JPH06226489A - Material for joining metal and joining method for joined parts - Google Patents

Abstract

PURPOSE:To assure long-term reliability and to reduce a cost by lowering the joining temp. in joining of metallic joining parts. CONSTITUTION:A part or the entire part of the joining parts are heated to a temp. above the m.p. +30 deg.C of the material for joining metals and <=410 deg.C and are joined by using the material for joining metals contg. over 10wt.% to <=70wt.% Sn and 2 to 10wt.% Al and consisting of the balance Zn and inevitable impurities. At least a part of the joining parts are otherwise coated with the material for joining metals and thereafter, a part or the entire part of the joining parts are heated the temp. above the m.p. +30 deg.C of the material for joining metals and <=410 deg.C and are joined.

Description

Detailed Description of the Invention

[0001]

The present invention relates to Al, Cu, Fe, N
The present invention relates to a metal joining material for joining various metals such as i, Co, Ag and Au, and a joining method for joining parts using the same, particularly, by lowering a joining temperature in a brazing or soldering step, It ensures long-term reliability and reduces costs.

[0002]

2. Description of the Related Art Conventionally, Pb-S has been used for joining metals.
N-based solder, Ag, Al braze, etc. are generally used. When high strength solder is required particularly, solder containing Pb as a main component and a small amount of Sn or Ag is used. Further, for joining Al or Al alloy, for example, in the case of Al heat exchanger, Al is generally used.
-Using a brazing sheet in which a Si-based alloy brazing material is clad with a core material as a part of the components of the assembly, and raising the temperature to about 600 ° C which is just below the melting point of the core material, Nocolock brazing method, vacuum brazing The components are integrated by joining them together by a furnace brazing method such as a brazing method.

[0003]

However, the above Pb-
Sn-based solder has a high density and has a problem of environmental pollution due to the toxicity of lead. Further, since the Al heat exchanger is brazed in the form of a brazing sheet using an Al—Si alloy brazing material, the joining temperature is as high as about 600 ° C., and the melting point of a material other than the brazing material approaches the melting point. Therefore, strict temperature control is indispensable, and since it is necessary to maintain the temperature in a vacuum or an inert gas atmosphere, there is a problem that equipment cost and running cost are high. In addition, the melting point of the brazing material used for the skin material also limits the material used for the core material. Further, since the clad material is used, there is a problem that the waste cannot be reused.

[0004]

As a result of various investigations in view of the above, the present invention can perform bonding of various metals such as Al at a lower temperature, reduce costs, and secure reliability for a long period of time. And a method of joining joined parts using the same.

That is, the metal bonding material of the present invention is Sn:
A Zn-based alloy containing more than 10 wt% and 70 wt% or less, Al: 2 to 10 wt%, and the balance Zn and unavoidable impurities.

Further, one of the joining methods of the present invention comprises, as a metal joining material, Sn: more than 10 wt%, 70 wt% or less, Al: 2-10 wt%, and the balance Zn and unavoidable impurities. Using a Zn-based alloy consisting of
It is characterized by heating to the following temperature and joining.

Further, another one of the joining methods of the present invention is
As a metal bonding material, Sn: more than 10 wt%, 70 wt%
% Or less, Al: 2 to 10 wt%, a Zn-based alloy containing the balance Zn and unavoidable impurities is used, and at least a part of the joint component is covered with the Zn-based alloy. , The melting point of the Zn-based alloy + 30 ° C. or higher, 410
It is characterized by heating to a temperature of ℃ or less and joining.

[0008]

According to the present invention, as described above, in the joining of metal parts, at least a part of the portion that needs to be thermally joined by using solder or brazing material exceeds Sn: 10 wt% and is 70% by weight or more.
Since a Zn-based alloy containing wt% or less and Al: 2 to 10 wt% and the balance Zn and unavoidable impurities is used for bonding, a good bonding state can be obtained even at a low temperature of 410 ° C. or less. . In particular, when joining aluminum heat exchanger parts, a brazing sheet is not required and the joining can be performed at a lower temperature.
It is also possible to use a high-strength material having a relatively low liquidus point such as (Mg-based alloy), and it is also possible to reduce the thickness of the joined parts.

