Low-Cycle Fatigue of VKNA Type Single-Crystal Intermetallic Alloy Under “Hard” Loading Conditions

Intermetallic alloys, created on the basis of Ni 3 Al compound, may be used up to 1200°C, retaining high thermal stability. These materials are used in aviation gas turbine construction. Contemporary single-crystal casting technology for high-temperature alloys makes it possible to prepare billets with different crystallographic orientation, and this provides a significant difference in mechanical properties. Low-cycle fatigue (LCF) resistance is studied under test conditions with controlled deformation in a loading cycle at 850 and 1050°C for intermetallic alloy based on Ni 3 Al with different crystallographic orientation. The effect of temperature and crystallographic orientation on LCF characteristics is studied. It is demonstrated that at both temperatures one of the orientations shows better results.