JPS61284506A - Formation of metal-sintered layer onto surface of metallic base material - Google Patents

Abstract

PURPOSE:To prevent the exfoliation of a tape-shaped metallic powder molding and to form a metal-sintered layer having a smooth surface by winding and fixing the metallic powder molding onto the surface of a metallic member by superposing partly the molding via an adhesive fixing material. CONSTITUTION:A tapered face 11a is formed to one surface side at one end 1a of the tape-shaped metallic powder molding. a length of the adhesive fixing material 2 is provided to the other end 1b and a tapered face 12b is formed onto the other surface side thereof. Such metallic powder molding 1 is wound and fixed onto the surface of the metallic base material 3 in a manner as to have overlap parts 10 by bringing the one surface 11 side of the molding to the inside. The member is then sintered in a non-oxidative atmosphere The material 2 induces the condensation polymn. reaction by thermal decomposition during sintering and is converted to a carbon precursor. Said precursor exhibits the function to assist the adhesive fixing of the molding 1 onto the material 3 surface in the temp. range up to about 700 deg.C at which the molding 1 begins to sinter.

Description

Detailed Description of the Invention (Industrial Field of Application) This invention provides a metal layer on the surface of a metal base material having an annular cross section, such as a rod-shaped body or a tubular body, for improving the wear resistance of the base metal surface. Concerning how to form.

[Conventional technology]

Conventionally, thermal spraying is known as a method for forming a metal layer with excellent wear resistance on the surface of a metal base material such as a rod-shaped body. However, this method has a limit on the thickness of the metal layer, and while it can be said to be an effective method for forming a thin metal layer, it cannot be When forming a metal layer, the surface of the metal layer tends to be rough (for this reason, a rather troublesome polishing process must be performed after thermal spraying, which makes it impractical.

On the other hand, as a method for forming a relatively thick metal layer on the surface of a metal base material, a metal powder compact such as a sheet formed by rolling a mixture of metal powder and a synthetic resin-based or rubber-based binder is used. A method is known in which a metal sintered layer is formed on the surface of a metal base material by placing it on the base metal and sintering it.

[Problem that the invention seeks to solve]

However, in the method of forming the metal sintered layer described above, if the surface of the metal base material is flat, a metal powder molded body having a shape corresponding to the flat surface is used and this is placed on the surface of the base metal. This can be easily achieved by sintering, but for metal base materials with annular cross sections such as rod-shaped bodies and tubular bodies,
It was actually very difficult to apply the above method.

The reason for this is that with a metal base material having the shape described above, it is difficult to successfully adhere and fix the metal powder compact to the surface of the base material prior to the sintering process, and this adhesion cannot be carried out until the sintering process is completed. This is because it is difficult to maintain the metal sintered layer well, and furthermore, it is not so easy to finish the metal sintered layer into a smooth surface through sintering treatment that takes such adhesive fixation into consideration.

Therefore, the present invention provides a method for forming a sintered metal layer on the surface of a metal base material having an annular cross section using the metal powder compact, in which the compact can be successfully adhesively fixed to the surface of the base material, and The sintering process does not cause problems such as falling off or peeling of the molded body during the sintering process. The purpose is to provide an industrially useful method for forming

[Means for Solving the Problems] As a result of intensive studies to achieve the above object, the inventor made the metal powder molded body into a tape shape, and attached it to the surface of a metal base material with a material for adhesive fixation. If the molded body is wrapped and fixed so as to have a partially overlapped part (lap part) through the molded body and subjected to the sintering process in this state, the molded body will not fall off or peel during the sintering process. (This invention was completed after learning that the sintering process can be performed with good workability and that the surface of the metal sintered layer formed by this sintering process can be smoothed at the same time.

That is, the present invention provides a tape-shaped metal powder compact formed by rolling a mixture of metal powder and a synthetic resin-based or rubber-based binder on the surface of a metal base material having an annular cross section.
A method for forming a metal sintered layer on a metal base material surface, which comprises wrapping and fixing the layer through an adhesive fixing material so that some parts overlap, and then sintering the layer in a non-oxidizing atmosphere. This is related to.

[Structure and operation of the invention]

The tape-shaped metal powder compact used in this invention is obtained by rolling a mixture of metal powder and a synthetic resin-based or rubber-based binder into a sheet shape, and then cutting it into a predetermined width. A tape having a thickness of usually about 0.5 to 5 mm and a width of about 10 to 50 mm is preferably used.

