COMPOSITIONAL DEPENDENCE OF ACOUSTIC PROPERTIES AND STRUCTURAL ROLE OF LEAD IN LEAD SILICATE GLASSES
V. Rajendran*, H. A. El. Batal** and F. A. Khalifa** *Department of Physics, Mepco Schlenk Engineering College, Mepco Nagar 626 005, Tamil Nadu, India **Glass Research Department, National Research Centre, Dokki, Cairo, Egypt
Keywords: Lead Silicate, Ultrasonic attenuation, elastic constant, network modifier/former, NDT
ABSTRACT
The longitudinal ultrasonic velocity and attenuation of X1PbO- X2SiO2 glasses for different mole fractions of X1 have been measured at room temperature by pulse echo overlap method. From the measured data, the longitudinal modulus, apparent molar volume of oxygen, packing density, acoustic impedance, thermal expansion coefficient, internal friction, Poison's ratio's and microhardness of the glass samples have been calculated. The velocity, attenuation and the derived parameters exhibit two distinct behaviour at lower and higher PbO concentrations. The compositional dependence of the acoustic and the derived parameters were studied in terms of structural changes of glass network. the results suggest that lead ions behave mainly as an ionic network modifier at lower PbO concentrations and as a covalent network former at very high PbO concentrations.
Publication Source: Trends in NDE Science & Technology; Proceedings of the 14th World Conference on Non-Destructive Testing, New Delhi, 8-13 December 1996.Vol. 2, pages 815 - 822 Publisher:Ashgate Publishing Company
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