JPH0629473B2 - Sliding member - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sliding member composed of two members that abut against each other and slide relative to each other. More specifically, one member is an alumina fiber or an alumina-made member. The present invention relates to a sliding member that is made of a composite material having silica fibers as reinforcing fibers and the other member is made of steel.

2. Description of the Related Art Components and members of various machines are often required to partially have special mechanical characteristics. For example, in automobile engines, as the demand for engine performance increases, the members such as pistons have excellent specific strength and rigidity, and the sliding surface has excellent wear resistance. It is becoming more and more important for me to live there. As one means for improving the specific strength and wear resistance of such members, it has been tried to construct them with a composite material in which a metal such as an aluminum alloy is used as a matrix with various inorganic fibers or the like as a reinforcing material. ing.

As one of such fiber-reinforced metal composite materials, Japanese Patent Application No. 60-09487 filed by the same applicant as the present applicant.
In No. 7, a fiber-reinforced metal composite material having alumina fibers and alumina-silica fibers as reinforcing fibers and an aluminum alloy as a matrix has already been proposed. According to such fiber-reinforced metal composite materials, It is possible to improve the specific strength and wear resistance of the configured members,
In addition, it is possible to obtain a composite material that is less expensive than a composite material that uses alumina fibers or the like as reinforcing fibers.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, in a sliding member composed of two members that abut each other and relatively slide, if one member is made of the fiber-reinforced metal composite material as described above. However, depending on the material of the other member, the wear of the other member increases remarkably, and therefore it cannot be used as a sliding member that abuts each other and slides relatively.

The inventors of the present application have proposed a sliding member composed of two members that come into contact with each other and slide relative to each other, and one member is far superior to alumina fiber and alumina fiber having excellent strength and rigidity. In the sliding member which is composed of a fiber-reinforced metal composite material in which a metal such as an aluminum alloy is used as a matrix with the inexpensive alumina-silica fiber as a reinforcing fiber and the other member is made of steel, both of them are used. As a result of various experimental studies on what kind of combination of materials and properties is appropriate to minimize the amount of wear of the members, I have found that I must have.

The present invention is based on the knowledge obtained as a result of the above-described experimental research conducted by the inventors of the present application, and one member uses alumina fibers and alumina-silica fibers as reinforcing fibers and a metal such as aluminum alloy as a matrix. A sliding member made of a fiber-reinforced metal composite material, the other member being made of steel, and made of two members that abut against each other and slide relative to each other. It is an object of the present invention to provide a sliding member having improved wear characteristics on the sliding surface against.

Means for Solving the Problems According to the present invention, the above-described object is a sliding member including a first member and a second member that abut on each other and slide relative to each other. At least the sliding surface portion of one member with respect to the second member is 80 wt% or more of Al ₂ O ₃ ,
The balance is alumina fiber having a composition of substantially SiO ₂ , 35 to 65 wt% Al ₂ O ₃ , and 65 to 35 wt% SiO 2.
_A hybrid fiber composed of a substantially uniform mixture with an alumina-silica fiber having a composition of _{2 is} used as a reinforcing fiber, and is selected from the group consisting of aluminum, magnesium, copper, zinc, lead, tin and alloys containing these as the main components. Is used as a matrix metal, and the hybrid fiber is made of a composite material having a volume ratio of 1% or more, and at least the sliding surface portion of the second member with respect to the first member has a hardness Hv ( 10 kg) is made of steel of 200 or more, or a sliding member composed of a first member and a second member that abut on each other and slide abuttingly. A of the sliding surface portion of the first member with respect to at least the second member is 80 wt% or more.
l ₂ O ₃ , the balance being alumina fibers having a composition of substantially SiO ₂ , and 35 to 65 wt% Al ₂ O ₃ , 65 to 35 wt
% SiO ₂ , 10 wt% or less of CaO, MgO, Na
₂ O, Fe ₂ O ₃ , Cr ₂ O ₃ , ZrO ₂ , TiO ₂ ,
PbO, SnO ₂ , ZnO, MoO ₃ , NiO, K
₂ O, MnO ₂ , B ₂ O ₃ , V ₂ O ₅ , CuO, Co ₃
A reinforcing fiber is a hybrid fiber composed of a substantially uniform mixture of alumina-silica fiber having a composition of one or more metal oxides of O ₄ , and aluminum, magnesium, copper, zinc, lead, tin, and a main component thereof. A metal selected from the group consisting of alloys as a matrix metal, and is composed of a composite material in which the volume ratio of the hybrid fiber is 1% or more, and at least for the first member of the second member. The sliding surface has hardness Hv (10k
g) is achieved by a sliding member characterized in that it is composed of 200 or more steel.

EFFECTS AND EFFECTS OF THE INVENTION According to the present invention, in the composite material constituting the sliding surface portion of the first member, the alumina fiber having high strength and hardness and lower than that of silicon carbide fiber, and alumina A volume ratio of 1 due to a hybrid fiber consisting of a substantially homogeneous mixture with alumina-silica fibers, which is much cheaper than fibers.
%, The matrix metal is reinforced, and the total amount of non-fibrous particles contained in the aggregate of alumina-silica fibers and the content of non-fibrous particles having a particle size of 150 μ or more are 20 wt% or less and 7 wt% or less, respectively. Since the sliding surface of the second member is made of steel having a hardness Hv (10 kg) of 200 or more, the sliding member is composed of two members that abut against each other and slide relative to each other. , The sliding surfaces of both of these members with respect to each other are excellent in wear resistance, so that the amount of wear on the sliding surfaces of both of these members is minimized, and it is caused by the falling of particles. Abnormal wear can be avoided, and one of the members has a specific strength,
It is possible to obtain a sliding member which is excellent in mechanical properties such as rigidity and machinability and is inexpensive.

Alumina-silica fibers are generally classified into alumina fibers and alumina-silica fibers in terms of their composition and manufacturing method. The so-called alumina having an Al ₂ O ₃ content of 70 wt% or more and a SiO ₂ content of 30 wt% or less. The fiber is manufactured by fiberizing with a mixture of an organic viscous solution and an inorganic salt of aluminum, and oxidizing and roasting this at a high temperature. Such alumina fibers have an Al ₂ O ₃ content of especially 80.
It is stable in the case of wt% or more, and the reaction of the matrix metal with the molten metal and the accompanying deterioration of the fiber are small. Therefore, in the sliding member of the present invention, 80% by weight or more of Al ₂ O ₃ ,
The balance is alumina fibers having a composition of substantially SiO ₂ .

