JPS6247408A - Autogenous alloy powder sheet and method for reforming surface of metallic base material using said sheet - Google Patents

Abstract

PURPOSE:To form a cermet layer on the surface of metal by sticking the laminated sheet of the 1st compsn. consisting of autogenous alloy powder and org. high-polymer binder and the 2nd compsn. further added with ceramic powder to the surface of 1st compsn. side and sintering the parts. CONSTITUTION:The autogenous alloy powder sheet laminated with the mixture layer composed of 100pts.wt. <=100mum powder of the Ni-base or Co-base autogenous alloy and 1-30pts.wt. org. high-polymer binder such as rubber-like polymer as the 1st compsn. and the mixture layer composed of 1-30pts.wt. org. high- polymer binder by 100pts.wt. mixture composed of 20-99wt% Ni-base or Co- base autogenous alloy powder and 1-80wt% ceramic particles consisting of hard metallic carbide or nitride such as WC, TiC, SiC, TiN or AlN as the 2nd compsn. is stuck to the surface of metallic products such as tools, machines or electrical parts. Such sheet is sintered at 900-1,200 deg.C in a non-oxidizing gaseous atmosphere, by which the cermet layer having the excellent wear resistance and heat resistance is formed.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention provides a self-fusing alloy powder sheet for surface modification of metal base materials constituting various metal products such as tools, machines, and electrical parts, and a self-fusing alloy powder sheet using this sheet. The present invention relates to a method for surface modification of the base material used.

[Conventional technology]

Traditionally, tungsten carbide (
A method of forming a cermet layer, that is, a co-sintered layer of metal and ceramics, on the metal base material surface by thermally spraying a mixed powder made by mixing ceramic powder such as tungsten carbide (tungsten carbide) onto the metal base material surface. Are known.

Metal products whose surface has been modified by this method have excellent wear resistance and heat resistance due to the cermet layer, so they can be applied to various applications that were not possible with metal base materials alone. It can be used under harsh conditions and has extremely high utility value.

[Problem that the invention seeks to solve]

However, the conventional thermal spraying method described above, which forms a cermet layer on the surface of the metal base material, requires skill in the thermal spraying process, tends to deteriorate the working environment due to noise and high heat during thermal spraying, and is difficult to completely burn out. The workability of forming the cermet layer was poor, as a post-treatment of heating and sintering was usually required after thermal spraying due to caking, and automation for mass production was difficult.

Moreover, in addition to these problems such as workability, there were also problems with the inherent characteristics of the cermet layer.

In other words, with the conventional thermal spraying method described above, it is difficult to increase the thickness of the cermet layer or make it uniform, and temperature control during sintering, including thermal spraying and the above-mentioned post-processing, is not easy. This tends to cause variations in the bonding conditions, and as a result, it may not be possible to obtain sufficient properties such as abrasion resistance and heat resistance that the cermet layer should have, or the bonding strength between the metal base metal surface and the cermet layer, or it may be difficult to obtain stable properties. The problem was that it was difficult.

Therefore, the present invention avoids the problems of the above-mentioned conventional method, has excellent workability especially when forming a cermet layer on a metal base material surface, is easy to automate, and has improved wear resistance of the cermet layer. Heat-resistant.

The purpose of the present invention is to provide a surface modification method that can improve characteristics such as bonding strength with a base material, and a specific surface modification material that is characterized by this method.

[Means for solving problems]

As a result of intensive studies to achieve the above object, the inventors used a specific self-fusing alloy powder sheet containing ceramic powder as a material for surface modification of the metal base material, and used this sheet as a surface modification material for the metal base material. According to a method in which a cermet layer is formed on the base material surface by adhering it to the surface and then sintering it,
We realized that all the problems of the conventional thermal spraying method can be solved and completed this invention.

