JPH02294441A - Wear-resistant fiber reinforced aluminum alloy member - Google Patents

Abstract

PURPOSE:To improve the settling resistance of the wear-resistant part in a fiber reinforced Al alloy member without deteriorating the strength in the fiber reinforced part by increasing the weight ratio of Si)2 as a binder to alumina short tiber in the wear resistant part. CONSTITUTION:In a wear-resistant A alloy having a fiber reinforced part reinforced by alumina short fiber bound by SiO2 as an inorganic binder, the weight ratio of SiO2 to alumina short fiber in the wear-resistant part of the fiber reinforced part is increased compared to that of the other part. For example, the weight ratio of SiO2 to alumina short fiber is regulated to about 15wt. in the wear-resistant part and the ratio is regulated to about 5% in the other part. In this way, the wear resistance and settling resistance of the wear-resistant part are improved and the strength of the fiber reinforced part excluding the wear-resistant part can be secured.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a wear-resistant fiber-reinforced aluminum alloy member composited with short alumina fibers.

[Prior art]

In recent years, various types of fiber-reinforced metals (FRM), which are composites of high-strength, high-elastic reinforcing fibers made of boron, carbon, alumina, silicon carbide, etc., with various metals or alloys, have been developed and have been widely used mainly for the purpose of weight reduction. Composites using reinforcing fibers have been progressing even in aluminum alloy parts, which had previously been
Among these, wear-resistant fiber-reinforced aluminum alloy members, which are composites of short alumina fibers as reinforcing fibers, are being widely put into practical use.

In the above-mentioned wear-resistant aluminum alloy member, a fiber-reinforced part is formed by compounding the peripheral part with alumina short fibers, including wear-resistant parts such as friction sliding parts and friction contact parts. In addition to increasing the wear resistance and fatigue resistance of the parts, the strength of the surrounding areas was also increased.

On the other hand, as described in Japanese Patent Publication No. 62-38412, the fiber-reinforced portion is formed into a composite structure of the alloy and fiber material by casting a fiber molded body into a molten aluminum alloy. That is, a fiber molded body is made by molding and firing a slurry containing alumina short fibers as the main raw material and an inorganic binder such as SiOH into a predetermined shape, fiber volume ratio, and fiber orientation, and then inserting the fiber molded body into a casting cavity. The molten aluminum alloy, which is poured under pressure into the casting cavity, penetrates into the fiber molded body.
A fiber-reinforced portion was formed by filling the fibers.

[Problem to be solved by the invention]

In general, the abrasion resistance and fatigue resistance of the wear-resistant part can be improved by increasing the fiber volume fraction of alumina short fibers in the fiber molded article. There is a limit value (fiber volume fraction limit value 15%) associated with the penetration and filling of molten metal into the fiber molded body at times, and if the fiber volume fraction is increased beyond that limit value, it becomes difficult for the molten metal to penetrate into the fiber molded body, so the molten metal It could not be put to practical use because it would lead to insufficient filling of fibers and reduce the strength of the fiber-reinforced part, and there was a limit to the ability to improve the wear resistance and fatigue resistance of the wear-resistant part by increasing the fiber volume percentage. .

Therefore, the applicant of the present application focused on the wear resistance of SiOz as an inorganic binder (usually added to about 11 t% based on the fiber component) used when forming a fiber molded body,
It has been confirmed that increasing the weight ratio of St 02 to alumina short fibers improves wear resistance and fatigue resistance, but in this case, increasing the weight ratio of St O■ to alumina short fibers above a certain value. This poses a problem in that the strength of the fiber-reinforced portion decreases, making it impossible to put it into practical use.

An object of the present invention is to provide a wear-resistant fiber-reinforced aluminum alloy member in which the abrasion resistance and fatigue resistance of the wear-resistant portion are improved without reducing the strength of the fiber-reinforced portion.

[Means to solve the problem]

The wear-resistant fiber-reinforced aluminum alloy member according to the present invention is a wear-resistant aluminum alloy member having at least a part of the fiber-reinforced portion reinforced with alumina short fibers bonded with S302 as an inorganic binder. The wear-resistant part of the reinforced part has a higher SiO2 content than the part other than the wear-resistant part of the fiber-reinforced part.
It has a higher weight ratio.

