JPH01218795A - Al alloy brazing filler metal having high fillet strength - Google Patents

Abstract

PURPOSE:To reduce the amt. of the Al alloy brazing filler metal to be used by forming the brazing filler metal of an Al alloy material contg. Si and Mn respectively at specific weight% and adding Mg and Zn independently or in combination at prescribed ratios thereto at need. CONSTITUTION:The brazing filler metal is formed of the Al alloy which contains, by weight, 6.5-10.5% Si and 0.6-1% Mn and consists of the balance Al and impurities. Further, 1-2% Mg and 0.1-1% Zn are added independently or in combination thereto at need. The Si component lowers the m.p. of the brazing filler metal and improves melt flowability and wettability. The Mn component disperses the Al-Mn compd. finely and uniformly into the fillet. The Mg component breaks the oxide film on the surface of the brazing filler metal and improves the melt flowability. The Zn provides corrosion prevention to the joining member. Since the fillet strength is thereby increased, the amt. of the brazing filler metal to be used is decreased.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention provides an M alloy brazing material that can form a brazing part with high fillet strength when used for brazing A1 and M alloy members. It is related to.

[Conventional technology]

Generally, when manufacturing an M alloy heat exchanger by brazing M alloy tube material and pure N or M alloy fin material in a vacuum or an inert gas atmosphere, pure M plate material or M alloy plate material is generally used. , Furthermore, two or more of these types of clad board materials have one side on one side.

A plated sheet □ is clad with M alloy brazing material, and a pipe is formed from this plated sheet.

and fin material is used, and the M alloy brazing material is 5 layers (hereinafter % indicates weight %), 8i:6.5
~10.5%.

It is also well known that an M alloy is used, which has a composition containing Al, with the remainder consisting of Al and unavoidable impurities.

[Problem to be solved by the invention]

On the other hand, from an economic point of view, the smaller the amount of 1M gold alloy used in the production of A1 alloy heat exchangers, the better. It is becoming more and more urgent to reduce the amount of M alloy brazing filler metal used, but if the amount of hA1 alloy brazing filler metal used is reduced, the shape of the fins and holes formed in the brazing parts will also become smaller, making it difficult to achieve the desired brazing effect. Currently, it is not possible to ensure strength.

[Means to solve the problem]

Therefore, the present inventors have discovered that even small-shaped fillets,
As a result of research, we found that if the strength of this fillet is high, sufficient brazing strength can be ensured and maintained, making it possible to reduce the amount of M alloy brazing filler metal used.
For the above Nagari M alloy brazing filler metal.

When a Mn component is included as an alloy component, the fillet formed in the brazing part will have a structure in which fine M-Mn compounds are dispersed in the base material, and the A of this fine fraction will be
It was discovered that the l-Mn compound gives the fillet significantly high strength, and that high brazing strength can be obtained.

This invention was made based on the above findings.

Si: 6.5~IO,5s, Mn:
0.6-1'%.

and, if necessary, Mg: l~2'14, Zn:
0.1-1%.

It is composed of an M alloy with a composition of 1 or 2 m, and the remainder is Al and unavoidable impurities, and the fillet strength is still << when brazing.

Therefore, the amount of brazing filler metal used is reduced.

Strong brazing is a characteristic of the M alloy brazing material that can form parts.

Next, the reason why the composition of the M alloy brazing material of the present invention is limited to the above-mentioned standard will be explained.

(a) Si The Si component has the effect of lowering the melting point of the brazing filler metal and making brazing possible by improving hot metal flow and wettability. If it is less than S, the desired effect cannot be obtained.

On the other hand, if the content exceeds 10.5%, the melting point will rise and the desired gluing will not be possible.
%.

(bl Mn ' The Mn component combines with 1Al to form an AH-Mn compound, and the fillet formed after brazing has a structure in which the An-M'n compound is finely and uniformly dispersed in the base material.) However, if the content is less than 0.6%, the desired high fillet strength cannot be obtained;
If it exceeds %, the flowability and processability will deteriorate.

Its content was determined to be 0.6 to 1.

fc) λ(g) The Mg component evaporates especially during brazing in a vacuum atmosphere, destroys the natural oxide film on the surface of the brazing material, prevents re-oxidation, and also prevents the flow of the brazing material. Because it has a getter effect that further improves sex.

