JP2000282209A - Thermal-spraying material and structural body obtained by forming this material as film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aluminum alloy-made sliding member excellent in wear resistance and burning resistance, even without obtaining an optimum thermal spraying condition such as that in the thermal spraying to the inner diameter of a cylinder bore. SOLUTION: This thermal-spraying material is obtained by mixing 5-30 wt.% Al-Si base alloy powder containing 12-30 wt.% Si, one or two kinds of 0.5-5.0 wt.% Cu and 0.2-0.3 wt.% Mg, and 1-15 wt.% of at least one kind among Fe, Mn and Ni and the balance Al with inevitable impurities with 95-70 wt.% cast iron powder containing 2-4 wt.% C, <=0.3 wt.% Si, 0.5-3.0 wt.% P and the balance cast iron with inevitable impurities. Then, when the thermal spraying material composed of the mixture of these is thermal-sprayed and stuck on the sliding surface in a piston or a cylinder bore, a film excellent in wear resistance can be formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sprayed material for imparting wear resistance to an aluminum alloy part and a structure formed by coating the material. Aluminum alloy parts include a cylinder bore (cylinder hole), a valve lifter, a valve seat, a piston, and the like, and are particularly effective for application to the inner surface of the cylinder bore.

[0002]

2. Description of the Related Art A lot of research has been conducted from a long time ago on thermal spraying methods for imparting wear resistance to aluminum alloy parts, in particular, application of inexpensive iron-based materials to sliding surfaces of cylinder bores of internal combustion engines.
For example, Japanese Patent Publication No. 51-10183, Japanese Patent Publication No. 51-18
No. 004, JP-B-54-42855, JP-B-57-1
No. 3739 and Japanese Patent Publication No. 57-34346 disclose that various carbon steels are applied to aluminum cylinders. Above all, JP-B-51-10183 and JP-B-54-4
Japanese Patent Publication No. 2855 aims to improve wear resistance by applying cast iron containing a large amount of carbon (C), and Japanese Patent Publication No. 51-18004 discloses that phosphorus (P) is added in an amount of 0.3 to 30% by weight. If not otherwise stated herein are weight%) to generate a steadite _{(Fe 3 C-Fe 3 P} -Fe) by including, aimed at improvement of the wear resistance. However, in the method of forming a carbon steel film on an aluminum cylinder, a problem of film peeling occurs due to a difference in thermal expansion between the substrate and the film.

[0003] US Patent 3,077,659 disclosed mixed spraying of powdered aluminum and powdered iron. In Japan, Japanese Patent Publication No. 58-54189 discloses a cylinder sprayed by mixing an AlSi-based alloy containing 16 to 40% of Si with a 5 to 50% high carbon ferrochromium alloy. Japanese Patent Laid-Open Publication No. H11-15083 discloses a thermal spraying method in which 50% or less of carbon steel is mixed and sprayed onto an AlSi-based alloy containing 20 to 40% of Si, and then T6 treatment is performed. Also, in the example of JP-A-7-62519, 50% carbon steel (0.
8% C) and heat-treating at a temperature lower than the melting point of the sprayed layer.

Further, Japanese Patent Application Laid-Open No. Hei 8-253856 discloses a piston sprayed by mixing and spraying an AlSi-based alloy containing carbon steel and 20% or less of Si and a carbide or an alloy containing a carbide having an Hv of 500 to 1500. These are intended to reduce the thermal expansion difference from the base material by mixing an aluminum alloy powder with an iron-based alloy, and the latter four cases use Si of an AlSi-based alloy to reduce the thermal expansion difference by 15 to 40%. % Also improves the wear resistance of the thermal expansion difference reducing layer. However, in the case of inner diameter spraying when applied to cylinders, a sufficient spray distance for melting the spray particles is not obtained, and in the case of high carbon ferrochrome alloy, ordinary carbon steel and cast iron, the bonding force between particles in the mixed spray coating is not sufficient. In addition, there were problems such as missing particles and abrasion.

