JP2001200328A - Gas compressor and method for producing wear resistant aluminum alloy extruded material for gas compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing an inexpensive wear resistant aluminum alloy extruded material for a compressor having high hardness and small permanent elongation and to provide a gas compressor using the same wear resistant aluminum alloy extruded material. SOLUTION: The base metal 31 of a vane 13 is produced by a wear resistant aluminum alloy extruded material. This wear resistant aluminum alloy extruded material contains 8 to 15% Si, 8 to 15% Cu, 0.1 to 2.0% Mg, and the balance aluminum with inevitable impurities. Then, the surface is applied with Ni base plating 33 with a film thickness of about 10 to 30 μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas compressor and a method for producing a wear-resistant aluminum alloy extruded material for a compressor, and particularly to a wear-resistant aluminum for a compressor which has high hardness, small permanent elongation and is inexpensive. The present invention relates to a method for manufacturing an alloy extruded material and a gas compressor using the wear-resistant aluminum alloy extruded material.

[0002]

2. Description of the Related Art Gas compressors are used for indoor air conditioning and refrigeration. The gas compressor 50 has a compressor main body 1 as shown in FIG. 14, and the compressor main body 1 includes a cylinder 4 interposed between a pair of side blocks 2, 3, and a rotor 5 is provided in the cylinder 4. Are rotatably arranged.

The rotor 5 is integrally provided with a rotating shaft 6 penetrating between the end faces, and the rotating shaft 6 is rotatably fitted in bearing holes 7 and 8 provided in both side blocks 2 and 3 respectively. Further, the rotation shaft tip side 6a protrudes from the bearing hole 7 and is formed to extend so as to penetrate the front head 9. A seal chamber 10 is provided on the outer surface side of the rotary shaft tip side 6a, and lubricating oil is supplied to the seal chamber 10 through a bearing clearance G between the bearing hole 7 and the rotary shaft 6.

FIG. 15 is a sectional view taken along the line AA in FIG. A vane groove 12 is formed on the outer peripheral surface of the rotor 5 in a radial direction, and a vane 13 is slidably mounted in the vane groove 12. When the rotor 5 is rotating, the vane 13 is driven by the centrifugal force and the oil pressure at the bottom of the vane groove.
It is urged to the inner wall.

The interior of the cylinder 4 is partitioned into a plurality of small chambers by a pair of side blocks 2, 3, a rotor 5, and vanes 13, 13,. These chambers are compression chambers 14, 1
.., And the size of the volume is repeatedly changed by the rotation of the rotor 5.

In such a compressor body 1, when the rotor 5 rotates and the volume of the compression chambers 14, 14,.
And compresses the low-pressure refrigerant gas. The discharge chamber 19 is formed by the side block 3 and the case 52. The compressed high-pressure refrigerant gas is supplied to the discharge port 16 and the discharge valve 1.
7. Discharged to the discharge chamber 19 via the oil separator 18 and the like.

At this time, the oil separator 18 separates oil from the high-pressure refrigerant gas, and the separated oil accumulates at the bottom of the discharge chamber 19 to form an oil reservoir 20 for lubricating oil. The high-pressure refrigerant gas from which oil has been separated is supplied from a discharge port 36 to an external heat exchanger or the like (not shown). The lubricating oil in the oil sump 20 passes through the oil passage 21 to the bottom of the vane groove and the bearing clearance G (sliding contact portion).
Side is pressure fed.

In such a gas compressor 50, the rotor 5
And the vane 13 are both formed of an aluminum alloy. For this reason, as shown in FIG.
Reference numeral 3 denotes a base material 31 on which a Ni-based plating 33 having a thickness of about 10 to 30 μm is applied. Ni-based plating 3
Reference numeral 3 denotes, for example, a compound of nickel and phosphorus, a compound of nickel, phosphorus, and cobalt, a compound of nickel and boron, and a compound of nickel, phosphorus, and boron.

Since the plating 33 is hard, if the base material 31 is soft, the deformation of the plating 33 cannot follow the deformation of the base material 31 when an external force is applied, and the plating 33 cracks. Therefore, a relatively high hardness aluminum alloy is required for the base material 31. Conventionally, sintered aluminum of about 15 to 25% Si containing about 5 to 10% by weight (hereinafter abbreviated as%) of iron, nickel and the like is used. The alloy was used after T6 treatment.

