JP2782966B2 - Sliding member - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composition of a sliding member such as a vane (blade) member or a rotor member for a rotary compressor, and a combination structure of the compositions.

[0002]

2. Description of the Related Art A rotary compressor used in an air conditioner, for example, includes a rotary cylinder, a rotor supported eccentrically rotatable in the rotary cylinder, and slidable in a vane groove on the inner peripheral surface side of the rotary cylinder. And a vane which is always in sliding contact with the rotor surface, a front head and a rear head on both sides of the cylinder, and the like. When the driving motor rotates, the rotor rotates eccentrically in the cylinder due to the rotation of the cam of the camshaft portion, whereby the refrigerant gas flows into the cylinder from the suction port, is compressed, and is discharged from the discharge port. You. At this time, the vane performs a reciprocating sliding (projecting / retracting) motion at a considerable speed in a radial direction of the rotor in accordance with the eccentric rotation of the rotor. By the way, the sliding members such as the rotor and the vane as described above have generally been formed of steel or cast iron in terms of wear resistance and thermal expansion coefficient.
However, recently, in the rotary compressor for an air conditioner as described above, since the inverter type phase control has become mainstream, a high-speed rotation is inevitable.

However, the above steel and cast iron naturally have a high specific gravity and a large mass. Therefore, the load on the rotor bearing part is large, and the swing width of the crankshaft is also large. Therefore, a problem such as contact between the rotor and the stator in the motor section also arises, and there is a disadvantage that it cannot cope with high-speed rotation of a certain level or more.

[0004] Further, with respect to the vane, when the rotation speed is higher than a predetermined value, the inertia force is increased, so that the reciprocating motion cannot follow the rotation of the rotor, and there is a problem that the sealing property is impaired and gas leakage occurs.

[0005] Under such circumstances, it has been recently studied to manufacture the sliding members such as the rotor and the vane from an aluminum alloy that is lightweight and has high wear resistance.

However, in the case of an aluminum alloy alone, the coefficient of thermal expansion is about twice that of iron, so that the variation in clearance with other iron parts becomes too large, and the wear resistance is low. There is a problem, and it cannot be put to practical use as it is.

Therefore, a composite material containing various reinforcing materials has been devised for the purpose of improving wear resistance and reducing the coefficient of thermal expansion.

For example, a composite material comprising SiC whiskers and an aluminum alloy (JP-A-63-230983),
An aluminum composite material in which ceramic particles are dispersed as a reinforcing material (JP-A-62-30838) is one example.

[0009]

SUMMARY OF THE INVENTION First, Japanese Patent Application Laid-Open No.
The composite material of SiC whisker and aluminum alloy disclosed in Japanese Patent No. 230983 has a sufficiently reduced coefficient of thermal expansion, but has the following problems in terms of abrasion resistance and aggressiveness to a mating material. .

[0010] That is, the SiC whisker has a feature that when it is combined with a metal such as an aluminum alloy, the strength and hardness are remarkably improved. There is a drawback that when the aluminum composite material falls off, it acts like an abrasive on the sliding surface and wears the aluminum composite material body and the mating material significantly.

On the other hand, an aluminum composite material in which ceramic particles such as Al ₂ O ₃ , Si ₃ N ₄ , SiC and BN are mixed as a reinforcing material disclosed in Japanese Patent Application Laid-Open No. Sho 62-30838 has been invented. On the other hand, ceramic particles have a disadvantage that they fall off the sliding surface more easily than short fibers or whiskers due to their shape (granularity), and still have a problem in abrasion resistance.

[0012]

Means for Solving the Problems The inventions described in claims 1 to 4 of the present application have been made with a common object to solve the above-mentioned problems, respectively. It is provided with means for solving the problem (configuration).

(1) The sliding member according to the first aspect of the present invention is a sliding member according to the first aspect of the present invention, which comprises a hybrid molded body of aluminum borate whiskers and alumina short fibers,
An aluminum borate whisker forming the hybrid molded body, which is a sliding member impregnated with an aluminum alloy as a matrix alloy, wherein the total volume ratio of the hybrid molded body in the entire sliding member is 25 to 30%. The volume fraction of each of the alumina short fibers in the entire sliding member is at least 5% or more, and the aluminum alloy is, in addition to Si having a weight ratio of 20 to 25%,
It contains 2.5 to 5.0% by weight of Cu, 0.5 to 2.0% by weight of Mg, and 0.1 to 0.2% by weight of Ti, and the balance is substantially aluminum.

(2) The sliding member according to the second aspect of the present invention is a sliding member according to the second aspect of the present invention, which has the basic configuration of the sliding member according to the first aspect of the present invention. The volume ratio of the aluminum borate whiskers and the alumina short fibers forming the hybrid compact in the entire sliding member is in the range of 0.2 to 5.0.

(3) The sliding member according to the third aspect of the present invention is the sliding member according to the third aspect of the present invention.
The sliding member according to the invention described above has a basic configuration, and a mating member that abuts on each other and slides relatively is made of a cast iron-based material.

(4) The sliding member according to the fourth aspect of the present invention is a first and second sliding member that slides relative to each other by contacting each other. In the combination structure of the above, the first sliding member is formed of a carbon member impregnated with aluminum in the entire sliding member, while the second sliding member has a total volume ratio in the entire sliding member. A hybrid formed body of aluminum borate whiskers and alumina short fibers having a volume ratio of 25 to 30% and a volume ratio of 0.5 to 2 in the entire sliding member,
The Si component in the entire aluminum alloy is 20 by weight.
It is formed of an aluminum composite material obtained by impregnating and solidifying an aluminum alloy of about 25%.

[0017]

The sliding members according to the first to fourth aspects of the present invention are configured as described above, and as a result, the sliding members exhibit the following operations corresponding to the respective configurations.

(1) Operation of the Sliding Member of the Invention According to Claims 1 to 3 The above-mentioned problems in the prior art such as the coefficient of thermal expansion, abrasion resistance, and aggression to a mating material are solved by the above-described method. As in the first aspect of the present invention, a hybrid molded body in which aluminum borate whiskers and alumina short fibers are mixed is impregnated with an aluminum alloy as a matrix alloy under a predetermined pressurized state and then solidified. The use of the sliding member can be effectively achieved.