[0005] Further, not only iron-based materials but also aluminum-based materials need to be improved in order to improve the bonding force between particles in the mixed sprayed coating and to improve the yield. Furthermore, Japanese Patent Application Laid-Open No. 8-25 / 1989 discloses mixing three kinds of powders to improve abrasion resistance.
In the invention disclosed in Japanese Patent No. 3856, it is difficult to uniformly disperse each material component in the film. JP-A-6-240
No. 436 discloses that aluminum and an iron-based metal (cast iron or iron-molybdenum alloy) are used as a composite powder in order to produce a uniform dispersion state in the film. However, in order to produce a composite powder, the respective powders of the aluminum and the iron-based metal need to be fine particles, which increases the powder cost. Further, aluminum and iron-based metals are highly reactive and involve the danger of dust explosion.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has excellent abrasion resistance and seizure resistance even under conditions where optimum spraying conditions such as inner diameter spraying cannot be obtained. A low-cost thermal spray material that can maintain sufficient adhesion strength to the aluminum alloy base material and sufficient inter-particle bonding force in the coating even when the thermal load is repeatedly applied in the engine and thermal spraying it It is an object of the present invention to provide a sliding member adhered thereto.

[0007]

The thermal sprayed material of the present invention comprises:
2 to 30% by weight of Si, 0.5 to 5.0% by weight of Cu or one or two kinds of Mg of 0.2 to 3.0% by weight, and at least one of Fe, Mn and Ni ~
5 to 30% by weight of an AlSi-based alloy powder containing 15% by weight and the balance being Al containing unavoidable impurities, and 2 to 4% by weight of C, 0.3% by weight or less of Si, and 0.5 to 0.5% by weight. 3.0
95-70% by weight of cast iron powder, which is cast iron containing P by weight and the balance containing unavoidable impurities. Further, the structure formed by coating the thermal spray material of the present invention has a thickness of 12 to 3
0% by weight of Si, one or two kinds of 0.5 to 5.0% by weight of Cu or 0.2 to 3.0% by weight of Mg, and F
e, at least one of Mn and Ni is contained in an amount of 1 to 15% by weight, and the balance is Al containing unavoidable impurities.
30% by weight of AlSi-based alloy powder, 2 to 4% by weight of C, 0.3% by weight or less of Si, and 0.5 to 3.0% by weight
And the balance is cast iron containing unavoidable impurities 9
5 to 70% by weight of cast iron powder is mixed, and a sprayed coating made of the mixture is formed on the sliding surface of the sliding member.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the thermal spray material of the present invention and a structure formed by coating the thermal spray material will be described. In the present invention, the wear resistance of the sprayed coating by changing the components,
AlSi-based alloy powder that improves seizure resistance and anti-adhesion properties, and further improves morphology by improving the inter-particle bonding force and material yield during film formation, and adjusting the components to achieve inner diameter spraying Even in such a situation where a sufficient spraying distance cannot be obtained, the bonding force between particles can be improved by giving sufficient fluidity of droplets. Further, by suppressing the decomposition of Fe ₃ C (cementite) in the raw material powder to form a thermal sprayed coating, it is excellent in wear resistance and seizure resistance, and even when the thermal load is repeatedly applied in the engine, the thermal spray coating is formed. A sprayed coating capable of maintaining a sufficient adhesion strength and a sufficient bonding force between particles in the coating is formed.

Hereinafter, the components of the sprayed material will be described in detail. [AlSi-based alloy powder] Various component compositions of the AlSi-based alloy were determined as follows. If the content of Si is 12% or less relative to the weight of the AlSi-based alloy, sufficient wear resistance cannot be obtained because primary crystal Si which is below the eutectic point and contributes to wear resistance cannot be obtained. On the other hand, if it exceeds 30%, the solid capacity of Si and other components becomes too large, and it becomes brittle. Cu, Mg, Fe, Mn and Ni are Al
It is a component that contributes to the high-temperature strength of the Si-based alloy. 0.5 ~
By containing one or two kinds of 5.0% Cu or 0.2-3.0% Mg, it has excellent high-temperature strength up to 150 ° C., and further contains at least one of Fe, Mn and Ni by 1 to 15%. By containing it, an AlSi-based alloy excellent in high-temperature strength up to about 250 ° C. is obtained. In the thermal spraying, the coating formed by rapid heating and quenching is also used for forming the coating of other parts by 150 to 20 times.
Since heat is applied to about 0 ° C., these components having excellent high-temperature strength are required. Therefore, if the value is below the lower limit of each component, the hardness of the sprayed coating decreases, and if the value exceeds the upper limit, the solid solution becomes too brittle due to an excessive amount of solid solution.

