high molecular compound which is practically vanished by thermal decomposition is mixed with one or more kinds of metallic powders such as powders of Zn, Sn, Ni, Al, Ti, Cr and an alloy thereof preferably in the form of particles of <=0.5mm particle size. The liq. mixture is applied to the surface of a base material selected among Ni, an Ni alloy, Al and an Al alloy so that different kinds of metals are used. It is then heated to form an alloy layer contg. all or part of the applied components. A polymer contg. acrylic acid, a polymer having urethane bonds or urea resin is suitable for use as the org. high molecular compound.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to surface treatment techniques for metal materials, particularly nickel and aluminum materials.

[Conventional techniques and their problems] Conventionally, methods for forming alloy layers with different compositions on the surface of metal materials to modify the surface include plating, thermal spraying, vapor deposition,
There are methods of coating the surface with a metal or alloy by ion blasting or the like and heat-treating the surface, or of cladding with a different material and heat-treating it.

For example, when an alloy layer containing additives is formed on the surface of an aluminum alloy, this layer exhibits a so-called sacrificial scratching effect, thereby improving the corrosion resistance of the aluminum alloy. This is widely used to improve the corrosion resistance of heat exchangers. Furthermore, if an alloy layer containing, for example, aluminum can be easily formed on the surface of a nickel alloy, its corrosion resistance and surface hardness can be greatly improved. However, when trying to do these things, conventional technology involves cladding different materials and heat-treating them.
Alternatively, methods such as coating dissimilar metals with ion blasting and heat treatment have been used, but all of these require special technology and dedicated expensive equipment, resulting in a significant increase in manufacturing costs. It has drawbacks.

LLObject of the Invention] An object of the present invention is to produce nickel, nickel alloy, aluminum, and aluminum alloy materials by a cheaper and simpler method. l
The purpose is to avoid forming an alloy layer on the surface of the metal.

[Summary of the Invention] In the present invention, pure metal or alloy powder is used as the metal to be coated, and in order to make it easier to coat, it is dissolved in an organic polymer compound and a solvent to form a paint, and further as a polymer compound. A material that is thermally decomposed during heating to form an alloy layer is selected, and the decomposed gas has the role of protecting the object to be treated and the coated metal from oxidation.

Organic polymer compound (resin) necessary for carrying out the method of the present invention
The characteristics that the resin should have are: (1) The solution or dispersion can form a hard film on the metal surface, and (2) The material can be removed from the film by thermal decomposition by heating at a temperature suitable for each resin. The total volatilization loss is 1J.

An organic polymer compound capable of forming a general organic practical paint film was sufficient as having the above characteristic (1). However, in order to have the property (2) above, it was necessary to have a special chemical drawing.

The present inventors have investigated thermal analysis curves (thermal analysis curves) of organic polymer compounds measured in air, or more specifically, in nitrogen.
TGA curve) exhibits a decomposition rate of 95% or more at 200 to 700°C, and as a result of test research on a large number of organic polymer compounds, as expected, these compounds meet the objectives of the present invention. It was confirmed. However, the TGA curve changes depending on the shape of the measurement sample, heating rate, etc., and even the same compound shows differences depending on its polymerization degree distribution.

Although it may be difficult to make a determination based only on the curve, the following are suitable for implementing the method of the present invention.

a) Polyahital resin (260°C [95% thermal decomposition point,
The same applies hereinafter]) b) Acrylic acid, methyl-, ethyl-, isopropyl-1n-buboulou, 2-ethylhexyl- of acrylic acid
12-hydroxyethyl-, hydroxypropyl-ester, methacrylic acid, methyl-, ethyl-, isopropyl-1n-butylene, n-hexyl-,
lauryl-12-hydroxyethyl-, hydroxyb [
Polymer of one type of compound selected from esters of acrylic acid and methacrylic acid such as I-bil-ester, hydroxy esters, fumaric acid, maleic acid, itaconic acid (350-450°C) C) Polymer Polyethers (350
~400℃) d) Addition of polyesters or polyethers with 2.4- or 2.6-dolylene diisocyanate and other polyisocyanates 1 to 1.F
A small compound (380-5
00°C) e) Urea resin (350°C) [) Melamine resin (350°C) g) Benzoguanamine resin (370°C) 1]) Alkylated modified urea resin (400°C) i) Alkyl modified melamine resin (400°C) J) Alkylated modified benzoguanamine resin (420℃k) Polycarbonate resin (530℃k)
1) Aromatic polyesters (580°C) m) Budral resin (600°C) n) General Electric (Cencra)
Aromatic polyester imides (630°C) such as +Electric) products p) Kapton l for formal wear from DuPont in the United States
Aromatic polyimides (670°C) such as ``Kapton It'' or mixtures thereof or (
Yuko Φ compound.

