JPH0649560A - Powdered aluminum composite material - Google Patents

Abstract

PURPOSE:To reduce the thermal expansion coefficient and improve the mechanical strength of a formed scroll for the compressor made of the aluminum composite material. CONSTITUTION:An aluminum borate whicker or a ceramic powder of aluminum borate grains, etc., is mixed with the aluminum powder or the powder consisting essentially of an aluminum alloy, and the mixture is sintered to form a scroll member for the air compressor. According to the test result, the thermal expansion coefficient of this scroll member is reduced, and the strength is improved. Consequently, the airtightness at the compressive part is enhanced, and the compression ratio is increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a powder aluminum composite material formed by sintering aluminum powder as a main component.

[0002]

2. Description of the Related Art A compressor of a scroll type compressor currently used in an air conditioner is relatively rotatable by combining a fixed scroll 2 and a movable scroll 3 in a cylindrical casing as shown in FIG. It is configured by arranging in. The fixed scroll 2 and the movable scroll 3 both have a spiral vane structure, and a plurality of compression chambers 4a that are point-symmetrical to each other are provided between the vane portions 2a and 3a of the two sets of scrolls 2 and 3. ~ 4e are formed.

The blade portion 2 of the fixed scroll 2
By rotating the blade portion 3a of the orbiting scroll 3 around the central axis O of a without rotating by the drive motor, the plurality of compression chambers 4a to 4e are sequentially moved from the outer peripheral portion to the central portion. The volume of the compression chambers 4a to 4e is gradually reduced so that the compression action occurs.

Conventionally, the fixed scroll 2 is
For example, it was formed of aluminum alloy AC8C, and the movable scroll was formed of gray cast iron or aluminum alloy.

[0005]

In the scroll type compressor as described above, it is generally required to increase the compression ratio as much as possible in order to increase the compression efficiency. However, in order to increase the compression ratio, it is necessary to increase the compression ratio. Is required to increase the airtightness between the two sets of scrolls 2 and 3 as much as possible. For that purpose, the coefficient of thermal expansion of the scroll member itself should be further reduced and the mechanical strength should be further improved. Is required.

[0006]

The invention described in each of claims 1 to 7 of the present application has been made for the purpose of responding to the above requests, and is configured as follows.

(1) Structure of the Invention According to Claim 1 The powder aluminum composite material according to claim 1 is formed of a mixed sintered body of a metal powder containing aluminum as a main component and a ceramic powder. .

(2) Structure of the invention of claim 2 In the powder aluminum composite material of the invention of claim 2, in the structure of the invention of claim 1, the ceramic powder is aluminum borate whiskers. It is characterized by.

(3) Structure of the Invention of Claim 3 The powder aluminum composite material of the invention of claim 3 comprises an alloy powder containing aluminum and silicon as main components and aluminum borate whiskers having a volume ratio of 10% or more. It is formed of a mixed sintered body.

(4) Structure of the Invention According to Claim 4 The powder aluminum composite material of the invention according to claim 4 contains aluminum as a main component, and also contains silicon having a volume ratio of 15% or more and copper having a predetermined volume ratio. It is formed of a mixed sintered body of an alloy powder containing magnesium and aluminum borate having a volume ratio of 10% or more.

(5) Constitution of the invention of claim 5 The powder aluminum composite material of the invention of claim 5 is a rapid solidification material which contains aluminum as a main component and further contains silicon in a volume ratio of 15% or more and copper and magnesium. It is formed of a mixed sintered body of aluminum alloy powder and aluminum borate whiskers having a volume ratio of 10% or more.

(6) Structure of the Invention of Claim 6 In the powder aluminum composite material of the invention of claim 6, a mixture of metal powder containing aluminum as a main component and aluminum borate whisker powder is further added with potassium titanate. It is formed of a mixed sintered body containing a predetermined amount of whiskers.

(7) Structure of the Invention of Claim 7 In the powder aluminum composite material of the invention of claim 7, zinc oxide whiskers are further added to a mixture of metal powder containing aluminum as a main component and aluminum borate whiskers. It is formed of a sintered body that is mixed and sintered by adding a predetermined amount.