[0010]

However, since such a sintered aluminum alloy has a high cost, it has been required to use a cheaper molten aluminum alloy as a base material for cost reduction.

Here, when various durability evaluations were performed on the ingot aluminum alloy, the initial hardness after plating was HR.
It was found that when the B (R Rockwell's B scale) was 78 or more, the plating 33 was not cracked even with a smelted aluminum alloy and could be used.

At this point, the molten aluminum alloy treated with T6 is sufficiently usable in terms of hardness, but has a permanent elongation (for example, 180 °, elongation of 50 μm in 50 hours) due to heat generated during operation. Occurs. Permanent elongation refers to a state in which elongation caused by heat does not return to its original dimensions even when cooled to its original temperature.

When permanent elongation occurs, the space between the vane 13 and the side block 2 or 3 becomes too close to each other, causing problems such as heat generation and breakage. If the gap is set wide between the vane 13 and the side block 2 or 3 in consideration of the permanent elongation, there is a possibility that the refrigerant gas leaks from the gap. For this reason, it was difficult to use the T6 treated ingot aluminum alloy.

In order to suppress such permanent elongation, a conventional ingot aluminum alloy is treated with T7. However, in this T7 treatment, HRB 78 or more could not be guaranteed in mass production.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and has a high hardness, a small permanent elongation, and a method of manufacturing an inexpensive wear-resistant aluminum alloy extruded material for a compressor. An object is to provide a gas compressor using an aluminum alloy extruded material.

[0016]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a gas compressor having a compression chamber in which refrigerant gas is sucked, compressed and discharged, and a sliding member forming the compression chamber or a sliding member of the sliding member. 8-15% Si and 8-15%
% Cu and 0.1 to 2.0% Mg, the balance being aluminum and unavoidable impurities, and 60 particles / mm of Si particles of 10 μm to 100 μm in the alloy structure.
It is characterized by using an abrasion-resistant aluminum alloy extruded material containing ² or less and uniformly dispersing Si particles of 10 μm or less and other crystallized substances at a total area ratio of 40% or less.

A sliding member forming a compression chamber of the gas compressor or a base material of the sliding member is made of a wear-resistant aluminum alloy extruded material. The sliding member can be processed and used as it is without plating or the like, but may be used as a base material of the sliding member and the outer periphery thereof may be plated and used.

By using a wear-resistant aluminum alloy extruded material, the life of the gas compressor can be extended and the cost can be reduced. Further, the invention is characterized in that the sliding member or the base material of the sliding member has a hardness of HRB78 or more.

Since the hardness is HRB78 or more, the plating crack of the vane can be prevented. Since HRB78 is guaranteed at the minimum hardness during mass production, it is suitable for a sliding member forming a compression chamber.

Further, the present invention is characterized in that the sliding member or the base material of the sliding member has a coefficient of thermal expansion of 21.5 × 10 ⁻⁶ or less.

Since the coefficient of thermal expansion is small, the expansion of the vane due to heat during operation can be suppressed to a small value. For this reason, the permanent elongation is small, inexpensive, and suitable for a sliding member forming a compression chamber.

Further, according to the present invention, the sliding member is a vane that slides along an inner peripheral surface of the outer wall of a cylindrical cylinder forming an outer wall of the compression chamber.
A base material using the wear-resistant aluminum alloy extruded material,
And a plating containing Ni adhered in a film shape around the base material.

By using the wear-resistant aluminum alloy extruded material for the vane forming the compression chamber of the gas compressor,
Plating cracks of the vane are less likely to occur, and the elongation of the vane due to heat during operation can be kept small. And a vane can be manufactured cheaply.

Further, the present invention provides a wear-resistant aluminum alloy for a compressor.
Is a method for producing an aluminum alloy extruded material, wherein 8 to 15% of Si
And 8 to 15% of Cu and 0.1 to 2.0% of Mg
The balance is made up of aluminum and unavoidable impurities.
The gold was solution treated at 480-500 ° C. for 2-4 hours.
After quenching, over-aging at 190-210 ° C
Thereby, in the alloy structure, 10 μm or more and 100 μm or less
60 Si particles / mm² Including below and below 10μm
Area of less than 40% of total Si particles and other crystallized substances
Wear-resistant aluminum alloy extruded material with uniform distribution
Is manufactured.