For example, when alumina short fibers or aluminum borate whiskers are each independently compounded with aluminum, an aluminum composite material having excellent wear resistance and a low coefficient of thermal expansion can be obtained. There is a problem in the aggressiveness to the counterpart material when moving, and there is a problem that the thermal expansion coefficient is slightly higher than that of the current cast iron-based material. On the other hand, a composite material of aluminum borate whisker alone and aluminum has a problem that abnormal wear occurs during a wear resistance test under severe sliding conditions.

However, when a sliding material is formed by impregnating an aluminum alloy into a hybrid molded body formed by mixing these alumina short fibers and aluminum borate whiskers to form a sliding material, the alumina short fibers and boric acid are mixed. The advantages of each of the aluminum whiskers are combined to provide an aluminum composite material having low aggressiveness to a mating material and exhibiting good wear resistance even under severe sliding conditions. Further, the coefficient of thermal expansion can be further reduced by an interference effect between the alumina short fiber and the aluminum borate whisker as compared with an aluminum composite material using only one of them. Further, the bending strength can be further increased as compared with the case of using only aluminum borate whiskers or alumina short fibers.

Still another operational advantage is that a wide composite ratio of alumina short fibers and aluminum borate whiskers can be obtained. Each of the reinforcing materials effectively contributes to improvement of wear resistance and reduction of low thermal expansion coefficient. Accordingly, the range of the mixing ratio for obtaining a composite material having good characteristics according to the application can be widened, and the ratio can be relatively freely selected according to each required characteristic. For example, regarding the volume ratio and mixing ratio of these materials, the total volume ratio of the alumina short fiber and the aluminum borate whisker is 25 to 30% of the entire sliding member, and the sliding ratio of the alumina short fiber and the aluminum borate whisker is A relatively wide range is possible, such that the volume ratio in the entire member only needs to be 5% or more.

The specific volume ratio and mixing ratio for obtaining an aluminum composite material having good sliding characteristics that solves the above-mentioned conventional problems are, as described above, aluminum borate whisker and alumina short material. The total volume ratio of the fiber hybrid molded body is 25 to 3 of the entire sliding member.
The range of 0% is optimal.

For example, when the sliding member of the present invention is used for a vane or a rotor of a rotary compressor, the coefficient of thermal expansion of the sliding member may not be different from that of a mating cast iron material constituting the periphery of these members. desirable. Therefore, the target coefficient of thermal expansion is also set based on this. And, as a result of the experiment, when the total volume ratio of the aluminum borate whisker and the alumina short fiber in the sliding member is 25%, when the ratio of the alumina short fiber is maximized, it is the lower limit of the target range, In order to enter the thermal expansion coefficient in the target range, it was found that at least the total volume ratio was 25% or more.

On the other hand, if the total volume ratio exceeds 30%, it is necessary to considerably increase the compression ratio in order to increase the volume ratio during the production of the hybrid molded article.
As a result, the whiskers and short fibers are finely broken and the aspect ratio is very small, that is, the whiskers and short fibers have a shape closer to granular rather than the shape of the whiskers and short fibers. It has been found that a deteriorating problem occurs.

Further, in the manufacturing process of the aluminum composite material as in the present invention, it is difficult with current technology to uniformly impregnate the above-mentioned hybrid compact having the same total volume ratio of 30% or more with the molten aluminum alloy. is there. Therefore, the total volume ratio of the aluminum borate whisker and the alumina short fiber hybrid molded body in the sliding member needs to be in the range of 25 to 30%, and from the viewpoint of the target coefficient of thermal expansion. That's enough in practice.

As described above, in the present invention, the total volume ratio of the aluminum borate whisker and the alumina short fiber hybrid molded product in the entire sliding member can be as wide as 25 to 30%. Of course, the size of the thermal expansion coefficient itself can be controlled relatively freely, but the thermal expansion coefficient can also be controlled by the volume ratio and volume ratio of aluminum borate whiskers and alumina short fibers. It becomes possible.

In the sliding member of the present invention, the volume ratio of each of the aluminum borate whiskers and the alumina short fibers of the hybrid molded body in the entire sliding member is set to 5% or more.

As described above, when a sliding member is formed by impregnating and solidifying an aluminum alloy into a hybrid formed body of aluminum borate whiskers and alumina short fibers, the volume ratio of aluminum borate whiskers and alumina short fibers is the same. Even so, the wear resistance is improved as compared with the case where the alumina short fiber is used alone, and generally the wear resistance is higher than the current cast iron vane material. Also, the aggressiveness to the opponent material is reduced. However, when a wear test is performed under more severe conditions, abnormal wear also occurs, and the amount of wear increases. According to the experimental results, the lower limit of the volume fraction of the alumina short fiber is optimally 5% in order for the wear resistance under the severe conditions to be at the level of the current cast iron-based material. In addition, as for the thermal expansion coefficient, the case where the total volume ratio in the sliding member was 25% was the upper limit of the target cast iron level, and the lower limit of the aluminum borate whisker was 5%.

Therefore, in order to obtain the above-mentioned target properties and to uniformly disperse the reinforcing material in the composite material, it is necessary to make the alumina short fiber and the aluminum borate whisker of the above-mentioned hybrid molded body the entire sliding member. It is necessary to set the volume ratio in each case to 5% or more.

This means that the total volume ratio of the aluminum borate whiskers and the alumina short fibers forming the hybrid molded product in the entire sliding member is 25 to 30% as in the second aspect of the present invention. In the range, the volume ratio of the aluminum borate whisker and alumina short fiber is
The range of 0.2 to 5.0 indicates that the most excellent wear characteristics and excellent characteristics of a low coefficient of thermal expansion can be obtained.

Further, it can be seen that the coefficient of thermal expansion can be reduced as the volume fraction of the alumina short fiber decreases, and as a result, the same volume ratio can be selected from a wide range of 0.2 to 5.0. Also becomes easier.

The aluminum alloy as the matrix alloy in the above-described structure is, in addition to Si, Cu,
Mg and Ti, and the content of Si therein is 20% by weight.
-25%, Cu content is 2.5-5.0% by weight, Mg content is 0.5-2.0% by weight, and Ti content is 0.1-0.1% by weight.
When the sliding member is made of an aluminum composite material obtained by impregnating and solidifying the aluminum alloy, the coefficient of thermal expansion is low, and the wear resistance is high. Become. That is, the matrix material has a Si content of 20 to 25% by weight,
Cu content is 2.5-5.0% by weight, Mg content is 0.5% by weight.
It is preferable to use an aluminum alloy having 5 to 2.0%, a Ti content of 0.1 to 0.2% by weight, and the balance being substantially Al.

