AN INVESTIGATION TO DETERMINE THE COMMERCIAL FEASIBILITY OF IN SITU CU-NB COMPOSITES FOR HIGH STRENGTH, HIGH CONDUCTIVITY APPLICATIONS

A PROCEDURE FOR DETERMINING THE COMMERCIAL FEASIBILITY OF FABRICATING IN SITU CU-NB MULTIFILAMENTARY COMPOSITES FOR HIGH STRESS, HIGH CONDUCTIVITY APPLICATIONS IS DISCUSSED. THESE MATERIALS OFFER ANOMALOUSLY HIGH STRENGTHS WHEN COMPARED WITH CONVENTIONAL COMPOSITES. ULTIMATE TENSILE STRENGTHS AS HIGH AS 323 KSI WITH 18.2 VOL % NB HAVE BEEN REPORTED, AND THE HIGH STRENGTH IS ESSENTIALLY UNCHANGED AT TEMPERATURES ABOVE THE RECRYSTALLIZATION TEMPERATURE OF PURECOPPER. AN IMPORTANT BENEFIT OF THE LOW VOLUME PERCENT OF NIOBIUM IS THAT THE DESIRABLE ELECTRICAL AND THERMAL PROPERTIES OF COPPER ARE RETAINED IN THE COMPOSITE. IN SPITE OF THESE EXCELLENT MECHANICAL AND ELECTRICAL PROPERTIES, NO EFFORT HAS BEEN MADE TO PRODUCE A COMMERCIAL IN SITU CU-NB COMPOSITE WIRE WHICH IS OPTIMIZED FOR HIGH STRESS APPLICATIONS. A PROCEDURE FOR ASSESSING THE COMMERCIAL FEASIBILITY OF FABRICATING SUCH A MATERIAL IS PRESENTED.