[Effect]

In the wear-resistant fiber-reinforced aluminum alloy member according to the present invention, the wear-resistant part of the fiber-reinforced part has a high weight ratio of SiOx to alumina short fibers, so that the wear resistance is improved due to the wear resistance of Si02. It can improve the properties and resistance to fatigue.

On the other hand, the part of the fiber reinforced part other than the wear-resistant part is St
Since the weight ratio of 02 to the short alumina fibers is low, the molten metal is sufficiently filled into the fiber molded body, resulting in a high-strength composite.

〔Effect of the invention〕

According to the wear-resistant fiber-reinforced aluminum alloy member according to the present invention, as explained in the [Function] section above, the weight ratio of St 02 to alumina short fibers in the wear-resistant part of the fiber-reinforced part can be increased. It is possible to improve the wear resistance and fatigue resistance of the wear-resistant part,
Effects such as being able to prevent a decrease in strength of parts other than the wear-resistant parts can be obtained.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

In this embodiment, the present invention is applied to an aluminum alloy rotor of a rotary piston engine.

To briefly explain the above-mentioned rotary piston engine RE, as shown in FIG. A planetary rotational motion is performed along the trochoid peripheral surface 4 of the rotor housing 1 while forming a working chamber 3 between the rotor housing 1 and the rotor housing 1 .

A shaft hole 5 is formed in the center of the side surface of the rotor 2, a rotor gear 6 is provided on the inner peripheral surface of the end of the shaft hole 5, and an eccentric shaft 8 has an external gear 7 that meshes with the rotor gear 6 in the shaft hole 5. is installed.

Furthermore, two oil seals 9 are provided on the side surface of the roller 2 concentrically with the shaft hole 5 to make the rotor 2 oil-tight.
A side seal 10 is provided around the side surface of the rotor 2 to make the space between each working chamber 3 and the side housing airtight.

As shown in FIG.
is formed, an apesox seal groove 13 is formed in the apesox part 11, a corner seal 14 connecting the side seals 10 on both sides is attached to the corner seal mounting hole 12, and the apesox seal groove 13 is provided with a seal groove 13 for connecting the side seals 10 on both sides. Metal apex seal 15 for airtightly sealing
The outer end of the apesox seal 15 protrudes from the apesox seal groove 13 and comes into contact with the trochoid circumferential surface 4.
The trochoidal circle is biased through the force.

During the planetary rotation motion of the rotor 2, the aberthox seal 15 always slides in contact with the trochoid circumferential surface 4 and repeatedly protrudes and retracts from the aberthok seal groove 13. Is it possible to increase the strength of the Avex Seal Hawk l3 and corner seal mounting hole 12 to which the Avex Seal 15 is attached? For this purpose, a fiber-reinforced part 17 reinforced with alumina short fibers is formed in the part of the avex part 11 shown by the dashed line in FIG. A wear-resistant portion 18 with improved wear resistance and fatigue resistance is formed in the portion shown by the chain line.

That is, as will be described later, the portion of the fiber-reinforced portion 17 excluding the wear-resistant portion 18 is made of SiO2 as an inorganic binder.
A predetermined strength is ensured by compounding the fiber molded body with a weight ratio of 5 wt % to the alumina short fibers in aluminum alloy, and the wear-resistant part 18 has a weight ratio of 15 wt % to the alumina short fibers of SiOz. I made it into % lol! i
By combining fiber molded bodies with aluminum alloys, it is possible to improve wear resistance and fatigue resistance.

Figures 3 and 4 show the results of testing the mechanical properties of the wear-resistant portion 18. For comparison, the weight ratio of SiO■ to the alumina short fibers was 5%, 10%, and 2.
Regarding the wear-resistant part 18, which is a composite of 0% fiber molded body and aluminum alloy? The test was conducted.

The rotor 2 used in the test was manufactured using the same method as described below. It was manufactured by 8 hot water forging, and was subjected to heat treatment by water cooling at 500°C for 5 hours, followed by aging treatment at 180°C for 6 hours.

In the tensile strength test results shown in FIG. 3, the tensile strength of the wear-resistant portion 18 decreases as the weight ratio of Si 2 O to short alumina fibers increases.

On the other hand, in the Brinell hardness test, which shows wear resistance and set resistance, as shown in FIG. Si O! When the weight ratio is 15%, the hardness is increased by about 4% compared to the conventional case (weight ratio 10%), and the wear resistance and set-out resistance of the wear-resistant portion 18 are improved.