The above configuration and operation are optimal when the mating members that abut against each other and slide relatively to each other are made of a cast iron-based material as in the third aspect of the present invention. When the sliding member of the present invention is used for a rotary compressor vane, a rotor, or the like, the sliding member has appropriate characteristics corresponding to a mating cast iron-based material constituting the periphery of the member.

(4) Operation of the sliding member according to the fourth aspect of the present invention The above-mentioned problems in the prior art are further brought into contact with each other and relatively sliding as in the fourth aspect of the present invention. First
In the combined structure of the second sliding member and the second sliding member, the first sliding member is formed of a carbon member impregnated with aluminum, while the second sliding member has a total volume of the entire sliding member. The hybrid component of aluminum borate whisker and alumina short fiber having a ratio of 25 to 30% and a total volume ratio of 0.5 to 2 in the whole sliding member has a Si component in the whole aluminum alloy. The problem can be solved more effectively by using a pair of sliding members formed of an aluminum composite material obtained by impregnating and solidifying an aluminum alloy having a weight ratio of 20 to 25%.

The first sliding member made of a carbon member impregnated with aluminum has a small thermal expansion coefficient and relatively excellent wear resistance in addition to the lightness obtained by the properties of the material itself. . Further, a hybrid formed body of aluminum borate whiskers and alumina short fibers having a total volume ratio of 25 to 30% of the total in the sliding member and a ratio of the same volume ratio in the range of 0.5 to 2 is used in the entire aluminum alloy. The second sliding member formed of an aluminum composite material obtained by impregnating and solidifying an aluminum alloy whose Si component has a weight ratio of 20 to 25% has a low coefficient of thermal expansion and a small resistance in addition to being light in mass. High wear properties.

Accordingly, the relative sliding portion formed by the combination of the first and second sliding members can sufficiently withstand high-speed rotation, and requires a small amount of wear.

[0037]

Therefore, according to the structure of the sliding member according to the present invention, the sliding member has considerably superior wear resistance as compared with the existing vane and rotor members. Further, it is possible to provide a vane, a rotor member, and the like for a rotary compressor having a low coefficient of thermal expansion, light weight, high bending strength, and low aggressiveness to a mating material.

[0038]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (1) First Embodiment A first embodiment of the present invention will be described below in detail.

In this embodiment, the total volume ratio of potassium titanate whiskers (K ₂ O.6TiO ₂ ) and alumina short fibers (Al ₂ O ₃ ) is 25% and 30% of the entire sliding member. By selecting the types and selecting two types each having a different volume ratio of potassium titanate whisker / alumina short fiber in each of the volume ratios, a total of four types of hybrid molded bodies were finally adopted. Then, each of these is set in a predetermined mold and first preheated to a predetermined temperature,
A matrix material Al-Si-based aluminum alloy melt is poured, sufficiently impregnated under a pressurized state of, for example, about 1 t / cm ² by a plunger, and then solidified to form a slide for a rotary compressor such as a vane or a rotor. A moving member was manufactured.

In this case, as shown in the following (Table 1), the Al—Si-based aluminum alloy as the matrix material has a Si content of 20 to 25% by weight and a C content of 20 to 25%.
u content 2.5-5.0% by weight, Mg content 0.5-0.5% by weight
Those having a Ti content of 2.0% and a weight ratio of 0.1 to 0.2% were selected and used.

[0041]

[Table 1]

Then, the test piece of the sliding member thus manufactured was subjected to a T6 heat treatment (500 ° C.) based on JIS.
After heating for 4 hours, water quenching, and again heating at 200 ° C. for 4 hours) to form a precipitated phase, and then measuring the coefficient of thermal expansion and performing a wear test with a pin-on-disk friction and wear tester shown in FIG. Was.

When the sliding material according to the embodiment of the present invention is used for a vane or a rotor for a rotary compressor, the coefficient of thermal expansion of the sliding material is essentially the same as that of the cast iron-based material constituting the peripheral portion of those members. It is desirable that there is no difference.

From the above, the above test piece was used to obtain a volume fraction (Vf) of potassium titanate whisker and alumina short fiber in the sliding member as shown in the following (Table 2).
Were prepared, and the thermal expansion coefficients of the samples A to C were measured first. The range of the coefficient of thermal expansion targeted in this embodiment is the level of the coefficient of thermal expansion of the cast iron-based material constituting the periphery of the current vane, rotor, etc., ie, 10.8 / 10 ⁶
C. to 13.4 / 10 ⁶ C.

[0045]

[Table 2]

From the above (Table 2), the total volume ratio (V) of the potassium titanate whisker and the alumina short fiber in the entire sliding member was determined.
When f) is 25%, it indicates that it is the lower limit of the target range. In order to enter the thermal expansion coefficient of the target range, it is necessary that at least the total volume ratio be at least 25%. However, if the total (TOTAL) volume ratio exceeds 30%, it is necessary to considerably increase the compression ratio in order to increase the volume ratio during the production of the molded product, and the whiskers and short fibers are finely folded and the aspect ratio is reduced. Is very small, that is, the shape is close to granular rather than the shape of whiskers or short fibers, resulting in a disadvantage that wear resistance is significantly reduced.

In general, in the manufacturing process of an aluminum composite material such as the material of the present invention, a compact having a total volume ratio of 30% or more in a sliding member is uniformly impregnated with a molten aluminum alloy. Is difficult with current technology.

Therefore, the total (TOTAL) volume ratio of potassium titanate whiskers and alumina short fibers must be in the range of 25 to 30% of the entire sliding member.

Although the coefficient of thermal expansion changes somewhat depending on the volume ratio of potassium titanate whiskers / alumina short fibers,
It is apparent from the above (Table 2) that the thermal expansion coefficient of the material of the present invention can be sufficiently controlled by the total (TOTAL) volume ratio.

Next, the test piece was connected to the pin shown in FIG.
A wear test is performed using an on-disk friction and wear tester. In FIG. 1, reference numeral 1 denotes a first disk on the fixed side of the tester, 2 denotes a second disk on the rotation drive side,
Reference numerals a, 3b, and 3c (3c is not shown) indicate three pin test pieces fixed to the first disk 1 side, respectively. Then, the pin test pieces 3a, 3b, 3c and the second disk 2 are slid, and the wear amount of the pin test pieces 3a, 3b, 3c and the counterpart material of the second disk 2 is measured.