[0014]

The powdered aluminum composite material of the invention described in each of claims 1 to 7 of the present application is configured as described above, and as a result, the following effects are achieved corresponding to each configuration.

(1) Operation of the invention of claim 1 The powder aluminum composite material of the invention of claim 1 is made from a mixed sintered body of a metal powder containing aluminum as a main component and a ceramic powder as described above. Has been formed.

In the metal powder mixture in which the metal alloy powder containing aluminum (Al) as the main component and the ceramic powder are mixed, both of them are powders, and therefore, compared with the case of mixing in a molten state. The dispersity of both is particularly improved in the mixture, and the uniform dispersibility is significantly increased.

Generally, when a ceramic material is compounded with an aluminum alloy, an aluminum composite material having excellent wear resistance and a low coefficient of thermal expansion can be obtained even when a molten metal having a poor degree of uniform dispersion is mixed.

Therefore, as in the case of the material of the present invention, when the degree of uniform dispersion among them is particularly high, the same effect is further improved.

(2) Operation of the invention of claim 2 In the powder aluminum composite material of the invention of claim 2, as described above, the ceramic powder in the constitution of the invention of claim 1 is specifically It is composed of aluminum acid whiskers.

When a metal alloy powder containing aluminum (Al) as a main component and an aluminum borate whisker powder, which is one of the ceramic-based powders, are mixed, both are powders, so that the mixture in the molten state is Compared with the case, the degree of dispersion of both in the mixture is particularly improved, and the degree of uniform dispersion is remarkably increased.

In general, when aluminum borate whiskers, which is a type of ceramic material, are compounded with an aluminum alloy, an aluminum composite material having excellent wear resistance and a low coefficient of thermal expansion is obtained even when a molten metal having a poor degree of uniform dispersion is mixed. Obtainable.

Therefore, when the degree of uniform dispersion among them is particularly high as in the present invention, the same effect is further improved.

(3) Action of the Invention of Claim 3 As described above, the powdered aluminum composite material of the invention of claim 3 comprises an alloy powder containing aluminum and silicon as main components and a boro alloy having a volume ratio of 10% or more. It is formed from a mixed sintered body with aluminum acid whiskers.

When a metal alloy powder containing aluminum (Al) and silicon (Si) as main components and aluminum borate whisker powder, which is a type of ceramic material, are mixed, both are powders, so that the molten metal Compared with the case of mixing, the dispersity of both in the mixture is particularly improved, and the uniform dispersity is remarkably increased.

Generally, when aluminum borate whiskers, which is a type of ceramic material, are compounded with an aluminum alloy, an aluminum composite material having excellent wear resistance and a low coefficient of thermal expansion can be obtained even when molten metal is mixed. When the aluminum alloy contains silicon (Si), the abrasion resistance thereof is further improved.

Therefore, when the degree of uniform dispersion between them is particularly high, the same effect is further improved, and
In that case, the volume ratio of the aluminum borate whiskers in the whole is best at 10% or more.

(4) Action of the invention of claim 4 The powder aluminum composite material of the invention of claim 4 contains aluminum as a main component, and further contains silicon having a volume ratio of 15% or more and copper having a predetermined volume ratio. It is formed of a mixed sintered body of an alloy powder containing magnesium and aluminum borate having a volume ratio of 10% or more.

When a metal alloy powder containing aluminum (Al) as a main component and containing silicon and copper or magnesium in a volume ratio of 15% or more and a ceramic powder are mixed, both are powders. In addition, as compared with the case of mixing the molten metal, the dispersity of both in the mixture is particularly improved, and the uniform dispersity is remarkably increased.

Generally, when aluminum borate whiskers, which is one type of ceramic material, are compounded with an aluminum alloy, it is possible to obtain an aluminum composite material having excellent wear resistance and a low coefficient of thermal expansion even when molten metal is mixed. In that case, when the above aluminum alloy contains silicon, the wear resistance is particularly improved, and copper and magnesium also improve the mechanical strength.

