JPH0364222B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a resistance diffusion bonding method that utilizes resistance heating.

(Prior art) As shown in FIG. 3, this type of conventional technology uses a bonded material 102 between opposing electrodes 101a and 101b.
For example, a low melting point metal 103 is placed between a and 102b.
A filter medium containing Si, B, etc. is inserted and arranged,
While the material to be welded is pressurized by pressurizing the electrodes 101a and 101b with the pressurizing device 104, the power source 1 is turned on.
Electricity is applied to the electrodes 101a and 101b from 05 to melt the low melting point metal 103 with resistance heat.
The bonding process is performed by diffusing diffusion components such as Si and B contained in the metal, and the temporal changes in the pressing force and heating current are shown in Figure 4.
It is constant both in the state before melting as shown in 03 and when the diffusing components are diffused after melting.

(Problems to be Solved by the Invention) The prior art as described above has a problem of large deformation because the heating current and pressing force are large.

(Means and effects for solving the problem) A low-melting metal is inserted between the joining surfaces of materials to be joined, which have joining surfaces consisting of planes or curved surfaces parallel to each other,
In the resistance diffusion welding method, which applies electricity to the materials to be joined while pressurizing the low-melting metal at the joint surface, the resistance heat generated by the current application melts the low-melting metal and joins the materials. Pressure is applied and primary energization is applied, the displacement of the material to be welded is measured, and based on the measured value, pressure is applied with a secondary pressure smaller than the primary pressure and secondary energization is applied smaller than the primary energization. The characteristic resistance diffusion bonding method was adopted.

(Example) An example of the present invention will be described based on FIGS. 1 and 2.

FIG. 1 is a block diagram showing a resistance welding apparatus for implementing the present invention. In FIG. 1, materials to be joined 2a and 2b are placed facing each other between opposing electrodes 1a and 1b. The joining surfaces of the materials to be joined 2a and 2b may be of any shape, such as flat or curved surfaces, as long as they are parallel to each other (no gap occurs when they come into contact) when they are placed facing each other. A Ni-type amorphous flow material 3 is inserted between the joint surfaces 2a and 2b, respectively. For example, a hydraulic pressure device is placed above the electrode 1a, and the electrodes 1a,
A power supply 5 for passing current through 1b, a current control device 6 for controlling the phase of the current, and amplifiers 7 and 8 for amplifying signals from the control device 9 are arranged. A displacement meter 11 measures the displacement of the reference plate 10 attached to the electrode 1a and sends a signal to the control device 9.

Next, the operation will be explained.

In response to the primary pressure setting signal set in the control device 9, the pressurizing device 4 presses the electrode 1a with the primary pressure to release the Ni-based material sandwiched between the bonding surfaces of the materials 2a and 2b. The amorphous flow medium 3 is pressurized. Next, in response to the primary energization signal set in the control device 9, primary energization is applied from the power supply 5 to the Ni-based amorphous brazing material 3 via the electrodes 1a, 1b and the materials to be joined 2a, 2b, and the Ni is heated by resistance. The amorphous flow medium 3 melts and begins to be discharged from between the joint surfaces of the materials 2a and 2b, and therefore the electrode 1a
The displacement of the reference plate 10 increases, and the displacement of the reference plate 10 also increases accordingly. The displacement meter 11 measures the displacement of the reference plate 10 and sends a signal to the control device 9, and the control device 9 senses the inflection point where the displacement becomes large and sends a set secondary pressure signal to the amplifier 8. A secondary energization setting signal is transmitted to each amplifier 7. amplifier 8
amplifies the secondary pressure setting signal and operates the pressurizing device 4 with the set secondary pressurizing force. The amplifier 7 amplifies the secondary energization setting signal and sends it to the current control device 6,
The current control device 6 instructs the power supply 5 to perform a set cycle and current amount, that is, secondary energization, and the power supply 5 instructs the electrode 1
Secondary current is applied to the filter material 3 via a, 1b and the welded materials 2a, 2b. The secondary pressure is set to be lower than the primary pressure, and since the secondary energization is sufficient to maintain the temperature of the joint interface at a temperature slightly higher than the melting point of the filter material 3, the current is smaller than that of the primary energization. Second
The figure shows a diameter of 12 mm using the resistance welding equipment shown in Figure 1.
mm, length 100 mm, and resistance diffusion bonding is performed on a round bar made of S43C.
FIG. 3 is a diagram showing displacement and temperature at a bonding boundary surface.

In the first step, a Ni-based amorphous flow medium is inserted between the round bars and set, and in the second step, the primary pressure is applied at 550 kg, and 18500 A is applied for 17 cycles.
Next, electricity is applied.During this time, the temperature of the joint surface rises, causing thermal expansion of the round bar, and the position of the upper electrode rises slightly.

Since the filter medium begins to melt at the beginning of the third step, the downward displacement of the electrode suddenly increases. Here, pressurize with a secondary pressure of 100Kg, 5000A, 30 cycles 2
Next, turn on the power. Since the secondary current is applied with a smaller current than the primary current, the temperature of the joint boundary surface is maintained at a temperature slightly higher than the melting point of the filter material, and the filter material is discharged from the joint surface. In the fourth step, the same current is applied while applying the same pressure as in the third step, so the temperature at the joint interface is maintained at a temperature slightly higher than the melting point of the filter material, and the diffusing components are diffused. stop.

In addition, when measuring the temperature of the joint interface when the secondary energization is stopped in the third step, it is as shown by the dotted line in Figure 2 without the secondary energization, and the temperature is lower than the melting point of the filter medium. Therefore, the filter medium 3 is not discharged and no diffusion occurs.

As a result of performing resistance diffusion bonding under the above conditions, the amount of deformation was 0.5 mm, which was 1/7 of that of the conventional method, and the strength of the bonded portion was equivalent to that of the conventional method.

In the examples described above, Ni-based amorphous amorphous was used as the filter medium, but similar results were obtained using BNi-2.

(Effects of the Invention) As explained above, according to the present invention, since the filter material at the joint is discharged, the alloy layer between the filter material and the material to be joined becomes very thin, so the strength of the joint is reduced. It is similar to a bonding material, and resistance diffusion bonding with very little deformation can be performed.

[Brief explanation of drawings]

Fig. 1 is a block diagram of a resistance welding device that implements the present invention, and Fig. 2 shows the pressure, current, displacement, and
FIG. 3 is a diagram showing the prior art, and FIG. 4 is a diagram showing changes in pressing force and current. 1a, 1b...electrode, 2a, 2b...material to be joined, 9...control device, 11...displacement meter.

Claims (1)

[Claims] 1. A low-melting metal is inserted between the joining surfaces of materials to be joined that have joining surfaces consisting of planes or curved surfaces parallel to each other, and electricity is applied to the materials to be joined while the low-melting metal is pressurized at the joining surface. In the resistance diffusion bonding method, in which materials to be joined are joined by melting a low-melting metal using the generated resistance heat generation, the displacement of the materials to be joined is measured by applying primary pressure and applying primary current. A resistance diffusion bonding method characterized in that the pressure is applied at a secondary pressure lower than the primary pressure based on the value, and the secondary energization is applied lower than the primary energization.