The wear test in this case is as described above.
Among the materials (A) to (D) of the present invention examples (Table 2), for example,
(A) and (B) were selected, while the following were used as comparative materials:
Materials (E) to (H) shown in (Table 3) were selected. Also, the other party
As the material of the (second disk), Ni-Cr-Mo cast iron generally used as a rotor material was used. The wear test was conducted at a sliding speed of 1 m / sec and a surface pressure of 64.
Each pin test piece after 7 hours under the condition of 5 kg / cm ² k (FIG. 1)
3a, 3b, 3c) and the wear volume of the second disk (2 in FIG. 1).

[0052]

[Table 3]

As shown in FIG. 2, the result of the above measurement is the volume fraction (Vf) of whiskers and short fibers in the sliding member.
However, the material of the present embodiment in which potassium titanate whiskers and alumina short fibers are hybridized is superior in abrasion resistance as compared to the case where potassium titanate whiskers and alumina short fibers are each used alone, and is excellent in mating materials. Shows that there are few attacks. Comparing (A) and (B) of the material of this example, the wear amount is slightly increased when the amount of potassium titanate whisker is increased, and therefore, the amount of attack on the partner material is also increased. (B) The wear amount of the sample (volume ratio of potassium titanate whisker in the sliding member is 10%) slightly exceeds the wear amount of the current cast iron vane material (G). Since the wear property is a target, it is considered that the upper limit of the volume ratio of the potassium titanate whisker is 10% when the total (TOTAL) volume ratio is 30%.

However, when the volume ratio of the potassium titanate whisker is less than 5% of the sample (A), the degree of uniform dispersion of the potassium titanate whisker in the molded body is sharply reduced, and uniform wear characteristics and the like are obtained. Disappears. From the above, the TOTAL volume ratio in the sliding member is 30%.
In the material of the present embodiment using the hybrid molded product of potassium titanate whisker and alumina short fiber, the volume ratio of potassium titanate whisker may be in the range of 5 to 10% of the whole in order to obtain target properties. is necessary.

This is the same tendency when the TOTAL volume ratio is in the range of 25 to 30% of the entire sliding member, while the volume ratio of potassium titanate whisker / alumina short fiber is 0.2 to 0.5 as described above. In the range, the amount of wear is small, indicating that excellent characteristics with little attack on the mating material can be obtained.

The aluminum composite material sample (H) (composite material of SiC whisker and aluminum alloy: Vf of SiC = 30%) invented as a vane material for a rotary compressor among the comparative materials and the material of the present invention. When the sample (H) was compared, the amount of abrasion and the amount of attack on the counterpart material were also very large, indicating that the material of this example is also superior.

Therefore, according to the configuration of the sliding member of the present embodiment, it is possible to provide a vane, a rotor member, etc., which have considerably better wear resistance than the existing vanes and rotor members and are lightweight. Will be able to

Further, the coefficient of thermal expansion can be made close to that of the existing cast iron type.

(2) Second Embodiment Next, a second embodiment of the present invention will be described in detail.

In this embodiment, aluminum borate whiskers (9Al ₂ O ₃ .2B ₂ O ₃ ) and alumina short fibers (Al ₂
O ₃ ) to 25% and 30% of the entire sliding member.
By selecting two kinds of those, and further changing the mixing ratio of aluminum borate whisker / alumina short fiber in each volume ratio, a total of seven kinds of sample molded bodies are eventually adopted, and these are used. Is set in a predetermined mold and preheated, and then a molten Al-Si-based aluminum alloy as a matrix material is injected and sufficiently impregnated under a pressurized state of, for example, about 1 t / cm ² by a plunger. By solidification, a sliding member for a rotary compressor such as a vane or a rotor was manufactured. In this case, as shown in the following (Table 4), the Al-Si based aluminum alloy as the matrix material has a Si content of 20 to 25% by weight and a Cu content of 2.5 to 5.0 by weight. %, Mg content is 0.5-2.0% by weight,
Those having a Ti content of 0.1-0.2% by weight and the balance being substantially aluminum were selected and used.

[0061]

[Table 4]

Then, the test piece of the sliding member thus manufactured was subjected to a T6 heat treatment (500 ° C.) based on JIS.
, Followed by water quenching, and again heating at 200 ° C. for 4 hours) to form a precipitate phase, and then measuring the coefficient of thermal expansion and using the same pin-on-disk friction and wear as in the first embodiment shown in FIG. A wear test was performed using a test machine.

In general, when the material of the present invention is used for a vane or a rotor for a rotary compressor, it is desirable that the coefficient of thermal expansion of the material does not differ from that of the iron-based material constituting the periphery of these members.

From this, the thermal expansion coefficient was measured for each of seven types of samples in which the volume ratio (Vf) of aluminum borate whiskers and alumina short fibers in the sliding member shown in the following (Table 5) was changed. Similar to the first embodiment, the target range of the thermal expansion coefficient is the level of the thermal expansion coefficient of the cast iron-based material constituting the periphery of the current vane, rotor, etc., that is, 10.8 /
10 is in the range of ^{6 · ℃ ~13.4 / 10 6 ·} ℃.

[0065]

[Table 5]

From the above (Table 5), the total (TOTAL) volume ratio (Vf) of aluminum borate whiskers and alumina short fibers was obtained.
When the ratio of alumina short fibers is 25% of the entire sliding member, the ratio of alumina short fibers is maximized, indicating that it is the lower limit of the target range. It is necessary that the rate be 25% or more. On the other hand, when the total (TOTAL) volume ratio exceeds 30%, it is necessary to considerably increase the compression ratio in order to increase the volume ratio during the production of the molded product, and the whiskers and short fibers are finely broken. It has a very small aspect ratio, that is, a shape close to granular rather than a whisker or short fiber, which causes a problem of falling off from the sliding surface and significantly reducing wear resistance.

In the manufacturing process of the aluminum composite material such as the material of the present invention, it is difficult to uniformly impregnate the compact having the total volume ratio of 30% or more with the molten aluminum alloy by the current technology. . Therefore, TOTA of aluminum borate whisker and alumina short fiber
It is necessary that the L volume ratio be in the range of 25 to 30% of the entire sliding member, which is sufficient in practice.

