Application of vacuum brazing technology in aerospace field

Vacuum brazing technology has developed to date and has become a very promising brazing technology. Its application in the aviation field has become increasingly popular. When brazing aviation alloys such as aluminum alloys, stainless steel, high-temperature alloys, titanium, niobium, tantalum and other high-melting-point metals, vacuum brazing is generally used. Aircraft engines are one of the most widely used fields for vacuum brazing. In order to meet the design and manufacturing requirements of high thrust-to-weight ratio, high reliability, long life and low cost of aircraft engines, new materials, new structures and new processes are increasingly used in the aerospace field, which puts higher requirements on processing and manufacturing methods. At the same time, it also promotes the continuous development of aerospace manufacturing technology. As a means of aerospace manufacturing process, welding technology has also developed rapidly. Vacuum brazing technology has unique advantages and flexibility for the connection of new materials and the manufacture of complex and precise structural parts. For some refractory welding materials and complex components, vacuum brazing is the only feasible and effective connection technology, and it can even achieve a “seamless” welding effect without processing the brazed joints. Therefore, vacuum brazing technology is increasingly used in the aviation industry and other industrial fields. The manufacture of many important parts on aircraft engines, such as turbine blades, compressor blades, combustion chamber parts, honeycomb sealing structures, stainless steel heat exchangers, fuel mains and other pipelines, involves vacuum brazing technology.

A factory produces an aviation precision part, which is made of 0.3mm thick GH3536 honeycomb material by vacuum brazing. Welding technical requirements: the number of core cell deformation is not more than 30%, there is no obvious oxidation and macro defects on the surface of the honeycomb core, the continuity of the brazing seam is greater than 98%, the length of each discontinuous brazing seam is not more than 5mm, and the grain grade of the welding point and the welding heat affected zone after welding is not less than 6. The production trial processing is carried out according to the process of energy storage spot welding energy of 550J, brazing temperature of 1055℃, insulation time of 14min, and furnace cooling. The first part was inspected and qualified by the relevant department. After a period of mass production, the qualified rate of the product reached more than 99%. Actual production shows that this process has a short production cycle, low cost, high reliability and high efficiency.

High Temperature Vacuum Brazing Furnace