JPH0118146B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing a composite material that has improved erosion resistance, soundproofing, vibrationproofing, and thermal insulation properties, as well as excellent strength, workability, and cost. The Thixocast method (by KP Young et al.,
AFS Transaction, vol84, 1976, 76−128,
P169-174) and the Rheocast method (written by MCFlemings et al., AFS International Cast
Metals Journal, September 1976, P11-22). However, the above-mentioned method for manufacturing composite materials has limitations in stirring methods and temperature control, making it difficult to manufacture parts with complex shapes, and also having problems such as insufficient strength and increased costs. Also, when thermal spraying ceramics, a mixture of metal powder (e.g. Ni-Al) and non-metallic powder (e.g. ZrO ₂ ) is used as an intermediate layer to improve the adhesion between the material to be thermally sprayed and the ceramics. The technology is known. However, in this case, since thermal spraying is carried out under thermal spraying conditions in which both the metal powder and the non-metal powder are in a molten state, the non-metal powder is
O1 is the material to be thermally sprayed, O2 is the build-up layer, and O3 is the non-metallic material.
Not only is the fragile non-metallic material O3 likely to become a starting point for cracking or peeling, but if it is flat, there is a high possibility that it will connect with the adjacent flat non-metallic material, making it easier for cracking or peeling to progress, resulting in insufficient strength. , cannot be used as erosion-resistant or wear-resistant materials. The present invention provides a method for producing a composite material that is not only excellent in terms of workability, strength, and cost, but also can improve erosion resistance, sound insulation, vibration insulation, and heat insulation. That is, the present invention uses metal powder and ceramic powder as spraying materials for plasma spraying or flame spraying, and supplies the metal powder to a position on the high temperature side and the ceramic powder to a position on the low temperature side of the plasma flame or flame. The present invention relates to a method for producing a composite material, which comprises applying thermal spray overlay to a material to be thermally sprayed and uniformly dispersing the ceramic powder in the form of lumps within the thermal spray overlay. The metal powder of the present invention includes powders of ferrous and non-ferrous (copper, aluminum, alloys thereof, etc.) metal materials that can be thermally sprayed in general, and the ceramic powders include Al ₂ O ₃ , SiO ₂ , SiC, Si _3N4 , other ceramics, or foundry sand that is a mixture _of ceramic powder can be used. The metal powder and ceramic powder described above are plasma sprayed using, for example, a spray gun shown in FIG. In FIG. 2, 1 is a tungsten electrode, 2 is a copper nozzle, and 3 is a powder supply nozzle, and the configuration up to this point is the same as a normal thermal spray gun. In the case of normal plasma spraying, a plasma jet is generated between a tungsten electrode 1 and a copper nozzle 2, and a metal powder 4 is supplied from a powder supply nozzle 3 into a plasma flame 5, onto the surface of a material to be thermally sprayed (not shown). When the metal powder and ceramic powder are mixed and sprayed from this powder supply nozzle 3, both the metal and ceramic powders become molten, making it possible to distribute the ceramic powder in a spherical shape within the thermal spray overlay layer. Can not. Therefore, in the present invention, a ceramic powder supply nozzle 3A is separately provided as shown in the figure, the metal powder 4 is supplied from the normal powder supply nozzle 3 to a normal position (that is, a high temperature position) and melted, and the ceramic powder 4A is From the powder supply nozzle 3A to the low temperature side (approximately 2000℃ or less) of the plasma flame 5
It is supplied with a delay of 80 mm and distributed in the form of a lump (for example, spherical shape) within the thermal sprayed overlay layer without melting. The particle size of metal powder and ceramic powder depends on the performance of the thermal spray gun, i.e. output, powder supply amount, working gas,
Alternatively, it can be selected as appropriate depending on the material of the metal or ceramic powder, but for example, when using cast steel as the metal powder, 70 to 100μ is preferable, and when using foundry sand as the ceramic powder, 20 to 70μ allows the foundry sand to be uniformly spherical. This is preferable in terms of distribution. In addition, if the amount of ceramic powder is less than 5wt%, it will not be effective as a composite material, and if it is more than 50wt%, the amount of ceramic powder will be too large, weakening the bond between metal powders and causing the overlay layer to be missing. The content is preferably 5 to 50 wt%, since this may cause peeling. Furthermore, the powder supply amount is 0.5~ ^2.0cm3 /m of metal powder.
In, the ceramic powder is preferably 0.01 to 1.0 cm ³ /min. Note that if the thickness of the thermal sprayed overlay is too thin, the overlay will easily chip or peel due to the particle size of the ceramic powder, and if it is too thick, the number of thermal spraying steps will increase, leading to increased costs. 0.3~10mm
degree is preferred. Taking the above points into consideration, the thermal sprayed overlay of the composite material of the present invention has a damping capacity that is almost equivalent to that of ordinary cast steel, about 7 times that of Al alloy, and about 12 times that of mild steel, and has anti-assay properties. Since the composite material of the present invention has good erosion resistance, it can be used for mechanical parts that require erosion resistance (e.g. various impellers, propellers, etc.), soundproofing,
It can be preferably applied to mechanical parts, soundproof walls, sound insulation walls, etc. that require vibration isolation and heat insulation properties. Next, examples of the present invention will be given. Example Particle size of ceramic powder with composition shown in Table 1
Using foundry sand of 20 to 70μ as metal powder and cast steel (SC42) powder with a particle size of 70 to 100μ with the composition shown in Table 2 as the metal powder, the spray gun with the composition shown in Table 2 was used. Thermal spray overlay was carried out using cast steel (SC42) as the material to be thermally sprayed under the following thermal spraying conditions. Note that the surface of the material to be thermally sprayed was subjected to a blast treatment and a degreasing treatment as pretreatment. Thermal spraying conditions Current: 300A (tolerable range 200-400A) Voltage: 30V (tolerable range 25-55V) Distance between sprayed material and spray gun: 100mm Cast steel powder supply rate: 0.18cm ³ /min Foundry sand supply rate: 0.02cm ³ /min Amount of foundry sand: 10wt% Thickness of sprayed overlay layer: 5mm

