JPH045102A - Wheel for car - Google Patents

Abstract

PURPOSE:To acquire a protective layer which is high in hardness and hardly damaged by forming an amorphous metal layer made of a high hardness metal or mainly of the high hardness metal on a part or on the whole part of the surface of a wheel main body made of a magnesium alloy. CONSTITUTION:A wheel made of a magnesium alloy consists of a center disc member 1 and rim members 2, 3 connected to both sides of this center disc member 1 with bolts 4 and nuts 5, and the center disc member 1 and the rim members 2, 3 constitute a wheel main body and are formed of the magnesium alloy and preliminarily treated for corrosion prevention. A surface amorphous metal layer 6 is formed all over the surface including contact parts with the bolts 4... and a contact part 1a with an iron made bolt or nut to install this wheel on a car or others. This amorphous metal layer 6 is formed, for example, with spattering, and besides Ta, Ti, W and Zr are used.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a wheel mainly made of a magnesium alloy for use in vehicles, aircraft, and bicycles.

[Prior Art] Magnesium alloys are close-packed hexagonal crystals, are extremely lightweight, and have good machinability, so they are suitably used as materials for wheels of vehicles, aircraft, bicycles, and the like. However, on the other hand, magnesium alloys are also known as metals that easily corrode. Due to their nature, wheels for vehicles such as those described above are used in extremely harsh environments, and are often damaged by collisions with pebbles, glass fragments, etc. while driving. If a vehicle wheel made of only a magnesium alloy receives such damage, corrosion may progress due to this damage, and the wheel may become unusable in a relatively short period of time.

For this reason, magnesium alloy wheels used for vehicles and the like are coated with a protective film to prevent corrosion.

Conventionally, this protective film has been made of, for example, ammonium nitrate, sodium dichromate, or
The ammonium water mixture was kept warm at 50 to 60°C, and the temperature was 0.
It was obtained by chemical conversion treatment under treatment conditions of 2 to IAdm and an electrolysis time of 10 to 30 minutes. Thus, conventional protective films are formed by anodizing methods, which can provide long-term corrosion protection. Conventionally, a synthetic resin paint is baked onto the protective film obtained by this anodizing method, thereby achieving a considerable corrosion-preventing effect.

[Problems to be Solved by the Invention] However, the conventional protective film as described above cannot be said to have sufficient hardness, and there is a risk that the protective film itself may be damaged by collisions with pebbles or the like.

In addition, wheels are not only subject to collisions with pebbles, etc., as described above, but are also subject to repeated minute deformation external forces due to impacts from being pushed up from the road surface, bending and distortion during cornering. On the other hand, the conventional protective film as described above has a problem in that it often peels off due to such external forces.

In addition, the parts that come in contact with iron bolts and nuts when attaching a wheel to a vehicle, the screw holes where each piece is tightened with bolts in a 2-piece or more wheel, and even the parts that attach and remove wheel caps and the car body. In the case of concealment by mounting etc., it is necessary to consider countermeasures against dissimilar metal contact corrosion that occurs between the magnesium alloy forming the wheel body and the iron forming the bolt etc., or the adhesion strength of conventional protective films is insufficient. Because of its weakness, it would peel off from the wheel body in these areas, making it impossible to prevent the contact corrosion of dissimilar metals as described above.

The object of the invention is to provide a wheel for vehicles, etc., which is mainly made of a magnesium alloy, which prevents the above-mentioned damage and corrosion caused by contact between dissimilar metals, and which has a protective layer that is highly hard and does not easily get damaged. There is.

Another object of the invention is to provide a wheel for a vehicle, etc., which has a protective layer that has high adhesion strength and toughness that is suitable for practical use.

Still another object of the invention is to provide a wheel for a vehicle, etc., in which an effective protective layer is formed on the parts that come into contact with iron bolts and nuts when the wheel is mounted on the vehicle, etc.

As a means of improving the surface hardness and wear resistance, attempts have been made to use hard chrome plating, nitriding, etc., but no effective technique has been established at present.

[Means for Solving the Problems] In order to achieve the above object, a wheel for vehicles, etc. according to the first invention is a wheel for vehicles, aircraft, and bicycles mainly made of a magnesium alloy, the wheel body being made of a magnesium alloy. It is characterized in that an amorphous metal layer made of or mainly composed of a high-hardness metal is formed on part or all of the surface.

