JPS6199654A - Al alloy for connector - Google Patents

Abstract

PURPOSE:To improve the corrosion resistance, strength and brazability of the joint of a bolt hole extrusion by using an Al alloy contg. specified amounts of Mn, Mg and Zn. CONSTITUTION:The composition of an Al alloy for a connector is composed of, by weight, 0.5-1.5% Mn, 1-3% Mg, 1-3% Zn and the balance Al with inevitable impurities or 0.5-1.5% Mn, 1-3% Mg, 1-3% Zn, <0.3% Cr and/or <0.3% Zr, and the balance Al with inevitable impurities.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial application field The present invention relates to connectors (), - unions and nuts) which are piping parts for At heat exchangers such as automobile air conditioners.
This invention relates to an Al alloy suitable for use.

(B) Conventional technology As shown in Figure 1, a conventional automobile air conditioner has a condenser 1 made of an At heat exchanger and an evaporator 2 connected by a pipe 6, between which a refrigerant such as Freon is compressed. It consists of a compressor 4 and a receiver 5, and trap half unions 6 and nuts 7 are used as connectors to connect the respective parts. Generally, this half union is made of Al alloy, and the nut is also increasingly made of Atium in recent years. The material is generally JIS 7NO1, JIS 5004 and J
IS 6061 alloy etc. are used. These alloy compositions are shown in Table 1. (In this specification, % by weight for each component) Extruded rods or drawn rods are used as raw materials for connecting parts such as half unions and nuts, and are finished into final parts by external and boring processing. Later, in order to reduce the cost of these cutting processes, hollow rods with cross-sectional shapes such as hexagonal shapes were manufactured using the mandrel extrusion method. The extrusion speed is faster than the extrusion method, and there is no burning problem (hollow rods with a clean surface can now be manufactured using the boathole extrusion method (no change in content).

? →Problem to be solved by the invention Hollow rods manufactured by this porthole extrusion method 9 always have a seam (welded part) 8 as shown in the cross section of the hollow rod in Figure 2 due to hot press bonding. .

9 is a hollow part. (Refer to page 16B of plastic processing of nonferrous metals and metals, by Hiroshi Tanaka, published by Nikkan Kogyo Shimbun, 1972) JIS, which is most commonly used for half unions and nuts.
The 7NO1 alloy had a defect in that when this joint part was exposed to a corrosive environment, it corroded preferentially over other parts. This corrosion is specific to °7NO1 alloy,
This does not occur with alloys such as 5004 and 6061, but connectors are soldered directly to condensers and evaporators.For 51/C alloys, aging is achieved by natural cooling after the heat of brazing. case,
Alloys such as 3004 and 6061 are inferior in strength to 7NO1 alloy, so connector K is brazed.
.

is inappropriate. For this reason, the boathole joints are not preferentially corroded (it has excellent brazing properties, and its strength after brazing heat is close to that of 7NO1 alloy (and it is possible to develop an alloy with excellent boathole extrudability). It was wanted.

In view of the above-mentioned problems, the present invention has developed various materials for use in connectors manufactured by the boathole extrusion method. We have discovered an alloy that has good brazing properties and higher strength than the commonly used JIS 3004 and JIS 6061 alloys. That is, the alloy of the present invention has the composition range shown below. (1), Mn
o, 5-1-5%, Mg 1-3% + Zn
1 to 5, an Al alloy for connectors consisting of the balance Al and unavoidable impurities. (21, (
26 (e) Effect: In the present invention, the alloy composition is limited as described above. This is due to the following reasons.

The purpose of adding Mn is to increase the strength, and the seed content is increased from 0.5 to
The reason why it is limited to 1.5 inch is that if it is less than 0.5 inch, sufficient strength cannot be obtained, and if it exceeds 1.5 inch, a huge Al-Mn compound will crystallize, which will impair plastic workability. be.

The addition of porcelain was to further increase the strength, and the porcelain content was reduced to 1.
The reason why it is limited to ~6% is that if it is less than 1%, sufficient strength will not be obtained, and if it exceeds 6%, the melting point will be low (and brazability will be impaired. Furthermore, the addition of Zn is due to the coexistence of ceramics. The reason for limiting the Zn content to 1 to 5% is that less than 1% is insufficient because the Zn content is limited to 1 to 5%. This is because the strength does not increase, and if the length exceeds 3 inches, the boat hole joints will be preferentially corroded.

Moreover, the reason for adding one or both of Cr and Zr to the above alloy composition is to further increase the strength.
The reason why the r content is set to 0.3% or less is that if the r content exceeds this value, coarse intermetallic compounds are formed, which not only impairs plastic workability but also deteriorates brazeability. This is also because it deteriorates the cut surface during cutting.

