JPS58159995A - Flux for brazing - Google Patents

Abstract

PURPOSE:To provide a flux for brazing which is suited particularly for joining plates, pipes and the other structures of Al or Al alloys, by consisting the same of the composite fluoride of K, Al, and a metal forming metal on the surface of the materials to be brazed by reacting with the materials to be brazed at the brazing temp. CONSTITUTION:A flux for brazing having the compsn. corresponding to 30-55% AlF3 in molar ratio, 35-60% KF and <=20% the fluoride of a metal forming metal on the surface of the materials to be brazed by reacting with the materials to be brazed. The above-described metallic fluoride is contained at the ratio corresponding particularly to 6-15% ZnF2, and has the composite fluoride of the above-described metal with K and Al. Such flux is produced by the method of melting the fluoride of AlF3, KF and fluoride of the above-described metal compounded so as to have the prescribed compsn., then cooling, solidifying and grinding the melt. The flux has the characteristic that it does not require the removal of the flux after brazing when used for brazing materials of Al-Si, etc. in joining.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel soldering flux, and particularly to a soldering flux suitable for bending casings, plates, pipes, and other structures made of A1 alloy.

Conventionally, chloride-based fluxes are commonly used for brazing Mut1 and AAt alloys, but the WK humidity is extremely hot, and corrosion resistance deteriorates significantly unless the residual flux in the brazing layer is completely removed. do. Removal of residual flux requires a cleaning process, which is expensive in terms of equipment, and is difficult to completely remove from ridge-shaped structures. Recently, the 7 lux of US patent JllaQj1328 has K.
A brazing method using fluorides of F and AtF has been proposed.

This creates a compound of Kg AtFs and KAlF3 by mixing and dissolving KF, which is highly hygroscopic, with ktF@. This compound has very low hygroscopicity, and it is said that there is no need to remove residual flux remaining on the surfaces to be joined with a brazing machine. However, even if there were no corrosive components in the IK housing, there was nothing to improve the corrosion resistance, and there was still a drawback in terms of improving the corrosion resistance of the members to be joined.

An object of the present invention is to provide a tux using an HT-SI brazing filler metal.

An essential condition for the 72x, which makes it difficult to remove the flux from the brazed part, is that the residual flux does not contain any hygroscopic components. The non-hygroscopic 7-sixes contain many fluoride-based ingredients, and chloride-based ingredients are generally used to remove oxide films on aluminum and At alloy members and to increase wettability. There are n. However, most of the simulants have hygroscopic properties, and the residual flux in the brazed parts (if not completely removed, the corrosion resistance will deteriorate significantly) does not meet the purpose of Ke6.

In order to achieve this purpose, fluoride-based materials, especially A
AtFs, KF, which has a suitable melting point when t
As a result of investigating adding various fluorides, which were thought to be effective in improving corrosion resistance, mainly to acid components, it was found that ZNH also has good photographic properties. 1 post 1-11 Umbrella! t+mFs uses At as the welding material, decomposes at the brazing temperature, and becomes metal 7.
．． The corrosion resistance of the aluminum layer is improved by coating the wax part with n. Zn is responsible for AjK and protects Mut from corrosion by 7 lux.

In this way, it is sufficient that the metal of the flux reacts with the covering wax member, coats the surface thereof, and provides corrosion resistance.

In terms of light-fi ratio, AlPm is 30-55%.

KF3S ~ 60% and metal O fluoride which reacts with the solder sealing material at the brazing temperature to form metal on the wrinkle brazing 1w surface.
The present invention provides a 7-lux for wax elbows, which has a composition of 0% or less, 411 and 6 to 15% ZnFg, and has a compound fluoride of K, the metal, and At. Lis NIl# Rb, Cs, which further improves wetting spread p
At least one fluoride based on the Mg*Cm evaluation is added in a molar ratio of 3 to +725%. Among the additive ingredients, LiF is the most effective.
It's big.

The flux of the present invention is produced by a method in which a mixture of AtFs, KF, and the above-mentioned metals is melted, cooled, solidified, and pulverized so as to have a predetermined composition. A method in which ALFs and KF are melted in advance, then cooled, solidified, and crushed, and the metal fluoride is melted, cooled, solidified, crushed, and mixed together. It is manufactured by dissolving the three components in water to form a cream, and then drying it to form a powder.