The reason why the additive elements in the Zn-based alloy are limited as described above in the present invention will be described below. Zn
The addition of Sn to the base alloy lowers the melting point of the Zn base alloy and enhances the fluidity of the alloy to improve spreadability (wettability with metal, especially Al), hot dip galvanizability and bondability. is there. However, the amount of Sn added is limited to more than 10 wt% and 70 wt% or less because these effects are insufficient at 10 wt% or less, and at a joining temperature of 410 ° C. or less, metal, especially Al-based material A sound joint cannot be obtained, and if it exceeds 70% by weight, the melting point is further lowered, but no further improvement in fluidity is observed, and addition of more than necessary Sn increases the cost of the joining alloy (solder). Because it will be.

The addition of Al is for preventing the oxidation of molten Zn and molten Sn, lowering the melting point, facilitating the hot dipping and joining work, and improving the wettability with metal, especially Al. However, the amount of Al added is limited to 2 to 10% by weight because these effects are insufficient if it is less than 2% by weight, and if it exceeds 10% by weight, the melting point increases and the spreadability of the Zn-based alloy deteriorates. This is because the workability of joining at a low temperature of 410 ° C. or lower is deteriorated.

Further, using the above Zn-based alloy, the temperature for joining the joined parts is set to the melting point (liquidus point) of the Zn-based alloy +30.
The reason why the temperature is set to ℃ or higher and 410 ℃ or lower is as follows. This is because if the bonding temperature is lower than the melting point of the Zn-based alloy + 30 ° C., the spreadability of the Zn-based alloy cannot be secured, and sound bonding cannot be performed easily. The melting point of the Zn-based alloy in the present invention is 410 ° C.
This is because heating above 410 ° C. is unnecessarily heating, which is disadvantageous in terms of energy cost.

To join metals with each other using the Zn-based alloy of the present invention, a method of joining the alloy of the present invention in an amount suitable for the size of the joint and a suitable flux, or joining prior to joining It is possible to use a method in which at least a part of the component is coated with the alloy of the present invention, and then the components are bonded using an appropriate flux.

In the case of the latter joining method, as a method of coating the alloy of the present invention on a part of the joining parts, hot dip plating using flux, or hot dipping using ultrasonic waves in combination therewith is economically possible. This is a useful method. At this time, when joining copper-based materials, Ni, Sn, Co, etc.
After coating the material with a thickness of about 1.0 μm by electroplating or hot dipping as a base, the alloy of the present invention may be coated on the material by using the flux together with the above method.

[0014]

EXAMPLES Next, examples of the present invention will be described. Example 1 A 0.5 mm thick Al plate (JIS 1100 alloy), C
u plate (Cu-0.03% Zr), Fe plate (JIS G
3101) was used to assemble a solder bondability test piece 1 having the shape shown in FIG. 1 and bonded using the solder alloy of the present invention. That is, a solder alloy having a composition of Sn: 40 wt%, Al: 5 wt% and the balance Zn was used, and this was melted in a graphite crucible. Next, each of the above plate materials is cut into a size of 30 × 30 mm, coated with a flux containing zinc chloride as a main component, and then immersed in the solder alloy melting bath of the present invention kept at 400 ° C. to form the solder coating material 2. Created. Also, each of the above plate materials is cut into a size of 20 × 40 mm and bent into an L shape,
After applying the flux, the L-shaped material 3 was placed on the solder coating material 2 to assemble the solder bondability test piece 1.
The solder bondability test piece 1 thus obtained was inserted into a furnace at 400 ° C. and heated for 15 minutes to solder bond the solder coating material 2 and the L-shaped material 3. As a comparative example, each of the above plate materials is
Dip in a molten Zn bath maintained at 50 ° C to apply solder coating 2
After preparing the above, a solder bondability test piece 1 was assembled by the same method as in the example of the present invention. The solder bondability test piece 1 thus obtained was inserted into a furnace at 450 ° C. and heated for 15 minutes,
The solder coating material 2 and the L-shaped material 3 were joined by soldering. For these test pieces, the joint state between the solder coating material 2 and the L-shaped material 3 and the surface state of the joint portion were visually inspected, and the results are shown in Table 1.
It was shown to.