Note that the addition of a small amount of Ti or B for grain refinement, which is carried out in general Al alloys, is also effective in the alloy of the present invention, and is preferably added within the range of 0.15% or less. Further, the unavoidable impurities are normal impurities contained in normal Al metal.

(F) Examples Six types of alloys according to the present invention (N (L 1 to 6) and five types of comparative alloys (1'
1kL7~11) and JIS 3004 as conventional alloy
(Nctl 2), JIS 6061 (1'&1
3), 14 types of alloys with compositions shown in Table 2, such as JIS7NO1 (:414), are melted and cast using a conventional method 9 to produce billets, the ingots are soaked, and a A shape member having a cross-sectional shape as shown in the figure was manufactured.

Mn.

Comparative alloy N117 containing a large amount of porcelain outside the range of the present invention was somewhat difficult to extrude. Furthermore, the extrudability of the alloy of the present invention was excellent.

Using these materials, the quality of brazing properties and the strength 10 days after brazing were measured. The sample shape for wax elbow was cut into the shape of half union 6 shown in Fig. 6, and JIS 300
! Combined with l pipe 10, JISBA4047 (Al-
12% St alloy) Brazing material 11 was placed, applied in a flux manner, and brazed for 5 minutes at a temperature of 610°C in an electric furnace to form a fillet shape at the joint! ! The quality of the brazing properties was determined by: In addition, the strength after brazing is 10% after heating at 610°C for 5 minutes.
The hardness was evaluated by measuring the hardness using a Vickers hardness meter on the second day.

Furthermore, regarding corrosion resistance, the above-mentioned brazing heat wave, JIS
Based on H8601, a CASS test was conducted for 500 hours to investigate the presence or absence of corrosion at the hoardhole joints.

These results are summarized in Table 3.

As is clear from Tables 2 and 6, conventional alloy 30
04.6061.7NO1 has strength, brazability,
It is inferior in terms of corrosion at the porthole joints and is not suitable as an alloy for connector materials made by the porthole extrusion method.

On the other hand, it can be seen that alloys 1 to 6, which are outside the range of the present invention, do not suffer from preferential corrosion at the joints, have good strength and brazeability, and are superior to conventional alloys.

Ming#Ikichi's r, +;', (no change in content) 2nd
Table 9 List of components outside the scope of the present invention (No change in content) Table 3 ○ Good Δ Fairly bad Alloys are inferior in one or both of preferential corrosion at joints, plastic workability during extrusion, brazing performance, and strength.

(G) Effects of the Invention The alloy of the present invention has superior characteristics such as corrosion resistance, strength, and brazability at the joint portion of porthole extrusion compared to conventional alloys.

Used as piping parts, i.e., connectors (half unions and nuts) for heat exchangers such as automobile air conditioners, in particular to improve the corrosion resistance of boat hole joints, increasing their service life and producing remarkable industrial effects. .

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram showing an automotive air conditioner system. FIG. 2 is a sectional view of a hollow rod formed by extruding a porthole, and FIG. 3 is an explanatory view showing a state in which a half union and a condenser pipe are brazed. 1: Condenser 2: Evaporator 3: Piping 4: Compressor 5: 94t-oγ
Chizuchi 6: Half union ~ Igu- 7: Nut 8: Joint 9: Hollow 10: Pipe 11: Brazing material 21) $31! L Procedural Amendment (Spontaneous 1985 ÷ Month A6 Commissioner of the Patent Office/Shi・π'su Indication of the Tonoichi case #Inscriptionnu"5ri'1-2-2-03 No. - Person making the amendment Relationship to the case Patent applicant address: 2-6-1 Marunouchi, Chiyoda-ku, Tokyo Name: Etsuji Moshibe, representative representative of Furukawa Aluminum Industries Co., Ltd. Agent address: 4-17-6 Komone, Itabashi-ku, Tokyo 1 - Self-patented patent = $f, s-b mouth entry king 1゜1
Inventor station Ki T Tsui Yami Tsue Tsuki A...2, "45134
44 (fEI "5tCJ, 'ILL/'-C3
Fj Tsu J > Two (9 t or 0 people 1 Δ. 7'7
Sen't G3 dried beast. r, r-4υLsu~, 65 t=r+-devitrification Taboko, 7. Heniji ζ / Tobatsu I11 Thoughts - Non-Nitsu 14 - Correct - T3゜1 ("2 Procedural Amendment Cao June 1, 1985)

Claims (2)

[Claims] (1) Mn0.5-1.5%, Mg1-3%, Zn1-
An Al alloy for connectors characterized by comprising 3% Al, the balance being Al and unavoidable impurities. (2) Mn0.5-1.5%, Mg1-3%, Zn1-
An Al alloy for connectors, characterized in that it contains 3% of Cr and 0.3% or less of Cr and 0.3% or less of Zr, and one or both of these, and the remainder consists of Al and inevitable impurities.