The powder is suitable for thermal spraying because the powder rapidly solidified by atomization is uniform in composition. But,
Atomized powder of the AlSi-based alloy is likely to form fine powder, which causes problems such as obstruction of powder supply during thermal spraying and clogging in the thermal spray gun. Therefore, classification by a sieve is usually performed. In the classification with a sieve, 400 mesh, preferably 325, is used to remove fine powders which are problematic.
Classified by mesh. For example, JP-A-54-2823
No. 9 discloses 400 mesh, Japanese Patent Publication No. 58-54189.
In the publication, classification is performed at 350 mesh. this is,
This is due to clogging of the sieve, which is the limit for industrially inexpensive sieving. When handling fine aluminum powder,
Because of the danger of dust explosion, 4
Classification with a sieve smaller than 00 mesh is avoided.
In addition to the sieve, there is a flying classification method, but aluminum powder containing fine powder is not used because of the high risk of dust explosion.

In the spraying of the mixed inner diameter of the AlSi-based alloy powder and the iron-based alloy powder, it is better to mix a fine powder so as not to cause the problem of powder supply and clogging, thereby obtaining a better film property. This is because if the powder is fine, even if a sufficient spraying distance is not obtained, the powder is sufficiently melted, the dispersion state in each film is finely dispersed, and a more dense film is obtained. Therefore, it is necessary for particles to contain finer powder than 325 or 400 mesh in order to improve film properties.
Further, classifying the atomized powder deteriorates the yield of the powder and increases the cost.

In order to solve these problems, in the present invention, an AlSi-based alloy granulated powder granulated with an organic binder is used. As the organic binder, ethylene bissteramide, polyvinyl alcohol, polyvinyl acetate, methylcellulose, ethylcellulose, or the like, which burns in the thermal spraying step, can be used, and the organic binder does not remain in the coating after thermal spraying. By granulating fine powder that causes a problem when supplying the thermal spray material, the supply of the thermal spray material becomes smooth, and the fluidity of the powder itself is improved by attaching an organic binder.

When the granulated powder enters the thermal spraying frame, the organic binder is incinerated instantaneously and the particles are dispersed. As a result, fine molten particles are also taken into the film, and an ideal mixed film in which a dense AlSi-based alloy and cast iron are finely dispersed is formed. There is also a method of granulating an AlSi-based alloy together with cast iron to form a composite powder (Japanese Patent Application Laid-Open No. 6-240436), but in order to produce a composite powder, it is necessary to produce fine particles of each. Yes, the cost rises due to poor yield and the like. In addition, the step of mixing highly reactive Al and Fe fines is dangerous and should be avoided.

[Cast Iron] It is known that the wear resistance of cast iron changes depending on the C content. In the present invention, the content of C is defined as a ratio of 2. to the total weight of cast iron in the present invention.
0% to 4.0%. If the C content is less than 2.0%, the powder does not have chill crystals and the amount of target Fe ₃ C is small, so that sufficient wear resistance cannot be obtained. When C becomes 4% or more, F
e ₃ C becomes too large and becomes brittle. Next, Si
Was made 0.3% or less. The addition of Si in excess of 0.3% in cast iron powder chill of containing a large amount of Fe ₃ C, Fe ₃ C is decomposed graphite occurs during the thermal spray coating formed. Since this graphite acts as an impurity that lowers the bonding force between particles of the thermal sprayed coating, it is desired to suppress its generation as much as possible. Further, when Fe ₃ C is decomposed, the film hardness decreases, and sufficient wear resistance cannot be obtained. With the above contents of C and Si, the viscosity of the droplets is high, and the particles at the time of forming the thermal spray coating are less likely to be wet, so that the bonding force between the particles is reduced. In particular,
In a situation where a sufficient spray distance cannot be obtained, such as inner diameter spraying, it is necessary to improve the fluidity of the droplet. Therefore, P is added to improve the fluidity of the droplet. The added amount of P is 0.3
効果 3.0%, if less than 0.3%, the effect is poor and 3.0%
%, The coating becomes brittle.

