JP3841547B2 - Method for producing copper alloy powder, and laser cladding method using the copper alloy powder - Google Patents

Description

【００１９】
表１から明らかなように、本発明実施例による銅合金粉末はひっかかり度がゼロであり、理想的な流動性を有するのに対し、比較例の粉末はいずれも流動性が不良でひっかかり度が大きいことがわかる。これらから本発明法に従って上記の如き銅合金粉末を製造する工程と、該粉末の供給工程と、該粉末を用いたレーザ加工工程とを一連の工程として連続形成することにより、効率的なレーザ肉盛り加工が行えることがわかる。
【図面の簡単な説明】
【図１】粉末供給装置から銅合金粉末を供給する場合における粉末供給量と時間との関係図である。[0001]
[Industrial application fields]
The present invention has excellent wear resistance in automobile parts and the like, and is particularly suitable for use as a material for overlaying an engine sliding member, such as a bubble sheet (valve seat) portion of an aluminum alloy cylinder head. the method of producing fine alloy powder, and to a laser padding method using the copper alloy powder.
[0002]
[Prior art and its problems]
Recently, for the purpose of improving the wear resistance and heat resistance of a part of base material made of aluminum alloy etc. in automobile parts, etc., dissimilar metals are supplied on the base material in the form of powder and melted using a laser beam. The technology to fill up is attracting attention. In many cases, these dissimilar metal powders are usually made of an alloy mainly composed of copper manufactured by a gas atomizing method.
[0003]
The metal powder produced by the gas atomization method is spheroidized by the surface tension of the molten grains in the course of cooling in the gas phase. A characteristic of the metal powder obtained by the gas atomization method is that it has excellent sphericity. However, if a product with a particle size of several tens of μm is manufactured, a protrusion of a few μm level is partially formed on the surface ( (Hereinafter referred to as satellites) are often scattered (see Japanese Patent Laid-Open No. 2-225678). When such a satellite-containing powder is used in a laser clad powder supply device, many phenomena occur in which the satellite is dropped from the satellite-containing powder by an external force such as impact or vibration in the supply path of the device. At that time, the fluidity deteriorates in the powder supply pipe of the supply path, and there is an adverse effect such as causing the phenomenon that the supply amount to the processing position fluctuates due to blockage or pulsation. Based on this cause, when laser overlay processing is performed, defects such as generation of clad and unstable deposition amount have occurred in the processed product.
[0004]
Regarding the above problems, the present inventors have a phenomenon in which, when used in the powder supply apparatus, the fluidity of the powder deteriorates in the powder supply pipe of the supply path, and the supply amount to the processing position due to blockage or pulsation varies. Is the result of diligent research aimed at developing optimum characteristics and production methods that bring about it, focusing on the fact that it depends on the average particle size of the powder and the presence of satellite powder. The purpose is to solve the above problem by reducing the influence of satellite powder as much as possible.
[0005]
[Means for solving problems]
That is, the copper alloy powder according to the present invention has the above-mentioned problem due to the copper alloy powder having an average particle size in the range of 30 to 150 μm and a fluidity by a test method based on JIS Z2502 of 15 seconds / 50 g or less. Achieved. Such copper alloy powder is obtained by grinding a copper alloy powder obtained from a molten copper alloy by a gas atomizing method using a pan mill or a roller mill, and classifying the obtained copper alloy powder into a particle average particle size of 30 to 150 μm. can get. In order to build up using these copper alloy powders, the manufacturing process of the copper alloy powder, the supply process of supplying the copper alloy powder manufactured by the manufacturing process onto a dissimilar metal, and melting the copper alloy powder This is achieved by a laser overlaying method comprising a laser processing step of overlaying a copper alloy on a dissimilar metal. As described above, the obtained copper alloy powder is excellent in fluidity, and is supplied onto a dissimilar metal and melts the copper alloy powder using a laser beam to build up the copper alloy on the dissimilar metal by laser. It is extremely suitable as a copper alloy powder for laser cladding, and can be suitably built up.
[0006]
Aspects of the Invention
Hereinafter, the present invention will be described in more detail. First, it is important to specify the average particle size of the copper alloy powder according to the present invention within a range of 30 to 150 μm. That is, when the average particle size of the particles is less than 30 μm, the copper alloy particles are too small, and are affected by humidity in the atmosphere or moisture contained in the fume from the processing position, and are likely to cause aggregation of the particles. This is likely to cause clogging or catching of powder in the pipe line. On the other hand, when the average particle diameter exceeds 150 μm, for example, when used for laser cladding, the dissolution of the powder by the laser tends to become unstable, which may hinder the mechanical strength of the built-up portion.
[0007]
In the copper alloy powder according to the present invention, the fluidity according to the test method based on JIS Z2502 needs to be 15 seconds / 50 g or less. That is, when the fluidity exceeds 15 seconds / 50 g, it means that the satellite is not sufficiently removed, which tends to cause clogging or catching of the powder in the conduit of the powder supply device.
[0008]
The copper alloy powder according to the present invention as described above can be obtained by grinding and classifying a copper alloy powder obtained from a molten copper alloy by a gas atomizing method. In order to reduce satellites as much as possible from the copper alloy powder obtained by the gas atomization method, it is necessary to select a processing apparatus that is excellent in the grinding effect and does not impair the shape of the powder. In the present invention, a pan mill or a roller mill is used as a processing apparatus that satisfies such requirements. Typical examples of the pan mill as an apparatus used in the processing of the present invention include an edge runner, a mix muller, and an Eyrich mill. Typical examples of the roller mill include a ring roller mill, a roller race mill, and a ball race mill. In processing apparatuses other than the pan mill or the roller mill, it is difficult to change the shape of the powder or to adjust to a desired fluidity.
[0009]
The copper alloy powder treated with the above processing apparatus is contaminated with the dropped satellites, so that the sieving classification, which is a conventional method, is performed to remove the contaminants and the copper alloy powder is adjusted to fall within a predetermined particle size range. Then, by continuously forming the copper alloy powder manufacturing process, the powder supplying process, and the laser processing process using the powder as a series of processes, an efficient laser overlay process can be performed. Become.
[0010]
【The invention's effect】
The copper alloy powder according to the present invention is a copper alloy powder whose average particle size is in the range of 30 to 150 μm and whose fluidity by a test method based on JIS Z2502 is 15 seconds / 50 g or less. Powder is obtained by grinding a copper alloy powder obtained from a molten copper alloy by a gas atomizing method using a pan mill or a roller mill, and classifying the obtained copper alloy powder into a particle average particle size range of 30 to 150 μm. Therefore, a spherical copper alloy powder that does not contain satellites often generated by the gas atomization method can be obtained. Therefore, these copper alloy powders of the present invention are excellent in fluidity, and clogging and catching in the pipeline of the supply device are extremely reduced during powder conveyance. When used as a copper alloy powder for laser cladding to melt alloy powder and build up copper alloy on dissimilar metals, it is possible to prevent abnormal transport such as pulsation of powder caused by satellite, stable processing position Can be supplied stably, and a uniform build-up can be obtained.
[0011]
Examples of the present invention will be described below together with comparative examples, but the present invention is not limited to these examples.
【Example】
Using a high-frequency induction furnace, prepare a molten copper alloy having the following composition in a graphite crucible, and pulverize it by a gas atomization method in which nitrogen gas is injected while it is downstream from the bottom of the crucible having a nozzle with a hole diameter of 4.5 mm for dehydration treatment And degassing treatment. Thereafter, the powder was put into an edge runner and the powder obtained by treating for 3 hours was classified with a vibration sieve to obtain a copper alloy powder having an average particle size of 83 μm and a fluidity of 13.5 seconds / 50 g. (Copper alloy composition)
Ni: 15.5wt%
Co: 14.1wt%
Al: 0.9wt%
V: 1.6wt%
Nb: 1.8wt%
Si: 2.8wt%
Cu: balance [0012]
[Comparative Example 1]
A copper alloy powder was obtained in the same manner as in the example except that the nozzle diameter at the bottom of the crucible when applying the gas atomizing method was 7 mm.
[0013]
[Comparative Example 2]
A copper alloy powder was obtained in the same manner as in the example except that the nozzle diameter at the bottom of the crucible when applying the gas atomizing method was 2 mm.
[0014]
[Comparative Example 3]
A copper alloy powder was obtained in the same manner as in Example except that the edge runner treatment was not performed.
[0015]
[Comparative Example 4]
A copper alloy powder was obtained in the same manner as in Example except that the edge runner treatment was performed for 30 minutes.
[0016]
[Comparative Example 5]
A copper alloy powder was obtained in the same manner as in Example except that the ball mill treatment (1.5 kg of atomized powder was introduced into a 300 mm diameter ball mill into which 10 kg of 6.3 mm balls were added) was performed for 1 hour instead of the edge runner treatment.
[0017]
The shape of the copper alloy powder obtained as described above, the average particle diameter, the fluidity by the test method based on Z 2502, and the degree of powder catching of the powder supply device were measured, and the results are shown in Table 1. In addition, the measurement of the degree of powder trapping is performed by connecting an electronic balance with an output terminal and a personal computer, and copper alloy powder so that a constant supply amount is obtained from the powder supply device in the electronic balance tray set at the actual processing point position. The amount of powder supplied per hour was measured and recorded from the balance weight and time that increased with the supply of powder. Moreover, the case where the powder supply amount appeared as a sudden change as shown in FIG. 1 was regarded as occurrence of a catch, and the same test was repeated 20 times to check the number of catches.
[0018]
[Table 1]

