Use this URL to cite or link to this record in EThOS: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.623694
Title: Ultrasonic propagation in liquid alloy systems
Author: Webber, Gerald Michael B.
Awarding Body: University of London
Current Institution: Imperial College London
Date of Award: 1970
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Abstract:
An ultrasonic interferometer has been used to measure the sound velocity in liquid zinc, cadmium, mercury, indium, tin, lead and bismuth at temperatures up to 520°C. Experimental techniques and sound velocity measurements on various liquid metals are reviewed. The adiabatic and isothermal compressibilities, together with the ratio of the principal specific heats, are evaluated for eighteen liquid metals. The results of sound velocity measurements as a function of temperature and concentration across the whole alloy system for mercury-zinc, mercury-cadmium, mercury-indium, mercury-tin, mercury-lead and mercury-bismuth alloys are presented. It is found that the addition of solute to mercury causes the adiabatic compressibility to decrease rapidly with concentration. It is seen that the Bohm-Stayer sound velocities are in fair agreement with experimental values for sound velocity in alkali metals. As the valency Z in the polyvalent group of metals increases, then the Bohm-Staver sound velocity becomes progressively larger than the experimental sound velocity. An empirical compressibility defined by Z βT(eᴥ) gives better agreement with experimental values for isothermal compressibility than does the free-electron compressibility BT(eᴥ). Various theoretical approaches to compressibility of metals are dis-cussed. The semi -phenomenological model due to Ascarelli is found to give good agreement with experimental compressibilities. EXpressions for the free-electron compressibility and Bohm-Staver sound velocity for alloys are derived and compared with the present alloy results. The pseudo-potential approach and semi-phenomenological model for compressibility are also extended to liquid alloys. Measurements of sound absorption in mercury are reported. The value for the ratio of bulk to shear viscosity is found to be 0.86± 0.3. Experimental values of nB/ns for various liquid metals are reviewed and it is seen that the values for this ratio evaluated from the dense-gas formulation are in reasonable agreement with experiment.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.623694  DOI: Not available
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