That is, the present invention provides a first composition layer containing a Ni-based or Co-based self-fusing alloy powder and an organic polymer binder,
The present invention relates to a material for surface modification of a metal base material comprising a self-fusing alloy powder sheet formed by laminating a second composition layer containing a Ni-based or CO-based self-fusing alloy powder, a ceramic powder, and an organic polymer binder. 1, and this material is attached to the base metal surface so that the first composition layer side is in contact with the metal base metal surface, and then heated and sintered in a non-oxidizing gas atmosphere. This invention consists of a second invention relating to a method for surface modification of a metal base material, characterized in that cermet a is formed on the surface of the base material.

As described above, in the present invention, a desired cermet layer is formed on the surface of the metal base material by a very complicated operation such as adhering the specific self-fusing alloy powder sheet as described above to the surface of the metal base material and then sintering it. It is possible to form a cermet layer without the problems of requiring skill or deteriorating the working environment as in the thermal spraying method, and since there is no need for post-treatment after the sintering process, it is possible to form a cermet layer. In addition, the above-mentioned pasting work and sintering work can be performed in an assembly-line manner, and automation in mass production can be facilitated.

In addition, in the method of attaching a self-fusing alloy powder sheet to the metal base metal surface as described above, since the thickness of the sheet is originally uniform, the thickness of the cermet layer formed from it is also uniform, Moreover, by increasing the thickness of the sheet, the thickness of the cermet layer can be made arbitrarily thick.Furthermore, when performing the sintering process after pasting, a heating furnace or the like is used to maintain a constant temperature increase rate. Since it can be sintered at a constant temperature, stable sintering can be performed without variations in sintering conditions.

Therefore, the cermet layer formed by the method of the present invention has excellent inherent properties such as wear resistance and heat resistance, and a part of the self-fusing alloy diffuses well into the metal base material. By increasing the bonding strength with the base metal surface, and while these characteristics can be stably obtained,
Compared to the conventional method, this method can exhibit much superior effects in terms of the properties of the cermet layer.

Moreover, an even more significant feature of the present invention is that the above-mentioned self-fusing alloy powder sheet is composed of a second composition layer containing ceramic powder and a first composition layer that does not contain the above-mentioned powder. By adhering and sintering so that the first composition layer side is in contact with the metal base material surface,
There is an advantage in that it is possible to successfully achieve both the excellent wear resistance and heat resistance of the cermet layer and the bonding strength to the base metal surface.

That is, in order to improve the wear resistance and heat resistance of the cermet layer, it is better to increase the amount of ceramic powder contained in the self-fusing alloy powder sheet, but in this case, if the sheet has a single layer structure, As a result of the relative amount of the self-fusing alloy powder decreasing accordingly, there is a problem that the conformability to the metal base material and the diffusivity during sintering are reduced, and the bonding strength of the cermet layer to the base metal surface is deteriorated.

In contrast, in the present invention, the self-fusing alloy powder sheet has a two-layer structure as described above, and the first composition layer side that does not contain ceramic powder is brought into contact with the metal base metal surface. The bonding strength to the base metal surface can be maintained, and by increasing the amount of the powder in the second composition layer containing ceramic powder, the cermet layer after sintering treatment, especially the wear resistance and heat resistance of the surface side, can be improved. good results can be obtained. In other words, bond strength and wear resistance.

This allows for a good balance between heat resistance and heat resistance.

[Structure and operation of the invention]

The self-fusing alloy powder sheet of the present invention has a Ni-based or Co-based
Ni-based or Go
It has a structure in which a second composition layer containing a base self-fusing alloy powder, a ceramic powder, and an organic polymer binder that disperses and binds these powders is laminated.

The Ni-based or Co-based self-fusing alloy powder contained in the first and second composition layers has a relatively low sintering temperature, and is sintered at a temperature of about 900-1,200°C. The metal powder was selected as a metal powder that exhibits good wettability and can provide a cermet layer with high bonding strength to the base material.

