الفهرس 
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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).