Vacuum brazing is added as necessary when used, but if the content is less than 1, the desired effect will not be obtained, while if the content exceeds 2%, the workability will be affected. The content was set at 1 to 2 yen because not only did the amount of h Mg decrease, but also the contamination in the furnace due to evaporation of Mg became significant. □(d) Zn'・ Zn1.5 minutes has the effect of electrochemically making the brazing filler metal less noble, causing the brazing filler metal to exhibit a sacrificial anode effect, and preventing corrosion of structural members such as pipe materials and fin materials. However, if the content is less than 0.14, the desired corrosion protection improvement effect cannot be obtained;
%, the corrosion resistance of the brazing filler metal itself deteriorates significantly, so the content was set at 0.01 to 1%.

〔Example〕

Next, the M alloy of the present invention will be specifically explained using examples.

M alloy molten metals each having the composition shown in Table 1 were prepared by a normal melting method, and after being formed into an ingot, it was subjected to 1 open cutting, 1 homogenization heat treatment under normal conditions, and then hot rolling. A hot-rolled plate having a thickness of 28 μm is obtained, and this hot-rolled plate is subjected to appropriate intermediate annealing and then cold rolling to produce a cold-rolled plate having a thickness of 10 mm. ~
No. 12 and conventional M alloy brazing materials 1 to 5 were manufactured, respectively.

The various AQ gold alloy filling materials mentioned above all contain Fe: 0.35% or less + Mn i Mg as unavoidable impurities.
sZn, Cu, Cr, and Zr: Each contained 0.01% or less of Q.

Next, these various M alloy brazing filler metals are separately used.
1 Made of hot rolled plate with nominal thickness = 9B, Mn: 1.2
3%, Cu: 0.12%, the rest is Al and unavoidable impurities (Sl: 0.25% or less, Fe: 0.35%
Hereinafter, it is laminated on one side of an M alloy core material with a composition consisting of Mg, Zn, Cr, and Zr (all containing 0.01% or less), and hot rolled to a plate thickness of 2IIj.
11 clad material, and further subjected to appropriate intermediate annealing and cold rolling from scissors to a plate thickness of 1.2 wj
A plating sheet with a brazing filler metal thickness of 0.12 mm.

This plating sheet was placed with the brazing metal side facing upward, and an M alloy plate material having the same composition as the M alloy core material and having a thickness of 1 mm was vertically arranged in an inverted T shape on this plating sheet, and in this state.

(a) Apply flux and place in a dust atmosphere.

Hold at 600°C for 5 minutes (hereinafter referred to as condition a).

(b) In a vacuum of l O”” torr, 60
Hold at 0°C for 5 minutes (hereinafter referred to as conditions).

That’s all (a)! , or Fb), and after brazing, the M alloy plate is pulled vertically with the plating sheet pressed and fixed from above, and the brazing is formed at the corner. The tensile force when the fillet broke was measured to evaluate the fillet strength. These results are shown in Table 1.

〔Effect of the invention〕

From the results shown in Table 1, 1 Invention M@Gold brazing filler metal 1-1
2 are conventional M alloy waxes 1 to 1 which do not contain Mn.
It is clear that the fillet strength is much higher than that of No. 5.

As mentioned above, the M alloy brazing material of the present invention can form a cylindrical brazing part with fillet strength.
This makes it possible to reduce the amount of AM alloy brazing filler metal used, which not only contributes to the weight reduction and labor saving of various devices, but also brings about a great economic effect.

Applicant: Mitsubishi Aluminum Corporation

Claims (1)

[Claims] (1) Si: 6.5-10.5%, Mn: 0.6-1%
, with the remainder consisting of Al and unavoidable impurities (
An Al alloy brazing filler metal having high fillet strength, characterized in that it is made of an Al alloy having a fillet strength of at least 1% by weight. (2) Si
: 6.5 to 10.5%, Mn: 0.6 to 1%, further contains Mg: 1 to 2%, and the remainder is Al and inevitable impurities (weight %) An Al alloy brazing filler metal having high fillet strength, characterized in that it is made of an Al alloy having the following properties. (3) Si:
Contains 6.5 to 10.5%, Mn: 0.6 to 1%,
Furthermore, an Al alloy brazing filler metal with high fillet strength, characterized in that it is made of an Al alloy having a composition (the above weight %) containing Zn: 0.1 to 1%, and the remainder consisting of Al and unavoidable impurities. (4) Si:
Contains 6.5 to 10.5%, Mn: 0.6 to 1%,
Furthermore, fillet strength characterized by being constructed of an Al alloy having a composition (weight %) containing Mg: 1 to 2%, Zn: 0.1 to 1%, and the remainder consisting of Al and unavoidable impurities. High aluminum alloy brazing filler metal.