Application characteristics of vacuum brazing

Vacuum brazing technology can be rapidly developed and applied, mainly because it has a series of advantages compared with other welding methods.
(1) During the entire brazing process, the brazed parts are in vacuum conditions (10-2Pa ~ 10 Pa range), and there will be no oxidation, expansion, decarburization, pollution and deterioration, and the cleanliness and strength of the welded joints are relatively high.
(2) During vacuum brazing, the parts are heated evenly as a whole, the thermal stress is small, and the deformation can be controlled to a minimum, which is particularly suitable for the brazing of precision products.
(3) The low pressure around the base metal and the brazing material can remove the volatile gases and impurities released by the metal at the brazing temperature, which can improve the performance of the base metal and obtain a very bright joint.
(4) Because no brazing flux is used, there will be no defects such as pores and inclusions. The process of cleaning residual flux after brazing can be omitted, saving time, improving working conditions, and no pollution to the environment.
(5) The vacuum heat treatment process of the parts can be completed simultaneously during the brazing process. By selecting appropriate brazing process parameters, brazing can also be arranged as the final process to obtain a brazed joint with performance that meets the design requirements.
(6) Multiple adjacent welds can be brazed at one time, or multiple components can be brazed in the same furnace. The welding efficiency is high.
(7) There are many types of basic metals that can be vacuum brazed, especially suitable for brazing aluminum and aluminum alloys, titanium and titanium alloys, stainless steel, high-temperature alloys, etc. It is also suitable for brazing connections of the same or different metals such as titanium, zirconium, niobium, molybdenum, tungsten, and tantalum. For the connection of refractory metals, vacuum brazing is one of the best methods to produce flawless joints. It is also applicable to composite materials, ceramics, graphite, glass, diamond and other materials.
(8) It has opened up product design avenues and can be used for parts with narrow grooves, extremely small transition platforms, blind holes, closed containers, and parts with complex shapes, without having to consider corrosion, cleaning, damage, etc. caused by brazing flux. However, vacuum brazing also inevitably has some disadvantages:
① Metals are easy to volatilize under vacuum conditions, so vacuum brazing is not suitable for base metals and brazing materials containing volatile elements. If it is necessary to use it, relatively complex process measures should be adopted.
② Vacuum brazing is sensitive to the influence of surface roughness, assembly quality, matching tolerance, etc. of parts before brazing, and has high requirements for the working environment.

Vacuum Brazing Furnace