УДК 621.9.016 T. Babul, J. Senkara, A. Nakonieczny INFLUENCE OF TECHNOLOGICAL PARAMETERS ON BRAZING AIRCRAFT ENGINE TUBES The article discusses selected aspects of vacuum brazing of joints in fuel, hydraulic and pneumatic systems of modern aero engines. <...> The effect of surface roughness, as well as that of temperature and time of brazing on the flow properties of AgCu42Ni2 and Au-18Ni brazing alloys on the 18-8 austenitic grade steel is discussed. <...> The morphology of steel- filler alloy-steel joints is analyzed. <...> Phenomena taking place during the displacement of the front interface of the filler alloy in gaps of varied width are discussed. <...> This technology is applied, among other, to the brazing of pipe ducts used in aero engines (Fig. 1). <...> These are ducts or systems of ducts which form part of fuel, oil and air systems, components of hydraulic installations, as well as anti-icing systems. <...> Fig. 2 shows a schematic of an assembled simplest ending - pipe – filler alloy joint, prepared for the process of vacuum brazing and after the operation. <...> For the brazing operations, the most widely used filler material used is the silver - based AgCu42Ni2 (AMS 4765), (AMS 6574). as well as gold - based Au-18Ni a. b. <...> Schematic of assembled system comprising ending-pipe-filler: a – before brazing, b – after brazing Quality control of the joint obtained comprises checking whether, as the result of brazing, 100% of the meniscus line was obtained around the circumference of the joint, the degree of coverage of the joint by the filler material, which should be at least 80% of the surface. <...> SELECTED ASPECTS OF VACUUM BRAZING WITH Ag42Cu2Ni SILVER – BASED FILLER MATERIAL For hard brazing of components, usually silverFig. 1. <...> Examples of aerospace hydraulic piping before the brazing operations based filler is used, with a eutectic composition or with a small difference between the solidus and liquidus temperature. <...> However, for special purpose applications, such as strength at elevated temperatures, there is a need to use other fillers with a different chemical composition and more difficult to braze. <...> A filler with a big difference between the solidus and liquidus temperatures is a rarely used type. <...> The range of solidus-liquidus temperatures of this alloy is, accordingly, 771-893 °C. <...> In order to determine the effect of surface roughness, which is <...>