JP3199809B2 - Manufacturing method of composite extruded 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 method of manufacturing a composite extruded member, and more particularly to a method of manufacturing an extruded member composited with a reinforcing material by a powder metallurgy method.

[0002]

2. Description of the Related Art Recently, in order to reduce the weight of an automobile body, wheels and the like have been manufactured from an aluminum alloy. However, from the viewpoint of achieving further weight reduction, a magnesium alloy having a smaller specific gravity than an aluminum alloy is used. (Hereinafter referred to as “Mg alloy”).

However, the Mg alloy itself has low rigidity and large thermal expansion. Therefore, a method of compounding with a reinforcing material such as ceramic has been adopted. As one method of this compounding, for example, as disclosed in JP-A-2-182806, a mixture of an Mg alloy powder and a reinforcing material is hot-pressed by powder metallurgy, compression-molded, and extruded. There is a way.

[0004]

However, the above-mentioned conventional method of manufacturing an extruded member by powder metallurgy has the following problems.

(1) As the Mg alloy powder used in the powder metallurgy method, a fine powder having an average particle diameter of 0.5 mm or less is used. It costs.

(2) The reinforced material is not uniformly dispersed simply by mechanically mixing the reinforcing material particles and the Mg alloy particles. In addition, Mg previously compounded with a reinforcing material by a casting method
The method of collecting the powder from the alloy ingot is troublesome twice, and the yield is low.

(3) The manufacturing process is complicated, and it is necessary to enclose the can while vacuum degassing.

[0008] In view of the above problems, the present invention provides a method for manufacturing an extruded member in which a reinforcing material is uniformly dispersed and a composite extruded member having high rigidity can be obtained without depending on can encapsulation. Aim.

Another object of the present invention is to achieve effective utilization of resources by recycling chips.

[0010]

According to the present invention, there is provided a method of manufacturing a composite extruded member, which comprises the steps of: a maximum particle length (length in a major axis direction) and a thickness;
Ratio, ie maximum length / thickness, or long axis of the particle
And the ratio of the length of the short axis, ie, the length of the long axis / length of the short axis
Is attached to the surface of the flake-like metal particles having a particle size of 10 or more via a volatile liquid, the reinforcing particles having an average particle size smaller than the metal particles. Step to mix with other metal particles that do not have
And flop, given in a heated state by filling the mixture into the mold
The mixture is formed by compression molding in the compression direction of
Metal particles to be oriented almost perpendicular to the compression direction
Forming a allowed compression molded product, followed by extrusion in the compression direction of the compression molded body using an extrusion die, the metal grains forming the compression molded body
Forming a composite extruded member with its cores oriented in the extrusion direction
And a step of performing

One example of the metal particles is light alloy particles, and one example of the reinforcing particles is ceramic metal particles.

[0012] An extrusion forming method for forming a composite extruded member is also provided.
The shape is changed to the mold used in compression molding to form a compression molded body.
You may make it perform by inserting an extrusion die.

[0013]

According to the present invention, the maximum length and thickness of a particle
Of the particle or the ratio of the major axis to the minor axis is 10
On the surface of the flake-shaped metal particles as described above, a reinforcing material particle having an average particle size smaller than the metal particles is adhered via a volatile liquid, and further, the particles to which the reinforcing material is adhered and the reinforcing material are adhered. Not mixed with other metal particles
Powder metallurgy compresses the metal particles that make up the mixture.
Compression molded body oriented almost perpendicular to the shrinking direction
After forming the metal, the metal particles constituting the compression molded body are pressed.
To form a composite extruded member oriented in the dispensing direction
Since it has to, co the reinforcement particles Ru are uniformly distributed
A, it can be metallic particles are sufficiently close contact in one direction only compressed to yield and strength <br/> high degree of composite extrusion member.

[0014] Further, resources can be effectively utilized by reusing the swarf generated during the cutting process of the metal product as the flake-shaped metal particles.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method for manufacturing a composite extruded member according to an embodiment of the present invention will be described with reference to the drawings.

(1) Material Used The flake-like Mg alloy particles used in the present embodiment are AZ80A (ASTM standard), and are chips generated by lathing, milling, drilling and the like. The original material of the cutting powder may be a cast product and a heat-treated product thereof, a die-cast product, a plastic processed product such as forging, and a heat-treated product thereof. As the swarf, use one having a maximum particle length (length in the long axis direction) and a particle thickness ratio of 10 or more, or one having a particle long axis and short axis length ratio of 10 or more. . The composition (% by weight) of AZ80A is shown in Table 1 below.

[0017]

[Table 1]

As the reinforcing material, the average particle size is 0.6 μm, the specific gravity is
3.2 SiC particles were used. The composition (% by weight) of the SiC particles is shown in Table 2 below.

[0019]

[Table 2]

(2) Adhesion of reinforcing particles to metal particles Figure 1 (a)
(D) shows the step of attaching SiC particles to the Mg alloy chips.

Volatile liquid: ethanol 200 cc Reinforcement: SiC powder 6 grams (volume ratio Vf 6%) Mg alloy chips: AZ80A 50 grams Stirring method: mechanical stirring (may be by ultrasonic vibration) First, FIG. 1 (a) As shown in FIG.
And SiC particles 17 and stirred with a stirring rod 18 to obtain SiC
The particles 17 are uniformly dispersed.