As described above, there are various types of alumina having various crystal structures, and among them, α-alumina is the most stable structure, and it is known that the hardness and elastic modulus are high. For example, in the case of commercially available alumina fiber as a heat-resistant material, the α-alumina content (the ratio of the weight of α-alumina to the weight of all alumina in the alumina fiber) is 60 wt% or more from the viewpoint of heat resistance and dimensional stability. There are many things. Judging from the properties of the α-alumina and the alumina fiber containing the α-alumina, the α-alumina content is not high in the composite material in which the alumina fiber containing the α-alumina is the reinforcing fiber and the aluminum alloy is the matrix metal. It is presumed that the mechanical strength, rigidity, wear resistance and the like of the composite material itself are improved as the content increases, but the amount of wear of the mating member increases and the workability decreases.

However, according to the results of the experimental research conducted by the inventors of the present application, contrary to the above-mentioned expectation, when the α-alumina content of the alumina fiber is in the range of 5 to 60 wt%, particularly 10 to 50 wt%, the composite material is It is noted that it is possible to improve the wear resistance and workability of the alloy, reduce the amount of wear of the mating member, and further that the above range is preferable for mechanical properties such as fatigue strength. It was Therefore, according to one particular feature of the invention, the alumina fiber has an α-alumina content of 5 to 60% by weight, preferably 10 to 5%.
It is set to 0 wt%.

On the other hand, the Al ₂ O ₃ content is 35 to 65 wt% and SiO ₂
The so-called alumina-silica fiber having a content of 35 to 65 wt% has a low melting point in the mixture of alumina and silica as compared with alumina, so that the mixture of alumina and silica is melted in an electric furnace or the like and melted. It is produced at a relatively low cost and in a large amount by making it into a fiber by a blowing method or a spinning method. Particularly, when the Al ₂ O ₃ content is 65 wt% or more and the SiO ₂ content is 35 wt% or less, the melting point of the mixture of alumina and silica becomes too high and the viscosity of the melt is low, while Al ₂ O ₃ When the content is 35 wt% or less and the SiO ₂ content is 65 wt% or more, it is difficult to apply these low-cost production methods because the appropriate viscosity required for blowing and spinning cannot be obtained.

Further, for the purpose of adjusting the melting point and viscosity of the mixture of alumina and silica and imparting special performance to the fiber, CaO, MgO, Na ₂ O, Fe are added to the mixture of alumina and silica.
₂ O ₃ , Cr ₂ O ₃ , ZrO ₂ , TiO ₂ , PbO, S
nO ₂ , ZnO, M0O ₃ , NiO, K ₂ O, Mn
Metal oxides such as O ₂ , B ₂ O ₃ , V ₂ O ₅ , CuO, and C0O ₄ may be added. According to the results of the experimental research conducted by the inventors of the present application, these components are 10 wt.
It has been recognized that it is preferable to be suppressed to less than or equal to%.
Further, in the alumina-silica fiber, the higher the alumina content is, the less the deterioration due to the reaction of the matrix metal with the molten metal and the decrease in the strength of the fiber due to the deterioration. Therefore, the composition of the alumina-silica fiber in the sliding member of the present invention is 35 to 65 wt% Al ₂ O ₃ , 65 to 35 wt% Si.
O ₂ , or 35 to 65 wt% Al ₂ O ₃ , 65 to 35 wt%
SiO ₂ , 10 wt% or less of CaO, MgO, Na ₂ O,
Fe ₂ O ₃ , Cr ₂ O ₃ , ZrO ₂ , TiO ₂ , Pb
O, SnO ₂ , ZnO, MoO ₃ , NiO, K ₂ O, M
It is set to one or more metal oxides of nO ₂ , B ₂ O ₃ , V ₂ O ₅ , CuO, and Co ₃ O ₄ , and preferably 40 to 65.
wt% Al ₂ O ₃ , 40-35 wt% SiO ₂ , or 40-
65 wt% Al ₂ O ₃ , 40-35 wt% SiO ₂ , 10 wt
% Or less of CaO, MgO, Na ₂ O, Fe ₂ O ₃ , Cr
₂ O ₃ , ZrO ₂ , TiO ₂ , PbO, SnO ₂ , Zn
O, MoO ₃ , NiO, K ₂ O, MnO ₂ , B ₂ O ₃ ,
It is set to one or more metal oxides of V ₂ O ₅ , CuO, and Co ₃ O ₄ .

Further, in the production of alumina-silica fibers by the blowing method or the spinning method, a large amount of non-fibrous particles are unavoidably produced at the same time as the fibers, so that a relatively large amount (50 wt. %) Non-fiberized particles are included. According to the results of the experimental studies conducted by the inventors of the present application, such non-fibrous particles deteriorate the mechanical properties and processability of the composite material and cause the strength of the composite material to decrease, and further, the particles fall off. Also causes a problem such as abnormal wear to the mating material, and such a problem is remarkable in the case of particles having a particle size of more than 150 μm.

When the total amount of non-fibrous particles and the content of non-fibrous particles having a particle size of 150 μ or more are reduced to 22 wt% and 14 wt%, respectively, compared to the case where the total amount of non-fibrous particles is about 50 wt% The machinability of the material is significantly improved, for example, the wear amount of the cutting tool, which is a cutting tool, is reduced to about half. When it is reduced to 17 wt% and 7 wt%, the wear amount of the cutting tool is 22 wt% and 14 wt% for the total amount of non-fibrous particles and the content of non-fibrous particles having a particle size of 150% or more, respectively.
If it is (hereinafter referred to as "comparison standard"), the wear amount is about 7
Reduced to 0% and the total amount of non-fibrous particles and particle size 15
The content of non-fibrous particles of 0μ or more is 10wt%,
When set to 2 wt%, the wear amount of the cutting tool is reduced to about 25% of the wear amount in the case of the comparison standard, and the total amount of non-fibrous particles and the content of non-fibrous particles with a particle size of 150 μm or more are respectively When set to 7% by weight and 1% by weight, the wear amount of the cutting tool is reduced to about 20% of the wear amount in the comparison standard.