[Blending Ratio] The blending weight ratio between the AlSi-based alloy powder and the cast iron powder is 5-30% for the above-mentioned AlSi-based alloy and 70% for the above-mentioned cast iron in a ratio to the total weight of the resulting sprayed material. ９５95%. With cast iron exceeding 95%, the effect of dispersing the AlSi-based alloy is small, and there is a problem in adhesion strength with the base material, so that there is a possibility that film peeling may occur. Further, when the AlSi alloy is blended in an amount of 30% or more, the volume ratio exceeds 50% by volume in the film.
A problem may arise in the wear resistance.

[Spraying Method] In the present invention, plasma spraying,
H. V. O. There is no limitation on the thermal spraying method such as F (high-speed gas flame thermal spraying), arc thermal spraying and gas thermal spraying. The thermal spray material of the present invention is particularly effective in disadvantageous thermal spraying methods such as inner diameter thermal spraying. Examples of the base material of the sliding member of the present invention include an aluminum alloy casting or a wrought material usually used for engine parts of an internal combustion engine such as a cylinder bore and a piston. The parts to be applied are sliding members such as cylinder bores, valve lifters, valve seats or pistons. When applied to a cylinder bore, compared to a cast iron sleeve cylinder, it can be expected to be lighter, more compact, and have higher performance due to better heat conduction due to sleevelessness. Hereinafter, a detailed description will be given using some test examples.

[Test 1] A sprayed material having the following composition was used. As a sample, Al-20% Si-
3.3% Cu-1.3% Mg-5% Fe, Al-12% Si-3.4% Cu-1.2% Mg-
3% of 5% Fe, Al-12% Si as a comparative sample
Seed samples were prepared. In addition, the simplified notation of the composition of each sample in the above will be described. For example, in the above, 20% by weight of Si, 3.3% by weight of Cu, 1.3%
Wt% Mg, 5 wt% Fe and the balance Al and A
1 and unavoidable impurities. Other samples are simplified by the same notation. Each of the above three types of samples was subjected to an aluminum substrate (AC4C) under the conditions shown in Table 1.
T6 treatment) and the coating cross-sectional hardness HV (Vickers hardness) was measured. Table 2 shows the measurement results.

[0018]

[Table 1]

[0019]

[Table 2]

The measurement results are all average values of 10 point measurements. The sample was sprayed with the thermal spray material of the component according to the present invention and had a coating hardness of 250 HV0.3 or more, while the comparative sample had a coating hardness of less than 130 HV0.3. This is because the comparative sample does not contain components such as Cu, Mg, and Fe. If Cu, Mg, Fe, or the like is present, Cu, Mg,
Mg, Fe, etc., dissolve in the coating matrix to harden the matrix. Since the hardness of the matrix directly leads to the wear resistance of the film, it can be said that the wear resistance is improved by including Cu, Mg and Fe. In this test example, Fe
However, Ni and Mn other than Fe have the same effect.

Test Example 2 The following materials were used as the thermal spray material. Al-20% Si-
Three types of powders having compositions of 3.3% Cu-1.3% Mg-5% Fe and different particle sizes, and Al-20% Si-3.3% Cu-1 as an AlSi-based alloy granulated powder. 0.3% Mg-
A powder prepared by granulating a powder having a composition of 5% Fe with ethylene bissteroamide is prepared. Table 3 shows the particle size distribution of each powder. AlSi alloys 1 to 3 are not granulated.

