STUDY OF THE POSSIBILITY OF USING NICKEL-BASED INTERMEDIATE LAYERS WHEN WELDING TITANIUM ORTHOALUMINIDE WITH A NICKEL ALLOY

Autor: Lidiia Petrushynets, Oleg Novomlynec, Iurii Falchenko
Rok vydání: 2022
Zdroj: Technical Sciences and Technologies. :38-51
ISSN: 2519-4569
2411-5363
DOI: 10.25140/2411-5363-2022-2(28)-38-51
Popis: Titanium aluminides have a low density and maintain high strength at elevated temperatures, which makes them prom-ising for the manufacture of aircraft engine elements. In the presented work, the problem of welding in the solid phase ortho-rhombic titanium aluminide based on the intermetallic compound Ti2AlNb and heat-resistant alloy ЭИ437Бon a nickel base is considered. A review of the state of the problem of welding heat-resistant alloy ЭИ437Бbased on nickel and titanium or-thoaluminide Ti2AlNb was carried out. It was established that the main problem in welding Ti2AlNb alloy with nickel alloy is a strong tendency to the formation of brittle phases in the joint zone, which negatively affect the mechanical properties. A promising method of joining this group of alloys is diffusion welding in a vacuum.The purpose of the work is to study the influence of multilayer and gradient foil on the formation of the zone of titanium orthoaluminide joints with a nickel-based alloy during vacuum diffusion welding.In the work, multilayer and gradient foil based on Al-Ni and Ni-Tisystems were used according to the original structure. The foils were obtained by electron beam evaporation and condensation in a vacuum. The deposition process consists in the layer-by-layer condensation of elements on a horizontal substrate.The work presents the method of conducting experiments, welding modes, chemical composition of materials and foil.The work shows for the first time that during the direct welding of titanium orthoaluminide with the ЭИ437Бalloy, as a result of the strong tendency ofthe materials to form brittle phases at the joint, a significant increase in microhardness is observed in the joint zone up to 2...4 times compared to the base material (up to 11.94 GPa). It was established that the useof layered foil (Ni/Ti, Al/Ni) as intermediate layers allows to significantly reduce the difference in microhardness values in the joint. At the same time, the microhardness in the central part of the joint zone reaches 6.69...8.79 GPa, which is close to the microhardness values of Ti2AlNb.The presented materials can be used as a basis for the development of welding technologies in the solid phase of heter-ogeneous titanium orthoaluminide materials with nickel-based alloys.
Databáze: OpenAIRE
Externí odkaz: