ELASTIC AND ACOUSTIC PROPERTIES OF HEXAGONALCr2NbCOMPOUND

Abstract

The ultrasonic properties like ultrasonic sound velocity in the hexagonal structured Cr2Nb compound have been studied along unique axis at room temperature. The second- and third-order elastic constants (SOECs and TOECs) have been calculated for this compound using Lennard–Jones potential. The velocities VLand VS1have minima and maxima respectively with 45° with unique axis of the crystal, while VS2increases with the angle from unique axis. Debye average sound velocities of Cr2Nb have been found to be increasing with the angle and has maximum at 55° with unique axis at room temperature. Hence, when a sound wave travels at 55° with unique axis of this material, then the average sound velocity is found to be maximum. The inconsistent behavior of angle dependent velocities is associated to the action of SOECs. The ultrasonic properties are discussed in correlation with elastic, thermal and electrical properties. It has been found that the thermal conductivity is the main contributor to the behavior of ultrasonic attenuation and the cause of attenuation is phonon–phonon interaction. The mechanical properties of Cr2Nb are better than other chromium-based alloys ( Cr2Ta , Cr2Zr and Cr2Hf ) at room temperature, because it has high ultrasonic velocity and low ultrasonic attenuation.