[0022]

[Table 3]

Three kinds of powders having different particle sizes were prepared by changing the atomizing conditions of the AlSi alloy. When these AlSi-based alloys 1 to 3 are sprayed under the conditions shown in Table 1 above, all the powders are sprayed through the powder blowing ports of the spray gun during sample preparation.
The lSi-based alloy powder was melted and clogged. this is,
It can be seen that this phenomenon is caused by the poor fluidity of the powder due to the inclusion of the fine powder, and cannot be fully accommodated by changing the atomizing conditions. Therefore, in order to spray the AlSi-based alloy, some treatment such as classification and granulation must be performed. However, in the classification process, even if the particles are classified at 45 μm, about 30% of the powder is discarded, and the powder cost is greatly increased.

When the AlSi alloy is granulated with ethylene bissteroamide as an organic binder, as shown in Table 3, the AlSi alloy shifts in a direction in which the particle diameter is slightly increased. When this powder was sprayed under the conditions shown in Table 1, clogging occurred in the AlSi-based alloys 1 to 3 did not occur, and a sprayed coating could be produced. Although the granulated powder contains many particles smaller than the AlSi alloys 2 and 3, the fluidity is improved because the organic binder covers the whole. Therefore, all the atomized powder can be used for thermal spraying by granulation treatment, and high coating performance can be achieved even in a situation where a sufficient thermal spraying distance such as inner diameter thermal spraying cannot be obtained by containing more fine powder. can get. Figure 1,
FIG. 2 shows the X-ray diffraction results of the AlSi-based alloy granulated powder and the coating obtained by spraying this powder under the spraying conditions shown in Table 1 above. It can be seen that the organic binder present at the powder stage does not exist in the thermal spray coating. That is, in the present AlSi-based alloy granulated powder shown in the column of peak data in FIG. 1, the peaks of the organic binder (C ₇ H ₁₁ N ₃ O ₃ ) _n and C ₅ H ₁₀ O ₅ appear on the left side of the peak data column. However, after thermal spraying shown in FIG.
It can be seen that the organic binder has disappeared as shown on the left side of the column of the peak data representing the thermal spray coating.
In addition, A shown under the column of the peak data in FIG.
The peak of l _3.21 Si _0.47 is a general AlSi alloy, and the lower part of the peak is (C ₇ H ₁₁₎
N ₃ O ₃ ) _n similarly indicates C ₅ H ₁₀ O ₅ of the organic binder.

Test Example 3 A sample and a comparative sample were prepared using the following powders in order to investigate a difference in particle size of the AlSi-based alloy powder. Al-20% Si-3.3% Cu-1.3% Mg-
A powder having a composition of 5% Fe classified at 45 μm or more and an AlSi-based alloy granulated powder of Al-20% S
i-3.3% Cu-1.3% Mg-5% Fe having a composition of Fe-3.1% C-0.03 % Si
A sample having a composition of -0.97% P-0.018% S was prepared, and as a sample, a mixed powder of 20% by weight of an AlSi-based alloy granulated powder and 80% by weight of cast iron 1, and as a comparative sample, 20% by weight. A mixed powder of AlSi-based alloy 1 ′ in weight% and 80% cast iron 1 was prepared. Using the sample and the comparative sample, a film was formed under the spraying conditions shown in Table 1 above, and the film cross-sectional hardness (HV)
1.0). As a result, the sample was 482HV1.
Although it was 0, it was slightly lower at 429 HV1.0 in the comparative sample. This is because fine AlSi particles are not included in the comparative sample, and the denseness of the coating and the bonding force between the particles are lower than those of the sample.