The two files created in this way are KmLiAJ
! Compounds such as Pg, KAlF3 and KsZn Snow Fy, ZnFl by melting AIFs and KV
For powders prepared by pre-mixing and additive ingredients, KsL1mujFs, KAtFa > and Z! Compounds such as IFm-1 are further made into a cream with water, dried and made into a powder.
l@#Contains compounds such as AtFs and KF.

These compounds have extremely low hygroscopicity and are effective in improving corrosion resistance against moisture.

The flux's attractive sta'ti, molar ratio, Al
Pm30~55% and KF8S ~60% components @IIL, 1llllllL9 components in advance in molar ratio LI
It may be prepared by adding to a mixed-t-molten component prepared with 60-64% F and 40-36% ZnFm.

The component range of main 1 component OALFm and KF is special K11l
In the case of At and At alloy members, the material to be joined is III! The ingredients range that meets the requirements for melting is as follows. Among them, AlFm in mol% is 40 to 5
When the component is 0.0 and KFt50 to 45, it melts at 600C or less and is fully activated at the brazing temperature.

In addition, as a metal that is a main component for improving corrosion resistance, 41
K Z n F m is the range necessary to form a KZn coating near the joint surface of the brazed part and on the entire surface, and its Φ
The amount will be 6-15 mol%. The components of the octopus consist of AtF, KF, which are the raw components of the flux, and their melting points vary within a small range.

L1# Additional components such as Na, Rb, Cs, Mg, Ca, etc.
The range of 3 to 25 mol % was set based on the fact that it was confirmed that the effect was almost unchanged even if the Toc was increased in the 5 iui range of 7 lux and added more than that. Although the lower limit of the amount added varies slightly depending on the added components, it has been found through experiments that containing 3 mol% or more of any of the components has an effect on wetting and spreading.

As a method of adding AtF1 to LiF1 in mole%,
When 45-52 and KF are combined with 65-48 components and heated, 1 lll at 600C or less, and other mo/'%teL I
F t" 60~64 ttL and ZIIFm 40~3
6 has a melting point of 620C or less, and even if this component is added to a 25 mol% S melted good component, the melting point does not increase, and it spreads during brazing and has good p property and corrosion resistance. It turns out that excellent brazed joints can be obtained.

Hereinafter, the results of wet spreading and corrosion tests on the 7 luxes of the present invention will be explained with reference to specific examples.

The dried powder containing 504% of each of 9KF and ALFs was filled into a graphite crucible and melted in an @asoc electric furnace. The melt was stirred with a graphite rod and approved by JII, after which it was poured into a black ship mold and solidified. *Flux is 15 when melted.
Grind it so that it passes through a sieve of 0 mesh.K150
LIP62Jf Nil% and Z! 1F1
Mixed at 38 mol%, stirred well, and melted the above nine components to make nine powder, 204% (Al), 36 mol (42)
Add nine.

Produced as above) 9 fluxes with a flux concentration (residual moisture) KL of about 10%, At plate (A1050!
500XI') and φ24 to φ13 and 9434
3. The wetting and spreading property was tested by attaching it near the brazing filler metal. Further, a plating sheet (core material: 300B, skin material: 4343) was placed at right angles on a corrosion test Fi A1050 board, and 7 lux was adhered near the wax.

Both of the wet spread and corrosion test pieces were heated at 615 tll' for 10 seconds in an NX electric furnace.

For comparison, a wetting spread and corrosion test piece with the same shape as that used in the present invention was used, and the flux had a composition of 787 mol% N and 43 mol% AlFm (Comparative Example 2).
52 mol % of KF and 48 mol % of AlFm (Comparative Example 1) without addition of flF were similarly converted to 10 wt % Ilf, and as a result, using the 7 lux of the present invention,
In terms of wet spread, 20 mol% of mul is 20 to 23 times, mul 2
035 (L% is 2.0-12 times, whereas the flux of Comparative Example 2 shows L6-L8 times, the flux without ZflFm shows 1.7-'LO times, and the present invention's 7 Lux is excellent.Corrosion test is JISH8601
9, which was conducted in continuous operation for 144 hours in the Cath test. the result,
AIFs 4! : In the 9 test pieces using only KF and 7lux without ZnFm addition, a lot of pitting corrosion (AI05011K) was detected near the base metal and filler metal, but also in other distant places, and pitting corrosion S It can even reach α4~0.7■.