The average particle size of this alloy powder is preferably 100 μm or less; if the particle size is too large, it may impede the formation of a uniform cermet layer, which is not preferable.

Note that the Ni self-fusing alloy powder refers to Ni as a metal element.
, Cr, B, Si, and Fe, and the content of each element is generally 0 to 25% by weight for Cr and 0.5 to 0.5% for B.
5% by weight, about 0.5 to 7% by weight of Si, about 0 to 7% by weight of Fe, and the balance is Ni. In addition, Co-based self-fusing alloy powder refers to Co, Ni, Cr, B, St as metal elements.
, Fe, and the content of each element is generally N
i: 0 to 40% by weight, CrT: 10 to 30% by weight,
B Te0゜5~5wt%, Si 0.5~5wt[%, F
e is approximately 0 to 7% by weight, and the remainder is Co.

Furthermore, the ceramic powder included in the second composition layer includes various powders such as carbide ceramics, nitride ceramics, and oxide ceramics. Among these, powders made of carbide-type ceramics or nitride-type ceramics are particularly preferred. Specific examples of carbide type ceramic powders include powders of tungsten carbide, titanium carbide, silicon carbide, etc., and specific examples of nitride type ceramic powders include powders of titanium nitride, aluminum nitride, etc. These powders may be used alone or in combination of two or more.

Such ceramic powder must have an appropriate particle size because it needs to exist uniformly within the surface layer of the cermet layer after sintering and exhibit good properties such as heat resistance and wear resistance. Desirably, the average particle size is generally 70
The thickness is preferably less than μm, usually about 5 to 50 μm.

The amount of ceramic powder to be used is generally such that the ratio of the ceramic powder to the total amount of the Ni-based or Co-based self-fusing alloy powder contained in the second composition layer is 1.
It is preferable to set the amount to 80% by weight, particularly 5 to 60% by weight. By using the amount in such a range, good results can be obtained in both the heat resistance and abrasion resistance of the cermet layer and the bonding strength to the metal base material.

Next, as the organic polymer binder to be included in the first and second composition layers, it is preferable to use a binder that has good sheet formability and can impart good flexibility to a sheet-like product, and among these, a rubbery binder is particularly preferred. Polymers are preferred. Examples of this rubbery polymer include acrylic rubber, chloroprene rubber, silicone rubber, natural rubber, ethylene-propylene rubber, polyisobutylene rubber, etc., and one or more of these can be used as a mixture. do it.

Of course, in addition to the above-mentioned rubbery polymers, various thermosetting resins such as phenolic resins, xylene resins, epoxy resins, polyester resins, polyimide resins, polyamide resins, acrylonitrile-butadiene-styrene copolymers, etc. It is also possible to use other polymers consisting of thermoplastics.

Regarding the molecular weight of these organic polymer binders,
Although not particularly limited, in the case of thermoplastic polymers such as the above-mentioned rubbery polymers, generally 10,000 or more, preferably 10,000 or more, preferably 10,000 or more,
It is preferably about 00,000 to 100,000. If the molecular weight is too low, the dispersion and binding properties of the self-fusing alloy powder or a mixture thereof with ceramic powder will be poor, and if the molecular weight is too high, the workability for sheet forming will be difficult, and both are unfavorable.

The amount of this organic polymer binder used is determined based on 100 parts by weight of the Ni-based or Co-based self-soluble alloy powder in the first composition layer, and the amount used in the second composition layer is based on the Ni-based or Co-based self-soluble alloy powder. 1 to 30 parts by weight, preferably 2 to 30 parts by weight, per 100 parts by weight of mixed powder of alloy powder and ceramic powder.
It is preferable that the amount is about IO parts by weight. If the amount used is too small, it will be difficult to form the sheet or the mechanical strength of the sheet will not be maintained, and if it is too large, the amount of volatile matter that will be carbonized and lost during the sintering process will increase, resulting in a decrease in the density of the cermet layer. This is not preferable because it may impair properties such as wear resistance.