When the total amount of non-fibrous particles and the content of non-fibrous particles having a particle size of 150 μ or more are reduced to 17 wt% and 7 wt%, respectively, the abnormality of the second member, that is, the composite material that wears and slides against the other material Abrasion is greatly reduced, scuffing is completely eliminated, and the total amount of non-fiberized particles and the particle size are 15
The content of non-fibrous particles of 0μ or more is 10wt%,
If it is set to 2 wt%, abnormal wear of the mating material will be eliminated.

Therefore, according to one particular feature of the invention, the alumina-
The total amount of non-fibrous particles contained in the aggregate of silica fibers is 17 wt% or less, preferably 10 wt%, more preferably 7 wt%.
The content of the non-fibrous particles having a particle size of 150 μm or more is suppressed to 7 wt% or less, preferably 2 wt% or less, and more preferably 1 wt% or less.

According to the results of the experimental research conducted by the inventors of the present application,
A composite material in which a hybrid fiber made of a substantially uniform mixture of alumina fiber and alumina-silica fiber is used as a reinforcing fiber, and aluminum, magnesium, copper, zinc, lead, tin and an alloy containing them as a main component are used as a matrix metal. In this case, the abrasion resistance of the composite material is remarkably improved even if the volume ratio of the hybrid fiber is about 1%. Therefore, in the sliding member of the present invention, the volume ratio of the hybrid fiber is 1% or more, particularly 3% or more, and further 10% or more.

According to the results of the experimental research conducted by the inventors of the present application,
The effect of improving the wear resistance of the composite material by hybridizing the alumina fiber and the alumina-silica fiber in combination is, as will be described in detail later in the case where the mating material is steel, the effect of improving the wear resistance of the alumina fiber in the hybrid fiber. Volume ratio is 5
It is remarkable in the case of -80%, especially in the case of 10-70%. The wear amount of the composite material and the mating material that rubs against the composite material is 20 to 9 when the volume ratio of the alumina fiber in the hybrid fiber is
It becomes a small value in the range of 0%, especially in the range of 40 to 80%. Therefore, according to another detailed feature of the present invention,
The volume ratio of the alumina fiber in the hybrid fiber is 20 to 9
It is set to 0%, preferably 40 to 80%.

Further, according to the results of the experimental research conducted by the present inventors, when the counterpart material is steel and the volume ratio of the alumina fiber in the hybrid fiber is within the above-described preferable range of 5 to 80%, the hybrid fiber is It is difficult to secure sufficient abrasion resistance of the composite material unless the volume ratio of the hybrid fiber is 1%, particularly 3% or more, and the volume ratio of the hybrid fiber is 25%, especially 3%.
If it exceeds 0%, the amount of wear of the mating material increases. Therefore, according to yet another detailed feature of the present invention, the volume ratio of alumina fibers in the hybrid fibers is 20-90%, especially 4%.
0 to 80%, and the volume ratio of the hybrid fiber is 1 to 30
%, Preferably 3 to 25%.

According to the results of the experimental research conducted by the inventors of the present application,
Regardless of the volume ratio of the alumina fibers in the hybrid fibers, the volume ratio of the alumina-silica fibers is 20%, especially 2
If it exceeds 2.5%, the strength and wear resistance of the composite material deteriorate. Therefore, according to another further detailed feature of the present invention, the volume ratio of the alumina-silica fiber is 22.5% regardless of the volume ratio of the alumina fiber in the hybrid fiber.
The following is preferably set to 20% or less.

As a constituent material of the first member, in order to obtain a composite material having excellent mechanical properties such as strength and wear resistance, and further excellent friction and wear characteristics with respect to the mating material, the alumina fiber is According to the results of the experimental studies carried out, in the case of short fibers an average fiber diameter of 0.5-30 μ and 1 μ-50
mm average fiber length, and in the case of long fibers, it is preferable to have a fiber diameter of 5 to 30 μm. On the other hand, the alumina-silica fiber has a relatively low viscosity in the molten state of its constituent material, the alumina-silica fiber, and the alumina-silica fiber is relatively fragile as compared with the alumina fiber and the like. The fibers are manufactured in the form of short fibers (discontinuous fibers) having a fiber diameter of 0.5 to 10 μm and a fiber length of 1 μm to about 5 cm. Therefore, considering the availability of inexpensive alumina-silica fibers, the average fiber diameter of the alumina-silica fibers used in the composite material of the present invention is about 1 to 7 µ, and the average fiber length is 10 µ to 0. It is preferably about 5 cm. Considering the manufacturing method of the composite material, the average fiber length of the alumina-silica fibers is about 10 μm to 0.5 cm in the pressure casting method, and 10 μm in the powder metallurgy method.
It is preferably about 3 mm.

Further, alloys as matrix metals of the composite material constituting the first member in the present invention are AC4C, AC8A, AC8B, ADC10, ADC1 according to JIS standards, respectively.
Aluminum alloys such as 2, MDC1-A, MC2, M
Magnesium alloys such as C7 and MC8, KJ3, KJ
4, copper alloys such as PBC2A, HBsBE1, ZDC
1, zinc alloys such as ZDC2, lead alloys such as WJ8 and WJ10, and tin alloys such as WJ1 and WJ2.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

Example 1 Alumina fibers manufactured by ICI Co., Ltd. (trade name "SAFIL") were subjected to a particle-removing treatment so that the total amount of non-fiberized particles contained in the fiber assembly and the content of non-fiberized particles having a particle size of 150 μm or more were measured. Alumina fibers as shown in Table 1 below were prepared by adjusting the respective amounts to 0.1 wt% and 0.02 wt%.

Further, the total amount of non-fibrous particles contained in the fiber assembly was obtained by subjecting alumina-silica fibers (trade name "Kawool") manufactured by Isolite Babcock Fireproof Co., Ltd. shown in Table 2 below to a particle-removing treatment. And the content of non-fibrous particles having a particle size of 150 μ or more are 0.5 wt% and 0.1 wt%, respectively.
And

Then, the above-mentioned alumina fiber and alumina-silica fiber are dispersed in colloidal silica in various volume ratios, and the alumina fiber and alumina-silica fiber are uniformly mixed by stirring the colloidal silica, and thus the alumina fiber and alumina Forming a 80 × 80 × 20 mm fibrous form 1 as shown in FIG. 1 from colloidal silica in which silica fibers are uniformly dispersed by a vacuum forming method, and then calcining it at 600 ° C. The individual alumina fibers 2 and the alumina-silica fibers 2a were bonded by silica. In this case, as shown in FIG. 1, the individual alumina fibers 2 and the alumina-silica fibers 2 are
The a was randomly oriented in the xy plane, and was oriented in a stacked state in the z direction.

