JPS61170546A - Forming of amorphous metal layer - Google Patents

Abstract

PURPOSE:To form the amorphous metal layer on the surface of metal, etc., with high productivity by forming an alloy layer having a specific composition on the matrix surface, irradiating an high-energy electromagnetic wave to melt the alloy layer, and making the molten part amorphous. CONSTITUTION:Alloy powder of Fe-B-Si or the like having a composition appropriate for making amorphous is sprayed on the surface of a matrix of iron material, etc., to form the alloy layer, which is irradiated with a high-energy electromagnetic wave, such as laser light, to melt the alloy layer. At this time the heat is absorbed into the inner part of the matrix rather than its surface, so that the irradiated part is cooled very quickly to be made amorphous. In this way, the productivity is improved and the cost of products can be reduced.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for producing an amorphous metal layer, which is used as a magnetic material for electromagnetic powder clutches, torque sensors, etc. It is valid.

[Conventional technology]

Amorphous metals have long been known to have excellent magnetic, mechanical, and chemical properties, and these properties have attracted particular attention in recent years.

However, currently, when forming an amorphous metal layer or thin film on the surface of a base material such as a metal material, vapor deposition methods, sputtering methods, CVD methods, plating methods, etc. have been devised, but all methods are difficult to form an amorphous layer. Productivity was low because the speed was extremely slow. For example, the production rate in the vapor deposition method is 5 to 10 people/s, the sputtering method is 1000 people/min, and the plating method is 0.01 m/h, which are all very low.

[Problem that the invention seeks to solve]

The present invention has been made in view of the above points, and an object of the present invention is to improve productivity when forming an amorphous metal layer on the surface of a metal or the like.

[Means for solving problems]

As a means for solving the above-mentioned problems, the present invention provides an alloy layer forming step of forming an alloy layer of a composition material that can be in an amorphous state on the surface of a base material, and An amorphous metal layer is produced by comprising an irradiation melting step of irradiating the alloy layer with high-energy electromagnetic waves having an energy higher than that of melting the alloy layer to melt the alloy layer and make the melted portion amorphous. do.

[Effect]

By irradiating the alloy layer formed in the above alloy layer forming step with high-energy electromagnetic waves, the irradiated area is instantly melted. Since the heat is absorbed from the surface of the base material to the inside thereof, the irradiated area is cooled extremely rapidly and becomes amorphous.

〔Example〕

Next, one embodiment of the present invention will be described.

First, the alloy layer forming process will be explained. Using an alloy material of a desired uniform composition suitable for forming powder, linear, or rod-like amorphous materials, fine particles of the alloy material heated and melted from a gas-type (electric type, plasma type, etc.) spray gun are applied to a base material, e.g. Spray on the surface of iron materials. The thermal spraying conditions at that time are as follows: When using alloy powder with a particle size of 30 to 100 μm, the voltage is 5
The alloy powder was sprayed at a spraying distance of 100 to 200 g per minute at a current of 0 to 100 v and a current of 300 to 1000 A. In addition, N1-Aj with a thickness of about 50 to 100 μm is used as a binder to facilitate the formation of an alloy layer during thermal spraying.
The alloy, Ni-Cr-Al1 alloy, may be formed on the surface of the base material in advance.

The molten metal fine particles sprayed in this way were brought into close contact with the surface of the base material to form an alloy coating layer (thickness: 20 to 300 μm). The surface of the base material must be cleaned and roughened in advance by blasting, degreasing, acid roughening, etc. as a pretreatment. The alloy coating layer produced under the above conditions not only had good adhesion to the base material, but also had high density and few pores.

