JPS6046837A - Manufacture of composite metalic wire - Google Patents

Abstract

PURPOSE:To cover a core wire with metallic powder without having no defect by leading the core wire whose surface is purified and which is heated in an oxidizing atmosphere, into the metallic powder, deoxidizing the surface oxide, also making both of them stickable easily, and thereafter, press-welding and joining them by a working tool. CONSTITUTION:A steel wire 1 whose surface has been purified by defatting and polishing is heated to about 400 deg.C in an oxidizing atmosphere of a heating furnace 4 and a uniform oxide film is formed on the surface, and thereafter, it is led into an Al powder tank 5, iron oxide of the surface of the steel wire 1 is deoxidized by Al powder 2, and also the Al powder 2 is made stickable easily to the surface. Subsequently, the steel wire 1 is passed through a die 3 provided on the other end of the tank 5, and in this case, the Al powder 2 is led into the die 3 by a frictional sticking force to the steel wire 1, and in this die, the Al powder 2 is press-welded and covered to the surface of the steel wire 1 in a cold or heated state, and an Al covered steel wire 6 is obtained. In this way, a composite metallic wire having a covered layer which has no defect and is good in its adhesive property is obtained continuously.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a composite metal wire, particularly a method for manufacturing a composite metal wire such as an aluminum-coated steel wire (As wire).

Generally, the following methods are known or practiced when manufacturing composite metal wires such as AS steeled wires.

(1) Co-pulling method A method of creating a composite base material by covering the core wire with a coated metal tube, etc., and drawing this with a die.

(2) A method of pressure welding by winding a coated metal tape around the clad normal core wire.

(3) A method in which a hot-dip plated core wire is passed through a molten aluminum bath and aluminum is coated on its surface.

(4) Powder sintering method (Almoweld method) A method in which aluminum powder is heated and sintered around a core wire and then rolled.

(5) Forward tension extrusion method By applying forward tension, the coated metal is applied around the core wire under high pressure as in the case of lubricant in body lubrication and drawing, and is drawn into the die together with the core wire, and the powder is pressed around the core wire. how to. (Japanese Unexamined Patent Publication No. 55-82610).

Among these methods, the most advantageous method in terms of production efficiency is the hot-dip plating method (3), but since this method melts aluminum and handles it as a plating bath, it is difficult to control the hot-dip plating bath. There are many problems in terms of equipment and equipment, and
When using aluminum-coated steel wire, there are quality problems such as the formation of a hard and brittle intermetallic compound layer between the steel and aluminum.

For these reasons, the powder sintering method (4) and the powder sintering method (6) are methods that have manufacturing efficiency equivalent to or second to the hot-dip plating method and can solve the above-mentioned problems specific to the hot-dip plating method. Powder drawing methods are being studied.

However, the powder sintering method (4) has the drawback of requiring expensive equipment and complicated technology from the viewpoint of quality control. In addition, in method (6), when the coated metal powder enters the die hole, high internal pressure is generated and adhesion occurs between the coated metal powder and the core wire, resulting in a composite coating. The frictional force due to the relative sliding of the particles alone does not have the ability to forcefully draw the powder into the die inlet, and even if the powder is drawn into the die hole and becomes composite within the die hole, the continuity is poor and defects such as pinholes occur. It has the disadvantage of insufficient adhesion.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the drawbacks of the prior art described above and to provide a method for manufacturing a composite metal wire in which a core wire is continuously coated with metal powder without defects.

The present invention includes a step of heating a core wire whose surface has been cleaned in an oxidizing atmosphere to form an oxide film on the surface, and a step of heating the core wire whose surface has been cleaned in an oxidizing atmosphere to form an oxide film on the surface. , or further heated and then introduced, heating if necessary to cause a reaction to reduce the oxide on the core wire surface with the coated metal powder to facilitate adhesion of the powder to the core wire surface, and a step in which the core wire and the powder are bonded together. A method for manufacturing a composite metal wire, comprising the steps of drawing the powder into the inlet of a processing tool using the frictional adhesive force of the wire, and at the same time performing processing in a cold or heated state to coat and composite the powder on the surface of the core wire. It is.

Generally, metals are bonded together after the surfaces to be bonded are cleaned and activated.

Therefore, even in the conventional powder sintering method and powder drawing method,
Before adhering to coated metal, the core wire is cleaned and, if necessary, the core wire is heated in an inert atmosphere to improve adhesive properties while preventing the formation of an oxide film on the surface. We are making improvements.