The self-fusing alloy powder sheet of the present invention made of such constituents can be obtained by preparing sheet-like materials corresponding to the first and second composition layers and laminating them by hot pressing, or by laminating them by hot pressing, or It can be obtained by laminating via a liquid or film adhesive containing a polymer similar to the polymer binder.

In order to produce a sheet material corresponding to the first and second composition layers, for example, first a solution is prepared by dissolving an organic polymer binder in an appropriate organic solvent such as acetone, toluene, methyl ethyl ketone, etc., and then The self-fusing alloy powder described above is added to this solution in the first composition layer, and the mixed powder of the self-fusing alloy powder and ceramic powder is added to the second composition layer, and these are kneaded. In general, a method of forming a sheet by pouring it onto a mold covered with release paper, evaporating the solvent, and passing it through a rolling roll is preferably employed. Alternatively, without using a solvent, the organic polymer binder and the above-mentioned self-fusing alloy powder or a mixed powder of this and ceramic powder can be mixed under heating or heated vacuum as necessary to form presses, molds, etc. Pressure molding may be carried out using the same method.

In addition, as another method for producing the self-fusing alloy powder sheet of the present invention, for example, one sheet-like material corresponding to the first or second composition layer is produced by a method similar to the above,
The kneaded material for the other composition layer may be applied onto this sheet-like material, and if the kneaded material contains a solvent, the solvent may be evaporated and then pressure molded.

In addition, in producing such a self-fusing alloy powder sheet, it is not necessary that the self-fusing alloy powder and organic polymer binder constituting the first composition layer and the second composition layer be the same between the two layers. Not particularly. That is, if necessary, either or both of the self-fusing alloy powder and the organic polymer binder may be different between the two layers.

The thickness of the self-fusing alloy powder sheet of the present invention produced in this way is 0.02 to 4.1 mm in the first composition layer.
self, preferably 0.1 to 2 mm, and 0.0 mm in the second composition layer.
3 to 8 mm, preferably 0.5 to 5 mm, and the total thickness of the sheet is 0.05 to 101 g+, preferably 0.5 to 7 mm.
A value of about 11 is good. Note that the second composition layer is
It is desirable that the thickness be at least 0.5 times, usually 1 to 7 times, the thickness of the composition layer.

The self-fusing alloy powder sheet of the present invention having such a thickness has very good flexibility, which is desired when the sheet is attached to a metal base material surface, and also has no problems in handling. It also has good mechanical strength.

In the surface modification method of the present invention, using such a self-fusing alloy powder sheet, the first composition layer side of the sheet, that is, the first composition layer side not containing ceramic powder, is first coated with a metal matrix. Attach it to the base material surface so that it is in contact with the surface of the material. At this time, it is convenient to wet-treat the surface of the first composition layer with an appropriate organic solvent (this facilitates adhesion).

Further, if necessary, an adhesive substance containing a polymer similar to the organic polymer binder described above may be interposed between the metal base material surface and the first composition layer of the self-fusing alloy powder sheet.

After adhering in this way, a cermet layer is formed on the surface of the base material by heating and sintering in a non-oxidizing gas atmosphere. Here, the reason for the non-oxidizing gas atmosphere is as follows.
This is to prevent oxidation of the self-fusing alloy powder during the sintering process. Examples of non-oxidizing gas atmosphere include hydrogen gas atmosphere and argon gas.

In addition to an inert gas atmosphere such as nitrogen gas, a vacuum atmosphere may be used.

Further, as methods of heating and sintering, there are a method using a fusing torch for thermal spraying, a method using induction heating, a method using furnace heating, and the like. Among these methods, the method using furnace heating is particularly suitable because the temperature and atmosphere can be easily controlled. The conditions for heating and sintering are appropriately determined depending on the type of self-fusing alloy powder or ceramic powder, but for example, in the case of a method using furnace heating, the final heating is performed at a heating rate of 10 to 40°C/min. The temperature may be set within a range of 900 to 1,200°C, and the holding time may be varied between 5 and 180 minutes.