Since the total volume ratio of aluminum borate whiskers / alumina short fibers can be made as wide as 25 to 30%, the thermal expansion coefficient can be controlled by the total volume ratio. It is said that it is possible to control the coefficient of thermal expansion also by the ratio
It is clear from (Table 5).

Next, the results of a wear test performed by using a pin-on-disk friction and wear tester shown in FIG. 4 will be described. In FIG. 4, as in the case of the first embodiment, reference numeral 1 denotes a fixed-side first disk, and reference numeral 2 denotes a rotation-drive-side second disk, 3a, 3b, 3c (3c is not shown). 3 shows three pin test pieces fixed to the first disk 1 side. Then, the pin test pieces 3a, 3b, 3c and the second disk 2 are slid, and the pin test pieces 3a, 3b, 3
The amount of wear of c and the second disk 2 as the mating material is measured. As the wear test, samples (A) to (E) were used for the wear test I and the same for the wear test II from the materials of the present example (Table 5).
(A), (D), and (E) were selected, while the following were used as comparative materials.
Materials (H) to (K) shown in (Table 6) were selected. Also, the other party
As the material of the (second disk), Ni-Cr-Mo cast iron generally used as a rotor material was used. The wear test I was performed at a sliding speed of 1 m / sec and a surface pressure of 64.
Under the condition of 5 kgf / cm ² , the wear volume of each pin test piece (3a, 3b, 3c in FIG. 4) and the second disk (2 in FIG. 4) after 7 hours were measured. On the other hand, as wear test II, the wear volume of the pin test pieces (3a, 3b, 3c in FIG. 4) was measured after one hour under the severe conditions of a sliding speed of 1 m / sec and a surface pressure of 850 kgf / cm ² . .

[0070]

[Table 6]

The results of the wear test I are shown in FIG.
Even if the volume ratio (Vf) of the whiskers and short fibers in the sliding member is the same, the wear resistance is improved as compared with the case where the alumina short fibers are used alone. In addition, the volume ratio was changed (A) ~
Both (E) have improved wear resistance over the current cast iron vane material (J). Regarding the aggressiveness, all of (A) to (E) indicate that the aggressiveness to the opponent material is small.
However, in this test, the composite material (H) in which the volume ratio of the aluminum borate whisker in the sliding member was 30% was also higher in the volume ratio and the aggressiveness compared to the present Examples (A) to (E). Similarly, it can be seen that the characteristics are slightly better. However, when the wear test II under more severe conditions was performed, as shown in FIG. 6, abnormal wear occurred on the (H) sample, and the amount of wear was extremely large. And it is the material of this example.
The samples (A) to (E) exhibited good wear resistance even under the severe conditions of Wear Test II. However, the results of the wear test II of the sample (E) show that the amount of wear slightly increased, and that the wear resistance under severe conditions was at the current material level (J). It is considered that the lower limit of the volume fraction of the alumina short fibers in the above is 5%. Considering the coefficient of thermal expansion, as shown in Table 5 and FIG. 7, the sample (H) when the total (TOTAL) volume ratio Vf in the sliding member was 25% was 13.4 / 10 ⁶ · ° C. This shows that the upper limit of the cast iron level is shown, and the lower limit of the aluminum borate whisker is 5%.

Therefore, in order to obtain the desired properties and to uniformly disperse the reinforcing material in the composite material, as shown in FIG. 8, both the alumina short fiber and the aluminum borate whisker are used for the entire sliding member. % Must be kept in the range of at least%.

This means that when the volume ratio of TOTAL is in the range of 25 to 30% of the entire sliding member, and the ratio of the volume ratio of aluminum borate whisker / alumina short fiber is in the range of 0.2 to 5.0, the abrasion characteristics are low. It shows that excellent characteristics such as good and low coefficient of thermal expansion can be obtained.

From Table 5, it can be seen that the coefficient of thermal expansion can be made smaller as the volume fraction of the alumina short fibers in the sliding member decreases, and the ratio of the same volume fraction is selected from a wide range of 0.2 to 5.0. It is possible.

Further, among composite materials, aluminum composite material sample (K) (composite material made of SiC whisker and aluminum alloy: volume ratio Vf =
Comparing the material of this example with (30%), (K) shows that the amount of abrasion and the amount of attack on the mating material are very large, and that the material of this example is superior.

(3) Third Embodiment Next, a third embodiment of the present invention will be described in detail.

[0077] aluminum borate whiskers in the present embodiment _{(9Al 2 O 3 · 2B 2} O 3) and potassium titanate whisker (K ₂ O · 6TiO ₂₎ and alumina short fibers (Al ₂ O ₃₎
First, two types having a total volume ratio of 25% and 30% of the entire sliding member are selected, and further two types having different ratios of potassium titanate whisker / alumina short fiber at each volume ratio are selected. As a result, after all, a total of four types of sample molded bodies were adopted, these were set in a predetermined mold and preheated, and then the matrix material Al-Si was formed.
A sliding member for a rotary compressor, such as a vane or a rotor, was manufactured by injecting a molten aluminum alloy, sufficiently impregnating it under a pressurized state of, for example, about 1 t / cm ² with a plunger, and then solidifying.

In this case, as shown in the following (Table 7), the Al-Si-based aluminum alloy as the matrix material has a Si content of 20 to 25% by weight and a C content of 20 to 25%.
u content 2.5-5.0% by weight, Mg content 0.5-0.5% by weight
Those having a Ti content of 2.0% and a weight ratio of 0.1 to 0.2% were selected and used.

[0079]

[Table 7]

Then, the test piece of the sliding member thus manufactured was subjected to a T6 heat treatment (500 ° C.) based on JIS.
After heating for 4 hours, water quenching, and again heating at 200 ° C. for 4 hours) to form a precipitated phase, and then measure the coefficient of thermal expansion, and wear test with a pin-on-disk friction and wear tester shown in FIG. Was done.

As described above, when the material of the present invention is used for a vane or a rotor for a rotary compressor, the coefficient of thermal expansion itself is not different from that of the cast iron material constituting the periphery of those members. It is desirable.

