Home – Home – Jornals – Thermophysics and Aeromechanics 2015 number 1

The article presents the results of an experimental study of the influence of powder nanomodifiers of refractory compounds on the mechanical properties, macro– and microstructure of heat-resistant alloys ZhS–6K and Inconel 718. It is shown that the introduction of nanomodifiers into the melt leads to the refinement of the alloy structure: the average grain size decreases 1.5–2 times, and their morphology becomes similar to equiaxial at significant reduction of the particle size in the carbide phase. The service life of ZhS–6K alloy under cyclic loading at 600 ºC increases 2.7 times, and at 975 ºC by 40 %, and relative elongation increases more than twice. The mechanical properties of Inconel 718 significantly increase: long-term strength at 650 ºС increases 1.5–2 times, and the number of cycles before the collapse at 482 ºС grows more than three times. It has been found out that addition of nanomodifiers to the melt, in alloys, forms clusters of particles of refractory compounds at borders and joints of the formed grain structure that may help slowing down the processes of recrystallization (prevents the increase in the size of the contacting grains by their associations) and stabilizes the strength properties of the alloys at higher temperatures.