【table】

[Table] The test piece has a shape as shown by reference numeral 14 in Figure 5 below, and has a square surface of 40 x 40 mm.
Weld overlay was applied to 4b so that it became the state of 14a. As a result of the above, a composite material was obtained in which foundry sand was spherical and uniformly dispersed within the sprayed overlay layer. In order to evaluate the erosion resistance of this composite material, the following experiment was conducted. An attachment erosion tester shown in FIG. 3 was used. The test piece was attached as shown in FIG. 4, which is a plan view taken from the line arrow in FIG. 3, and FIG. 5, which is a side sectional view of the section 14 in FIG. 3 to 5, a test piece 14 is attached to a mounting plate 13 of a test piece 14 connected to a motor 11 by a shaft 12.
Install and rotate. Air mixed with ashes having the composition shown in Table 3 is sprayed onto the test piece 14 from the arrow A using the injection valve 15. In Figures 3 to 5, B is the spraying situation of the ash, 16 is the test tank, 17 is the exhaust port, 18 is the air suction port with a wire mesh, and 13 is the mounting plate for the test piece 14. The above test piece 14 was placed 18 times at a time on the surface of the concentric circle 13.
Attachment bolts 19 are provided so that up to 10 pieces can be attached, and a screw hole 19a into which the attachment bolts 19 are screwed is bored at the lower end of the test piece 14. In addition, in FIG. 5, a test piece 14 of the present invention material is shown.
has a built-up layer 14a with a thickness of 5 mm on the ash spraying surface 14b, and the angle of the ash spraying surface 14b is 45 degrees with respect to the ash spraying direction. The attachment resistance was tested using the above testing machine under the conditions shown in Table 4. For comparison, ordinary cast steel (SC42), spheroidal graphite cast iron (FCD40), and aluminum alloy (JIS H400 2017 Al−
Similar tests were also conducted on Cu-based alloys. The above results were as shown in Table 5.

【table】

【table】

[Table] From Table 5, it was confirmed that the assemblage erosion resistance of the composite material of the present invention is approximately 8 times that of ordinary Al alloy, approximately 3.6 times that of cast steel, and approximately 4.6 times that of spheroidal graphite cast iron. . The above test results also show that the composite material of the present invention has excellent erosion resistance.

[Brief explanation of drawings]

Fig. 1 is a diagram schematically showing an intermediate layer made of a mixture of metal powder and non-metal powder used in conventional ceramic spraying, and Fig. 2 is a thermal spray gun used in preparing the composite material of the present invention. FIG. 3 is a schematic diagram showing an example of the attachment erosion testing machine used in the example. FIG. FIG. 5 is a side sectional view of the section 14 in FIG. 3 showing the cross-sectional shape and mounting condition of the test piece.

Claims (1)

[Claims] 1 Metal powder and ceramic powder are used as spraying materials for plasma spraying or flame spraying, and the metal powder is supplied to the high temperature side and the ceramic powder is supplied to the plasma flame or low temperature side of the flame to coat the material to be thermally sprayed. A method for producing a composite material, which comprises performing thermal spray overlay and uniformly dispersing the ceramic powder in the form of a lump within the thermal spray overlay.