Test Example 4 Samples and comparative samples were prepared using the following powders in order to investigate the differences due to the components of the iron-based material. As the cast iron 1, Fe-3.1% C-0.
03% Si-0.97% P-0.018% S, as cast iron 2, Fe-3.0% C-0.52% Si-0.09%
P-0.11% S, AlSi-based alloy granulated powder, Al
-20% Si-3.3% Cu-1.3% Mg-5% Fe
A powder prepared by granulating with ethylenebissteroamide of the formula (1) is prepared. As a sample, a mixed powder of 20% by weight of an AlSi-based alloy granulated powder and 80% by weight of a cast iron 1, and as a comparative sample, a 20% by weight of an AlSi-based alloy A mixed powder of alloy granulated powder and 80% by weight of cast iron 2 was prepared.

A film was formed on the sample and the comparative sample under the thermal spraying conditions shown in Table 1, and the film cross-sectional hardness (HV1.0) was determined. As a result, the sample was 482 HV1.0 and the comparative sample was 35
7HV1.0. The sample formed a rhombus with a clean impression even at a load of 1.0 kgf, whereas the comparative sample cracked between the particles and increased the impression. this is,
The sample cast iron contained 3.1% C and 0.03% Si.
%, The Fe ₃ C (cementite) remains in the coating to improve the hardness of the coating.
Is considered to be 0.97% to improve the fluidity of the droplets, thereby making the droplets well wet to the already formed film and increasing the bonding force between the particles.

On the other hand, in the comparative sample, C was 3.0%
But 0.52% of Si._ThreeC (S
(Mentite) is decomposed to form graphite, so that
Is considered to be weakened. The Fe_ThreeWith C
In order to confirm the absence, the powder of the cast irons 1 and 2 and
X-ray diffraction results of the film are shown in FIGS. Figure 3 shows cast iron 1
FIG. 4 shows the X-ray analysis results of the powder of cast iron 2.
FIG. 5 shows the results of X-ray analysis of the thermal spray coating of the powder of cast iron 1.
FIG. 6 shows the results of X-ray analysis of the thermal spray coating of the powder of cast iron 2.
It is a line analysis result. In addition, in the powder of the cast iron 1, P is set to 0.
97% and within the preferred range (0.5-3.0%)
And the powder of cast iron 2 contains only 0.09% of P.
It just works. As shown in FIGS. 3 and 4, in the powder stage
Fe present in both cast irons 1 and 2 _ThreePeak showing C
However, as shown in FIG. 5, only the sprayed coating of the cast iron 1 remains.
(See the left side from the center of the column of peak data), shown in FIG.
The peak disappears in the thermal spray coating of cast iron 2
(See the left side of the column of peak data). this is,
Since the amount of P is small, the intermolecular bonding force is weak and Fe_ThreeC is iron and black
This is because it has been decomposed into lead. Also, P is 0.9
In cast iron 1 containing 7%, steadite (Fe_ThreeC-Fe_ThreePF
The peak of e) could not be detected.

Test Example 5 In order to investigate the difference in the adhesion strength between the aluminum base material and the sprayed coating due to the mixing ratio of the cast iron 1, the adhesion strength at various mixing ratios was measured. In the experiment, a sample and a comparative sample were prepared using powder having the following composition. As AlSi-based alloy granulated powder, A
1-20% Si-3.3% Cu-1.3% Mg-5% F
e, bis-steroamide granulated powder and Fe-3.1% C-0.03% Si-0.97% P as cast iron 1
-Prepare 0.018% S, 20% by weight as a sample
Spray coating of AlSi-based alloy granulated powder and 80% by weight of cast iron 1, mixed sprayed coating of 10% by weight of AlSi-based alloy granulated powder and 90% by weight of cast iron 1, and comparative sample And a thermal spray coating of only cast iron 1 was prepared.
The adhesion strength of each sample was measured by an adhesive peeling method. Table 4 shows the measurement results.

[0030]

[Table 4]

From Table 4, it can be seen that as the blending amount of the cast iron 1 increases, the adhesive strength decreases.
0 kgf / mm ² was cut.

