JP2904638B2 - Brazing method and brazed joint - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of brazing two base materials, at least one of which is metal.

[0002]

2. Description of the Related Art The joining of parts which cannot be heated as a whole,
In the case of joining of a member to which an electrode is difficult to be attached or joining of a pipe which is too long to enter the furnace, brazing has been conventionally performed by local heating. For example, ceramic 1
Metal pipe 300 to the flange 200
When air-tightly brazing, as shown in FIG. 5, a brazing material 400 (wire) is placed on the upper end surface of the flange 200, and a heating coil (not shown) is wound around the outer periphery of the overlap margin, and a high-frequency wave is applied to the heating coil. The current is applied.

[0003]

In the above-mentioned brazing method, the magnitude of the high-frequency current depends on subtle differences in brazing conditions such as the size of the gap between the flange 200 and the metal pipe 300 and the manner in which the brazing material 400 is placed. Even if the time for pouring is the same, the flow of the brazing material tends to be uneven, and the brazing material as shown in FIGS. 5 and 6 is discarded as a failed brazing product. In the brazed product D of FIG. 5 , the portion 410 is insufficiently flown, and has low bonding strength and poor airtightness. In addition, FIG. 6
In the brazed product E, the brazing material 400 flows into the portion 420 too much and the brazing is generated.
The stress of 00 may cause cracks in the ceramic 100. The purpose of the present invention is that one is ceramic
The other is to provide a brazing method and brazing conjugate can be attached without low defect two matrix metal.

[0004]

Means for Solving the Problems To solve the above problems,
The present invention employs the following configuration. (1) According to the brazing method of the present invention, two base materials, one of which is ceramic and the other is metal, are joined by locally heating a brazing material having a lower melting point than these base materials. In the brazing method, a groove having a V-shaped or U-shaped cross section is provided around the metal base material, and the groove is located at an edge of a brazing portion. (2) In the brazing method of the present invention, two base materials, one of which is ceramic and the other is metal, are joined by locally heating a brazing material having a lower melting point than these base materials. In the brazing method, a flange having a substantially L-shaped cross section is joined to the ceramic base material to be erected, and a groove having a V-shaped or U-shaped cross section is provided in the metal base material, The groove is located at the edge of the brazing point, and the metal base material and the flange are brazed. (3) In the brazed joint of the present invention, two base materials, one of which is ceramic and the other is metal, are joined by locally heating a brazing material having a lower melting point than these base materials. In the brazed joint body thus formed, a groove having a V-shaped or U-shaped cross section is provided around the metal base material, and the groove is located at the edge of the brazed portion. (4) The brazed joint of the present invention joins two base materials, one of which is ceramic and the other is metal, by locally melting a brazing material having a lower melting point than these base materials. And a flange having a substantially L-shaped section is joined to the base material of the ceramic, and the metal base material is provided with a groove having a V-shaped or U-shaped cross section. The groove is located at the edge of the brazing point, and the metal base material and the flange are brazed.

[0005]

When the brazing material is melted by local heating according to the brazing method according to the first aspect, the molten brazing material spreads to the brazing portion, and the molten brazing material surrounds the edge of the brazing portion of the metal base material. Since the brazing material is blocked by the groove, the brazing material does not flow into unnecessary portions of the ceramic, the brazing material flows evenly around the circumference, and the brazing material is concentrated at the brazing point, so that the ceramic base material and metal The base material is brazed firmly.
Further, even when brazing is performed by rapid heating of local heating, the flow of the brazing can be easily controlled, and even when brazing ceramic, the shape of the brazing flow can be appropriately maintained, and cracks generated in the ceramic can be prevented. According to the brazing method of claim 2, the same effect as in claim 1 is obtained,
The ceramic base material is firmly brazed to the metal base material via the flange, and cracks generated in the ceramic can be prevented. According to the configuration of claim 3,
The joined body has the same effect as that of the first aspect, can firmly braze the ceramic base material and the metal base material, and can prevent cracks generated in the ceramic. According to the configuration of the fourth aspect, the joined body can have the same effect as the second aspect, and also can prevent cracks generated in the ceramic.