Si is added in an amount of 8 to 15%. By adding Si, hard primary crystal Si and eutectic Si particles are dispersed in the base material,
Improves base material altitude and wear resistance. In addition, the coefficient of thermal expansion decreases as the amount of addition increases (FIG. 10).

However, when the Si content is less than the lower limit, the effect is small, and when the Si content is more than the upper limit, coarse primary crystal Si is generated, so that the mechanical properties are deteriorated and the extrudability is poor. And problems such as shortening of the tool life in cutting occur. Therefore, the above composition range is desirable, and especially 10.0 to 12.0% is preferred.

Further, Cu is added in an amount of 8 to 15%. Cu is solid solution hardened in the aluminum matrix, or A
The hardness of the base material is improved by precipitating the l-Cu (-Mg) phase. Cu has the effect of reducing the coefficient of thermal expansion (FIG. 10).

According to the phase diagram, the maximum solid solution amount of Cu in Al is 5
However, considering that it occurs as a crystallized substance during casting, it is desirable to add 8.0% or more in order to make the amount of Cu effective for the solid solution / precipitation effect sufficient, and 15.0%.
%, The above effect is saturated, and at the same time, mechanical properties are degraded due to an increase in coarse crystals. A more preferred composition range is 9.0 to 12.0%.

Further, Mg is added in an amount of 0.1 to 2.0%.
Mg forms precipitates with Si and Cu and improves the hardness of the base material. If the addition amount is less than 0.1%, the effect is small, and if it exceeds 2.0%, the effect is saturated. Therefore, the composition range was determined as described above.

The extruded wear-resistant aluminum alloy is formed by extrusion after melt casting. A predetermined mechanical property is obtained by subjecting the extruded product to a solution treatment and an aging treatment.

After a solution treatment at 480 to 500 ° C. for 2 to 4 hours, quenching is performed. The solution treatment is performed for the purpose of sufficiently dissolving the solute elements of Cu, Mg, and Si in the parent phase to form precipitates in the subsequent aging treatment. If the temperature is lower than 480 ° C., the solid solution amount of the solute element is not sufficient, which causes insufficient hardness after aging.

If the temperature exceeds 500 ° C., eutectic melting occurs, and there is a possibility that defects such as blisters may occur in the material. Therefore, the solution treatment temperature should be within the above range, and particularly preferably about 495 to 500 ° C. On the other hand, if the solution time is less than 2 hours, the solid solution of the solute element will not be sufficiently dissolved.

Next, an overaging treatment is performed at 190 to 210 ° C. The aging temperature is preferably around 200 ° C. The reason is that, when the present alloy is aged at a temperature higher than 210 ° C., the maximum hardness in the aging curve decreases, and it becomes impossible to obtain a predetermined hardness. Also, it is preferable to use this alloy by overaging to obtain high dimensional stability,
When aging at low temperatures, it takes a long time to reach overaging. Therefore, the above aging temperature is desirable.

The aging time should be determined within the range of 2 to 10 hours, depending on the application, in which sufficient hardness and good dimensional stability can be achieved at the same time. As described above, the wear-resistant aluminum alloy extruded material has high hardness, small permanent elongation, and can be made inexpensive.

[0035]

Embodiments of the present invention will be described below. In FIG. 16, the base material 31 of the vane 13 is
Made of extruded wear-resistant aluminum alloy. This extruded wear-resistant aluminum alloy has an S content of 8 to 15%.
i, 8 to 15% of Cu, and 0.1 to 2.0% of Mg, with the balance being aluminum and unavoidable impurities. Then, a Ni-based plating 33 having a film thickness of about 10 to 30 μm is applied to this surface.

[0036]

FIG. 1 shows the chemical composition of a trial alloy of a wear-resistant aluminum alloy extruded material. Alloy No. whose Cu content is 8.0% or more. 10 (Example 1) and alloy no. 5 (Example 2), alloy no. 6 (Example 3), alloy no. No. 7 (Example 4) is an example of the present invention. 0 (Comparative Example 1) and Alloy No. 1 (Comparative Example 2) was compared as an example of a conventional product. The manufacturing conditions are
It is as follows.

An alloy having the above composition was added to 3 inches (prototype alloy N
o. 1, No. 5-No. 7) and 8 inches (Alloy N)
o. 0, No. 10) After casting into a billet,
The homogenization treatment is performed at 90 to 500 ° C for 10 hours, and the extruded product speed is 2 to 2.5 m / min. And extruded into a 3.5 mm thick flat plate. The product thus produced was cut into about 30 mm, subjected to a solution treatment at 495 ± 2 ° C. × 2.5 hours, quenched with water, and immediately subjected to an aging treatment at 200 ° C. × 2 to 8 hours.