Test Example 6 A bench test using a two-wheel engine was performed to prove the effect of the present invention. The engine test was performed on a sample sprayed using powder having the following composition and a comparative sample. Al-20% Si-3.3% Cu-1.3% M as AlSi-based alloy granulated powder
g-5% Fe granulated powder of ethylene bissteroamide, and AlSi-based alloy 1 ′ as Al-20% Si—
A powder obtained by classifying 3.3% Cu-1.3% Mg-5% Fe at 45 μm or more, and Fe-3.1% C—
0.03% Si-0.97% P-0.018% S, and as the cast iron 2, Fe-3.0% C-0.52% Si-0.
09% P-0.11% S and prepare 2% as a sample.
A cylinder block sprayed with a mixed powder of 0% by weight of the above-mentioned AlSi-based alloy granulated powder and 80% by weight of cast iron 1, and as comparative samples, 20% by weight of AlSi-based alloy 1 'and 80% by weight of cast iron 2 And a cylinder block sprayed with the mixed powder. The cylinder block, which is the base material,
It was made of an aluminum alloy (AC4C T6 treatment), and was sprayed after blasting with an alumina grid. Thermal spraying was performed by using an inner diameter spray gun under the conditions shown in Table 1 above. After the spraying, honing treatment was performed to finish each sample. Table 5 shows the engine specifications and test conditions used in the bench test.

[0033]

[Table 5]

[Results of Test] FIGS. 7 and 8 show the inner surface of the cylinder bore after the test was performed by attaching the sample and the comparative sample. As shown in FIG. 7, honing marks 3 were left on the sliding surface of the inner wall 2 of the cylinder 1 on which the sample was adhered, and good results were obtained with a diameter change of about 2 μm. FIG.
On the inner wall 2 of the cylinder 1 to which the comparative sample shown in FIG.
Due to the low interparticle coupling force, particles in the film fall off when the piston, which is a sliding member, moves up and down, and the particles are caught between the cylinder inner wall 2 and the piston or piston ring and slide. Many vertical scratches 4 occurred on the inner wall 2 of the cylinder 1. Further, the dropped particles also enter the ring groove and make the piston ring slippery after the test, and if a longer test is performed, it is expected that problems such as seizure of the piston ring will occur. From these results, it is understood that the bonding force between particles is an important factor in the case of the thermal spray coating. Reference numeral 5 in the drawing indicates the upper sliding position of the piston ring at the top dead center of the piston.

As can be seen from the above, according to the present invention, even in a situation where optimum spraying conditions such as inner diameter spraying cannot be obtained, the abrasion resistance and seizure resistance are excellent, and the repetition in the engine is repeated. It is possible to provide a low-cost aluminum alloy sliding member that can maintain a sufficient adhesion strength to a substrate and a sufficient bonding force between particles in a film even when a thermal load is applied.

[0036]

The thermal sprayed material according to the composition of the present invention has 12 to
By containing 30% of Si, the brittleness of the thermal spray coating can be suppressed, and high wear resistance can be maintained. In addition, 0.5 to 5.0
% Of Cu or 0.2 to 3.0% of Mg, and AlSi alloy powder containing at least one of Fe, Mn and Ni in 1 to 15% of Al. By solidifying the components, the hardness of the sprayed coating is improved, and a coating excellent in high-temperature strength can be formed. Further, by using cast iron powder containing 2 to 4% of C, 0.3% or less of Si and 0.5 to 3.0% of P, Fe ₃ C (cementite) can be reduced while suppressing the formation of graphite. By remaining in the film to improve the film hardness, the fluidity of the droplets is further improved to make it easier to wet the already formed film, thereby increasing the bonding force between particles. Furthermore, Al
By mixing 5 to 30% of an Si-based alloy and 70 to 95% of cast iron, it is possible to obtain a film having abrasion resistance and a strong adhesion strength. However, if it exceeds 95%, there is a problem in adhesion strength to an aluminum substrate.)

According to the sprayed material of the present invention, which is a granulated atomized powder, since the AlSi-based alloy powder is an atomized powder, the content of components (Si, Fe, etc.) in each particle is constant, and Since each component is finely dispersed, it is easy to solidify during film formation. In addition, when granulation is performed using an organic binder, the organic binder can be eliminated during film formation. Furthermore, by making granulated powder, AlS
The yield of the i-based alloy powder can be improved, and finer particles can be used for film formation. For this reason, an ideal film that is dense and well dispersed can be formed.