Next, as shown in FIG. 2, the fiber molded body 1 is placed in the mold cavity 4 of the mold 3, and an aluminum alloy (JIS standard A
C8A) molten metal 5 is poured, and the molten metal is pressurized to a pressure of 1500 kg / cm ² by a plunger 6 fitted in the mold 3,
The pressurized state is maintained until the molten metal 5 is completely solidified, and as shown in FIG. 3, the outer diameter is 110 mm and the height is 5 mm.
The composite material 1 'silica fiber reinforcing fibers and to the aluminum alloy matrix - cast a 0mm of cylindrical solidified body 7, further該凝solid to a heat treatment T _6, the solidified body of alumina fibers and alumina A block test piece for cutting out, which is cut out and has a size of 16 × 6 × 10 mm larger than those composite materials and has one surface (16 × 10 mm, perpendicular to the xy plane of FIG. 1) as a test surface. A _{0 to} A ₁₀₀ were made by machining. Each of the above-mentioned composite materials A _{0 to} A
The volume ratio of ₁₀₀ alumina fibers and alumina-silica fibers, the total volume ratio of the reinforcing fibers, and the volume ratio of the alumina fibers to the total amount of the reinforcing fibers were as shown in Table 3 below.

For comparison purposes, aluminum alloy (JIS standard AC
A block test piece A having the same dimensions and subjected to the heat treatment T ₆ consisting of only 8A) was prepared.

Next, each block test piece is set in sequence on the friction wear tester, and brought into contact with the outer peripheral surface of a cylindrical test piece made of a bearing steel (JIS standard SUJ2, Hv = 810) having an outer diameter of 35 mm, an inner diameter of 30 mm and a width of 10 mm, which is a mating member. , Normal temperature (20 ° C) lubricating oil (castle motor oil 5W)
-30) was supplied, a wear test was conducted by rotating the cylindrical test piece for 1 hour at a contact surface pressure of 20 kg / mm ² and a sliding speed of 0.3 m / sec. The results of this wear test are shown in FIG. In FIG. 4, the upper half represents the amount of wear of the block test piece (wear depth μ), and the lower half represents the amount of wear of the mating cylindrical test piece (wear loss mg). The horizontal axis represents the volume ratio (%) of the alumina fibers to the total amount of the reinforcing fibers.

From FIG. 4, the wear amount of the block test piece made of the aluminum alloy reinforced with the alumina fiber and the alumina-silica fiber is much smaller than the wear amount of the block test piece A made of only the aluminum alloy. I understand. Further, the wear amount of the block test piece decreases as the volume ratio of the alumina fibers increases, particularly in the range where the volume ratio of the alumina fibers is 0 to 60%, and the volume ratio of the alumina fibers is 80% or more. It can be seen that the value is substantially constant. Also, it can be seen that the wear amount of the cylindrical test piece increases slightly linearly as the volume ratio of the alumina fiber increases. Therefore, in order to reduce the amount of wear of both the block test piece and the cylindrical test piece when steel is used as the counterpart member, the volume ratio of the alumina fiber is preferably 20 to 90%, particularly preferably 40 to 80%. I understand.

Composite materials are generally said to be designable materials, and it is considered that the composite rule holds. Assuming that the volume ratio of the alumina fibers to the total amount of the reinforcing fibers is X%, the wear amount of the block test piece is 32μ when X = 0%,
= 100%, the wear amount of the block test piece is 10
Therefore, if the compound law is satisfied with respect to the wear amount of the composite material, the wear amount of the block test piece in the range of X = 0 to 100% is Y = (32-10) X / 100 + 10. Presumed to be.

The phantom line in FIG. 4 represents the estimated value of the wear amount of the block test piece based on such a composite rule. In addition, FIG. 5 shows the difference ΔY between the estimated value and the actually measured value of the wear amount of the block test piece based on the composite rule with the volume ratio X of alumina fibers to the total amount of reinforcing fibers as the horizontal axis.

From FIGS. 4 and 5, the wear amount of the block test piece is smaller than the estimated value regardless of the value of the volume ratio X of the alumina fiber,
Especially in the range of 5 to 80% of the volume ratio X, further 10
In the range of .about.70%, it is significantly lower than the estimated value, which is nothing but the effect obtained by hybridizing the alumina fiber and the alumina-silica fiber with respect to the wear amount of the composite material.

Example 2 Alumina fibers manufactured by ICI Co., Ltd. (trade name “SAFIL”) shown in Table 4 below and alumina-silica fibers manufactured by Isolite Babcock Fireproof Co., Ltd. shown in Table 5 below (trade name “ 80 × 80 consisting of various volumes of alumina fibers and alumina-silica fibers uniformly mixed with each other by a vacuum forming method in the same manner as in Example 1 above using A fiber molding of × 20 mm was formed. Then, a hybrid fiber composed of alumina fiber and alumina-silica fiber was reinforced by a high pressure casting method (melt temperature 1100 ° C., pressure green to the melt of 1000 kg / cm ² ) in the same manner as in Example 1 described above. A composite material using a copper alloy (Cu-10 wt% Sn) as a matrix metal was manufactured. Next, the size of each composite material is 16 × 6 × 10 mm, and one side (16 × 1
Block test pieces B _{0 to} B ₁₀₀ having a test surface of ₀ mm and perpendicular to the xy plane in FIG. 1) were prepared by machining. The volume ratios of the alumina fibers and the alumina-silica fibers of the composite materials B _{0 to} B ₁₀₀ described above, the total volume ratio of the reinforcing fibers, and the volume ratio of the alumina fibers to the total amount of the reinforcing fibers are shown in Table 6 below. It was as it was.

For the purpose of comparison, a block test piece B of the same size made of only a copper alloy (Cu-10 wt% Sn) was prepared.