From the above, as shown in the following (Table 8), the volume ratio (Vf) of aluminum borate whiskers, alumina short fibers, and potassium titanate whiskers in the sliding member is shown.
The coefficient of thermal expansion was measured for six types of samples having different values. The target range of the thermal expansion coefficient is the level of the thermal expansion coefficient of the iron-based material constituting the periphery of the current vane, rotor, and the like, that is, the range of 10.8 / 10 ⁶ · ° C to 13.4 / 10 ⁶ · ° C.

[0083]

[Table 8]

From the data in Table 8, all of (A) to (E) sufficiently show the thermal expansion coefficients in the target range.
It can be seen that among the samples (C) and (D), even the cast iron level reached a lower level. 11 and 12
As shown in FIG. 7, even when the volume ratio Vf in the sliding member is the same, the above-mentioned coefficient of thermal expansion can be further reduced by mixing three types of ceramic reinforcing materials as in this embodiment. The sliding material of the present embodiment is characterized by the effect of mixing these three types, and if the three types of reinforcing materials do not have a certain volume fraction, they form a uniform state in the composite material. Hateful. In order to uniformly disperse the three types of reinforcing materials throughout the composite material and to improve the effect, the lower limit must be set to 5% for all three types as shown in FIG.

The volume ratio of TOTAL is 30% of the entire sliding member.
%, It is necessary to considerably increase the compression ratio in order to increase the volume ratio during the production of the molded article, and therefore the whiskers and short fibers are finely broken and the aspect ratio is very small, that is, whiskers and short fibers. Rather than the shape, the shape becomes closer to granular, and the wear resistance is significantly reduced. Further, in the manufacturing process of the aluminum composite material such as the material of the present invention, it is difficult to uniformly impregnate the above-mentioned compact having a volume ratio of 30% or more with the molten aluminum alloy by the current technology. Therefore, as a practical matter, the volume ratio is appropriately up to 30% of the entire sliding member.
That's enough.

Next, an abrasion test was performed by using the above-mentioned pin-on-disk friction and abrasion tester shown in FIG. As the wear test I, samples (A) to (E) for wear test were selected from the materials of this example in (Table 8), and (G) to (G) shown in (Table 9) below as comparative materials. The material of K) was selected. As the material of the other party (second disk), Ni-Cr-Mo cast iron, which is commonly used as a rotor material, was used. The wear test I was performed at a sliding speed of 1 m / se.
c, each pin test piece (3a, 3b, 3c in FIG. 4) and the second disk (FIG. 4) after 7 hours under the conditions of a contact pressure of 645 kgf / cm ² .
The wear volume of 2) was measured. On the other hand, as a wear test II, pin test pieces (3a, 3 in FIG. 4) were set under strict conditions of a sliding speed of 1 m / sec and a surface pressure of 850 kgf / cm ² , and after one hour.
The wear volume of b, 3c) was measured. Materials for wear test II
(A) to (E) of the materials of this example, as comparative materials,
(G), (I), (J) and (K) were selected.

[0087]

[Table 9]

The results of the wear test I are shown in FIG.
The materials (A) to (E) of this example show very good abrasion resistance and have low aggressiveness. The wear of the (E) sample having a TOTAL volume ratio (Vf) of 25% in the sliding member slightly exceeds the wear of the current iron-based vane material (J). In sample (E), the sum of the volume fraction (Vf) of the aluminum borate whiskers and the alumina short fibers, which are the reinforcing material contributing to the improvement of the wear resistance, in the sliding member is 20%. It is thought that it has increased. Therefore, the TOTAL volume ratio (Vf) in the sliding member is 25% lower limit.
is necessary. Since the wear resistance requires a sample level of (A) to (E), the potassium titanate whisker which does not contribute to the improvement of the wear resistance cannot be increased any more. Therefore, the potassium titanate whisker must be suppressed to about 5% of the entire sliding member.

From these facts, the TOTAL volume ratio of the reinforcing material is in the range of 25 to 30% of the whole sliding member, the potassium titanate whisker is 5% of the whole, and the remaining part is aluminum borate whisker and alumina. It can be seen that the target material can be obtained by setting the volume fraction of the short fibers to 5% or more in the whole.

FIG. 10 shows the results of the abrasion test II, and all of the materials (A) to (D) of the present embodiment are cast iron-based vane materials.
(J) level of abrasion resistance.

The aluminum composite material sample (K) (composite material composed of SiC whiskers and an aluminum alloy: Vf of SiC = 30%), which was invented as a vane material for a rotary compressor among the comparative materials, and the material of this example were used. In comparison, (K) shows that the amount of abrasion and the amount of attack on the counterpart material are very large, and that the material of this example is superior.

As is clear from the above description, according to the sliding member of the present embodiment, a high speed, such as a rotary compressor having a low aggressiveness to a mating material, a light weight, a low coefficient of thermal expansion and a high friction and wear characteristic, is used. A sliding member suitable for rotation can be provided.

Therefore, even if it is applied to a rotor member or a vane member of a rotary compressor for an air conditioner, high-speed rotation is possible and a stable clearance can be maintained. Can be eliminated.

(4) Fourth Embodiment Next, a fourth embodiment of the present invention will be described in detail.

In this embodiment, for example, the following (Table 1)
As shown in samples 1 and 2 of 1), aluminum borate whiskers, one of ceramic whiskers,
(9Al ₂ O ₃ · 2B ₂ O ₃ ) and alumina short fiber (Al ₂ O ₃ ), the total volume ratio in the entire sliding member is 30%, and
Their mixing ratio is 2/1 (20:10) and 1/1 (15: 1)
5) The two sets of hybrid compacts are adopted, preheated in a mold, and then a molten Al-Si-based aluminum alloy Al-Si-Cu-Mg-Ni as a matrix material is injected, for example, 1 ton. / Cm ² was impregnated and solidified under pressure, and the Fe component in the matrix material was suppressed to 0.2% (or less) at that time to produce a sliding member for a rotary compressor such as a vane or a rotor.

[0096] In this case, the matrix material Al-Si based aluminum alloy is as follows.
As shown in Table 10, the Si content was 23.5% by weight,
Content is 3.5% by weight, Mg content is 1.0% by weight, Ni
Those having a content of 1.0% by weight and a content of Fe of 0.2% or less by weight were selected and used.

With the test piece manufactured in this way, a bending test piece (test piece) 5 as shown in FIGS.
And a three-point bending test was performed. On the other hand, an aluminum composite material manufactured in the same manner as a comparative material, Fe
Only the component was set to 0.8% (the other components were the same as those in Table 10).

