SU579109A1 - Method pf soldering hard-to-solder materials - Google Patents

Description

(54) METHOD OF BRAZING OF EARGED MATERIALS

one

This invention relates to soldering, in particular, to methods for surface preparation. details for soldering.

There is a known method of soldering metal parts, in which the preliminary, tinning of the surfaces being welded with gallium, followed by heat treatment and soldering with low-melting solder

The heat treatment is carried out at a temperature not lower than 80 ° C. The connection of the parts and the solidification of the solder takes place at room temperature or slightly heated. The described method is applied in cases where heating is not possible for parts to be soldered and undesirable to use fluxes. The strength of the compounds is largely determined by the adhesion of gallium to the substrate. Gallium is serviced by joining surfaces mechanically (rubbing gallium with a spatula) or ultrasonic. Materials that are not wetted with gallium or wetted poorly cannot be joined in the same way. Ceramics (oxide, beryllium, alundum) and some metals (porous beryllium metal, stainless steel, etc.) are known to be poorly known in a known manner. The mechanical strength of the compounds of porous beryllium beryllium oxide, ruby, stainless steel, made by self-hardening solders after preliminary mechanical or ultrasonic galvanizing, is insufficient (0.2-0.6 kg / mm). At the same time, the low-temperature Beafluse compound of these materials is of great practical interest.

There is also known a method of soldering refractory trudnopaemye materials, in which the preliminary welding of the brazed surfaces with gallium in vacuum, heat treatment at a temperature of 50 ° -800 ° C in TeAemie 2-10 ksn and subsequent soldering 123.

The disadvantage of this is that the strength of the soldered joints is low, since during the soldering only the wetting of the surface occurs without the solder penetrating deep into the surface. During long-term storage, the mechanical adhesion of the solder to the substrate is broken. The purpose of the invention is to increase npoHHOCT of solder joints in the case of brazing of ceramic and metal-ceramic materials. This is achieved by the fact that, according to the proposed method, when joining difficult materials, mainly ceramic and metal-ceramic, by soldering, the gallium surfaces are pretreated on the surfaces with vacuum heat treatment, consisting of extracts at 300-500 ° C for 30 -120 m and 6OO-900 ° C for 60-120 minutes, followed by soldering. During heat treatment, diffusion of galli into the depth of the machined parts occurs. As a result, the edge angle at the gallium-substrate interface decreases, wetting improves, the binding energy at the coating-substrate interface increases, and the strength of the subsequent joining of gallium materials made by self-hardening solders increases. When the annealing temperature decreases, satisfactory galling does not occur, as the temperature rises, the physicomechanical properties of the materials may change. Example 1. Porous beryllium tablets 4 mm thick are placed in a pressure chamber over a gallium crucible after a vacuum of 10 mm Hg has been reached. Art. immerse the tablets in a crucible with liquid gallium and heat. After holding at 300 ° C for 30 minutes and 600 ° C for 90 minutes, the tablets are cooled.

Connected materials

Ruby copper

Stainless steel beryllium ceramics

Stainless steel-porous beryllium

Porous beryllium berillian ceramics

Porous beryllium nickel

Beryllium ceramic

Formula of the invention. Method of soldering of hard-to-wear materials, mainly ceramics and metal 60

Tensile strength

kg / mm

0.3-0.4 1.0-1.2 O, 7-1.0 1.0-1.3 0.6-0.8 0.8-1.1

ceramic, in which the pre-vertical maintenance of the soldered surfaces is performed with gallium in vacuum, heat treatment Example 2, Plates of beryllium ceramics with a thickness of 1 mm in ana) 1rgichnyh. conditions are maintained at 50 ° C for 1 hour and at 9OO C - 1 hour. Galli penetration depth 0.5 mm. Example 3. Samples of a ruby cylindrical shape under the same conditions are dipped into gallium with an end face, preparations of 1 m are kept at 400 C for 2 hours of compound and at 8 ° C for 1 hour. In such a way, samples of ruby, beryllium, beryllium oxides are combined with samples of copper, nickel, stainless steel, tinned using ultrasound with self-hardening galpium solders GISM-65 (eutectic alloy gallium-indium-silver is included in the solder. - 35% by weight copper powder - 65 wt.%. Paste-like solder is applied onto the joining surfaces in an even layer, the samples are ground to each other, fixed in the desired position with a clamp and kept in a thermostat at 70 ° C until solidification hardens. Compounds of various materials are shown in Table 1. The results obtained for these combinations of materials are quite high and significantly (2-3 times) higher than the strength of the compounds obtained using other known methods for gallium surface tinning.

S6

and the follow-up soldering, which distinguishes the sources of information, taken into account in order to increase the strength during examination:

steam connection, heat treatment of pro-1. USSR author's certificate

water with aging at 300-500 C in t Th-270464, nl. J 23 K 1/20, OZ.O2.69.

ZO-120 min and then at 60O-900 Cj USSR Copyright Certificate

within 6О-120 min. № 247022, кп. At 23 K 1/20, 12/06/67.

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