JPS60203384A - Production of composite metallic product and piston - Google Patents

Abstract

PURPOSE:To reduce the size of a production installation by welding a composite material composed of ceramics and metal and a metallic material by means such as electron beam, laser or the like. CONSTITUTION:SiC whiskers are disposed in a metallic mold and a molten AC8AAl alloy is poured into the mold then the molten alloy is forged to form a piston head part 1 consisting of the composite material in production of, for example, a piston. On the other hand, a piston body 2 consisting of the AC8AAl alloy is die-cast and the above-mentioned head part 1 is pressed to the body 2. While both materials are rotated, the materials are welded by an electron beam to form a piston 3. The similar effect is also obtainable with a laser, etc. in place of the above-mentioned electron beam. The SiC whiskers may be fibers, particles, foil, etc. and the ceramics may be Al2O3, Si3N4, etc. in addition to SiC as far as the m.p. thereof is >=1,000 deg.C. The matrix and the metallic material may not be of the same alloy as far as both materials have good wettability and are weldable to each other.

Description

DETAILED DESCRIPTION OF THE INVENTION Conventionally, for example, aluminum alloy pistons for diesel engines have been used to improve their heat resistance strength.

As shown in FIG. 1, ceramic fibers were arranged around the head of the piston 7010.

By the way, this piston 01 is cast by placing a ceramic fiber mat in a mold, pouring aluminum alloy hot water into the hot water and applying a pressure of 50 to 100 MPa to the hot water, and infiltrating the aluminum alloy into the ceramic fiber mat. let me,
was forming.

However, in this method, it is necessary to pressurize the entire hot water that forms the piston 01, so there is a problem that the casting equipment becomes large and expensive.

As a result of various researches, the inventors of the present invention discovered that a composite material of ceramics and metal and a metal material can be welded using means such as an electron beam or a laser, thereby making it possible to form a composite material separately. As a result, manufacturing equipment and costs can be significantly reduced.

Two embodiments of the present invention will be specifically described below.

First Example Silicon carbide (SiC) whiskers having the properties shown in Table 1 are placed in a mold, AC8A fulminium alloy melt is poured into the mold and a pressure of 100 MPa is applied (molten metal forging).
A round bar-shaped composite material of 60φ100++l+l+ is formed.

Table 1 Diameter 0.1 to 1.0 μm (mostly 0.2 to 0
．． 5 μm) Length: 50-200 μm Aspect ratio: 50-300 Density: 3.17 gS Bulk density: 003-005 gβ A composite material with a heat resistance of 1.600° contains 18 inches of SiC whiskers (weight ratio).

Next, a round bar-shaped metal material with a diameter of 60 mm and a diameter of 1100 mm was cast using AC8A aluminum alloy.

Subsequently, after removing the oxide film on the end faces of the composite material and the metal material, the two end faces of the composite material and the metal material are brought into contact with each other and electron beam welding is performed under the following conditions while rotating the painting material to form a composite metal material.

Welding conditions Acceleration voltage 150KV Current 30mA Vacuum degree 1O-4Tart Beam diameter 06φ Welding depth 20+n+n Welding speed 1m/IVIIN Beam irradiation position (from the contact surface of metal material and composite material to metal material) 03-06mm JIS No. 4 test piece (10φ) from the part where the composite material and metal material of the above composite metal material are welded
I cut it out.

When a tensile test was conducted using this test piece,
Is the tensile strength 225kI? //ill+l! Met.

Therefore, the tensile strength of the composite metal material is approximately the same as the strength of AC8A alloy, which is 25 kg/lnd.

Moreover, the heat resistance strength of the composite material portion is greater than that of the AC3A alloy.

Furthermore, since only the composite material part is molten metal forged, the forging equipment for the above composite metal material is small, and the equipment cost is low and the cost is low.

In the above embodiment, the electron beam is emitted from the contact surface of the art material to 06 to 0
6. However, when the contact surface is irradiated with an electron beam, the air that has melted into the aluminum alloy during molten metal forging and the air that is in the air when the electron beam is irradiated onto the contact surface.
The aluminum oxide reacted with the SiC whisker is gasified, and a portion of the impurities attached to the surface of the SiC whisker is gasified, generating bubbles and reducing the bonding strength.

Therefore, by keeping the electron beam at least 0.2 degrees away from the contact surface of the art material, a significant rise in temperature of the composite material on the contact surface is prevented and the above-mentioned bubbles are not generated.

Moreover, since the abutting surfaces of the same materials are melted, the bonding strength between the two art materials can be obtained almost equal to that of the base material A1. Also.

If the electron beam is separated from the contact surface by more than 1.2 mrn, the temperature of the contact surface will not rise sufficiently and the two art materials will not be welded with sufficient strength.

Second Example Silicon carbide whiskers having the properties shown in Table 1 were placed in a mold, and AC8A alloy hot water was poured into the mold.

Molten metal forging is performed by applying a pressure of 100 MPa at the same temperature.

A piston head 1 made of a ring-shaped composite material as shown in FIGS. 2 and 3 was formed. The diameter of the head is 166 dragons.

Next, the piston body 2 having the shape shown in FIG. 4 is cast using AC8A alloy.