As the metal powder, various metal powders can be used depending on the properties to be imparted to the surface of the metal base material, such as self-fusing alloy powder and wear-resistant alloy powder. As a typical metal powder, Fe-M-C multi-component eutectic alloy powder, which is a wear-resistant alloy powder, can be mentioned. The above M has at least one of Mo, B, and P as a main component, and may contain Cr, V, W, Nb, Ta, and Ti as secondary elements, and other elements include Si, It can contain Ni, Mn, etc. Such multi-component eutectic alloy powder has a relatively low sintering temperature (generally, the liquid phase becomes 10 to 50% by volume in the temperature range of 1,000 to 150 degrees Celsius, and this liquid phase does not wet the base material. It has the characteristic of having excellent properties.

The particle size of these alloy powders is generally preferably 150 mesh or less, since this affects the porosity after sintering. If it is larger than this, it becomes difficult to form a dense alloy layer.

Examples of the synthetic resin or rubber binder to be mixed with the metal powder include various synthetic resins and rubbers such as acrylonitrile-butadiene copolymer rubber, butyl rubber, butadiene rubber, isoprene-isobutylene copolymer rubber, chloroprene rubber, and natural rubber. A polymer having pressure-sensitive adhesive properties is preferably used as a base polymer.

Particularly preferred binders are acrylic polymers consisting of (meth)acrylic acid alkyl esters or monomers copolymerizable therewith, or alkylphenol resins, rosin resins, petroleum resins, coumaron indene resins, etc. This is an acrylic pressure-sensitive adhesive composition containing an adhesion-imparting resin such as.

The above synthetic resin-based or rubber-based binder is diluted with an appropriate organic solvent such as acetone, toluene, or methyl ethyl ketone, and the above-mentioned metal powder is usually added in an amount of 10 to 100 parts by weight per 1 part by weight of the solid content and kneaded. This is generally poured into a mold covered with release paper, the solvent is evaporated, and then passed through rolling rolls to form a sheet, which is further cut into a predetermined width to form the tape-shaped metal. A powder compact can be obtained.

Next, a method for forming a metal sintered layer on the surface of a metal base material using this tape-shaped metal powder compact will be explained with reference to the drawings.

In FIG. 1, first, one side of one end 1b of the tape-shaped metal powder compact 1 in the width direction X is scraped off along the tape longitudinal direction Y to form a tapered scraped surface 11a, A strip of adhesive fixing material 2 is provided along the tape longitudinal direction Y at the other end 1b in the width direction X on the same surface 11 side, and the other end 1b on the other surface 12 side corresponding to this material 2 is provided. is scraped off along the tape longitudinal direction Y to form a tape-shaped scraped surface 12b.

Here, the length of the cut surfaces 11a and 12b in the tape width direction cannot be determined unconditionally depending on the tape width, but generally, the length may be set to about 10 to 20% of the tape width. Of course, it is also possible to make it shorter or longer than this.

Further, the length of the adhesive fixing material 2 in the tape width direction is the above-mentioned scraped surface 11a.

It is approximately the same length as 12b, and is usually about 1 to 10 cm, and its thickness is generally 5 to 50 μm, preferably 10 to 30 μm.
That's about it.

The adhesive fixing material 2 is used to help adhere and fix the metal powder molded body 1 to the metal base material surface, which will be described later.If the thickness is too thin, the above effect cannot be obtained, and if it is too thick, the above effect cannot be obtained. During sintering, the amount of gas generated at the interface between the base material and the molded body increases, resulting in problems such as a decrease in fixation or bonding strength during sintering, which is not preferable.

The material composition of the adhesive fixing material 2 is the same as the synthetic resin or rubber binder used for producing the metal powder molded body 1, and is made of a geothermally curable resin material. Examples of the latter material include materials such as epoxy resins, phenol resins, unsaturated polyester resins, and polyimide resins, as well as polyurethane resin materials whose constituent materials are polyisocyanate and polyol. (The above-mentioned polyisocyanates and polyols include those that have been subjected to appropriate modification treatment such as acrylic modification.In addition, these various adhesive fixing materials 2 include the above-mentioned resin or rubber components. In addition, curing agents, curing accelerators, softeners,
Various additives such as fillers and plasticizers may be included.

The adhesive fixing material 2 is applied to one end 1 of the metal powder compact 1.
In order to provide the material in the manner described above, it is preferable to make this material into a tape-like material in advance and apply it by pasting it. However, in some cases, it is also possible to apply and dry a solution of the corresponding material to the other end 1b. It's okay.