[0015]

[Table 1] * 1 ○: Good bonding ×: Poor bonding (partially bonded, etc.) * 2 ○: No discoloration ×: Severe oxidation and dirty

As is clear from Table 1, the invention sample No. 1
Nos. 3 to 3 are good in both the bonding state (solderability) and the surface state. On the other hand, in Comparative Examples Nos. 4 to 6, the oxidation of the solder is severe and the surface condition is dirty, and Al and Fe are at a high temperature (450 ° C.).
Despite being heated, it is only partially bonded.

EXAMPLE 2 A JIS 1100 alloy (Al-0.12 wt% Cu) was used to form a multi-hole tube by extrusion, and a Zn-based alloy having the composition shown in Table 2 was formed by using ultrasonic waves on the outside of the tube. Is coated with a thickness of about 30 to 40 μm, the multi-hole tube (4) is bent into a serpentine shape as shown in FIG. 2, and a corrugated JIS 3003 alloy (Al-0.12
A fin material (5) made of wt% Cu-1.2 wt% Mn) was sandwiched and bonded at the temperatures shown in Table 2 to assemble a serpentine type capacitor. For comparison, JIS3003 is used for the core material.
JIS4045 alloy (Al-10wt% S
Using the conventional brazing sheet using i) as fins, a similar serpentine type capacitor was assembled by a conventional method.

With respect to these capacitors, the joint state between the fin and the tube was visually inspected, and the results are shown in Table 2. In addition, after cutting out a part of the joint from the capacitor and embedding and polishing in resin, the fillet shape in the cross section of the joint is observed with a microscope to check the wetting condition of the solder alloy with Al, and the results are also shown in Table 2. did.

[0019]

[Table 2] * 1 A: Good joining B: Partial joining C: Not joining * 2 A: Continuously good fillet formation B: Partial good fillet formation C: Incomplete formation of fillet (sufficient joining) No swelling of the alloy for use is observed) D: No fillet is formed

According to the invention examples No. 11 to 17, Al-
Compared with the conventional brazing using a Si alloy brazing material, at a temperature lower by about 200 to 250 ° C. (410 ° C. or lower), a good joint with a good fillet shape can be obtained. On the other hand, in Comparative Examples Nos. 18 to 20 in which the composition of the Zn-based alloy is out of the range of the present invention, joining is impossible or only partially joined at a temperature of 410 ° C or lower.

Although the example in which the alloy of the present invention is applied to Al, Cu, Fe, etc. has been described above, the joining by the alloy of the present invention is not limited to these materials only, and the Zn-based alloy of the present invention is used. It is generally applicable to metals that can be joined by using. Thus, the fields to which the alloy of the present invention can be applied include electric / electronic parts, industrial instrument parts, superconducting parts,
There are computer-related parts, switches, audio equipment, home appliances, vehicle control device parts, rotor bars, etc.

[0022]

As described above, according to the present invention, in joining aluminum heat exchangers and the like, the joining temperature can be lowered (to 410 ° C. or less) to reduce the running cost, and a good joining state can be obtained. It is possible to obtain a remarkable effect in industry such as being able to secure the above.

[Brief description of drawings]

FIG. 1 is a perspective view showing an appearance of a solder bondability test piece.

FIG. 2 is a perspective view showing an example of a serpentine type capacitor.

[Explanation of symbols]

 1 Solder bondability test piece 2 Solder coating material 3 L-shaped material 4 Multi-hole tube 5 Fin material

Claims (3)

[Claims] 1. Sn: more than 10 wt% and 70 wt% or less,
A metal bonding material containing Al: 2 to 10 wt% and the balance Zn and unavoidable impurities. 2. Sn: 10 wt% as a metal bonding material
Over 70 wt% and contains Al: 2-10 wt%,
A Zn-based alloy composed of the balance Zn and unavoidable impurities is used, and a part or the whole of the joint component is melted by the melting point of the Zn-based alloy +
A joining method for joining parts, which comprises joining by heating to a temperature of 30 ° C or higher and 410 ° C or lower. 3. Sn: 10 wt% as a metal bonding material
Over 70 wt% and contains Al: 2-10 wt%,
A Zn-based alloy composed of the balance Zn and unavoidable impurities is used, and at least a part of the bonded component is coated with the Zn-based alloy.
A joining method for joining parts, which comprises joining by heating to a temperature of 0 ° C or higher and 410 ° C or lower.