ПРИМЕНЕНИЕ УЛЬТРАДИСПЕРСНОГО ПОРОШКА НИКЕЛЯ ДЛЯ ДИФФУЗИОННОГО СОЕДИНЕНИЯ ТИТАНА С НЕРЖАВЕЮЩЕЙ СТАЛЬЮ

The paper deals with the features of joining titanium alloy PT-3V to steel 08Kh18N10T by diffusion welding with application of an interlayer of ultrafi ne nickel powder, produced by thermal decomposition of nickel formate Ni(COOH)2+2H2O. Comparison of the structures of welded joints of these materials for presence of intermetallic phases in welding without interlayers and with a nickel interlayer at different mode parameters was performed. Application of ultrafi ne nickel powder at temperatures of 965 and 890 °C leads to formation of a continuous layer of solid intermetallics. At the temperature of 790 °C the diffusion zone has a multilayer structure, differing from the microstructure of steel-titanium joint, produced without the nickel interlayer. Mechanical rupture testing of the welded joints showed that suffi cient strength properties are achieved at application of an interlayer of ultrafi ne nickel powder at lower temperature and pressure, preventing intensive growth of intermetallics. The highest values of ultimate strength were achieved at welding temperature of 760 – 790 °C and were equal to 346 MPa on average. 13 Ref., 3 Tabl., 4 Fig. [ABSTRACT FROM AUTHOR]