الفهرس 
Ch1.Introduction and literature surveyOnly 14 pages are availabe for public view
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Abstract
The purpose of this thesis is to describe the physical nature of lead-tin- antimony –calcium melt-quenched ribbons using melt-spinning technique . The physical view of a problem as contrasted to the metallurgical view or the engineering view typical emphasizes the structural and physical properties of the system . Thus the primary goal in the physical approach is usually the investigation the effect of rapid cooling from melt on structure ,electrical and mechanical properties of Pb-Sn-Sb and Pb-Sn-Sb-Ca melt spun ribbons for electrowinning. For this purpose the structure, resistivity, elastic moduli, Debye temperature and hardness tests were examined by x-ray diffraction, double bridge circuit, dynamic resonance technique, and Vickers microhardeness tester respectively. The x-Ray diffraction pattern and its analysis for Pb-5wt%Sn-x wt%Sb (x=2,4,6,8,10) melt spun alloys shows the existence of two kinds of phases ,Pb-phase with face centered cubic structure and antimony tin phase with rhombohedral (hex) structure. The x-Ray diffraction pattern and its analysis for Pb-5wt%Sn-2wt%Sb-x wt%Ca (x=0.5,1,1.5,2,2.5) melt spun alloys also shows the existence of two kinds of phases ,Pb-phase with face centered cubic structure and Antimony tin phase with rhombohedral (hex) structure. Experimental results have shown that the total resistivity pronounced minima at composition of Pb-5wt%Sn-2wt%Sb-1wt%Ca.This correspond to formation of ordered alloys. And it has highest value of thermal conductivity and suitable elastic moduli. So that the best quenched ribbon as anode for electrowinning , we can used the following alloy (Pb-5wt% Sn-2wt%Sb-1wt%Ca).