JPH03238196A - Production of brazing filler metal - Google Patents

Abstract

PURPOSE:To enhance the yield of production of square r circular flat rings independently of the workability of an alloy by filling metal powder of a specified average particle size into each casting mold and heating the filled powder at a temp. below the m.p. CONSTITUTION:Metal powder of 20-150 mum particle size is filled into a casting mold having a square or circular ring-shaped groove so that the surface of the filled powder is leveled with the top of the mold and the filled powder is heated at a temp. below the m.p. A square or circular flat ring-shaped brazing filler metal made of a hardly workable low m.p. alloy and used at the sealing part of the tubular body of a vacuum breaker, etc., can easily be produced in a high yield.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to a method for manufacturing a brazing filler metal, and more specifically to a method for producing a brazing filler metal in the form of a rectangular or round plate ring used in a cylindrical body sealing part such as a vacuum circuit breaker. This invention relates to a method for manufacturing brazing filler metal.

(Prior art and issues) In general, when brazing filler metals, the thermal effects of time can cause various problems, and especially when brazing is used for applications that require vacuum sealing, parts inside the vacuum part may be damaged due to the thermal effects. Ceramic brazing often causes problems such as deterioration and the formation of pinholes in the parts. Therefore, in order to suppress the thermal influence, a brazing filler metal with a low melting point is required for such uses. For example, adding In, Sn, Ge, etc. to the alloy is effective in order to lower the melting point.

However, both of these Ag-based and Au-based alloys have poor workability, and for example, even during hot working, it is difficult to maintain the heating temperature in the form of a thin plate, so they are more likely to break and are made into a thin plate. It is difficult to process the rings, and since the plate-shaped rings are pressed into round or square plate-shaped rings, scraps and scraps from hollowing out are produced, resulting in extremely poor yields and problems with productivity and work efficiency. there were.

(Objective of the Invention) The present invention has been made to solve the above-mentioned problems, and provides a method for easily producing rectangular and round plate ring-shaped brazing filler metals of low melting point alloys, which are difficult-to-process materials, with a high yield. It is something.

(Structure of the Invention) The technical means of the present invention for solving the above-mentioned problems is to place metal powder grains with a particle size of 20 to 150 μm into a mold having a square or round ring-shaped groove in the same manner as the mold surface. It is characterized in that it is filled so as to form a negative side, and then heated at a temperature below its melting point.

(Function) According to the present invention configured as described above, since a brazing material is made from metal powder particles by heating in a mold having a predetermined shape, there is no need to process an alloy material that is difficult to process. Not only does it not require any effort in processing or machining, but a plate-shaped ring can be obtained directly.Furthermore, by filling the ring so that it is flush with the mold surface, it shrinks after heating and the finished shape conforms to the predetermined shape. After filling the mold with metal powder particles, the surface of the mold is made flush by tilting, shaking, wiping, etc.

The purpose of heating below the melting point is to sinter the metal powder grains and form them into a predetermined shape.Although it is possible to use the brazing filler metal's own weight, it is also possible to apply a load such as pressing as appropriate to increase the mechanical strength. It is something. When heating below the melting point, the temperature must be approximately 100°C below the melting point. If the temperature is too close to the melting point, it will be difficult to control the temperature, resulting in melting and rapid changes in volume, making it impossible to obtain the desired shape. Moreover, if the temperature is too low below the melting point, the sintering time will be too long or mechanical strength will not be obtained after sintering.

Further, the powder particle size is preferably in the range of 20 to 150 μm, and 2
If it is less than 0 μm, it will be difficult to handle and workability will be poor.
If it exceeds μm, the sinterability will deteriorate, but it is not limited to this range (although it is preferable that the particle size is as uniform as possible).

Further, the material of the mold is appropriately selected from carbon, ceramics, etc., which have poor wettability with the brazing material. Furthermore, the heating time is 1
The heating time is preferably from 5 minutes to 3 hours, and the heating atmosphere is vacuum, hydrogen, argon, nitrogen, etc. In addition, the difficult-to-process materials are not limited to In, Sn, and Ge-added materials.

(Example) Examples and conventional examples will be described below.

First, as Example 1, Ag45%Cu30%1N25% powder was made by the atomization method, and after sieving to 50 to 100 μm, it was prepared in advance on a carphone plate with an outer diameter of 49 mm and an inner diameter of 45 mm.
Powder was filled into a round ring-shaped groove with a depth of 0.3 mm and heated in an electric furnace at 550°C for 60 minutes in hydrogen, and then cooled to form a mold with an outer diameter of 48.6 mm, an inner diameter of 45 mm, and a thickness. Sa0.2
100 pieces of 8 mm round ring-shaped brazing filler metal were obtained. In addition,
Using this, FeNi42 and Cu alloy were brazed and a good brazing condition was obtained. Note that the product yield was 98% based on the weight of the input powder.

Next, as Example 2, 27% AuIn powder was made by the atomization method, sieved to 50 to 100 μm, and then prepared in advance on a carbon plate with an outer diameter of 34 mm, an inner diameter of 30 mm, and a depth of 0.
The powder was filled into a 25 mm square ring-shaped groove, heated in an electric furnace at 420° C. for 160 minutes in hydrogen, and then cooled to obtain 100 pieces of square ring-shaped brazing filler metal. Note that the product yield was 95% based on the weight of the input powder.

On the other hand, as conventional example 1, Ag45%Cu3 was melted and cast.
An ingot of 0% In and 25% was made and an attempt was made to cold-roll it, but there were many cracks and it could not be processed.

Furthermore, hot working was attempted, but rolling was hardly possible, and the yield of the final product after pressing was extremely low at 10% of the ingot weight. Also, conventional example 2
As a result, an ingot of 1n27% Au was made by melting and casting and cold rolling was attempted, but it cracked and could not be processed. Although hot working was also attempted, rolling was hardly possible, and the yield of the final product after pressing was extremely low at 7% based on the weight of the ingot.

(Effects of the Invention) As described above, according to the method for manufacturing a soldering material of the present invention, metal powder particles with a particle size of 20 to 150 μm are filled into a mold and heated below the melting point, which improves the workability of the alloy material. Regardless, it has an excellent effect in that square and round plate rings can be easily produced with good yield.

Claims (1)

[Claims] 1) Metal powder particles with a particle size of 20 to 150 μm are filled into a mold with square or round ring-shaped grooves so that they are flush with the mold surface, and then heated at a temperature below the melting point. A method for producing brazing filler metal.