The above organic polymer compounds are water, alcohols, ketones, esters, cellosolves, calpitols,
It is soluble in one or a mixture of solvents such as dimethylformamide, dimethylaceamide, dimethylsulfoxide, etc., and the solution forms a film on the surface of the metal after volatilization of the solvent, and the temperature within the above 0. It undergoes thermal decomposition within the range of temperature and is virtually eliminated from the coating system. On the other hand, polyvinyl chloride, which is also soluble in organic solvents and has film-forming properties, epoxy resins that do not contain urethane bonds, and fiber cord-based resins have a temperature of 20 to 65 There is a residual content of %,
When heated in air, oxidative combustion occurs and the residual content decreases; however, in particular, in a film made of heat-resistant materials, combustion does not occur completely and a considerable amount of charcoal and other components remain. It is unsuitable as a practical material.

The organic polymer compound suitable for carrying out the present invention can be used not only as a water or organic solvent solution as described above but also as a colioid dispersion in water or a solvent. In particular, an aqueous stock solution of a resin produced by a so-called emulsion polymerization method from a compound that conforms to the above (a) can be used as it is as a suitable raw material for carrying out the present invention.

Suitable powder metals include at least one of zinc, tin, nickel, aluminum, titanium, chromium, and alloys containing these as main components. The particle size of this metal powder is preferably 0.5+++m or less for the following reasons. That is, if the particles are too large, when mixed with a resin solution, they tend to settle due to their high specific gravity, and when made into an alloy powder, they tend to separate. Furthermore, when melted, the finer the powder, the easier it is to uniformly alloy the powder.

[Example 1 Examples will be described below.

Example 1 As a paint, 55% aluminum paste for paint, 15% mecryl resin liquid, 7% n-butanol modified melamine resin liquid and 23% ethylceron rub were mixed, and this was mixed with o,
It was applied uniformly onto a nickel plate (JIS 134501) with a thickness of 5 mm, and heated in the air at 800° C. for 1 hour in an electric furnace.

After heating and cooling with water, the cross section of the nickel plate was examined under a microscope, and it was found that a uniform expanded aluminum layer was formed over a surface area of 15 μm.

When constant ω analysis of this layer was performed using an energy dispersive X-ray microanalyzer, it was found that A1 hemic% Ni and A
It was confirmed that the alloy layer had a composition of 1:1.

Example 2 Methacrylic acid stock solution, toluene, and metallic zinc powder of 200 mesh or less were mixed in weight M% of 10%, 30%, and 60%, respectively.
%, and add an appropriate amount of aluminum solder (d
It was applied to a pure aluminum plate together with a commercial flux. This was heated in the air at 550°C for 30 minutes in an electric furnace, and then cooled with water. Examine the cross section of this aluminum plate! It was confirmed that a zinc diffusion layer with a thickness of 20 to 30 μm was formed on the surface.

[Effects of the invention] By using the coating material containing metal powder according to the present invention, it is possible to easily adhere this coating material to the surface of nickel or aluminum materials, and it is suitable for special equipment for plating, vapor deposition, thermal spraying, etc. It is possible to form an alloy layer very simply by heating the coated state. In addition, by carefully selecting the resin components and bringing reducing properties to the decomposed gas during thermal decomposition, a so-called flux effect can be generated.
It is possible to perform more uniform treatment, and even when heat treated in the atmosphere, the material to be treated can be protected from oxidation, providing the same effect as when treated in a low-temperature atmosphere.

As described above, the method according to the present invention can be said to be a completely new method for forming an alloy layer, which involves mixing and applying a resin, a solvent, and a metal powder.

Patent Applicant Asia Kogyo Co., Ltd. Representative Saito Ko - Procedural Amendment

Claims (4)

[Claims] (1) One or more metal powders are mixed into a solution or colloidal dispersion of an organic polymer compound that itself substantially disappears by thermal decomposition, and then mixed with nickel powder having different component compositions. , nickel alloy, aluminum, and aluminum alloy, and then heating it to form an alloy layer containing all or part of the components applied to the surface of the base material. A method for forming an alloy layer, the method comprising: (2) The metal powder to be mixed into the solution or colloidal dispersion of the organic polymer compound is at least one of zinc, tin, nickel, aluminum, titanium, chromium, and alloys containing these as main components. The method described in Section 1. (3) The method according to claim 1, wherein the particle size of the metal powder is 0.5 mm or less. (4) The organic polymer compound is selected from [1] acrylic acid, acrylic ester, acrylic ester hydroxy derivative, methacrylic acid, methacrylic ester, methacrylic ester hydroxy derivative, maleic acid, fumaric acid, and itaconic acid. 1
Polymers of raw materials containing seeds or mixtures of one or more types, [2] Polymers having urethane bonds, [3] Urea resins, alkylated modified urea resins, melamine resins, alkylated modified melamine resins, benzoguanamine resins, alkylated Claim 1, which is at least one selected from modified benzoguanamine resin, butyral resin, polyacetal resin, polycarbonate resin, aromatic polyester, and aromatic polyesterimide, or a mixture of two or more thereof. The method described in section.