In FIG. 2, the tape-shaped metal powder compact 1 constructed as described above is wound and fixed around the surface of a metal base material 3. The base material 3 has a cylindrical shape and a prismatic shape.

It is made of various metal materials having an arbitrary annular cross section such as a cylindrical shape or a rectangular cylindrical shape, and a steel base material is typically used.

On the other hand, the above-mentioned winding and fixing is performed on one side of the molded body 1.
This is done by winding the tape with an appropriate tightening force so that the tape has a partially overlapped portion 10, that is, the required portions of both ends la and lb in the tape width direction are overlapped. . By this winding, the molded body 1 is closely fixed to the surface of the base material 3 via the adhesive fixing material 2 provided at one end 1b, and the overlapping portion 1
0, a uniform and complete coating layer is formed that is continuous in the longitudinal direction of the base material 3 and does not leave any part of the surface of the base material 3 exposed.

After being wound and fixed in this manner, it is subjected to sintering treatment in a non-oxidizing atmosphere. In this process, the adhesive fixing material 2 undergoes a pyrolysis polycondensation reaction during the temperature rising process and is converted into a carbon precursor, which is used in the temperature range up to about 700°C, at which the compact 1 starts to sinter. It functions to assist in adhesion and fixation of the molded body 1 to the three surfaces of the base material.

The reason why the sintering treatment is performed in a non-oxidizing atmosphere is obvious; in an oxidizing atmosphere, the molded body 1 is oxidized and degraded during the treatment, making it impossible to form the desired metal sintered layer. The non-oxidizing atmosphere may be a hydrogen gas atmosphere, a nitrogen gas atmosphere, or a vacuum.

When the temperature is raised to the sintering temperature and held for a predetermined time in this way, the carbon precursor is finally completely carbonized, and similar substances in the compact 1 also disappear by carbonization, while the carbon precursor in the compact 1 As the metal component diffuses into the base material 3, the metal sintered layer 100 is firmly adhesively bonded to the base material 3, as shown in FIG.
is formed.

In such a sintering process, the molded body 1 wrapped and fixed around the three surfaces of the base material contracts during the sintering process, particularly in the tape width direction, that is, the longitudinal direction of the base material.
Due to this contraction, a phenomenon is observed in which the upper layer 10A of the overlapping portion 10 shifts in the direction of arrow A in FIG. As a result, the width of the overlapping portion 10 is greatly reduced during the sintering process, and the existence of the overlapping portion becomes almost invisible after sintering is completed.

As explained in Figure 1, this phenomenon is caused by
One example of the molded body 1 is that tapered cut-off surfaces 11a and 12b are formed on one side 11 at the end 1a and on the other side 12 at the other end 1b, respectively, and the adhesive fixing material 2 is attached to the molded body 1. It becomes more noticeable by providing it only on the other end 1b side instead of providing it on the entire surface of the 11 surfaces.

That is, in the state shown in FIG. 2, the tapered cut surfaces 11a and 12b are opposed between the upper layer 10A and the lower layer 10B of the overlapping portion 10 of the molded body 1, so that the upper layer 10
The displacement of A in the direction of arrow A is performed more smoothly, and the thickness of the overlapping portion 1o after the displacement is not much different from the thickness of the non-overlapping portion due to the presence of the above-mentioned cut surfaces 11a and 11b. It becomes something that does not. In addition, such a shift of the upper layer 10A in the direction of arrow A is an example in which the above-mentioned shift should be caused by adhesively fixing only the other end 1b side of the molded body 1 to the base material 3 surface with the adhesive fixing material 2. This can be realized more ideally by leaving the end portion 1a side free and not adhesively fixed.

In this way, the metal sintered layer 100 formed by the above method
has a nearly smooth surface after sintering, so it can be used as is or by applying a very simple surface smoothing treatment to improve properties such as wear resistance on three surfaces of the metal base material. This results in a beautiful and high-quality metal coating layer that can sufficiently provide the following properties.

In the above explanation, the adhesive fixing material 2 is provided in advance on the metal powder molded body 1 side, but instead of this, the material 2 is provided on the metal base material 3 side and the same wrapping and baking as described above is performed. A binding process may also be performed.

〔Effect of the invention〕

As described above, in this invention, a tape-shaped metal powder compact is used, and this is attached to the surface of a metal base material having an annular cross section via an adhesive and fixing material so that there is a partially overlapped part. By having a structure in which the molded body is wrapped and fixed and subjected to the sintering process in this state, the above-mentioned molded body does not fall off during the sintering process.