As shown in Samples 3 and 4 in Table 11 below, aluminum borate whiskers (9Al ₂ O ₃
・ 2B ₂ O ₃ ), alumina short fiber (Al ₂ O ₃ ), and potassium titanate whisker (K ₂ O.6TiO ₂ ) are made of three types of ceramic materials having a total volume ratio of 30% in the entire sliding member. An aluminum composite material impregnated with the same aluminum alloy as described above using two sets of hybrid compacts blended in two types with volume ratios of 10, 15, 5% and 5, 20, 5%, respectively, A sliding material in which the Fe component in the alloy was determined to be two types of 0.2% and 0.8% of the entire aluminum alloy was manufactured, and a three-point bending test was performed under the following conditions (Table 12).

A comparison of the test results shows that the Fe component in the entire aluminum alloy was reduced in any of the above composite materials.
It was found that the bending strength was greatly improved by controlling to 0.2%. Therefore, in a reliable aluminum composite material that can be used for sliding members, etc., the Fe component in the entire aluminum alloy is reduced.
It has been clarified that a sufficient effect can be obtained when the content is suppressed to 0.2% or less.

As described above, at least the aluminum-silicon alloy (Al-Si-Cu-
The aluminum borate whisker (9Al ₂ O ₃ .2B ₂ O ₃ ) and the short alumina fiber (Al ₂ O) can be used as long as the Fe content in Mg—Ni) is suppressed to 0.2% or less of the whole.
₃ ) or a mixture thereof with potassium titanate whisker (K ₂ O.6TiO ₂ ).
₂ O ₃ ), (2) Alumina-silica short fiber compact (Al ₂ O _3.
(SiO ₂ ), (3) aluminum borate whisker compact (9)
Al ₂ O ₃ .2B ₂ O ₃ ), (4) The bending strength can be similarly reduced even when applied to a reinforcing material made of a ceramic material alone such as a potassium titanate whisker molding (K ₂ O.6TiO ₂ ). It is easily expected that it can be improved. Furthermore, in addition to the above-mentioned hybrid molded body of a combination of two or three types of ceramic materials, a hybrid molded body formed by arbitrarily combining the various ceramic materials of the above (1) to (4) is used as a reinforcing material. The same can be said for the case.

The aluminum borate whiskers, alumina short fibers, and alumina / silica short fibers, which are the reinforcing materials for the sliding member of the embodiment of the present invention, are different from the above-described conventional SiC whiskers and the like. Has moderate hardness as a sliding member at around 7.
Moreover, it also has solid lubricity.

Therefore, the abrasion resistance is improved, the amount of wear of the material itself during sliding is reduced, and the degree of attack on the mating material is also reduced.

In general, when the sliding member is used for a sliding member such as a vane (blade) for a rotary compressor or a rotor, the coefficient of thermal expansion of the sliding member is different from that of another member such as a cylinder as described above. It is necessary that there is no difference between the cast iron-based material as a constituent member, but in general, aluminum has a thermal expansion coefficient of about twice that of iron alone, and therefore, as it is, it differs from other iron parts as it is. Although the problem that the clearance between them becomes too large occurs, alloying can reduce the coefficient of thermal expansion. Therefore, when such an Al-Si alloy having such a low coefficient of thermal expansion is combined with the above-mentioned ceramic material such as aluminum borate whisker, it is possible to set the same coefficient of thermal expansion as that of cast iron. Thus, the problem of the occurrence of a clearance with other components can be solved at the same time.

Among the above ceramic materials, potassium titanate whiskers (K ₂ O.6TiO ₂ ) have relatively low hardness (for example, Mohs hardness of about 4) as compared with aluminum borate whiskers and the like. Although it cannot be said that an aluminum composite material having sufficiently excellent wear resistance can be obtained even when it is composited with the above-mentioned aluminum alloy, it has almost no aggression to the mating material, and a thermal expansion coefficient of the composite material. This has the advantage of greatly contributing to the reduction of

Therefore, the potassium titanate whisker is preferably used as a hybrid molded product in which, for example, alumina short fibers are mixed, and the hybrid molded product is impregnated with the above-described aluminum alloy under a predetermined pressurized state. When the composite is formed, an aluminum composite material having excellent wear resistance and low attack on a mating material and having a low coefficient of thermal expansion can be obtained.

In terms of price, the conventional SiC whisker is very expensive at about 50,000 to 100,000 yen / kg, but the price of the potassium titanate whisker is about 20 yen.
It is inexpensive at about 00 yen / kg. Therefore, mixing the potassium titanate whiskers will also ultimately lower the cost of the composite itself.

[0107]

[Table 10]

[0108]

[Table 11]

[0109]

[Table 12]

(5) Fifth Embodiment Next, a fifth embodiment of the present invention will be described in detail.

In this example, two sets of foamed Ni molded bodies having specific surface areas of 2500 m ² / m ² and 5600 m ² / m ² (FIG. 17)
(E), (F)) and a composite material of an Al-Si-based aluminum alloy C8C containing 23 to 25% of Si in an aluminum alloy as shown in the following (Table 13) were prototyped, and each of them was tested. Pieces were made.

Then, abrasion tests were carried out using the same pin-on-disk type testing machine as in each of the above-mentioned embodiments shown in FIG. The test conditions are as follows: Drying, sliding speed 1m / s, load 5kgf, sliding distance 36km, 3 ~
The test was repeated four times. First, the test is performed with a composite material pin and a monikro cast iron disk to measure the pin wear volume. Then, the wear volume of the pin was measured with the monicro cast iron pin and the composite material disk.

As a comparative material, as shown in FIG.
Two types of conventional SiC whiskers with different volume ratios (A),
(B), two types of aluminum composite materials (C) and (D), which are composites of alumina short fibers having different volume ratios, aluminum alloy C8C (G),
Hard-nable B2 cast iron (H) and MC-A (H).

As a result, the composite materials (E) and (F) obtained by impregnating an aluminum alloy into the foamed Ni molded body as the material of the present embodiment.
Showed very good abrasion resistance as compared with the other comparative materials (A) to (D) and (G) to (I). Further, the composite materials (E) and (F) of this example have mechanical properties as shown in the following (Table 14), have a relatively low coefficient of thermal expansion, and have a low mechanical strength. It was confirmed that it was high.