Next, as shown in FIG. 1 (b), a wire mesh basket 19 containing Mg alloy chips 20 was prepared.
As shown in (c), the wire mesh basket 19 is immersed in the ethanol solution 16 in which the SiC particles 17 are dispersed, and
The SiC particles 17 are adhered to the surface of 20. Next, as shown in FIG. 1 (d), the Mg alloy chip 20 having the SiC particles 17 adhered to the surface is dried, and all the ethanol liquid is evaporated.

The above ethanol solution contains SiC particles 17
Is used for the purpose of adhering to the surface of the Mg alloy cutting powder 20, and hot water may be used instead of ethanol.

(3) Mg with mixed SiC particles 17 attached
An alloy chip 20 and a Mg alloy chip to which no reinforcing material is adhered are mixed at a volume ratio of 1: 1 to obtain a chip mixture 1.
Get.

(4) Hot pressing and extrusion process diagram 2
(a) to (e) show a step of manufacturing an extruded member from the mixture 1. First, as shown in FIG. 2 (a), the swarf mixture 1 is placed in a container 2 of an extruder which also serves as a molding die in this case. Then, at a pressure of 20 kg / mm ² using the punch 3,
Pre-forming is performed by compressing in one direction at room temperature to obtain a pre-formed body 11. Note that this preforming step may be omitted.

Next, as shown in FIG.
Is heated by heater 4 at a temperature of 370 ° C and a pressure of 80MPa.
And hot pressing is performed to obtain compressed compacts 12 in which the particles of the cuttings are oriented in a direction substantially perpendicular to the compression direction (vertical direction in the figure) (horizontal direction in the figure) and adhere to each other.

Next, as shown in FIG. 2C, the die 5 is inserted into the container 2, and the die 5 is pressed in the compression direction of the compression molded body 12 by the extrusion ram 6 to perform extrusion molding. The composite extruded member 13 in which the particles of the original swarf are oriented in the extruding direction (the vertical direction in the figure) is obtained.

Table 3 below shows the manufacturing conditions for the composite extruded member.

[0029]

[Table 3]

The composite extruded member 13 thus obtained
3 (a), 4 (a) and 5 (a). For reference, FIGS. 3 (b) and 4 (b) show the structures of extruded members manufactured by extruding only Mg alloy chips to which SiC particles are attached.
5 (b). FIGS. 3 (a) and (b) show a magnification of 10
FIGS. 4 (a) and 4 (b) are optical microscope photographs at a magnification of 500 times. 5 (a) and 5 (b) are electron microscope photographs at a magnification of 500 times. As is clear from FIGS. 4 (b) and 5 (b), there is a cavity in the extruded member manufactured only from the Mg alloy chips to which the SiC particles are adhered. Mg alloy chips to which
There are almost no cavities in the composite extruded member made from the mixture with the Mg alloy chips to which nothing is attached.

The specific gravity of the composite extruded member obtained according to the present invention is shown in Table 4 below.

[0032]

[Table 4]

Further, Table 5 below shows the mechanical properties of the composite extruded member obtained by the present invention.

[0034]

[Table 5]

As is apparent from Table 5, the Mg composite extruded member manufactured according to the present invention has an extrusion ratio of 12, V
Those with f6% show excellent mechanical properties. Also,
It can be seen that if the extrusion ratio is 6 or more and Vf is 4% or more, the mechanical properties are not enhanced.

In this embodiment, the Mg alloy chips to which the SiC particles are attached are mixed with the Mg alloy chips, but may be mixed with other dissimilar metals, for example, Al alloy chips.

[Brief description of the drawings]

FIG. 1 is a diagram showing a reinforcing material attaching step in an embodiment of the present invention.

FIG. 2 is a diagram showing a hot press and an extrusion process in an embodiment of the present invention.

FIG. 3 is an optical micrograph showing the structure of an extruded Mg composite member obtained according to an example of the present invention at a magnification of 100 times together with the structure of a comparative example.

FIG. 4 is an optical micrograph showing the same tissue at a magnification of 500 times.

FIG. 5 is an electron micrograph showing the same tissue magnified 500 times.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 Mg swarf mixture 2 Container 3 Punch 4 Heater 5 Extrusion die 11 Preform 12 Compressed body 13 Mg composite extruded member 16 Ethanol liquid 17 SiC particles 20 Mg swarf

Claims (4)

(57) [Claims] 1. The ratio between the maximum length and the thickness of a particle, or a particle
Flake with a length ratio of major axis to minor axis of 10 or more
On the surface of the metal particles, a reinforcing material particle having an average particle size smaller than the metal particles is adhered via a volatile liquid, and the metal particles to which the reinforcing material is adhered are the other particles to which the reinforcing material is not adhered. a step of mixing the metal particles, a predetermined compression in a heated state by filling the mixture into the mold
By forming the mixture in the direction,
Orienting the metal particles substantially perpendicular to the compression direction.
Structure forming a compression molded article, followed by extruding the compression-molded body in the compression direction using an extrusion die, the compression molded article
Extrusion in which metal particles to be oriented are oriented in the extrusion direction.
Preparation of a composite extrusion member, wherein the step of forming the member, in that it consists of. 2. The method according to claim 1, wherein the metal particles are made of light alloy particles, and the reinforcing particles are made of ceramic particles. Preparation of a composite extrusion member according to claim 1, wherein the wherein a said flaky metallic particles swarf. 4. An extruder for forming the composite extruded member.
The shape used in the compression molding to form the compression molded body
Inserting the extrusion die into a mold is performed.
A method for producing a composite extruded member according to claim 1.