Behaviour of ultrasonic velocities and elastic constants in Ag-Zn alloys

Pramod Kumar Yadawa

doi:10.5185/amlett.2010.12190

Abstract

The ultrasonic properties of the hexagonal closed packed structured Ag-Zn alloys have been studied at room temperature for their characterization. For the investigations of ultrasonic properties, I have also computed second order elastic constants using Lennard–Jones Potential. The velocities V1 and V2 have minima and maxima respectively with 45 0 with unique axis of the crystal, while V3 increases with the angle from unique axis. The inconsistent behaviour of angle dependent velocities is associated to the action of second order elastic constants. Debye average sound velocities of these alloys are increasing with the angle and has maximum at 550 with unique axis at room temperature. Hence when a sound wave travels at 55 0 with unique axis of these alloys, then the average sound velocity is found to be maximum. Ag0.2Zn0.8 alloy is more suitable for industrial and other uses, as it having highest elastic constants and lowest attenuation in comparison to other Ag-Zn samples. The mechanical and ultrasonic properties of these alloys will not be better than pure Ag and Zn due to their low SOEC and high ultrasonic attenuation. Achieved results have been discussed and compared with available experimental and theoretical results.

Highlights

Ultrasonic offer the possibility to detect and characterize microstructral properties as well as flaws in materials, controlling materials behaviour based on physical mechanism to predict future performance of the materials
The ultrasonic velocity is directly related to the elastic constants by the relationship V= (C/ ), where C is the relevant elastic constants and is the density of that particular material
There are three types of ultrasonic wave velocities for each direction of propagation of wave, which are well related to second order elastic constants

Summary

Introduction

Ultrasonic offer the possibility to detect and characterize microstructral properties as well as flaws in materials, controlling materials behaviour based on physical mechanism to predict future performance of the materials. There are three types of ultrasonic wave velocities for each direction of propagation of wave, which are well related to second order elastic constants. All the three types of ultrasonic velocities and elastic constants of these alloys are not reported in the literature.

Results

Conclusion