Next, the method for manufacturing the rotor 2 will be explained in FIGS. 5 to 11.
This will be explained with reference to the figures.

The rotor 2 is manufactured by using a molten metal forging device 20 as shown in FIG. In the casting cavity 25 to be formed, three first molded bodies 26 for forming the fiber-reinforced part work 7 are arranged at predetermined positions through the upper mold 21 and the lower mold 22, and the upper core 23 A fiber-reinforced portion 2 is formed around the shaft hole 5 of the rotor 2 via the lower core 24.
A second molded body 28 for forming 7 is disposed.

Note that the first molded body 26 and the second molded body 28 are preheated together with the upper mold 21 and the lower mold 22, and the preheating temperature is set to 500°C.
Cast while maintaining the

After the upper mold 21 and the lower mold 22 are closed, a molten metal 29 of an aluminum alloy corresponding to JIS AC8A is poured into the casting cavity 25 under pressure via a plunger 30. The pressure of the molten metal 29 is set to 500 kg/cal, and the temperature is set to 720°C. During this casting, the molten metal 29 is instantly filled into the casting cavity 25 and held under pressure for a predetermined period of time until the molten metal 29 solidifies.

After pouring the molten metal, after a predetermined period of time has elapsed and the molten metal has solidified, the upper mold 21
The lower mold 22 is opened and the rotor casting 2A is taken out. FIG. 6 shows a rotor cast product 2A, in which a fiber-reinforced portion 17A (see FIG. 10) is formed in each abex portion 11A, and a rotor gear 6 is attached to the rotor 2 around the shaft hole 5. A fiber-reinforced portion 27 is formed to reinforce the area around the 12 pin holes. Here, a method for manufacturing the first molded body 26 will be explained.

The first molded body 26 includes a cylindrical inner molded body 26A that forms the wear-resistant part 18 of the fiber-reinforced part 17 and a cylindrical outer molded body 26B that forms the wear-resistant part 18 of the fiber-reinforced part 17. 7(a)-(C) show the manufacturing process of the inner molded body 26A, and FIG. 8(a)-(C) show the manufacturing process of the inner molded body 26A.
(e) shows the manufacturing process of the outer molded body 26B.

First, a method for manufacturing the inner molded body 26A will be explained.

In the first step, the raw materials for the inner molded body 26A shown in Table 1 are prepared, and as shown in FIG.
Prepare. Here, in order to improve the abrasion resistance and resistance to fatigue of the wear-resistant portion 18, St O. The weight ratio has been increased to 15%.

(Margin below this page) Next, the inner mold 34 is immersed in the slurry 32.

A filter 35 is attached to the upper end of the hollow molding part 34a of the inner mold 34, and a suction pipe 36 communicating with the molding part 34a via the filter 35 is installed to the upper part of the inner mold 34. Reference numeral 36 is connected to a pump (not shown), and by operating the pump, the slurry 32 is sucked and filled into the forming part 34a as shown in FIG. 7 (al).

In the second step, the slurry 3 filled in the forming part 34a
2 is shown in FIG. 7 (bl).
and a lower mold 39 into a molding chamber 40, and a pressurizing tool 41
The inner molded body 26A is molded by applying pressure so that it has a predetermined shape, fiber volume ratio, and fiber orientation.

In the third step, the inner molded body 26A is placed in the molding chamber 4.
100 to remove the moisture inside.
℃ atmosphere, followed by heat treatment at 600° C. for 2 hours to remove the organic binder, and then firing treatment at 1000° C. for 1 hour to bake the inorganic binder, SiOz. FIG. 7 (C>) shows a cylindrical inner molded body 26A manufactured in this manner.

Next, a method for manufacturing the outer molded body 26B will be briefly explained.

In the first step, the raw materials for the outer molded body 26B shown in Table 1 are prepared, and the slurry 33 prepared in the solution tank 50 as shown in FIG. Aspirate and fill.

Here, in order to ensure the strength of the portions of the fiber reinforced portion 17 other than the wear-resistant portion 18, an inorganic binder such as SiO.
The weight ratio of the fiber component to the fiber component is set at 5% as usual.