The results of microstructure observation, thermal expansion coefficient, hardness (HRB), and dimensional change measurement at 200 ° C. heat treatment are shown below. The coefficient of thermal expansion was from room temperature to 300 ° C., and the dimensional change was the maximum value of the dimensional change when the heat-treated product was aged at 200 ° C. for 2, 6, and 8 hours.

First, the microstructure will be described. 2 to 5 show the microstructure of the product of the present invention, and FIGS. 6 and 7 show the microstructure of the conventional product. In all the alloys, there were eutectic Si that appeared dark gray and Cu-based crystals that appeared pale gray, and rarely coarse primary crystal Si was observed.

The distribution of eutectic Si is determined by the alloy No. in the present invention.
10 looks uniform and finer than others. Alloy N
O. In No. 10, the primary crystal Si was extremely small. This is probably because the cooling rate during solidification is high. For other alloys, the eutectic Si size is not uniform,
i also had a thickness of 90 μm or less.

However, the average size of eutectic Si is alloy N
O. All alloys including No. 10 were 3.1 to 3.5 μm, and there was no significant difference. The area ratio of eutectic Si is determined by alloy N
O. 10 was large, but the difference in characteristics due to this is unknown.

Regarding the Cu-based crystallized product, the product of the present invention having a large amount of added Cu accounts for 20% or more, which is 1% of the conventional product.
It is more than 6%. However, the alloy NO. In No. 10, although the amount of Cu added was increased, it was 16.3%, which was comparable to that of the conventional product. The crystal size and area ratio were measured at 0.1
The observation was performed by observing a visual field of about 1 mm ^{2 in two} or three visual fields.

From the above results, the characteristics of the structure of the product of the present invention are as follows: primary crystal Si size: 90 μm or less, eutectic Si size: 4 μm
Hereinafter, the eutectic Si area ratio: 14 to 18%, and the Cu-based crystal area ratio: 16 to 21%.

Next, FIG. 8 shows a comparison of various properties of the invention product and the conventional product. The product of the present invention has a particularly increased Cu content as compared with the conventional product. In addition, the amount of Cu and the amount of Mg were changed and the influence was examined.

First, the coefficient of thermal expansion will be described. FIG. 9 shows the relationship between the alloy composition and the coefficient of linear expansion. According to FIG. 9, the effect of the amount of Mg on the coefficient of thermal expansion is small in the composition range in which it is performed, and the effect becomes smaller as the amount of Cu increases.

FIG. 10 shows the effect of the added elements on the coefficient of thermal expansion of the Al alloy. According to this, the addition of Cu decreases the coefficient of thermal expansion and the addition of Mg increases the coefficient of thermal expansion. This is because the coefficient of thermal expansion of Cu is smaller than the coefficient of thermal expansion of Al and the coefficient of thermal expansion of Mg is larger. It is considered that the combined effect of these effects determines the coefficient of thermal expansion of the product.

However, in this embodiment, since the amount of Mg added to Cu is small, it seems that the coefficient of thermal expansion seems to be influenced only by the amount of Cu. Therefore, the product of the present invention in which Cu was increased was able to reduce the coefficient of thermal expansion by at most 1.2 × 10 ^{−6 as} compared with the conventional product.

Next, the hardness (HRB) will be described.
The hardness is improved with an increase in both the amounts of Cu and Mg, and it is considered that the increase in Al—Cu—Mg or Mg ₂ Si precipitates contributes to the hardness.

FIG. 11 shows the relationship between the amount of Cu and the amount of Mg and HRB. The effect of increasing the hardness by Cu was confirmed when the amount of Cu added was up to 12%. In particular, the hardness is remarkably increased when the added amount of Cu is 7.5% to 9.5%. The hardness also increased with an increase in the amount of Mg, but the effect was small.

According to the microstructure observation results, the invention alloy No. having the same Cu crystallized amount was obtained. 10 and the conventional alloy No. 0
And alloy 1 when compared with alloy N under the same aging condition
O. 10 had the highest hardness. This seems to be due to the fact that the increment of Cu with respect to the conventional product forms a solid solution in the mother phase, and is effective for age hardening.