The sintering process can be performed with good workability without peeling, and the surface of the sintered metal layer formed by this sintering process can be easily smoothed.

〔Example〕

EXAMPLES Below, examples of the present invention will be described in more detail. Note that in the following, parts and % mean parts by weight and % by weight, respectively.

Implementing agent 1 Mo10.5%, Cr2. +%, P2.4%, C3,6
%, balance 48.5% of multi-component eutectic alloy powder with a particle size of 150 mesh or less consisting of a chemical component of Fe, 4865% of a powder of 5US410 with a particle size of 150 mesh or less, and further 3% of an acrylic acid (meth)alkyl ester resin. were wet-kneaded using acetone as a solvent, and then roll-rolled to give a thickness of 1.5 g/an and a density of 4.8 g/an! An alloy powder sheet was prepared, and this sheet was cut into a width of 10 mm to prepare an alloy powder tape.

Next, one side and the other side of both end portions of this tape were scraped off as shown in FIG. 1 to form two tapered scraped surfaces. The length of each of these scraped surfaces in the tape width direction was 1.5 mm. Further, an adhesive fixing material having a width of 2H was pasted on one side of one end of this tape as shown in FIG.

In addition, the above-mentioned adhesive fixing material was prepared by coating an acrylic acid (meth)alkyl ester resin on a release paper using acetone as a solvent to a dry thickness of 20 μm, drying it, and cutting it to a width of 21 m after peeling it off. I used something.

The alloy powder tape to which the adhesive and fixing material was attached in this way was wound and fixed around the surface of a rod-shaped steel base material having a radius of 20 mm so that the width of the overlapped portion was 2 mm. Thereafter, the temperature was raised to 1.090° C. at a rate of 15° C./min in a hydrogen gas atmosphere, maintained at this temperature for 20 minutes, and then slowly cooled.

In this way, the alloy powder tape does not fall off at all during the sintering process, and is firmly bonded and fixed onto the steel base material, with a thickness of 0.62 to 0.65 mm and a hardness of HRC 62.
~65. A wear-resistant alloy layer having a density of 7.6 to 7.75 g/- could be formed. This alloy layer had such a smooth surface that the presence of the overlapping portion was hardly visible.

Example 2 38.6% of the multi-component eutectic alloy powder used in Example 1 and 5U
Powder made of S410 and having a particle size of 150 mesh or less 57.
9% and acrylic acid (meth)alkyl ester resin 3
．． After wet-kneading the 5% and
/cnf alloy powder sheet is made, and this sheet is made into a width 2
It was cut into a size of 0 m to obtain an alloy powder tape. Two tapered cut surfaces with a length of 21 in the tape width direction were formed on both ends of this tape, similar to Example 1, and adhesive fixing material with a width of 2 mm was applied in the same manner as in Example 1. I pasted it.

This alloy powder tape was wound and fixed around the surface of a rod-shaped steel base material having a radius of 301 m so that the width of the overlapped portion was three fins. Then, 1
．． The temperature was raised to 100°C, held at this temperature for 20 minutes, and then slowly cooled.

In this way, the alloy powder tape does not fall off at all during the sintering process, and is firmly bonded and fixed onto the steel base material, with a thickness of 1.3 to 1.35 tm and a hardness of HRC 60. ~
62. A wear-resistant alloy layer having a density of 7.5 to 7.7 g/- could be formed. This alloy layer had such a smooth surface that the presence of the overlapping portion was hardly visible.

[Brief explanation of drawings]

Fig. 1 is a partially cutaway perspective view showing a tape-shaped metal powder compact used in the method of the present invention provided with an adhesive fixing material; FIG. 3 is a partially cutaway sectional view showing a state in which the material is wound and fixed on a surface, and FIG. 3 is a partially cutaway sectional view showing a state in which a metal sintered layer is formed on the metal base material surface by sintering after the wrapping and fixation. 1... Metal powder compact, 2... Adhesive fixing material, 3
...Metal base material, 10...Overlapping part, 100...
・Metal sintered layer

Claims (1)

[Claims] (1) A tape-shaped metal powder compact made by rolling a mixture of metal powder and a synthetic resin-based or rubber-based binder is placed on the surface of a metal base material having an annular cross section via an adhesive and fixing material. A method for forming a metal sintered layer on a surface of a metal base material, the method comprising: wrapping and fixing the metal so as to have a partially overlapping portion, and then sintering the metal in a non-oxidizing atmosphere.