Even if the present invention fails, the surface of the core wire is of course cleaned, but it is completely different from these conventional adhesives, and rather the core wire is actively oxidized to form a uniform oxide film of tens to thousands of layers on the surface. A chemical reaction (in the case of iron and aluminum, this is called the "thermite reaction") in which the oxide on the surface of the core wire is reduced by the powder of the coated metal, which is easier to oxidize (lower oxide formation energy). This is a method that makes bonding chemically easier than conventional methods by utilizing a chemical reaction (reactions that occur), and at the same time press-bonds them by drawing, rolling, swaging, etc. (without unnecessary heating). Therefore, according to the method of the present invention, adhesion between the core wire and the coated metal becomes easy and reliable. Regarding the oxide film formed on the surface of the core wire, it is desirable to make the thickness and quality as uniform as possible from the viewpoint of uniformity of the adhesion state and, ultimately, uniformity of quality of the product. For this purpose, it is very effective not only to simply heat-treat the core wire in an oxidizing atmosphere, but also to perform a cleaning treatment before that.

In the method of the present invention, wires made of iron-based metals and copper-based metals, for example, are used as the core wires. Moreover, a composite wire whose surface is made of these metals can also be used as a core wire.

Examples of the reducible coating metal used in the present invention include:
Powders of AA, Mg, Zn, Sn, Ti, Zr, Be, etc. are used.

The oxidation treatment may be a wet anodic oxidation treatment or a chemical oxidation treatment using chemicals, but the oxide film formed is
It is desirable that it be less than 0λ. For the oxidation treatment, in the case of steel wires, it is preferable to heat the wires at a temperature of 150 to 500°C in the air, and in the case of copper wires, it is preferable to heat them in the air at 150 to 500°C.
The temperature is preferably about 350°C.

When introducing and running an oxidized core wire into the coated metal powder, the powder generally moves together with the core wire due to the frictional adhesive force between the core wire and the powder, and is then drawn toward the processing tool placed next. However, the amount of retraction and continuity are not necessarily satisfactory. At this time, as a result of various experiments, it was found that the drawing effect is better if the core wire is heated and oxidized. The optimal heating temperature is 300 to 400°C, good results can be obtained even at 200 to 500°C, and the effect can be obtained at 150°C or higher.

When steel wire is heated to these temperatures, it oxidizes from pale yellow to yellowish brown, purple-blue, and dark blue, depending on the temperature. When the steel wire is passed through the aluminum powder in this state, the entire surface of the steel wire is coated with a thin layer of adhesive, and a sufficient amount of aluminum is drawn into the entrance of a tool such as a die.

This adhesion is thought to be due to the fact that the oxide film on the steel wire is reduced to the aluminum powder by a thermite reaction, and the chemical reaction causes temporary adhesion, and the surface becomes rough with the aluminum powder, increasing the frictional force with other aluminum powders. It will be done.

At this time, if the temperature of the steel wire and aluminum is high, the thermite reaction is likely to occur, so it is most effective to carry out the process at a high temperature.

By using the temperature of the steel wire during the oxidation treatment, the operation becomes simple and economical and sufficient effects can be obtained.

Further, a sufficient effect can be obtained by heating only the steel wire. It is of course possible to heat only the aluminum powder, but
It is more effective and economical to heat only the steel wire.

When a steel wire with aluminum powder attached to it is drawn into a processing tool such as a die, a hydrodynamic wedge effect occurs at the horizontal angle between the entrance angle of the tool and the steel wire, and the wire is strongly drawn in.
The pressure inside the tool deforms the aluminum powder, resulting in adhesive coating.

In this case as well, when the temperature reaches a high temperature of 150° C. or higher, the deformation resistance of the aluminum powder decreases and the reaction at the interface is promoted, resulting in a good adhesive coating and a good surface condition. The optimal heating temperature is 200 to 500°C, but it may be higher.

However, if the temperature is too high, an intermetallic compound of At and Fe will occur, so it is desirable to keep the temperature up to about 550°C.

The dies used as processing tools in the present invention are generally conical, trumpet, convex, arc, concape, and Sig.
A die such as a moidal (sicmoidal) type is used. Furthermore, a die for fluid lubrication wire drawing can also be used.

Further, as processing tools, roller dies, Turk's heads, driven rolling rolls, swagers, etc. are also used.

As a heat source for this step, the temperature during heating and oxidation can be used together with the step of temporarily adhering the aluminum powder and the core wire.

It is possible and preferred to contact the aluminum powder and the steel wire and draw them into the die at the same time.

As the heating source, direct current application, high-frequency or low-frequency induction heating, electric furnace heating, heating using a gas combustion furnace, etc. can be used.

Oxidative heating is performed in an oxidizing atmosphere such as oxygen, a mixed gas of oxygen and a neutral gas, a mixed gas of oxygen and combustion gas, or air.