According to the sliding member to which the thermal spray material of the present invention is adhered, the same effect can be obtained because the thermal spray material is adhered. In addition, when the thermal spray material of the present invention is used for a sliding member, even on the inner surface of the cylinder bore where a sufficient thermal spray distance cannot be obtained, the material is formed of a material capable of obtaining highly fluid droplets. And a sliding member suitable for an engine cylinder of an internal combustion engine, which can withstand repeated thermal loads caused by engine combustion and sliding of a piston ring, can be obtained.

[Brief description of the drawings]

FIG. 1 is a graph showing an X-ray diffraction result of an AlSi-based alloy granulated powder according to the present invention.

FIG. 2 is a graph showing an X-ray diffraction result of an AlSi-based alloy granulated powder thermal spray coating according to the present invention.

FIG. 3 is a cast iron 1 according to the present invention (the amount of P is an appropriate amount)
3 is a graph showing an X-ray diffraction result of the powder of Example 1.

FIG. 4 is a graph showing an X-ray diffraction result of a powder of cast iron 2 (the amount of P is smaller than an appropriate amount) in a comparative example.

FIG. 5 is a graph showing an X-ray diffraction result of a sprayed coating of cast iron 1 in the present invention.

FIG. 6 is a graph showing an X-ray diffraction result of a sprayed coating of cast iron 2 in a comparative example.

FIG. 7 is a perspective view showing a cylinder surface after a sample according to the present invention is attached to an inner wall of a cylinder and subjected to a bench test.

FIG. 8 is a perspective view showing a cylinder surface after a comparative sample is attached to the inner wall of the cylinder and a bench test is performed.

[Description of Signs] 1 Cylinder 2 Cylinder inner wall 3 Honing mark 4 Longitudinal wound 5 Upper position of piston ring

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Masashi Takahashi 300 Takatsukacho, Hamamatsu-shi, Shizuoka Suzuki Co., Ltd.F-term (reference) 3G024 AA22 FA06 FA13 FA14 GA00 GA19 HA07 4K018 BA08 BA15 BC11 BC12 BD09 4K031 AA02 AA08 AB08 CB03 CB25 CB28 CB29 CB37

Claims (5)

[Claims] 1. The method according to claim 1, wherein said Si is present in an amount of from 12 to 30% by weight and from 0.5 to 5.5% by weight.
One or two kinds of 0% by weight of Cu or 0.2 to 3.0% by weight of Mg, and 1 to 15% by weight of at least one of Fe, Mn and Ni, and the balance being Al containing inevitable impurities. Certain 5 to 30% by weight of AlSi-based alloy powder, 2 to 4% by weight of C, and 0.3% by weight or less of Si
And 95 to 70% by weight of cast iron powder containing 0.5 to 3.0% by weight of P and a balance of inevitable impurities. 2. The thermal spray material according to claim 1, wherein the AlSi-based alloy powder is a granulated powder obtained by granulating an atomized powder with an organic binder. 3. The method according to claim 1, wherein said Si is present in an amount of from 12 to 30% by weight.
One or two kinds of 0% by weight of Cu or 0.2 to 3.0% by weight of Mg, and 1 to 15% by weight of at least one of Fe, Mn and Ni, and the balance being Al containing inevitable impurities. Certain 5 to 30% by weight of AlSi-based alloy powder, 2 to 4% by weight of C, and 0.3% by weight or less of Si
And 95 to 70% by weight of cast iron powder containing 0.5 to 3.0% by weight of P and the balance containing unavoidable impurities. A structure formed on a moving surface. 4. The structure according to claim 3, wherein the AlSi-based alloy powder is a granulated powder obtained by granulating an atomized powder with an organic binder. 5. The structure according to claim 3, wherein the thermal spray coating is formed on at least one of an inner surface of a cylinder hole of the engine and a sliding surface of a piston sliding in the cylinder hole. body.