Therefore, when the degree of uniform dispersion among them is particularly high, the same effect is further improved.

(5) Action of the invention of claim 5 The powder aluminum composite material of the invention of claim 5 contains aluminum as a main component, and rapidly solidifies containing silicon and copper and magnesium in a volume ratio of 15% or more. It is formed of a mixed sintered body of aluminum alloy powder and aluminum borate whiskers having a volume ratio of 10% or more.

When a metal alloy powder containing aluminum (Al) as a main component and containing silicon in a volume ratio of 15% or more, and copper and magnesium, and a ceramic powder are mixed, both are powders. In addition, as compared with the case of mixing the molten metal, the dispersity of both in the mixture is particularly improved, and the uniform dispersity is remarkably increased.

Particularly, in the material of the present invention, since the aluminum alloy is powdered by the rapid solidification method, the fineness thereof is high and the uniform dispersion action is particularly high.

Generally, when a ceramic material is compounded with an aluminum alloy, an aluminum composite material having excellent wear resistance and a low coefficient of thermal expansion can be obtained even when molten metal is mixed. In that case, when the above aluminum alloy contains silicon, the wear resistance is particularly improved, and copper and magnesium also improve the mechanical strength.

Therefore, when the degree of uniform dispersion among them is particularly high, the same effect is further improved.

(6) Action of the invention of claim 6 The powder aluminum composite material of the invention of claim 6 comprises a mixture of a powder containing aluminum as a main component and aluminum borate whisker powder, and further potassium titanate whiskers. Is formed by a mixed sintered body to which a predetermined amount of is added.

When the metal alloy powder containing aluminum (Al) as the main component and the potassium titanate whisker powder are mixed, both of them are powders, and therefore, in the mixture compared to the case of mixing in the molten state. The degree of dispersion of both
The degree of uniform dispersion is remarkably increased.

Generally, by compounding potassium titanate whiskers with an aluminum alloy, an aluminum composite material having excellent wear resistance even when molten metal is mixed and having a particularly low coefficient of thermal expansion can be obtained.

Therefore, when the degree of uniform dispersion between them is particularly high, the same effect is further improved.

(7) Action of the invention of claim 7 The powder aluminum composite material of the invention of claim 7 further comprises zinc oxide whiskers in a mixture of metal powder containing aluminum as a main component and aluminum borate whiskers. It is formed of a sintered body that is mixed and sintered by adding a predetermined amount.

When a metal alloy powder containing aluminum (Al) as a main component and an aluminum borate whisker powder, which is a type of ceramic material, are mixed, both of them are powders, so that they are mixed in a molten state. Compared with the case, the degree of dispersion of both in the mixture is particularly improved, and the degree of uniform dispersion is remarkably increased.

In general, when aluminum borate whiskers, which is a kind of ceramic material, are compounded with an aluminum alloy, it is possible to obtain an aluminum composite material which is excellent in wear resistance even when molten metal is mixed and which has a particularly low coefficient of thermal expansion. .

Therefore, when the degree of uniform dispersion among them is particularly high, the same effect is further improved.

[0044]

As is clear from the above description, in any of the inventions described in claims 1 to 7, the coefficient of thermal expansion can be made sufficiently lower than the conventional one, Moreover, the mechanical strength can be improved.

As a result, when the aluminum composite material is applied to a scroll member of a scroll type compressor, for example,
The airtightness can be increased and the compression ratio can be increased.

Further, in that case, since it is a scroll molded product by powder sintering, it is possible to greatly reduce the number of processing steps.

[0047]

Embodiments of the present invention will be described in detail below.