[0006]

Next, a first embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 2, the brazing structure A of the heat pipe includes a ceramic 1, a flange 2 brazed to the ceramic 1 (brazing temperature 780 ° C. to 900 ° C.), a pipe part 3, and a silver brazing 4. Be composed.

The ceramic 1 is a ceramic sintered body mainly composed of alumina and has a ring shape. Flange 2
Is made of Kovar, plated with nickel, and has a substantially L-shaped cross section. The pipe part 3 made of copper and presenting a cylindrical shape has a lower end portion which is formed on an upright portion 21 of the flange 2.
, And are overlapped to almost the entire surface to form an overlap margin. A concave groove 31 having a U-shaped cross section (depth, width: 0.3 mm) is provided at the lower end of the brazing portion of the pipe part 3.

Silver Row 4 is BAg-8 having a melting point of about 780 ° C.
It is. The silver braze 4 uniformly flows into the gap between the pipe part 3 and the flange 2 and is solidified. The silver braze 4 located at the upper end of the brazing part due to surface tension is formed along the outer wall of the pipe part 3. The silver row 4 located at the lower end of the swelling is prevented from flowing downward by the concave groove 31.

Next, the procedure of brazing in this embodiment will be described. The pipe part 3 is fitted into the upright part 21 of the flange 2 in which the ceramic 1 is brazed to the lower surface of the laterally extending part 22, and the pipe part 3 is supported so that the fitting position does not change. A silver wire 4 in the shape of a wire is placed in a ring shape on the upper end surface of the flange 2 (see FIG. 1). When a heating coil (not shown) wound in a ring shape is wrapped around a brazing point and a high-frequency current is passed through the heating coil for a predetermined time, an induction current is generated by electromagnetic induction, and the silver row 4 is melted. In order to ensure that the silver solder 4 is melted, the magnitude of the high-frequency current and the energizing time are made slightly larger or longer than those in the conventional heat pipe brazing structure (without the groove 31). The melted silver solder 4 flows down, and flows uniformly into the gap between the pipe part 3 and the flange 2, which is a soldering point.
In addition, the silver row 4 located at the upper end of the brazing portion rises along the outer wall of the pipe part 3 due to the surface tension, and the silver row 4 located at the lower end flows in the circumferential direction by the groove 31, Downflow is prevented. When the high-frequency induction heating is stopped, the temperature at the brazing point decreases,
Solidifies.

Next, advantages of this embodiment will be described. (A) Since the silver row 4 melted by the groove 31 is blocked by the groove 31 and flows in the circumferential direction, it does not flow down below the groove 31. For this reason, the silver braze 4 does not flow into unnecessary parts, and the silver braze 4 uniformly flows into the gap between the pipe part 3 and the flange 2 at the brazing point, so that the pipe part 3 and the flange 2 are firmly brazed. Attached. Therefore, in the brazing structure A of the heat pipe, the pipe component 3 and the flange 2 can be brazed with high bonding strength, high airtightness, and high reliability. (I) Since the molten silver solder 4 can be blocked by the groove 31, the size of the high-frequency current to be supplied to the heating coil and the energization time are slightly larger or longer than those without the groove 31 so that the soldering can be easily performed. Can be done. For this reason, there is no insufficient melting of the silver solder 4 as shown in FIG. 6, and there is almost no unsuccessful soldering. (U) Since only the groove 31 is provided around the pipe part 3,
The increase in manufacturing cost is extremely small. As a result of various experiments, it was found that the cross-sectional shape of the groove (concave groove 31) capable of blocking the silver row 4 may be a V-shape as long as the groove bottom surface is not a curved surface. In addition, the groove must have a depth of 0.1 mm or more regardless of whether it is concave or V-shaped.