In such wheels for vehicles, as in the second invention, it is preferable to form an amorphous metal layer also on the contact portions with the screw holes, the hub cap attachment/detachment portion, the attachment portion to the vehicle body, etc. preferable.

As in the third invention, the amorphous metal layer can be formed by sputtering.

[Function] According to the first invention, since the amorphous metal layer is formed on the surface of the magnesium alloy wheel body, crystal grains with no regularity in atomic arrangement and crystal defects uniformly distributed are formed. The magnesium alloy wheel body is reliably protected from damage by the high hardness metal protective film.

According to the second invention, the attachment surface to iron bolts, vehicles, etc. also comes into contact via the amorphous metal layer.

According to the third invention, since the amorphous metal layer is formed by atoms being accelerated at a high potential, colliding and adhering to each other, the amorphous metal layer has high adhesion strength and extremely strong toughness. . In addition, the same hardness as the selected target material can be obtained.

[Example] The invention will be described in detail with reference to the figures.

The magnesium alloy wheel shown in FIG. 1 consists of a center disc member 1 and rim members 2 and 3 connected to both sides of the center disc member 1 by bolts 4 and nuts 5. It is a piece type vehicle wheel. The center disk member 1 and the rim members 2 and 3 constitute the wheel body, and are made of magnesium alloy, and have been previously subjected to type 2 rust prevention treatment specified in JISH8651. The center disk member 1 and the rim members 2 and 3 include contact portions with bolts 4 and contact portions 18 with iron bolts and nuts used when mounting this wheel on a vehicle, etc. An amorphous metal layer 6 is formed on all surfaces, as shown in a partially enlarged view in FIG. This amorphous metal layer 6
can be formed, for example, by sputtering, and in addition to tantalum (Ta), titanium (Ti), tungsten (
W), zirconium (Zr), titanium-tungsten alloy (TiW), titanium nitride (T i N), etc. Such an amorphous metal layer 6 is formed individually on the center disk member 1 and the rim members 2, 3, and the center disk member 1 and rim members 2, 3 are formed with the amorphous metal layer 6. They are later connected by bolts 4...

Another magnesium alloy wheel for a vehicle according to the invention shown in FIG. 3 is a one-piece type in which a center disk portion 11 and rim portions 12 and 13 on both sides of the center disk portion 11 constituting the wheel body are integrally molded from magnesium alloy.

The one-piece type wheel shown in FIG. 3 also has an amorphous metal layer formed on its surface, similar to that of the wheel shown in FIG.

In addition, wheels with an amorphous metal layer formed on the surface have a magnesium alloy wheel body that consists of two parts: a center disc part, one rim part integrally molded, and a rim part forming the other rim part. It may also be a piece type wheel.

Further, the wheel may be an aircraft or bicycle wheel as long as it has a wheel body made of magnesium alloy.

The amorphous metal layer can be formed by sputtering using a vacuum apparatus as shown in FIG. In FIG. 4, sputtering is performed on the center disk member 1 of a three-piece type vehicle wheel, which is not shown in FIG.

The vacuum apparatus consists of a container B to a platform, at least 10"8
It is designed to withstand pressures of TOrr.

Container B is divided into upper and lower parts at joint C.

By releasing the screw at the joint C and removing the upper part of the container B, the center disk member 1, which is the magnesium alloy wheel body, can be removed from the container B. Further, the center disk member 1 is rotatably supported by left and right support rods that also serve as electrodes. A cathode plate E is installed 400 mm below the center disk member 1 supported by a support rod, and a tantalum (Ta)-based tarp material F is arranged on this cathode plate E. .

A magnet G disposed below the cathode plate E improves the focusing ability of the ions j.

Now, the air in the container B is replaced with argon gas introduced through the gas introduction pipe H, and the gas is removed from the exhaust hole (2) using an air guide pump to reduce the pressure to 1.0-'Torr or less.

When a DC voltage of 2000 V is applied between the left and right support rods serving as electrodes and the cathode plate E, a glow discharge is excited between the center disk member 1 and the target material F. At this time,
The ions of the argon gas collide with the target material F, and material atoms of the target material F are expelled, and the atoms are struck and attached to the surface of the center disk material 1 on the anode side to form an amorphous metal layer 6. Since the material atoms a of the target material F are scattered over a wide range, in this vacuum apparatus, as shown in FIG. The scattering is prevented by the prevention cylinder J.

