Vacuum brazing of aero engine hydraulic duct joints using silver alloy

The subject of this innovation is a technique for vacuum brazing of reliable fuel, oil and air duct assemblies for aero engines used in different types of modern airplanes, as well as helicopters, both military and civilian. The technology was developed in a cooperation with Warsaw University of Technology and WSK "PZL-Rzeszów" S.A.

The technological process does not cause the formation of any waste products, and components produced with its application are 100% recyclable.

The technique developed here encompasses the full manufacturing process of piping assemblies starting from surface preparation, both from the point of view of cleanliness, as well as roughness, through the selection of geometry and shape of the joint, selection of amount of brazing material, selection of technological parameters, through the selection of final 100% quality control of brazed joints. In this technique, alloys have been selected which are characterized by a big difference between the solidus and liquidus temperature, reaching 140°C, as well as by a multi-phase microstructure which called for the development of special conditions of running the brazing process. This technique utilizes the eco-friendly process of vacuum brazing with the application of partial pressure of argon at an appropriate temperature. Thanks to this, toxic fluxes used in traditional brazing methods have been eliminated. This technique has been utilized to braze over 1,200 different types of piping assemblies used in military and civilian aero engines.

The invention "Vacuum brazing of aero engine hydraulic duct joints using silver alloy" was awarded with GOLD MEDAL on 54th World Exhibition of Innovation, Research and New Technologies, Brussels-Eureka 2006; BRONZE MEDAL on 34th International Exhibition of Inventions, New Techniques and Products, Geneva 2006; SILVER MEDAL on 9th Moscow International Salon of Industrial Property, Moscow 2006.; GOLD MEDAL on International Invention Fair "Genius - Budapest", Budapest 2006.