[0011]

[0012]

[0013]

[0014]

[0015] Next, a second embodiment of the present invention will be described with reference to FIG. As shown in FIG. 3 , a ceramic-pipe brazed body C is formed by brazing a ceramic 1 and a copper pipe 6 having a cylindrical length using a silver bran 4.

In this embodiment, the inner and outer wall surfaces of the copper pipe 6 located at the upper end of the brazing point have a width and a depth of 0.3 mm respectively.
mm concave grooves 61 and 62 are provided.

The brazed body C of the ceramic pipe has a lower end face of the copper pipe 6 approaching an upper end face of the metallized and nickel-plated ceramic 1 and supports the copper pipe 6 so that the position is not changed. The silver brass 4 preformed in a ring shape is fitted into the inside and the outside of the pipe 6, and brazing is performed by high-frequency induction heating as in the first embodiment.

This embodiment has the following advantages in addition to the advantages described above. (E) Due to the presence of the grooves 61 , 62 , the molten silver row 4 is blocked by the grooves 61, 62, flows in the circumferential direction, and does not go above the grooves 61, 62. For this reason, the thickness of the silver braze 4 to be brazed to the brazing location is increased, and the copper pipe 6 and the ceramic 1 can be brazed firmly and with high airtightness.

The present invention includes the following embodiments in addition to the above embodiments. a. The base material corresponding to the ceramic 1 may be plate-shaped or cylindrical, and the base material corresponding to the pipe part 3 and the copper pipe 6 may be rod-shaped.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a heat pipe brazing structure before brazing according to a first embodiment of the brazing method of the present invention.

FIG. 2 is a sectional view of a heat pipe brazing structure according to a first embodiment of the brazing method of the present invention.

[3] according to the second embodiment of the brazing method of the present invention, Se
It is sectional drawing of the brazing body of a lamic-pipe .

FIG. 4 is a cross- sectional view of a heat pipe according to a conventional brazing method.
It is sectional drawing before the brazing of a brazing structure .

FIG. 5 is a cross-sectional view of a brazed body having a heat pipe brazing structure according to a conventional brazing method.

FIG. 6 is a cross-sectional view of a brazed body having a heat pipe brazing structure according to a conventional brazing method.

[Description of Signs ] 1 Ceramic (base material) 2 Flange 3 Pipe part (base material) 4 Silver low (base material) 6 Copper pipe (base material) 31, 61, 62 Groove (groove)

Continuation of the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) B23K 1/14 B23K 1/18 B23K 33/00

Claims (4)

(57) [Claims] 1. A method of locally applying two base materials, one of which is ceramic and the other is metal, and a brazing material having a lower melting point than these base materials.
In a brazing method for joining base materials by melting by heat, a groove having a V-shaped or U-shaped cross section is provided in the metal base material, and the groove is an edge of a brazing portion. Brazing method located in the part. 2. A method of locally applying two base materials, one of which is ceramic and the other is metal, and a brazing material having a lower melting point than these base materials.
In a brazing method for joining base materials by melting by heat, a flange having a substantially L-shaped cross section is joined to the ceramic base material to be erected, and a cross section of the metal base material is V A brazing method in which a U-shaped or U-shaped groove is provided around the periphery of the groove, and the groove is located at an edge of a brazing portion, and the metal base material and the flange are brazed. 3. A method of locally applying two base materials, one of which is ceramic and the other is metal, and a brazing material having a lower melting point than these base materials.
In the brazed joint in which the base materials are joined by being melted by heat, a groove having a V-shaped or U-shaped cross section is provided around the metal base material, and the groove is formed at a brazing portion. Brazed joint located at the edge of the. 4. Locally adding two base materials, one of which is ceramic and the other is metal, and a brazing material having a lower melting point than these base materials.
By being melted by heat, in a brazed joint in which the base materials are joined together, a flange having a substantially L-shaped cross section is joined to the base material of the ceramic, and the base material of the metal is erected. , A groove having a V-shaped or U-shaped cross section is provided around the periphery of the groove, and the groove is located at the edge of the brazing portion, and the metal base material and the flange are brazed. .