In comparison with these, the alloy 5 with a large addition of Cu,
In Nos. 6 and 7, since the amount of Cu crystallized substances increased,
It seems that the Cu addition substantially approaches the saturated state at around 9.5%, and the hardness increase from 9.5% to 12% with Cu addition is small. However, it is not clear why the amount of crystallization does not change from 9.6% to 12% after the amount of crystallization increases from 9.4% to 9.6% of Cu addition.

In the case of the alloy containing a large amount of Mg, the hardness was slightly increased, but the effect is not clear. For example, alloy NO. When alloy 7 is compared with alloy 7, alloy 7 is alloy N
O. The amount of Cu is slightly higher than that of 10, but the amount of crystallized matter is also large,
It does not seem that Cu sufficiently contributes to precipitation hardening. In consideration of this, the alloy No. 7 of the alloy 7 was not used. It can be said that the hardness increase with respect to 10 is large.

The reason is as follows.
It is considered that the 79% increment influences the increase in hardness, while alloy NO. In alloy No. 0 and alloy 1, the increase in hardness of alloy 1 was small. As described above, in this experiment, in particular, by setting the Cu content to 9.4 to 12%, the Cu content was about 1.
The improvement of HRB of 5 to 4 was realized.

Next, a description will be given of a dimensional change (Mizuki growth) due to precipitation. The amount of dimensional change was measured by preparing a test piece having a size of 3 mm × 5 mm × 29 mm in length from the aged extrudate and measuring the length with a micrometer before and after heat treatment at 200 ° C.

FIG. 12 shows the amounts of Cu and Mg and 200 ° C. × 8.
The relationship of the maximum value of the dimensional change of the time-aged product was shown. According to this, it is understood that the dimensional change is reduced by the composition in which the added amount of Mg is large. This dimensional change is caused by the precipitation of the solute element, and it is considered that the value of the dimensional change increases as the degree of supersaturation of the initial parent phase increases.

Therefore, the product of the present invention, which has a large amount of added elements and high hardness, is considered to have a supersaturation degree equal to or higher than that of the conventional product under the same aging conditions, and therefore the dimensional change is larger than that of the conventional product. Is expected.

However, as shown in FIG. 8, there was a case where the dimensional change of the conventional product was larger than that of the product of the present invention. In this regard, as shown in FIG.
It has been reported that there is an effect of suppressing the dimensional change of the -Cu alloy, and in this experiment, too, the dimensional change of the alloy containing a large amount of Mg was small.

Although the reason for this is not clearly understood, it has been found that the value of the dimensional change differs depending on the type of the precipitated phase. In this experiment, Cu and Mg
Since an alloy with a different amount is made, Al-C
There are two types of u-Mg precipitates and Al-Cu precipitates,
It is believed that the ratio is different for each alloy. Of these two types of precipitates, the precipitation of Al-Cu-Mg has a smaller effect on the parent phase, so it is presumed that the dimensional change becomes smaller with more Mg.

According to FIG. 8, the hardness of the product of the present invention was higher than that of the conventional product under the same aging condition as described above.
On the other hand, the dimensional change varies between samples, and the invention is not particularly superior. However, considering that the product of the present invention has a higher hardness than the conventional product, it is possible to obtain the same hardness as the conventional product even if the dimensional change is made smaller by overaging, or while suppressing the increase in the dimensional change. High hardness can be obtained.

For example, alloy NO. Comparing Alloy No. 10 with Alloy 1, under the same aging conditions, Alloy 1 has smaller dimensional change, but the hardness is lower than that of Alloy No. 1. 10 is higher. However, alloy 1
200 ° C. × 6 hours and alloy NO. 10 is more overaged 2
When the temperature of the alloy NO. 10 has higher hardness and the same dimensional change. As described above, in the present invention, by adjusting the aging conditions, both the maintenance of the hardness and the suppression of the dimensional change can be achieved.

Next, the extruded wear-resistant aluminum alloy produced as described above is cut or polished to form the base material 31 of the vane 13. In addition, the base material 3 which has been processed
A plating 33 made of a compound of nickel and phosphorus having a film thickness of about 20 μm is applied to the surface of 1. The plating may be electrolytic plating or electroless plating. Since the silicon particles are eutectic, plating can be uniformly applied to the surface of the base material 31. The hardness of the base material 31 at this time is, for example, H
RB80.