After the desired alloy coating layer produced by thermal spraying is smoothed by machining, such as cutting or VRW, the alloy coating layer is made amorphous by irradiation with high-energy electromagnetic waves, such as laser light. Laser light irradiation uses a beam obtained from a laser light generator filled with CO2 gas, with an output of 300 to 1000 W, and a lens that converts the beam into a diameter of 0.
The aperture was adjusted to 1 to 0.5 wm, and either the beam or the substrate was moved. If the base material is planar, the moving speed is 100 to 1000x/sec in the X direction.
5 in the Y direction (perpendicular to the X direction) for each pass.
The surface of the thermal sprayed alloy layer was irradiated by sending the laser beam in steps of 0 to 200 μm (scanning the laser beam). That is,
The region of the alloy layer irradiated with laser light was continuously displaced and irradiated. Laser light irradiation is
Performed in an argon gas atmosphere to prevent oxidation.
The test was performed while cooling the surface of the sample other than the irradiated surface with liquid nitrogen or cooling water. The irradiated part of the sprayed metal layer is instantly melted by laser beam irradiation, but the heat is immediately absorbed from the surface of the base material into the interior, so the alloy part melted by the irradiation is cooled extremely rapidly and becomes amorphous. The amorphous alloy layer obtained in this way has a smooth surface and high hardness (thickness and depth can be increased by changing the irradiation conditions).
It is possible to adjust the thickness to about 0 to 200 μm.

As described above, the method of generating an amorphous metal layer (coating layer) on the surface of a base material using thermal spraying and laser irradiation is as follows:
Compared to conventional vapor deposition methods, sputtering methods, CVD methods, plating methods, etc., when forming an amorphous metal layer in a relatively narrow area, it is possible to generate an amorphous metal layer in an extremely short time, resulting in a significant increase in productivity. It leads to improvements in product quality and cost reduction of products, and has great industrial value. For example, when an amorphous metal having a thickness of about 20 to 300 μm is produced on a base material having an area of about 251, it can be produced in about 12 to 500 seconds. Regarding the alloy composition, this time Fe-B
-3i series, Fe-B series, Fe-Go-5i-B series, Fe
-N1-P-B system, co-3i-B system, Ni-3i-B
Although the present invention was conducted using a composition in which Cr - and Mo were added to the system, it is possible to use an appropriate composition that has undergone amorphization.

In the above example, the laser beam was moved in the x1y direction with respect to the alloy layer formed on the surface of the planar base material, but if the base material is cylindrical, the base material may be rotated. At the same time, the laser beam may be moved in the direction of the rotation axis to continuously change the region irradiated with the laser beam.

Furthermore, in the above embodiments, irradiation was performed with laser light, but it can be easily assumed that similar effects can be obtained even if irradiation is performed with a focused high-energy electron beam.

Next, an application example using the amorphous metal layer produced as described above as a magnetic material will be described.

First, Figure 1 shows an example of use as an I-lux sensor.
An amorphous metal layer 1 as a magnetic material is formed on the surface of the drive shaft 4 to a thickness of about 10 to 30 μm. Its basic structure and operation will be explained.

A coil 3 that excites the coating layer and a detection coil 2 that detects the magnetostrictive characteristics of the metal layer 1 are installed near the surface of the drive shaft 40 on which the metal layer 1 is formed. The electromotive force caused by the distortion caused by This electromotive force is amplified and extracted as an electrical signal. As a detection circuit, a signal output from an oscillator 11 is converted into a square wave by a drive circuit 12, and a current is applied to the excitation coil 3. The electromotive force generated by the distortion caused by driving in the detection coil 2 is amplified by an AC amplifier 13, sampled by a sampling circuit 14, and further compared with an excitation square wave to detect torque. .

FIG. 2 is a diagram showing the relationship between the torque applied to the drive shaft 4 on which the amorphous metal layer l having the composition FetsBeSits is formed and its output. According to this,
The torque applied to the drive shaft 4 on which the amorphous metal layer 1 is formed and the resulting output obtained from the amorphous metal layer 1 are different from that of the conventional one (20 μm thick by Ni plating).
A good proportional relationship is established compared to the coated one).

Furthermore, the difference in hysteresis due to the rise and fall of applied torque is smaller than that of the conventional one (Ni plating 20 μm), and the sensitivity (ratio of torque to output) is also good. As described above, when the present invention is used as a magnetic material for a torque sensor, the magnetic properties are improved.

Next, an example of use in an electromagnetic powder set clutch will be explained. .

In this example, amorphous metal layers 21' and 40' are formed on the surfaces of drive member 21 and driven member 40 by the method described above. In FIG. 3, 21 is a drive member which is a rotating body on the drive side, and this drive member 21 is a yoke 22a made of a magnetic material divided into left and right halves.