The cermet layer that is formed on the metal base metal surface as shown in the figure is a completely integrated thin inner layer made of a self-fusing alloy and a thicker outer layer made of a self-fusing alloy with ceramics uniformly dispersed in it. It is made of a co-sintered body layer with a high surface hardness and wear resistance (usually about 0.04 to 8 mm overall thickness), and has excellent heat resistance. ) A part of the capacitive alloy diffuses into the metal base material, resulting in extremely high bonding strength with the surface of the base metal.

For this reason, various metal products such as tools, machinery, electrical parts, and automobile parts made of metal base materials whose surface has been modified by such ZAMETSU I layer can be advantageously applied to various uses that take advantage of the above characteristics. can do.

〔Effect of the invention〕

As described above, in this invention, Ni-based or Co-based
A specific composition comprising a first composition layer containing the base self-fusing alloy powder and an organic polymer binder and a second composition layer containing the self-fusing alloy powder, ceramic powder, and an organic polymer binder. A self-fusing alloy powder sheet is used as a material for surface modification of a metal base material, and after this material is attached to the base metal surface so that the first composition layer side is in contact with the metal base material surface, Since the cermet layer is formed by sintering, it is possible to improve the workability of forming the cermet layer on the metal base metal surface compared to the conventional thermal spraying method, and it is easier to automate the process, and it is also more durable. It is possible to significantly improve the inherent properties of the cermet layer, such as properties such as abrasion resistance and heat resistance, and bonding strength with the base metal surface.

〔Example〕

Next, examples of the present invention will be described in more detail. In addition, in the following, parts shall mean parts by weight.

Example 1 Ni-based self-fluxing alloy MSFNi5 (with an average particle diameter of 40 μm)
A composition consisting of 97 parts of powder (JIS standard), 2 parts of butyl rubber, 1 part of phenolic resin, and 100 parts of toluene was mixed uniformly, poured onto a mold covered with release paper, the toluene was evaporated, and then rolled. By rolling, a sheet-like product for the first composition layer having a thickness of 0.5 fin was produced.

In addition, tungsten carbide (WC) with an average particle size of 20 μm
A composition consisting of 35 parts of powder, 62 parts of Ni-based self-soluble alloy MSFNi5 (JIS standard) powder with an average particle size of 40 pm, 4 parts of butyl rubber, 1 part of phenolic resin, and 100 parts of toluene was mixed uniformly. A sheet-like material for the second composition layer having a thickness of 1.0 mm was produced in the same manner as above.

Next, the sheet-like material for the first composition layer and the sheet-like material for the second composition layer are laminated by hot pressing,
A self-fusing alloy powder sheet of this invention was obtained. This sheet was cut into a size of 1 (JII I attached it so that it was touching.

After that, it was heated to 1°0 at a rate of 15°C/min in a vacuum atmosphere.
The temperature was raised to 60'C, held at this temperature for 20 minutes, and then slowly cooled to complete the sintering process.

This sintering process results in a thickness of 1.25 mm on the surface of the steel plate base material.
~1.3 A cermet layer with a good appearance could be formed. The hardness of this cermet layer was Hv 1.1.00 kg/-, and the bonding strength with the steel plate base material was 35 kg/-.

Example 2 Ni-based self-fluxing alloy MSFNi5 (
JIS standard) A composition consisting of 97 parts of powder, 3 parts of chloroprene rubber, and 100 parts of toluene is mixed uniformly, poured onto a mold covered with release paper, and after evaporating the toluene, rolling is performed. A sheet-like material for the first composition layer having a thickness of O and -2 fins was prepared.