Next, for each block test piece, bearing copper (JIS standard SUJ2, Hv = 8) was used under the same conditions as in the case of Example 2 described above.
A wear test was performed using a cylindrical test piece manufactured in 10) as a mating member. The results of this wear test are shown in FIG. In Fig. 6, the upper half shows the amount of wear of the block test piece (wear mark depth μ).
The lower half represents the amount of wear (wear loss mg) of the cylindrical test piece that is the mating member, and the horizontal axis represents the volume ratio (%) of alumina fibers to the total amount of reinforcing fibers. The line represents the estimated value of the wear amount of the block test piece based on the complex rule.

From FIG. 6, the wear amount of the block test piece made of the copper alloy reinforced with the alumina fiber and the alumina-silica fiber is much smaller than the wear amount of the block test piece B made of only the copper alloy. I understand. Also in this example, the amount of wear of the block test piece decreases as the volume ratio of the alumina fibers increases, and particularly, the volume ratio of the alumina fibers is 0 to 0.
It can be seen that the value decreases relatively in the range of 40%, and becomes substantially constant in the region where the volume ratio of the amina fibers is 60% or more. Further, it is understood that the wear amount of the cylindrical test piece increases only slightly as the volume ratio of the alumina fiber increases within a relatively small value range. Therefore, even when the matrix metal is a copper alloy, in order to reduce the wear amount of both the block test piece and the cylindrical test piece in the case of using steel as the counterpart member, the volume ratio of the alumina fiber is 20 to 90.
It will be seen that it is preferably%, especially 40-80%.

Further, FIG. 7 is a graph similar to FIG. 5, in which the estimated value and the measured value ΔY of the wear amount of the block test piece based on the composite rule are shown with the volume ratio X of the alumina fibers to the total amount of the reinforcing fibers as the horizontal axis. From FIGS. 6 and 7, the wear amount of the block test piece is smaller than the estimated value regardless of the value of the volume ratio X of the alumina fiber due to the effect of hybridization, and particularly, the volume ratio X is in the range of 10 to 70%. In the range of 20 to 60%, the value is significantly lower than the estimated value.

Example 3 α-alumina content is 4 wt%, 34 wt%, 48 wt%, 10
Three types of alumina fibers (trade name "Safir") manufactured by ICI Co., Ltd. having the same specifications as the alumina fibers shown in Table 1 above, except for 0 wt%, are shown in Table 2 above. Alumina-silica fibers of various volume ratios uniformly mixed with each other by the vacuum forming method in the same manner as in the above-mentioned Example 1 using the alumina-silica fibers thus prepared. A 80 × 80 × 20 mm fiber former was formed. Then, a high-pressure casting method (melt temperature 730 ° C., pressure applied to the melt 15) similar to that of the above-described Example 1 was used.
00kg / cm ²⁾ in the aluminum alloy (JIS standard AC
8A) as a matrix metal, the total volume ratio of the reinforcing fibers is 7.5%, and the volume ratio of the alumina fibers to the total amount of the reinforcing fibers is 0%, 20%, 60%, 100%.
Manufacture different types of composite materials and heat treat T ₆ for each composite material
Was applied.

Next, a block test piece for a friction wear test was formed from each composite material, and a cylindrical test piece made of bearing steel (JIS standard SUJ2, Hv = 810) was used as a mating member under the same conditions as in Example 1 above. A wear test was performed. The results of this wear test are shown in FIG. In FIG. 8, the upper half shows the amount of wear of the block test piece (wear depth μ), and the lower half shows the amount of wear of the cylindrical test piece which is the mating member (wear loss mg). The horizontal axis represents the volume ratio (%) of the alumina fibers to the total amount of the reinforcing fibers.

From FIG. 8, in order to reduce the amount of wear of both the block test piece and the cylindrical test piece when steel is used as the counterpart member,
The α-alumina content of the alumina fiber is preferably a relatively small value such as around 34%, and when the α-alumina content of the alumina fiber is a relatively small value such as 34%, the total amount of the reinforcing fibers is It is understood that the wear amount of the cylindrical test piece can be maintained at a small value even in the region where the volume ratio of the alumina fiber to the is relatively high.

Example 4 α-alumina content is 0 wt%, 4 wt%, 16 wt%, 25 wt%
%, 34 wt%, 48 wt%, 62 wt%, 83 wt%, 100
Using the alumina fiber having the same specifications as the alumina fiber shown in Table 1 above, except for wt%, and the alumina-silica fiber shown in Table 2 above, the above-mentioned operation was performed. Under the same procedure and under the same conditions as in Example 1, alumina fiber and alumina-silica fiber are used as reinforcing fibers, aluminum alloy (JIS standard AC8A) is used as matrix metal, and the total volume ratio of reinforcing fibers is Is 8%, and the volume ratio of alumina fibers to the total amount of reinforcing fibers is 5
0% composite materials were produced and each composite material was heat treated T ₆ .

Next, a block test piece for a friction wear test was formed from each composite material, and a cylindrical test piece made of bearing steel (JIS standard SUJ2, Hv = 810) was used as a mating member under the same conditions as in Example 1 above. A wear test was performed. The results of this wear test are shown in FIG. In FIG. 9, the upper half represents the amount of wear of the block test piece (wear depth μ), and the lower half represents the amount of wear of the cylindrical test piece (wear loss mg). Represents the α-alumina content (wt%) of the alumina fiber.

From FIG. 9, the wear amount of the block test piece is small when the α-alumina content of the alumina fiber is in the range of 5 to 60 wt% or 70 wt% or more, particularly in the range of 10 to 50 wt% or 75 wt% or more. The amount of wear of the test piece is small when the α-alumina content is 5 to 60 wt%, especially 10 to 50 wt%, and therefore the wear of both the block test piece and the cylindrical test piece is reduced when steel is used as the counterpart member. In order to do so, the α-alumina content of the alumina fiber is 5-60 wt%, especially 1
It is understood that it is preferably 0 to 50 wt%.

Example 5 An alumina fiber having the same specifications as the alumina fiber shown in Table 1 above and an alumina-silica fiber shown in Table 2 above were used except that the α-alumina content was 8%. do it,
Under the same procedure and under the same conditions as in the case of Example 1 described above, a hybrid fiber composed of alumina fiber and alumina-silica fiber was used as a reinforcing fiber, and an aluminum alloy (JIS
Standard AC8A) is used as the matrix metal, the total volume ratio of the reinforcing fibers is 5.6%, 15%, 20%, and the volume ratio of the alumina fibers to the total amount of the reinforcing fibers is 0%, 20%, 6%.
Twelve kinds of composite materials of 0% and 100% were manufactured, and each composite material was subjected to heat treatment T ₆ .