First, as a metal alloy powder containing aluminum as a main component, Al (aluminum) 50%, Si 25%,
The composition of Cu 4% and Mg 1% is adopted to enhance the mechanical strength. Then, in order to achieve both a low coefficient of thermal expansion and workability, the Si component therein is set to 25%. on the other hand,
Aluminum borate whiskers were selected as the ceramic powder for strengthening and the volume ratio thereof was 20% (material B of the present invention), and the ratio of Al alloy powder / aluminum borate whiskers was 60/10. One (inventive material A) and the same proportion of 40/30 (inventive material C) were used, and a total of three types of aluminum alloy powders were selected (Table 2).
Then, these were uniformly mixed and sintered in a plasma sintering apparatus to manufacture a powder aluminum composite material for scroll.

Next, the density and the thermal expansion coefficient of the powder aluminum composite material produced in this way were measured. It is desirable that this coefficient of thermal expansion be as small as possible in comparison with the above-mentioned existing gray cast iron and aluminum alloy AC8C (see Table 1).

Now, the scroll type compressor (2
HP) will be taken as an example to explain the relationship between the coefficient of thermal expansion and processing accuracy. The diameter of each scroll 2, 3 shown is about 100 mm
In operation, a temperature difference of about 80 ° C. occurs between the low temperature part (outer peripheral part) and the high temperature part (central part). Therefore, for example, if aluminum alloy AC8C (22.0 / 10 ⁶ ° C) is used, the expansion amount D is as follows. As mentioned above, the central part and the outer peripheral part
Since the temperature difference of (50 mm) is 80 ° C., D = 50 × 10 ³ × 80 × 22/10 ⁶ = 8.8 μm, and the processing accuracy is 8 μm or less.
If it is more than that, it causes a big processing error for the scroll.

Now, the above A, B and C are used as the material of the present invention.
Also, choose the conventional aluminum alloy AC8C as a comparison material,
The results of measuring the coefficient of thermal expansion in the range of 50 ° C. to 200 ° C. for each are shown in Table 3 and FIG. Expansion 6
When the target value of less than or equal to μm is set, the material ratios A, B, and B of the present invention, in which the volume ratio of aluminum borate whiskers is 10% or more,
In the case of C, it can be seen that the same target value can be achieved, and the target material can be reliably obtained. Also, for example, 1
When the densification of 00% is assumed, the composite material of the present invention can be considered to be substantially the same as the ingot material, and further, the wear resistance and the
It is considered that hardness increases.

[0052]

[Table 1]

[0053]

[Table 2]

[0054]

[Table 3]

[Brief description of drawings]

FIG. 1 is a characteristic diagram showing the relationship between the coefficient of thermal expansion and processing accuracy of a powder aluminum composite scroll-formed product according to an example of the present invention.

FIG. 2 is a cross-sectional view showing a configuration of a main part (scroll part) of a scroll compressor for an air conditioner.

[Explanation of symbols]

1 is a housing, 2 is a fixed scroll, 3 is a movable scroll,
4a-4e are compression chambers.

Claims (7)

[Claims] 1. A powder aluminum composite material comprising a mixed sintered body of a metal powder containing aluminum as a main component and a ceramic powder. 2. The powder aluminum composite material according to claim 1, wherein the ceramic powder is aluminum borate whiskers. 3. A powder aluminum composite material comprising a mixed sintered body of powder containing aluminum and silicon as main components and aluminum borate whiskers having a volume ratio of 10% or more. 4. A mixed sintered body of aluminum as a main component, and further, an alloy powder containing silicon having a volume ratio of 15% or more and copper and magnesium each having a predetermined volume ratio, and aluminum borate having a volume ratio of 10% or more. Powdered aluminum composite material. 5. A mixture of a rapidly-solidified aluminum alloy powder containing aluminum as a main component and further containing 15% or more by volume of silicon, copper and magnesium, and aluminum borate whiskers having a volume of 10% or more. Powdered aluminum composite material. 6. A powder aluminum composite material comprising a mixed sintered body obtained by further adding a predetermined amount of potassium titanate whiskers to a mixture of metal powder containing aluminum as a main component and aluminum borate whisker powder. 7. A powder aluminum composite material comprising a mixed sintered body obtained by further adding a predetermined amount of zinc oxide whiskers to a mixture of metal powder containing aluminum as a main component and aluminum borate whiskers.