[0019]
As is clear from Table 1, the copper alloy powder according to the embodiment of the present invention has a zero degree of catch and ideal fluidity, whereas the powders of the comparative examples all have poor fluidity and the degree of catch. You can see that it ’s big. From these, the process of producing the copper alloy powder as described above according to the method of the present invention, the supply process of the powder, and the laser processing process using the powder are continuously formed as a series of processes, whereby efficient laser meat is produced. It can be seen that heaping can be performed.
[Brief description of the drawings]
FIG. 1 is a graph showing the relationship between the amount of powder supplied and time when copper alloy powder is supplied from a powder supply device.

Claims (2)

Particles characterized by grinding a copper alloy powder obtained from a molten copper alloy by a gas atomizing method using a pan mill or a roller mill, and classifying the obtained copper alloy powder into a particle average particle size in the range of 30 to 150 μm. A method for producing a copper alloy powder having an average particle size in the range of 30 to 150 μm and having a fluidity of 15 seconds / 50 g or less by a test method based on JIS Z2502. A copper alloy powder produced from a molten copper alloy by a gas atomization method is ground using a pan mill or a roller mill, and the obtained copper alloy powder is classified into a particle average particle size in the range of 30 to 150 μm. A laser build-up process comprising: supplying a copper alloy powder produced by the production process onto a dissimilar metal; and a laser processing process for melting the copper alloy powder and depositing the copper alloy on the dissimilar metal Method.

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