Studies of Sputter Deposited CU1-XTAX Alloys

Abstract

ABSTRACTCopper-refractory metal composites/alloys are of interest for aerospace and related applications requiring good thermal conductivity and high strength at elevated temperatures[1]. These materials, due to generally very low mutual solubilities, may allow high strength microstructures to be developed which are stable at temperatures exceeding those suitable for precipitation strengthened alloys. Phase stability and mechanical property characteristics of bulk fabricated Cu-refractory metal composites were recently reviewed[2-3]. This paper reports the results of structure-property studies of a series of Cu1–xTax alloys created by RF sputter deposition. It will be shown that nanoscale face-centered-cubic and body-centered-cubic Ta particles form in the Cu matrix and that these Ta particles are very resistant to coarsening at temperatures up to 900ºC. Nanoindentation studies of these alloys reveal that their strengths are also essentially unaffected by exposure to 900ºC for times up to 100 hours.