In the second step, the slurry filled in the forming part 51a
33 as shown in FIG. 8(b), the upper mold 5 of the molding device 52
The outer molded product 26B is transferred to a molding chamber 55 formed by a lower die 54 and a lower mold 54, and pressurized with a pressurizing tool 56 to obtain a predetermined shape, fiber volume ratio, and fiber orientation.

In the third step, the outer molded body 26B is placed in the molding chamber 5.
The molded body 26A is taken out from No. 5 and subjected to drying treatment, heating treatment, and firing treatment in the same manner as the inch molded body 26A. FIG. 8(C) shows the cylindrical outer molded body 26B thus completed.

In the fourth step, as shown in FIG. 9, the first molded body 26 is completed by fitting the inner molded body 26A into the axial center of the outer molded body 26B. Note that the fiber volume percentage of the alumina short fibers in the first molded body 26 is 10%.
It is set to .

The first molded body 26 manufactured in this manner is cast in the molten metal 29 during the casting of the rotor 2 as described above, and is composited into the aphex portion 11A of the rotor cast product 2A as shown in FIG. This forms a fiber-reinforced portion 17A.

By cutting the rotor casting product 2A, the first
As shown in FIG. 1, an avex seal groove 13 and a corner seal mounting hole 12 are formed.As shown in FIG.
A fiber-reinforced part 17 in which the first molded body 26 is composited is formed in the apesox part 11, and the groove of the apesox seal ill 13 at the tip of the fiber-reinforced part 17 is formed. The upper half of the inner molded body 26
A wear-resistant portion 18 in which A is combined is formed.

Since the wear-resistant part 18 contains Si02 at a high weight ratio to the alumina short fibers, it contains high hardness Si02.
O■ improves the abrasion resistance and fatigue resistance of the wear-resistant part 18, while the fiber-reinforced part 17 excluding the wear-resistant part l8 has a weight ratio of SiO■ to the alumina short fibers of the wear-resistant part 18. Since it is lower, sufficient strength is ensured.

In this embodiment, the case where the present invention is applied to the aluminum alloy rotor 2 has been described, but in addition to this, for example, the aluminum alloy cylinder lychee (
The SiO■ content in the inner periphery is increased and the S content in the outer periphery is increased.
i 02 content) or a piston pin (by reducing the St 02 content on its inner periphery and SiO2 content on its outer periphery)
It goes without saying that the present invention can be similarly applied to aluminum alloy parts in which the entire fiber-reinforced part is made up of fibers, such as aluminum alloy parts in which the z content is increased.

[Brief explanation of the drawing]

The drawings relate to embodiments of the present invention, and Fig. 1 is a cross-sectional view of a rotary piston engine, Fig. 2 is a front view of the apex portion of the rotor, and Fig. 3 is a diagram showing the tensile strength of the wear-resistant portion of the rotor. A diagram showing the test results, Figure 4 is a diagram showing the hardness test results of the wear-resistant part of the rotor, Figure 5 is a sectional view of the main part of the molten metal forging device, and Figure 6 is a front view of the rotor casting. , FIG. 7 (al is a cross-sectional view showing the state in which slurry is sucked into the inner mold, FIG. 7 fb) is a cross-sectional view of the main part of the molding device, FIG. FIG. 8(a) is a sectional view showing a state in which slurry is sucked into the outer mold, FIG. 8(b) is a sectional view of the main part of the molding device, FIG. 8 (Cl is a perspective view of the outer molded body, and FIG. 9 The figure is a perspective view of the first molded body, Figure 10 is a front view of the abex part of the rotor casting, and Figure 11 is a front view of the abex part of the rotor casting after cutting. , 2... Rotor, 17... Fiber reinforced part, 18... Wear resistant part. Fig. 6 Fig. 17A Fig. 3 Sin. amount (wt%) Fig. 4 io 15 20 Sin. amount (wL %) Figure 10 Figure 11 Figure 7 (a) Figure (a) Figure 7 (b) Figure 8 (b) Figure 7 (C)

Claims (1)

[Claims] (1) In a wear-resistant aluminum alloy member having at least a part of the fiber-reinforced portion reinforced with alumina short fibers bonded with SiO_2 as an inorganic binder, the wear-resistant portion of the fiber-reinforced portion is fiber-reinforced. S for the alumina short fibers than for the parts other than the wear-resistant parts.
A wear-resistant fiber-reinforced aluminum alloy member characterized by having a high weight ratio of iO_2.