Next, a block test piece for friction and wear test is formed from each composite material, and a cylindrical test piece made of bearing steel (JIS standard SUJ2, Hv = 810) is used as a mating member under the same conditions as in the case of Example 1 described above. A wear test was performed. The results of this wear test are shown in FIG. In FIG. 10, the upper half represents the wear amount of the block test piece (wear depth μ), and the lower half represents the wear amount of the cylindrical test piece (wear loss mg). Represents the volume ratio (%) of alumina fibers to the total amount of reinforcing fibers.

From FIG. 10, it can be seen that the wear amount of the block test piece becomes smaller as the total volume ratio of the reinforcing fibers becomes higher, while the wear amount of the cylindrical test piece increases as the total volume ratio of the reinforcing fiber becomes higher. Understand.

Example 6 Using the alumina fiber and the alumina-silica fiber used in the above-mentioned Example 5, the alumina fiber and the alumina-silica fiber were used under the same procedure and under the same conditions as in the above-mentioned Example 1. A hybrid fiber consisting of a reinforced fiber, an aluminum alloy (JIS standard AC8A) as a matrix metal, the volume ratio of the alumina fiber to the total amount of the reinforced fiber is 50%, the total volume ratio of the reinforced fiber is 1%,
10%, 20%, 30%, to produce a composite material that is 35%, was heat-treated _{T 6} for each composite. Next, a block test piece for a friction and wear test was formed from each composite material. For comparison purposes, aluminum alloy (JIS standard A
A block test piece of the same size, which was made of only C8A) and was subjected to heat treatment T _6, was formed.

Next, for each block test piece, bearing steel (JIS standard SUJ2, Hv =
A wear test was performed using a cylindrical test piece made of 810) as a counterpart member. The results of this abrasion test are shown in FIG. The eleventh
In the figure, the upper half represents the wear amount (wear scar depth μ) of the block test piece, the lower half represents the wear amount (wear loss mg) of the cylindrical test piece, and the horizontal axis represents the reinforcing fiber. Represents the total volume ratio (%).

From FIG. 11, the wear amount of the block test piece is small when the total volume ratio of the reinforcing fiber is 1% or more, particularly 3% or more, and further 10% or more, and the wear amount of the cylindrical test piece is the total volume of the reinforcing fiber. It can be seen that the rate sharply increases when the rate exceeds 25%, particularly 30%. Therefore, in order to reduce the wear of both hands of the block test piece and the cylindrical test piece when steel is used as the counterpart member, the total volume ratio of the reinforcing fibers is 1 to 30%, particularly 3 to 25%.
It is understood that is preferable.

Example 7 Using the alumina fiber and the alumina-silica fiber used in the above-mentioned Example 1, a fiber molded body was formed in the same manner as in the above-mentioned Example 1, and the fiber molded body was reinforced. Material, magnesium alloy (JIS standard MDC1-A) as a matrix metal, the total volume ratio of the reinforcing fibers is 10%, and the volume ratio of the alumina fibers to the total amount of the reinforcing fibers is 50%. (The temperature of the hot water is 690 ° C., the pressure applied to the molten metal is 1500 kg / cm ² ), and the size of the composite material is 16 × 6 × 10 mm. One surface (16 × 10 mm, x− in FIG. 1) A block test piece C ₁ having a test surface (perpendicular to the y-plane) was prepared.

Further, using the alumina fiber and the alumina-silica fiber used in the above-mentioned Example 1, a fiber molded body was formed in the same manner as in the case of the above-mentioned Example 1, and the fiber molded body was reinforced. And zinc alloy (JIS standard ZDC1), lead alloy (JIS standard WJ8), tin alloy (JIS standard WJ2)
Is the matrix metal, and the total volume ratio of the reinforcing fibers is 10%.
And the composite material in which the volume ratio of the alumina fibers to the total amount of the reinforcing fibers is 50% is subjected to a high pressure casting method (each with a hot water temperature of 5
00 ℃, 410 ℃, 330 ℃, pressure 50 to the molten metal
0 kg / cm ² ) and the size of each composite material is 16
Block test pieces D _{1 to} F ₁ having a size of 6 × 10 mm and one surface (16 × 10 mm, perpendicular to the xy plane of FIG. 1) as a test surface were prepared. For comparison purposes, magnesium alloy (JIS standard MDC1-A), zinc alloy (JI
Block test pieces C _{0 to} F ₀ having the same dimensions and made of only S standard ZDC1), lead alloy (JIS standard WJ8), and tin alloy JIS standard WJ2) were prepared.

Next, the block test pieces C ₀ and C ₁ were set under the same conditions as in the above-mentioned Example 1, and the other block test pieces were set to a surface pressure of 5 kg / cm ² and a test time of 30 minutes, respectively. Bearing steel (JIS standard SUJ2, Hv = 81) under the same conditions as in Example 1 except for
A wear test was conducted using a cylindrical test piece manufactured in 0) as a counterpart member. The results of this wear test are shown in Table 7 below. In Table 7, the wear amount ratio of the block test pieces is the wear amount of the block test pieces C _{0 to} F ₀ (wear mark depth mm) with respect to the wear amount of the block test pieces C _{1 to} F ₁ (wear mark). Depth mm), and the amount of wear of the cylindrical test piece means the amount of wear of the cylindrical test piece rubbed with the block test pieces C _{1 to} F ₁ (wear loss mg). The wear amount of the cylindrical test piece rubbed with the block test pieces C _{0 to} F ₀ is so small that it cannot be measured.
It was substantially zero.

From Table 7, if magnesium alloys, zinc alloys, lead alloys, and tin alloys are reinforced with a hybrid fiber composed of alumina fibers and alumina-silica fibers, those alloys are not substantially increased in wear amount of the mating materials. It can be seen that the amount of wear of the can be significantly reduced. From the results of this example, when the matrix metal is a magnesium alloy, a tin alloy, a lead alloy, or a zinc alloy and the counterpart material is steel, the volume ratio of the hybrid fiber, the total amount of non-fiberized particles, and the particle size of 15
When the content of non-fiberized particles of 0 μ or more and the α-alumina content of alumina fibers are within the range of the present invention, the wear amount of both the block test piece and the cylindrical test piece may be a very small value. I understand.

