|KIRILLOVA Valentina||Institute of Metallurgy and Material Science of RAS|
|Spoluautoři BURKHANOV Gennadii, SDOBYREV Vladislav, DEMENTEV Vladimir, MINAKOV Alexsandr|
In this work we report on the cycling deformation of -and -molybdenum - rhenium (by an example of the Mo-7wt%Re alloy) single crystals at room temperature. Times of deformation cycle (tension+compression) are 20-30 sec (low) and 1 sec (high). Amplitudes of deformation are 1,5x10-4 – 5,0x10-3. Re-alloying was found to reduce the anisotropy degree and saturation stress (“σn”) of Mo-7%Re alloy up to 210-225 MPa in comparison of non alloying Mo (550 MPa). Moreover Re-alloying results in the modification of fatigue curves from linear (at small change of amplitude εpl/2 ≤ 2x10-3) to parabolic (at more high change of amplitude). High deformation cycle time (1sec) was found to increase “σn” up to 280 MPa (tensile deformation) and 300 MPa (compression deformation). Under such condition specimens withstand up to 80 000 cycles without the cracking. The studying of slipbands and cracks on the surface of deformed samples has been carried out by an Opton optical microscope using a Nomarskii interference-contrast method. As the number of cycles goes up the surface relief modifies from slip band to traces of substantial localized deformation. No microcracks on surface of specimens were found.