SU1225741A1 - Method of manufacturing articles with internal channels - Google Patents

Description

The invention relates to the field of soldering, in particular to methods of soldering products with internal channels, and can be used in the manufacture of skeletons of bi-electrodes of fuel cells for matrix current batteries with gaseous or liquid reagents and with an acidic or alkaline electrolyte.

The aim of the invention is to improve the quality of products by providing a predetermined cross-section of the channels.

FIG. Figures 1 and 2 show fragments of the item to be burned during assembly; in fig. 3 - the same, after channel calibration.

On thin-walled plates 1 and 2, as well as on auxiliary parts (frames) 3 and 4, a relief is formed, forming channels for reagents. The package of plates 1 and 2 and auxiliary parts 3 and 4 is assembled, placing solder solder (not shown) in the soldered gaps, and in the channels - solder bar stock 5 having a melting point below that of solder solder. The cross section of bar blanks is not less than the cross section of the channels of the product. The assembled package is compressed by pressure, which ensures the calibration of the product channels with solder rods 5 (5.8 10 - 11.6 10 N / m2).

Then the pressure is reduced to the usual value when soldering (55-2 10 N / m) and is heated to a temperature above the melting point of bar solder 5 by 30-100 ° C. The molten solder is drawn out of the channels of the product by powder solder due to the capillary forces of the latter and forms soldered joints of the components together with the powder solder.

The pressure value during calibration of the channels before soldering depends on the material from which the frame parts are made and the thickness of the parts. For example, for nickel it is in the lower limit, and for stainless steels it is in the upper limit.

At temperatures above the melting point of solder rods less than 30 ° C, complete solo outflow from the holes is not achieved, and at temperatures above the melting temperature of more than 100 ° C, the cross section of the channels may change due to erosion of thin-walled plates.

Solder bar stock is used not only for its intended purpose, but also as a tool for imparting a certain profile to the details of the product. The method allows to produce a relief on the plates with a lower degree of accuracy than is allowed by the technological process of their use, or on parts of parts the reliefs are partially not pre-fabricated.

To simplify the manufacturing technology, the frames on the plates form only part of the reliefs, and the rest are made in an assembly. To do this, hard solder rods are placed in preformed reliefs on the frames and plates, the rods are brought into contact with the flat surface of the plates, and under pressure they form reliefs in the reliefs of the opposite frames and plates.

Example. The frames of the bioelectrodes of the fuel elements are made by soldering on the contacting surfaces. The frames consist of two frames with a thickness of 0.63 mm and two thin-sheet plates with a thickness of 0.15 mm. Details are made by nz nickel. Pa frames and plates formed reliefs that form the channels during assembly. In the gaps between the parts, a silver spindle of 0.5 µm fraction is placed as solder. The deformation of parts in 72 places of relief is carried out with silver-based solder rods with a diameter of 0.8 mm and a pressure of 5.8 10 N / m2 on the flat surfaces of the parts. Channel length 3 mm. Rods are used whose length is 0.5 mm longer than the channel length. Then, the pressure on the flat surfaces of the parts is reduced to 55 P / m and the frame assembly is placed in a brazing furnace. There, the assemblies are heated to 820 ° C for 15 minutes, during which the rods melt and release the channels.

When using the proposed method, it is possible to manufacture skeleton channels with the same cross section, which makes it possible to obtain the same hydraulic resistance of the channels and, consequently, a uniform supply of reagents to the active surfaces of the electrodes with progressive processing methods (cold forming). Combining the operations of deforming the reliefs and calibrating the channels allows making reliefs on parts with a lower degree of accuracy, i.e. less labor intensive. The use of solder for calibrating and deforming the rod, which melts during heating and frees the channels, makes it possible to dispense with the use of additional operations and devices.

FIG. 2

Claims (1)

METHOD FOR PRODUCING PRODUCTS WITH INTERNAL CHANNELS, mainly skeletons of bi-electrodes of fuel cells, in which a relief forming channels for reagents is formed on thin-walled plates, a package of plates and auxiliary parts are assembled with placement of solder in the gaps and heated to soldering temperature simultaneously characterized in that, in order to improve the quality of products by ensuring a given section of the channels, powder solder is placed in the brazed gaps, and bar stocks are placed in the channels and the solder section is not smaller section of the channel, and a melting point below the melting temperature of the solder powder prior to heating to the package, pressure is applied providing calibration rods channels solder, and soldering is carried out at a temperature above the melting point of the solder on the wire rod 30 to 100 ° C. in FIG. 1>