As described above, the vane 13 of the gas compressor 50
Inexpensive abrasion-resistant aluminum alloy extruded material can be used, so that significant cost reduction can be realized.

[0063]

As described above, according to the present invention, a predetermined amount of Si, Cu,
By including Mg, the hardness can be increased, the permanent elongation can be reduced, and the cost can be reduced. Then, it is possible to guarantee the HRB 78 with the minimum hardness at the time of mass production.

Further, by using the wear-resistant aluminum alloy extruded material for a sliding member or the like forming a compression chamber of a gas compressor, the sliding member can be manufactured at low cost.

[Brief description of the drawings]

Fig. 1 Chemical composition of a trial alloy of wear-resistant aluminum alloy extruded material

FIG. 2 is a microstructure (micrograph) of Example 1.

FIG. 3 is a microstructure (micrograph) of Example 2.

FIG. 4 is a microstructure (micrograph) of Example 3.

FIG. 5 is a microstructure (micrograph) of Example 4.

FIG. 6 is a microstructure (micrograph) of Comparative Example 1.

FIG. 7 is a microstructure (micrograph) of Comparative Example 2.

FIG. 8 is a diagram showing a comparison of various properties of the invention product and the conventional product.

FIG. 9 is a diagram showing a relationship between an alloy composition and a linear expansion coefficient.

FIG. 10: Effect of added elements on thermal expansion coefficient of Al alloy

FIG. 11 shows a relationship between Cu amount and Mg amount and HRB.

FIG. 12 Relationship between Cu and Mg contents and maximum value of dimensional change of aged product at 200 ° C. for 8 hours.

FIG. 13 shows the effect of M on the maximum dimensional change of an Al—Cu alloy.
Effect of g

FIG. 14 is a configuration diagram of a gas compressor.

FIG. 15 is a sectional view taken along the line AA in FIG. 14;

FIG. 16 is a sectional view of a vane.

[Explanation of symbols]

 13 Vane 31 Base material 33 Plating 50 Gas compressor

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C22F 1/00 630 C22F 1/00 630D 651 651Z 691 691B 691C (72) Inventor Toshimitsu Tsutsui 6 Kaiyamacho, Sakai City 224, Showa Aluminum Co., Ltd. (72) Inventor Murata, etc. 6,224, Kaiyamacho, Sakai City Inside, Showa Aluminum Co., Ltd. (72) Isao Murase 6,224, Kaiyamacho, Sakai City Showa Aluminum Co., Ltd. F-term (reference) 4E029 AA06

Claims (5)

[Claims] 1. A gas compressor having a compression chamber in which a refrigerant gas is sucked, compressed and discharged, wherein a sliding member forming the compression chamber or a base material of the sliding member has 8 to 15%
Of Si, 8 to 15% of Cu, and 0.1 to 2.0% of M
g, and the balance consists of aluminum and unavoidable impurities. The alloy structure has a Si content of 10 μm or more and 100 μm or less.
It is characterized by using a wear-resistant aluminum alloy extruded material containing 60 particles / mm ² or less, and uniformly distributing Si particles and other crystallized substances of 10 μm or less at an area ratio of 40% or less in total. Gas compressor. 2. The gas compressor according to claim 1, wherein said sliding member or a base material of said sliding member has a hardness of HRB78 or more. 3. The gas compressor according to claim 1, wherein the sliding member or a base material of the sliding member has a thermal expansion coefficient of 21.5 × 10 ⁻⁶ or less. . 4. The sliding member is a vane that slides along an inner peripheral surface of a cylindrical cylinder forming an outer wall of the compression chamber, and the vane is made of the wear-resistant aluminum. 4. The gas compressor according to claim 1, further comprising: a base material using an alloy extruded material; and a plating containing Ni adhered in a film shape around the base material. 5. 8-15% Si and 8-15% Cu
And 0.1 to 2.0% of Mg, and the balance being an alloy of aluminum and unavoidable impurities of 480 to 500%.
C. for 2-4 hours, then quenched,
By overaging at 210 ° C., Si particles of 10 μm or more and 100 μm or less in the alloy structure are 60 particles / mm.
Abrasion resistant aluminum alloy extruded material containing at least ² and containing Si particles and other crystallized substances of 10 μm or less uniformly distributed at a total area ratio of 40% or less. Manufacturing method of extrudable aluminum alloy.