A wear test similar to the wear tests of Examples 1 to 7 described above was performed on a chromium steel (JIS standard SCr420) and a stainless steel (J
When the IS standard SUS340) was used as the mating material under the same conditions as those of the examples, the same results as those of the corresponding examples were obtained.

Example 8 Next, a specific example of the sliding member according to the present invention applied to the combination of the engine pist and the piston ring will be described.

FIG. 12 is a schematic longitudinal sectional view showing the above embodiment, FIG.
FIG. 14 is an enlarged partial vertical sectional view showing an essential part thereof, and FIG. 14 is an enlarged partial vertical sectional view showing a piston ring (top ring). In these figures, 11 is a piston, aluminum alloy (JIS standard AC8A)
It is composed of. The outer peripheral surface 12 of the piston 11 has two ring grooves 16 for receiving the compression rings 14 and 15 which prevent combustion gas from leaking from the combustion chamber of the engine through the space between the piston 11 and the cylinder wall surface of the cylinder block 13. And 17, and a ring groove 19 for receiving an oil ring 18 for scraping off excess oil is formed.

In the illustrated embodiment, the side outer peripheral surface 12 of the piston 11 is shown.
The portion from the piston head 20 along the lower part of the top surface groove 16 to the lower surface 21 of the top ring groove 16 has an average fiber diameter of 3.2 μ, an average fiber length of 2.5 mm, and an alumina fiber having an α-alumina content rate of 30 wt% (95 wt% Al ₂ O ₃ , 5 wt% SiO ₂ ) and alumina-silica fibers (55 wt% Al ₂ O ₃ , 45 wt% siO ₂ ) having an average fiber diameter of 2.8 μ and an average fiber length of 3.0 mm are uniformly mixed at various volume ratios. Mixed, with a bulk density of 0.18 g / cm
^A composite in which a fiber molded body that is substantially randomly oriented at ³ (corresponding to a volume ratio of 6%) is used as a reinforcing material, and an aluminum alloy (JIS standard AC8A) that constitutes the other portion of the piston 11 is used as a matrix. It is composed of the material 22.
This composite material 22 defines the wall surface of the top ring groove 16 that receives the top ring 14, and also defines a part of the top rad 23 and the second land 24 at the portion exposed on the side outer peripheral surface 12 of the pist. ing.

In this piston, the fiber molded body is placed on the bottom wall of the mold cavity of the mold for casting it, the molten aluminum alloy is poured, and the molten metal is injected by the plunger that fits liquid-tightly into the mold. It may be manufactured by solidifying while applying pressure to form a piston preformed body, subjecting it to heat treatment T ₆ , processing it to a predetermined size, and further forming ring grooves 16, 17, and 19.

The top ring 14 that is in contact with the piston 11 and slides relative to each other as described above is made of bearing steel (JIS standard SUJ).
2, Hv = 720). In particular, the illustrated embodiment is configured as a 7 ° keystone ring,
The molybdenum sprayed layer 25 is formed on the sliding surface portion of the cylinder block 13 with respect to the cylinder wall surface.

The piston and the piston ring configured as described above have four
A cylinder 4-cycle diesel engine was incorporated and a wear test was conducted under the test conditions shown in Table 8 below.

As a result of this abrasion test, the amount of abrasion of the upper surface 26 and the lower surface 21 of the top ring groove 16 is 20 wt% of the volume ratio of the alumina fibers.
In the above range, it is 3.5 μ or less, and in particular, in the case where the volume ratio of the alumina fibers is 50 to 80 wt%, it is a small value of 3.2 μ, and the wear amount of the lower surface 27 of the top ring 14 is small. The volume ratio of the alumina fiber is 3.0 μ or less in the range of 0 to 80 wt%, but the volume ratio of the alumina bed is 8 μm.
It was found that the value was as high as 6μ in the range of 0 wt% or more. From this test result, according to the combination of the piston and the piston ring according to the above-mentioned embodiment, compared with the combination of the piston made of the aluminum alloy (JIS standard AC8A) and the Pistonton ring made of the cast iron which are currently widely used. It can be seen that the wear amount of the ring groove is reduced to about 1/8, and the wear amount of the upper and lower surfaces of the piston ring is reduced to about 1/2.

In the above, the present invention has been described in detail with respect to various examples in relation to a part of the experimental studies conducted by the inventors of the present application, but the present invention is not limited to these examples. Rather, it will be apparent to those skilled in the art that various other embodiments are possible within the scope of the invention.

[Brief description of drawings]