The excitation coil 23 is housed in the cork 22b, and a flange 24 and a front cover 25 are attached to one cork 22a.
and drive holder 2 to the other yoke 22.
6, a rear labyrinth 27 fixed to the driven holder 26, and a slip ring 28, 28 as a current supply section also attached to the driven holder 26 are integrally attached. The front cover 25
The rear labyrinth ring 27 is formed of a non-magnetic material such as aluminum, and the front cover 25 and the front end portions 25a and 27a of the rear labyrinth 27 are opposed to the inner circumferential surface of the driven member 40, which is a driven rotating body. .

When used as a vehicle clutch, a ring gear 30 is connected to the flange 24 via bolts 29, and the ring gear 30 is connected to a crankshaft 31.

Brushes 32.32 are in sliding contact with the slip rings 28.28, and these brushes 32.32 are attached to a brush holder 33. Note that the brush holder 33 is fixed to a clutch cover (not shown).

The driven member 40 as a driven rotating body is made of a magnetic material, and has a hub 41 integrally fixed to the center with bolts (not shown). An input shaft 42 on the transmission side is engaged with the hub 41 via a spline 43, so that the driven member 40 and the input shaft 43 rotate integrally. The hub 41 includes a bearing 46 fixed by a circlip 44, 45, which supports the driven holder 26 rotatably but not axially. And driven member 4
Permanent magnets 35 and 36 are provided on the inner circumferential surface of the vehicle 0, facing the tip 25a of the front cover and the tip 27 of the rear labyrinth. Permanent magnet 35.36 is
Preferably, it is a rubber magnet, and has an annular shape over the entire inner peripheral surface of the driven member 40. These permanent magnets 35 and 36 and the tip portion 25 of the front cover 25
a and the tip 27a of the rear labyrinth 27.

An operating gap 47 is formed between the inner circumferential surface of the drive member 21 and the outer circumferential surface of the driven member 40, and the operating gap 47 is filled with magnetic particles 48. When this magnetic powder 48 is excited by the excitation coil 23, the magnetic powder 48
Mutual magnetic attraction and magnetic particles 48 and drive member 21
Also, due to the frictional force with the operating surface of the driven member 40, the rotational torque of the drive member 21 is transferred to the driven member 4.
0 and rotate both of them together.

The inner peripheral surface of this drive member 21 and the driven member 40
The outer peripheral surface of the is made of amorphous alloy (Fe
Amorphous metal layers 21', 40' consisting of s7Co+sB+4St+) have been produced by the method described above. The amorphous metal layers 21', 40' have a thickness of 20 to 50 μm in this example.

The operation of the embodiment with such a configuration will be explained.

In FIG. 3, power from the engine is transmitted from the ring gear 30 to the drive member 21 via the crankshaft 31, and therefore the drive member 21 rotates integrally with the rotation of the engine.

When the electromagnetic coil 23 is energized to generate a magnetic flux in the operating gap 47 where the magnetic particles 48 are present, the magnetic particles 48 are magnetized.
Engine power is transmitted to the driven member 40 by the magnetic coupling force between the magnetic particles and the frictional force between the magnetic particles 48 and the operating surface. Therefore, engine power is transmitted from the hub 41 to the input shaft 42 of the transmission via the spline 43. The coil 23 that generates magnetic flux in the operating gap 47 is supplied with power from the brush 32.32 via the slip ring 28.28, and current flows through the coil 23, passing through the yoke 22a122b, the operating gap 47, and the driven member 40. A magnetic circuit is formed to generate magnetic flux. Therefore, whether or not rotational torque can be transmitted is determined depending on the presence or absence of excitation current to the coil 23.