Next, the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is an explanatory diagram showing one embodiment of the present invention, where l is a core wire such as a steel wire, and in this example, a steel wire with a diameter of 3.8 mm was used. 2 used aluminum powder as the powdered ice material.

3 is a very commonly used ordinary die with a full approach angle of 16 degrees and a bearing inner diameter of 3.8 mm. 4 is a heating furnace.

The steel wire 1 is degreased with chisel-chloroethylene, polished with a wire foil made of stainless steel wire with a diameter of 0.5 mm, and then heated to 400° C. in an oxidizing atmosphere in a heating furnace 4. Next, the steel wire 1 is introduced into an aluminum powder tank 5, and in this tank, the aluminum powder 2 reduces iron oxide on the surface of the steel wire 1 and chemically reacts with the surface of the steel wire, so that the aluminum powder turns into steel. Weakly adheres to the wire surface.

10- A die 3 is provided at the other end of the powder tank 5 in the steel wire advancing direction, and the aluminum powder 2 has a frictional adhesive force with the steel wire 1,
The aluminum powder is drawn into the bearing of the die 3 by the adhesion effect and hydrodynamic flow effect due to the oxide reduction reaction, and the aluminum powder is pressure-coated on the circumference of the steel wire, and the aluminum powder is formed into an aluminum-coated steel wire 6 and exits from the die 3. It's coming.

There was no work interruption line, and the outer diameter of the aluminum-coated steel wire produced was a, s mm.

FIG. 2 is an explanatory diagram showing another embodiment of the present invention, in which the entire system is vertically shaped. Note that the symbols are the same as in FIG. In this example, the amount of aluminum powder 2 drawn into the die 3 is large due to the action of gravity and the drawing action of the steel wire 1, and the coating becomes complete and thick.

In this case, a more favorable effect can be obtained by applying vibration (preferably ultrasonic imaging) to the aluminum powder 2 and/or the hopper (tank) 5.

Next, a crush test was conducted to evaluate the adhesion of aluminum to aluminum coated steel wires with a diameter of 5 mm made by the conventional forward tension extrusion method and the method according to the present invention shown in FIG. The following table shows the comparison of the load required to peel off aluminum from aluminum.

As is clear from these results, the aluminum covered wire produced by the method of the present invention has adhesion between steel wire and aluminum that is equal to or better than that produced by the conventional forward tension extrusion method.

Although the case where the method of the present invention is applied to a core wire has been described above, the present invention can also be applied to other pipes, rods, etc.

Furthermore, it is also possible to obtain a composite wire with few defects and a thick coating by repeating the subsequent methods, excluding the surface oxidation treatment, twice or more on the composite wire obtained by the above method. In this case, a multilayer composite wire can also be obtained by using different metal powders in the second pass.

Further, as the outermost coating layer, a plastic powder such as polyvinyl chloride can be coated by the method described above to produce an insulating or corrosion-resistant composite wire.

As described above, the present invention eliminates the drawbacks of the conventional methods and makes it possible to continuously produce a composite metal wire without defects and having a coating layer with good adhesive properties, and also has the following effects. .

(1) According to the present invention, the coated metal powder lightly adheres to the steel wire through an oxidation-reduction reaction on the surface of the core wire, and the amount of the coated metal powder drawn into the die is increased (increasing the coating thickness).
At the same time, it is possible to easily apply adhesive coating using pressure applied by dies, rolls, etc. Therefore, a composite wire can be obtained using an ordinary die without using a drawing method using a fluid-lubricated die method.

(2) When a normal die is used, only a small drawing force is required, so it is possible to coat a soft steel wire with aluminum, and the range of production can be widened.

(3) The configuration of the device can be simplified.

13-

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing one embodiment of the present invention, and FIG. 2 is an explanatory diagram showing another embodiment. 1...Core wire, 2...Aluminum powder, 3.°°°°. Dice, 4... Heating furnace, 5... Aluminum powder tank, 6... Aluminum steel wire. 14-

Claims (1)

[Claims] (1) A step of heating a core wire whose surface has been cleaned in an oxidizing atmosphere to form a uniform oxide film on its surface, and introducing the core wire into powder of a coating metal that is more easily oxidized than the core wire metal to form a uniform oxide film on the surface of the core wire. A process of reducing the oxide of the powder with the coated metal powder to make it easier to adhere the powder to the surface of the core wire, and a process of drawing the powder into the processing tool inlet using the frictional adhesive force between the core wire and the coated metal powder, and simultaneously removing the core wire. A method for manufacturing a composite metal wire, comprising a step of processing in a cold or heated state to coat the surface with powder and form a composite.