Determining the Optimal Crystallographic Orientation in a Single Crystal Turbine Blade to Increase its Strength Reliability

The high-pressure turbine blades of most modern gas turbine engines are made of single-crystal alloys. Single-crystal materials have significant anisotropy characteristics; therefore, the orientation of the axes of the single crystal relative to the geometrical axes of the blade has a great effect on the stress-strain state, static strength, and dynamic characteristics of the blade. Here, the necessary optimization of both the axial orientation (the optimal value of which may differ from <001>) and the azimuthal orientation is confirmed. The problem was solved by considering the anisotropic temperature–orientation characteristics of the alloy and the uneven temperature field of the blade. The values of the optimal crystallographic orientations were determined. Notably, casting tolerances for the deviation of the crystallographic axes must be considered when searching for the optimal position of the axes of the single crystal.

Anisotropic Temperature-Dependent Interaction of Ferromagnetic Nanoparticles Embedded Inside CNT

We analyze the magnetization versus magnetic field curves of Fe-based nanoparticles embedded inside CNT. Measurements were performed at different temperatures and orientations of the magnetic field. We demonstrate that, for the parallel field the magnetic anisotropy dominates and the coherent anisotropy is of great importance at low temperatures. At high temperatures, the exchange coupling becomes stronger, but the coherent anisotropy still occurs. For the perpendicular field, the coherence anisotropy is absent, and the dimensionality of the system reduces to 2D. The results are discussed in the framework of the correlation functions of the magnetic anisotropy axes.