[0115]

[Table 13]

[0116]

[Table 14]

(6) Sixth Embodiment Next, a sixth embodiment of the present invention will be described in detail.

In this embodiment, in the combination structure of the first and second sliding members which abut against each other and slide relatively, the first sliding member is made of a carbon member impregnated with aluminum. On the other hand, the second sliding member is made of an aluminum borate whisker (9Al ₂ O) having a total volume ratio of 25 to 30% in the entire sliding member and a ratio of the same volume ratio of 0.5 to _{2. 3} · 2B ₂ O ₃₎ and alumina short fibers (a
(1 ₂ O ₃ ) is formed from an aluminum composite material obtained by impregnating and solidifying an Al-Si-based aluminum alloy containing 20 to 25% of an Si component as shown in Table 15 below. Respective sliding members ((A) in Table 16 below) such as a rotor and a vane for a compressor were manufactured.

Then, each of the test pieces 3a
-3c were manufactured and subjected to a wear test.

The abrasion test was performed using the same pin-on-disk friction and wear tester shown in FIG. 18 as in the above embodiments.
Performed in oil. As a sample material for a comparative test, as shown in the following (Table 16), a pair (B) of a hardenable B2 cast iron and a monicro cast iron material, which is a current combination of a rotor and a vane, and a light weight of both sliding members. Material (C) of carbon and the above aluminum composite material for the purpose of
Aluminum alloy and aluminum alloy / SiC whisker combination material (D) were selected respectively. Also, as the partner material,
Common N as rotor material for rotary compressor
i-Cr-Mo cast iron was used. The test was performed under the conditions of a sliding speed of 1 m / s and a surface pressure of 645 kgf / cm ² . As shown in FIG. 19, the wear test result shows that the combination (A) of the sliding members of the present example has very good wear resistance. However, the wear resistance tends to be slightly inferior to the current combination of cast iron materials (B), but taking this point into account, the weight of both sliding members is greatly reduced. It is a very good combination with great merits in that it is possible to reduce the weight and to guarantee high rotation performance. Table 17 shows the respective densities of the combination of the current sliding member and the combination of the embodiment of the present invention.

[0121]

[Table 15]

[0122]

[Table 16]

[0123]

[Table 17]

[Brief description of the drawings]

FIG. 1 is a perspective view showing the configuration of a pin-on-disk friction and wear tester for testing the wear resistance of a sliding member according to a first embodiment of the present invention.

FIG. 2 is a graph showing wear amount measurement data of the tester.

FIG. 3 is an experimental data graph showing a relationship between a fiber volume ratio and a thermal expansion coefficient of the potassium titanate whisker in the first embodiment.

FIG. 4 is a perspective view showing a configuration of a friction and wear tester for testing the wear resistance of a sliding member according to a second embodiment of the present invention.

FIG. 5 is a graph showing the results of a first wear test (I) of the second embodiment performed by the friction and wear tester of FIG. 4;

FIG. 6 is a graph showing the results of a second wear test (II) using the friction and wear tester of the second embodiment.

FIG. 7 is a graph showing measured data of the thermal expansion coefficient of the sliding member in the second embodiment in comparison with the current cast iron level.

FIG. 8 is a graph showing the respective mixing ratios of aluminum borate whiskers and alumina short fibers of the sliding member of the second embodiment in a correlated manner.

FIG. 9 is a graph showing the results of a first wear test (I) of a sliding member according to a third embodiment of the present invention.

FIG. 10 is a graph showing a result of a second wear test (II) of the sliding member in the third embodiment.

FIG. 11 is a graph showing measured data of the coefficient of thermal expansion of the sliding member in the third embodiment in comparison with the cast iron level.

FIG. 12 is a comparison graph of measured thermal expansion coefficient data similar to FIG.

FIG. 13 is a graph showing the mixing ratio of aluminum borate whiskers, potassium titanate whiskers, and alumina short fibers of the sliding member of the third embodiment.

FIG. 14 is a front view of a bending strength test piece (test piece) of a sliding member according to a fourth embodiment of the present invention.

FIG. 15 is a side view of the test piece (test piece).

FIG. 16 is a perspective view showing a configuration of a sliding member friction and wear tester according to a fifth embodiment of the present invention.

FIG. 17 is a graph showing the results of a wear test in the fifth embodiment of the present invention.

FIG. 18 is a perspective view showing a configuration of a friction member wear tester for a sliding member according to a sixth embodiment of the present invention.

FIG. 19 is a graph showing the results of a wear test in a sixth embodiment of the present invention.

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-240727 (JP, A) JP-A-63-319298 (JP, A) JP-A-63-319299 (JP, A) JP-A-59-1984 50149 (JP, A) JP-A-62-278239 (JP, A) JP-A-61-105316 (JP, A) JP-A-61-104037 (JP, A)

Claims (4)

(57) [Claims] 1. A sliding member obtained by impregnating a hybrid molded product of aluminum borate whiskers and alumina short fibers with an aluminum alloy as a matrix alloy, wherein a total volume of the hybrid molded product in the entire sliding member is provided. The aluminum alloy has a volume ratio of at least 5% to 25%, the volume ratio of each of the aluminum borate whiskers and alumina short fibers forming the hybrid molded body in the entire sliding member is at least 5% or more.
In addition to 20-25% by weight of Si, 2.5-5.0% by weight of
Cu, 0.5 to 2.0% by weight Mg, T: 0.1 to 0.2% by weight
include i, the balance substantially sliding member, wherein the aluminum der Rukoto. 2. The slide according to claim 1, wherein the ratio of the volume ratio of the aluminum borate whiskers and the alumina short fibers forming the hybrid molded body in the entire sliding member is in the range of 0.2 to 5.0. Moving member. 3. The sliding member according to claim 1, wherein the mating member that abuts on each other and slides relatively is made of a cast iron-based material. 4. In a combined structure of a first and a second sliding member which abut on each other and slide relatively, said first sliding member is formed of a carbon member impregnated with aluminum. On the other hand, the second sliding member is made of an aluminum borate whisker and an alumina having a total volume ratio of 25 to 30% in the entire sliding member and a volume ratio of 0.5 to 2 in the entire sliding member. A sliding member comprising a short-fiber hybrid molded body formed of an aluminum composite material obtained by impregnating and solidifying an aluminum alloy having a weight ratio of 20 to 25% in an aluminum alloy as a whole in the aluminum alloy.