FIG. 1 is a perspective view showing a fiber orientation state of a fiber molded body made of alumina fibers and alumina-silica fibers, FIG. 2 is a schematic view showing a manufacturing process of a composite material by a high pressure casting method, and FIG. 3 is FIG. Fig. 4 is a perspective view showing a solidified body formed by high pressure casting of Fig. 4, and Fig. 4 is a view showing wear carried out between a bearing steel and a composite material containing alumina fibers and alumina-silica fibers as reinforcing fibers and aluminum alloy as a matrix metal. The test result is a graph showing the volume ratio of alumina fibers to the total amount of reinforcing fibers on the horizontal axis, and FIG. 5 is a measured value based on the compound law of the composite material based on the data shown in FIG. 4 and an actual measurement. A graph showing the difference from the value on the horizontal axis of the volume ratio of alumina fibers to the total amount of reinforcing fibers, and FIG. 6 shows alumina fibers and alumina-silica fibers as reinforcing fibers and a copper alloy as a matrix metal. A graph showing the results of the wear test performed between the composite material and the bearing steel in which the volume ratio of the alumina fibers to the total amount of the reinforcing fibers is the total amount on the horizontal axis, and FIG. 7 is the data shown in FIG. A graph showing the difference between the estimated value and the actual measured value based on the composite rule of the wear amount of the composite material on the horizontal axis of the volume ratio of the alumina fiber to the total amount of the reinforcing fiber. The results of the wear test conducted between the set material of the composite material including the aluminum alloy having the alumina fiber and the alumina-silica fiber as the reinforcing fiber as the matrix metal and the bearing steel are the volume of the alumina fiber with respect to the total amount of the reinforcing fiber. Fig. 9 is a graph showing the ratio on the horizontal axis. Fig. 9 shows a matrix made of aluminum alloy with alumina fibers and alumina-silica fibers having various values of α-alumina content set as reinforcing fibers. FIG. 10 is a graph showing the results of the wear test performed between the composite material made of metal and the bearing steel with the α-alumina content of alumina fibers as the abscissa, and FIG. 10 shows reinforcing fibers of alumina fibers and alumina-silica fibers. The result of the wear test conducted between the bearing steel and the three kinds of composite materials in which the aluminum alloy is used as a matrix metal and the total volume ratio of the reinforcing fibers is different, and the volume ratio of the alumina fibers to the total amount of the reinforcing fibers is shown as FIG. 11 shows a graph for the axis between a composite material in which alumina fibers and alumina-silica fibers are reinforcing fibers, aluminum alloy is a matrix metal, and the total volume ratio of the reinforcing fibers is set to various values and the bearing steel. Graph showing the results of the abrasion test performed with the total volume fraction of reinforcing fibers as the horizontal axis, No. 12
FIG. 13 is a schematic sectional view showing a concrete embodiment of a sliding member according to the present invention applied to a combination of an engine piston and a piston, and FIG. 13 is a main part of the embodiment shown in FIG. FIG. 14 is an enlarged partial vertical sectional view showing a piston ring (top ring) in an enlarged manner. 1 ... Fiber molded body, 1 '... Composite material, 2 ... Alumina fiber, 2a ... Alumina-silica fiber, 3 ... Mold, 4
…… Mold cavity, 5 …… Molten metal, 6 …… Plunger, 7 …… Solid body, 11 …… Piston, 12 …… Side outer peripheral surface, 13 …… Cylinder block, 14, 15 …… Compression ring, 16, 17 ... Ring groove, 18 ...
… Oil ring, 19 …… Ring groove, 20 …… Piston head, 21 …… Lower surface, 22 …… Composite material, 23 …… Top land, 24 …… Second land, 25 …… Molybdenum sprayed layer, 26 …… Upper surface , 27 …… Bottom surface

Continuation of the front page (72) Inventor Tadashi Donomoto 1 Toyota-cho, Toyota-shi, Aichi Prefecture Toyota Motor Corporation (56) References JP-A-59-74247 (JP, A)

Claims (12)

[Claims] 1. A sliding member comprising a first member and a second member which are in contact with each other and slide relatively to each other, wherein at least a sliding surface portion of the first member with respect to the second member is provided. Alumina fiber having a composition of 80 wt% or more of Al ₂ O ₃ , the balance being substantially SiO ₂ , and 35 to 65 wt% Al ₂ O
₃ , a hybrid fiber made of a substantially uniform mixture with an alumina-silica fiber having a composition of 65-35 wt% SiO _{2 is} used as a reinforcing fiber, and aluminum, magnesium, copper, zinc, lead, tin and the main components thereof are used. Which is a metal selected from the group consisting of alloys as a matrix metal, and is composed of a composite material in which the volume ratio of the hybrid fiber is 1% or more, and the second member slides on at least the first member. The hardness of the moving surface is Hv (10k
g) is made of steel of 200 or more, a sliding member characterized by the above-mentioned. 2. The sliding member according to claim 1, wherein the alumina fiber has an α-alumina content of 5 to 60 wt.
% Is a sliding member. 3. The sliding member according to claim 1 or 2, wherein the volume ratio of the alumina fiber in the hybrid fiber is 20 to 90%, and the volume ratio of the hybrid fiber is A sliding member characterized by being 1 to 30%. 4. The sliding member according to any one of claims 1 to 3, wherein the volume ratio of the alumina-silica fiber is 22.5% or less. Element. 5. The sliding member according to any one of claims 1 to 4, wherein the total amount and the particle size of the non-fibrous particles contained in the aggregate of the alumina-silica fibers are 15
A non-fibrous particle content of 0 μ or more is 17 wt% or less and 7 wt% or less, respectively. 6. The sliding member according to any one of claims 1 to 5, wherein the alumina fiber has an α-alumina content of 10 to 50 wt%. . 7. A sliding member comprising a first member and a second member which are in contact with each other and slide relatively to each other, wherein at least a sliding surface portion of the first member with respect to the second member is provided. Alumina fiber having a composition of 80 wt% or more of Al ₂ O ₃ , the balance being substantially SiO ₂ , and 35 to 65 wt% Al ₂ O
₃ , 65-35 wt% SiO ₂ , 10 wt% or less CaO,
MgO, Na ₂ O, Fe ₂ O ₃ , Cr ₂ O ₃ , Zr
O ₂ , TiO ₂ , PbO, SnO ₂ , ZnO, Mo
O ₃ , NiO, K ₂ O, MnO ₂ , B ₂ O ₃ , V
Hybrid fiber composed of a substantially uniform mixture of alumina-silica fiber having a composition of one or more metal oxides of ₂ O ₅ , CuO, and Co ₃ O ₄ is used as a reinforcing fiber, and aluminum, magnesium, copper, zinc, The matrix member is a metal selected from the group consisting of lead, tin, and alloys containing these as the main components, and the hybrid fiber is made of a composite material having a volume ratio of 1% or more. Of at least the sliding surface portion with respect to the first member is made of steel having a hardness Hv (10 kg) of 200 or more. 8. The sliding member according to claim 7, wherein the alumina fiber has an α-alumina content of 5 to 60 wt.
% Is a sliding member. 9. The sliding member according to claim 7 or 8, wherein the volume ratio of the alumina fibers in the hybrid fibers is 20 to 90%, and the volume ratio of the hybrid fibers is A sliding member characterized by being 1 to 30%. 10. The sliding member according to any one of claims 7 to 9, wherein the volume ratio of the alumina-silica fiber is 22.5% or less. Element. 11. The sliding member according to any one of claims 7 to 10, wherein the total amount of non-fibrous particles and the particle size of 150 μm contained in the aggregate of the alumina-silica fibers are 150 μm. The above non-fibrous particle content is 17 wt%
Hereinafter, the sliding member is characterized by being 7 wt% or less. 12. The sliding member according to any one of claims 7 to 11, wherein the alumina fiber has an α-alumina content of 10 to 50 wt%. .