Due to the structure, it is impossible to expect the atoms a to wrap around the upper surface of the center disk material 1. Therefore, in this vacuum device, by rotating the support rod, the center disk material 1
is inverted, and sputtered atoms, that is, material atoms a of the target material F, are deposited on the remaining surface to form an amorphous metal layer 6 similar to that described above. In addition, since the support rod is inverted in this manner, a bearing K which also serves as a seal is provided between the support rod and the container B. Further, it is preferable that the support rod has a structure in which the holding portion of the center disk material 1 can be changed after the center disk material 1 is turned over so that the holding portion does not interfere with sputtering when the center disk material 1 is turned over.

By performing sputtering for a predetermined period of time as described above, approximately 20 μm of sputtering is applied to the entire surface of the center disk member 1.
After the amorphous metal layer 6 with a thickness of m is formed, air is introduced through the gas introduction tube H, and when the pressure reaches normal pressure, the screws at the joint C of the container B are released, and the upper part of the container B is removed. Take out the center disk material 1.

The amorphous metal layer 6 formed as described above is a passive film that is rapidly cooled from a liquid metal and solidified, so it has a chemically uniform composition without segregation or the like. Further, the center disk material 1 is formed uniformly and densely over the entire surface, and there are no pinholes. The hardness of the tantalum-based target material F in this embodiment is 1.3 times that of hard chromium. can have. Furthermore, unlike mere chemical plating or painting, the amorphous metal layer 6 is formed by sputtering, in which atoms are accelerated at a high potential and collided to adhere. The adhesion strength reached as high as 9 kg/mm2, indicating extremely strong toughness.

In a three-piece type wheel like this example, an amorphous metal layer is formed on the other rim members 2.3 in the same manner, and then each member 1, 2.3 is tightened with 4 bolts. assemble.

In addition to the tantalum-based target materials mentioned above,
Titanium (Ti) series, tungsten (W) series, zirconium (Zr) series, titanium-tungsten alloy (TiW)
Of course, other high hardness metals such as titanium nitride (TiN) may also be used. In particular, when titanium nitride is used as the target material, a gold-colored amorphous metal layer can be obtained and a product with excellent aesthetics can be obtained.

When sputtering as described above is performed, the degree of vacuum in the container B is preferably 10-4 to 10-8 Torr.

Furthermore, as the gas to replace the air in the container B, other inert gases can of course be used instead of the argon gas mentioned in the examples.

[Effects of the Invention] According to claim 1, since the magnesium alloy wheel body is covered with an extremely hard amorphous metal layer, the surface will not be damaged even if it is hit by a pebble or the like. (This has the effect of reliably preventing corrosion of the wheel body from such damaged parts.

According to claim 2, since the attachment surface to iron bolts, vehicles, etc. also contacts through the amorphous metal layer, corrosion occurring between the wheel body made of magnesium alloy and dissimilar metals can be avoided. It has the effect of being able to do it.

According to claim 3, since the adhesion strength of the amorphous metal layer can be extremely increased and strong toughness can be obtained, it is possible to obtain a protective layer that does not easily peel off even with repeated minute deformation external forces. be effective.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of a vehicle wheel, Fig. 2 is an enlarged view of the ■ part in Fig. 1, and Fig. 3 is a longitudinal sectional view of another vehicle wheel.
FIG. 4 is an explanatory diagram showing a state in which sputtering is performed. Patent applicant Washi Kosan Co., Ltd. Agent Patent attorney Takashi Suzue - 1st Peng procedural amendment = rate Atsushi (method) % formula % Relationship with the case of person who amends the name of the invention with foil for vehicles etc. Patent applicant Washi Kosan Co., Ltd.

Claims (3)

[Claims] (1) Wheels for vehicles, aircraft, and bicycles that are mainly made of magnesium alloy, where part or all of the surface of the magnesium alloy wheel body is made of a high-hardness metal or is amorphous mainly made of a high-hardness metal. A wheel for a vehicle, etc., characterized by having a quality metal layer formed thereon. (2) The wheel for a vehicle or the like according to claim 1, wherein the portion on which the amorphous metal layer is formed includes a screw hole portion, a wheel cap attachment/detachment portion, a portion that contacts a portion for attaching to a vehicle body, etc. (3) The vehicle wheel according to claim 1 or 2, wherein the amorphous metal layer is formed by sputtering.