Subsequently, the oxide film on the lower surface of the first head 1 and the upper surface of the piston body 2 is removed, and the second head 1 is placed on the upper surface of the piston body 2 and positioned as shown in FIG. Then, the piston body 2 and the head 1 are rotated about an axis passing through the center in the left-right direction in FIG.

Acceleration voltage: 150KV Current: 30mA 4 Degree of vacuum: 10Torr Beam diameter: 03φ Welding depth: Welding speed: 0.5 m/MIN From the abutment surface between the beam irradiation position M1 and the piston body 2, screw (screw) Z body (To the side) 06 to 0.6 m shoulder This piston filter had almost the same tensile strength as the base material.

In the above embodiment, the welding depth is constant at 30 mm, so the inner diameter of the welded portion is at the position shown by the broken line in FIG. 6, and the portion located between the piston and the cavity 4 is not welded. Therefore, the rotational speed (welding speed) of the piston outer circumference was set to 0.
．． Irradiate the electron beam to point a in Figure 6 at 5 m/min, and while gradually decelerating the piston from the above rotational speed,
→B→Rotate to point C, speed at 0 point is 0334IN
Then, K gradually accelerates and rotates from C to d to a and reaches a speed of 0.5 m/min at point a.

As a result, the head 1 and the piston body 2 are welded to the piston body 2 over the entire back surface of the head 1.

Sixth Embodiment As shown in FIG. 7, the outer peripheral side of the lower surface of the head 1 is formed by a method similar to that of the second embodiment, and the contact surface 5 is made to protrude downward.
, and lower the part of the piston body (Al 5 die-cast) 2 facing the abutment surface by -l to overlap the head 1 and the piston body 2, and place it 03 to 0.6 mu below the abutment surface 5. The piston body of 0.
25 yn/MIN and melted with an electron beam under the same welding conditions as in the second embodiment (excluding the welding speed), and the ring-shaped contact surface 5 of the piston body 2 and the head 1 was melted. are welded to obtain the piston 6 shown in FIG.

Fourth Embodiment In FIG. 8, one head 1 is treated in the same manner as in the second embodiment,
Further, the piston body 2 is formed by the same method as in the second embodiment. Next, the first abutment surface 6 is first welded together using an electron beam in the same manner as in the second embodiment, and then the second abutment surface 7 is welded together in the same manner as in the second embodiment using an electron beam.

Further, in each of the embodiments shown in FIGS. 9 and 10, the head 1 and the piston body 2 are respectively formed in the same manner as in the second embodiment, and the head 1 is formed using an electron beam in the same manner as in the second embodiment. The piston body 2 and the piston body 2 are welded together to obtain the piston 3.

In each of the above embodiments, welding is performed using an electron beam, but similar effects can be obtained using a laser.

In addition, in the above example, 1 cup of ceramic
(long fiber, short fiber, powder, etc.) may also be used.

It's fine if it's more than that.

In addition, although an aluminum alloy is used for the matrix and the metal material, other metals such as a magnesium alloy may be used, and the same alloys may not be used as long as the wetting property of the art material is good and welding is possible.

In addition, although the piston is formed in the above embodiment, other parts of the engine 1 such as the head and the valve seat.

liner, valve, ift connection, control/p throat, to

[Brief explanation of drawings]

FIG. 1 is a partial sectional view showing a conventional piston, and FIG. 2 is a plan view showing a head 1 of a second embodiment of the present invention. 6 is a view taken along arrows -■ in FIG. 2, FIG. 4 is a sectional view showing the piston body 2 of the second embodiment, FIG. 5 is a sectional view showing the piston 3 of the second embodiment, The figures are explanatory diagrams showing a modification of the second embodiment, FIG. 7 is a sectional view showing a third embodiment of the invention, FIG. 8 is a sectional view showing a fourth embodiment of the invention, and FIGS. FIG. 10 is a sectional view showing another embodiment of the present invention. 1: Head, 2: Piston body, 3 = Piston agent Engraving of the drawing by Yoshitake Himakata (no changes to the contents) Figure 1 Figure 4 Figure 5 Figure 6 d Figure 6 Figure 7 Figure 9 Figure 10 Procedural amendment (method) Date of July 1980 Patent Application No. 60150 Name of the invention Method for manufacturing composite metal products and relationship to the piston amendment case Patent applicant residence Address: 5-33-8 Shiba, Minato-ku, Tokyo Name (628)
) Mitsubishi Motors Corporation i Co., Ltd. Address: 8-8, Shiba 5-chome, Minato-ku, Tokyo

Claims (1)

[Claims] (1) A composite material having five ceramic fiber particles, thin particles, etc. in a matrix metal is brought into contact with a metal material. A method for producing a composite metal product, characterized in that the metal material near the contact surface is heated and melted using a laser, an electron beam, etc. to weld the art material (2) A composite metal product is composited by infiltrating a matrix metal into ceramic fibers. The composite material is formed into a predetermined shape, the molded product is brought into contact with the metal material,
Laser and electron beams are applied to the metal material near the contact surface. Manufacture of a composite metal product characterized by welding the above-mentioned art materials by heating and melting with an ion beam or the like. i! i
Ant (3) A head made of a composite material having ceramic fiber particles 2, 4, etc. in an aluminum-ram alloy. A piston characterized by having a piston body made of an aluminum alloy and fused to the same head.