When the coil 23 is energized, the magnetic particles 48 move into the operating gap 4.
7 is most strongly magnetized, but normally when the power is turned off, it becomes open, and the magnetic particles are attracted to the drive member 21 by centrifugal force.
It is pressed against the inner surface of the body and the connection is completely severed. When an electromagnetic powder clutch is engaged, power is transmitted by the magnetic coupling force between the magnetic particles and the frictional force between the magnetic particles and the operating surface. Hard chrome plating is applied to the operating surface in consideration of its wear resistance due to slipping between the operating surface and the operating surface.Since this hard chrome plating is non-magnetic, the coupling force of the magnetic particles on the operating surface is reduced and the power transmission ability is reduced. It is the cause of

To confirm this, the inventors conducted a model experiment to examine the effect of hard chrome plating on the tangential force.

Here, the tangential force refers to the force when one of the opposing operating surfaces is fixed and the other operating surface is pulled, and corresponds to the power transmission ability of the clutch. As shown in Fig. 5, two types of experiments were conducted, one in which hard chrome plating 51 was applied to the working surface 50 of a flat iron core to a thickness of 50 μm, and the other case in which an amorphous metal layer 52 with a thickness of 50 μm was formed. This was done by enclosing magnetic powder 48 in the gap between the flat iron cores and measuring the tangential force when they were connected by applying magnetic flux.

As shown in Figure 5, the results show that if the horizontal axis is the distance traveled by one operating surface (flat iron core) and the vertical axis is the tangential force, the tangential force is significantly reduced by applying hard chrome plating. was confirmed. Therefore, the application example focuses on this point and uses an amorphous metal layer, which is a high permeability material with excellent magnetic properties, on the inner circumferential surface of the drive member 21, which is the operating surface, and on the drive member 21, which is the operating surface. By generating uniformly on the entire outer circumferential surface of the member 40 and making the bond between the magnetic particles and the operating surface stronger when the clutch is engaged, the frictional force increases, making it possible to increase the transmittable power. did. Therefore, the clutch can be made smaller and lighter. Moreover, the experimental results are shown in FIG. In this figure, the torque capacity, which is the maximum value of clutch transmission torque, at each excitation current is measured, and the excitation current value is plotted on the horizontal axis and the torque capacity is plotted on the vertical axis.
The thickness of both amorphous metal layers is 50μm±10μm
It is. As is clear from FIG. 7, the torque capacity is significantly increased when an amorphous metal layer is formed compared to when hard chrome plating is applied. In addition, it has been confirmed through experiments that amorphous alloys have excellent wear resistance as well as hard chrome plating.

Further, the amorphous metal layer may be formed only on one of the operating surfaces of the drive member 21 and the driven member 40.

〔Effect of the invention〕

As explained above, after forming the alloy layer on the surface of the base material,
Methods for making the alloy layer amorphous using high-energy electromagnetic waves include conventional evaporation methods, sputtering methods, CVD methods,
Compared to plating methods, etc., it is possible to generate an amorphous metal layer in an extremely short time, leading to improved productivity and reduced product costs, which is highly effective from an industrial perspective.

[Brief explanation of drawings]

Figure 1 is a schematic diagram showing an application example in which the amorphous metal layer obtained by the present invention is used as a magnetic material for a torque sensor, and Figure 2 shows the torque of the drive shaft of the torque sensor shown in Figure 1 and its output. Figure 3 is a longitudinal sectional view of an application example in which the amorphous metal layer obtained by the present invention is used as a magnetic material for the operating surface of an electromagnetic powder clutch;
Figure 4(a) is a cross-sectional view of the main parts of the application example shown in Figure 3, Figure 4(b) is an enlarged view of part A in Figure 4(a), and Figure 5 is an explanatory diagram of the model experiment. , FIG. 6, and FIG. 7 are graphs representing the experimental results.

Claims (3)

[Claims] (1) An alloy layer forming step of forming an alloy layer of a composition material that can be in an amorphous state on the surface of the base material;
An amorphous metal having an irradiation melting step of melting the alloy layer by irradiating the alloy layer formed in the step with high-energy electromagnetic waves having more energy than melting the alloy layer and turning the melted portion into amorphous. How to form layers. (2) The method for producing an amorphous metal layer according to claim 1, wherein the high-energy electromagnetic wave is a laser beam. (3) The method for producing an amorphous metal layer according to claim 1, wherein in the irradiation and melting step, a portion of the alloy layer that is irradiated with the high-energy electromagnetic waves is continuously displaced.