In addition, 15 parts of titanium carbide (TiC) powder with an average particle size of 10 μm, Co-based self-fusing alloy MSF with an average particle size of 40 μm
A composition consisting of 82 parts of Co 1 (J Is standard) powder, 4 parts of butyl rubber, 1 part of phenolic resin, and 100 parts of toluene was mixed uniformly, and using this composition, the same procedure as above was carried out to form a powder with a thickness of 0.8 A sheet material for the +u second composition layer was produced.

Next, the sheet-like material for the first composition layer and the sheet-like material for the second composition layer are laminated with an acrylic film-like pressure-sensitive adhesive having a thickness of 10 μm interposed between them. Then, the self-fusing alloy powder sheet of the present invention was obtained. This sheet
After cutting into a size of am I pasted it like this.

After that, 1,
The temperature was raised to 050°C, held at this temperature for 20 minutes, and then slowly cooled to complete the sintering process.

Through this sintering process, the surface of the steel plate base material has a thickness of 0.75 mm.
A cermet layer with a good appearance of ~0.85 +n could be formed. The hardness of this cermet layer is Hv900kg/m
At IA, the bonding strength with the steel plate base material was 30 kg/nvM.

Example 3 Co-based self-fluxing alloy MSFCOL (
JIS standard) A composition consisting of 97 parts of powder, 3 parts of chloroprene rubber, and 100 parts of toluene is mixed uniformly, poured onto a mold covered with release paper, the toluene is evaporated, and then rolled. A sheet-like material for the first composition layer having a thickness of 0.4 μ was produced.

In addition, 16 parts of titanium nitride (TiN) powder with an average particle size of 20 μm, Cog self-fluxing alloy MSF with an average particle size of 40 μm
A composition consisting of 81 parts of Co 1 (JIS standard) powder, 3 parts of chloroprene rubber and 100 parts of toluene was mixed uniformly, and the same procedure as above was carried out using this composition.
A sheet material for the second composition layer having a thickness of 0.8 am was produced.

Next, the above sheet-like material for the first composition layer and the sheet-like material for the second composition layer were laminated with the same adhesive as in Example 2 interposed therebetween, and the present invention It was made into a self-fusing alloy powder sheet. This sheet was cut into a size of 1 crn x 1 cm, the surface of the first composition layer was wetted with a small amount of acetone, and then the first composition layer side was placed on the surface of the steel plate base material. It was attached so that it was in contact with the surface. Thereafter, the temperature was raised to 1,070° C. at a rate of 0° C./min under a vacuum atmosphere, maintained at this temperature for 30 minutes, and then slowly cooled to complete the sintering process.

Through this sintering process, the surface of the steel plate base material has a thickness of 0.95 mm.
~1. A cermet layer with a good appearance of OOam could be formed. The hardness of this cermet layer was Hv 800 kg/-, and the bonding strength with the steel plate base material was 32 kg/-.

Claims (4)

[Claims] (1) A first composition layer containing Ni-based or Co-based self-fusing alloy powder and an organic polymer binder is coated with Ni-based or Co-based
A self-fusing alloy powder sheet formed by laminating a second composition layer containing a base self-fusing alloy powder, a ceramic powder, and an organic polymer binder. (2) Claim (1) in which the ceramic powder is made of carbide-type ceramics or nitride-type ceramics.
A self-fusing alloy powder sheet as described in . (3) A self-fusing alloy powder sheet according to claim (1) or (2), wherein the organic polymer binder is a rubbery polymer. (4) A first composition layer containing a Ni-based or Co-based self-fusing alloy powder and an organic polymer binder on the metal base material surface.
A self-fusing alloy powder sheet formed by laminating a second composition layer containing a base-based or Co-based self-fusing alloy powder, a ceramic powder, and an organic polymer binder, with the first composition layer side facing the metal base material. A method for modifying the surface of a metal base material, the method comprising forming a cermet layer on the surface of the base metal by adhering the base metal so that they are in contact with each other and then heating and sintering it in a non-oxidizing gas atmosphere.