In the results of the corrosion test, almost no pitting corrosion was observed in Samples I and 2, and of course pitting corrosion *g did not appear. The feature of the corrosion mode according to the present invention is that it is a complete corrosion.

In other words, the coating of l+wKZfi and zn alloy was formed on some parts of the wax, the butterfly and other 9 parts, and the reason why the corrosion resistance was further improved was because the dense Zl(OH)s was formed on the entire surface of the solder sealing part.

]! F- was investigated for the flux created in
~11 m, and 4 to 7 mg of F- was detected in Comparative Example 2. On the other hand, mul is 4~6 mg, mu 2 is 2~! 5mg
In both cases, F- was low. The reason for this is the solubility of water (7 lux of K1g in 100mA water)
are KAtF40214 mg, KgAtF408
25 mg and 133 mg of KsLIAtF- are considered to be different from each other.

In the present invention, although the above description is made regarding ZnF snow, it is considered that the same applies to other components. Although AtK has been described as the member to be bonded, the 7 lux of the present invention can be applied to other members, such as PE group or CLI group, and similar effects will be obtained.

According to the flux of the present invention, a general At brazing filler metal standardized in JI3Z3268 can be used, and there is no need to remove the brazing flux.

Furthermore, it should have excellent corrosion resistance, and the reliability of lining parts - Procedural amendment (1st year) May 1930, April 1F43 Indication of the case of Mr. Kazuo Wakasugi, Commissioner of the Japan Patent Office, 1939 Patent Review No. 42620 Title of the invention Relationship with the case of the person making the amendment for the attached flux Patent applicant address: 5-1 Marunouchi-chome, Chiyoda-ku, Tokyo
Name (5101 Hitachi, Ltd. Representative 3 1) Masaru Katsu Shigeyo 5-1 Marunouchi-chome, Chiyoda-ku, Tokyo Subject of amendment ``Patent Claims 11llJ and '' in the specification
: Contents of the amendment to the "Detailed Description of the Invention" page J11. In closing, the following amendments have been made to the claims.

"16 molar ratio, AtPm 30-551g, KP
The fluoride of the metal that reacts with the brazing material during brazing for 35 to 60 seconds and forms the WK metal on the surface of the soldering sealing material. 7 lux for brazing with fluoride as a mold.

2. The metal is 7. Claims consisting of n and l, ZIIF proverbs! 1g Brazing flux described in item 1.

3. In molar ratio, ALFs a G-5511, KF35
~60%, metal fluorides that react with the brazing material to form the brazing surface WK gold metal during brazing am 2091 and below and L
i, N heat, : Rb * Cs s Mgs CaO has a composition that overlaps with at least 181 or more fluorides 2s- or less, and X and L' s N '' e & b
7 lux for brazing, characterized in that it has a composite fluoride of eCm, Mg, CaO, at least ill, and At. "Next, 2. Correct the detailed description column for the port."

(1) Correct the word ``noble'' in line 4 of page 1114 to ``base''.

(2) Delete "and AjJ on line 1s13 of the same page.

that's all

Claims (1)

[Claims] 1. In molar ratio, AjF, 30-551G, KF35-
A composite fluoride of K, the metal, and AL having a composition corresponding to 20 Ls or less of a metal fluoride that reacts with the brazing material to form a metal on the surface of the soldering material at the brazing temperature. Fusix for waxy elbows with monsters and t+V palms. 2. The flux for wax elbows according to claim 1, wherein the metal is made of Zn and Zr1F. 1 molar ratio "?', AjF830~5511.KF35
~60-1 Metal fluoride 20- or less and Li which reacts with the brazing material to form a metal on the brazing fitting surface at the brazing temperature
, Na, Rb, (), Mgl Cm IB having a composition corresponding to at least 4111 or more fluoride 25- or less, K, the above metal and L * Nut 'B
At least lII and A4 of rbt CawMg and Ca
It has complex fluoride with T4I mold and wax flux.