Oriented single copper fibers by a strain-anneal technique

Abstract

A vacuum furnace for high temperature anneal of metal fibers with a moving gradient was designed and constructed. The design specifications are detailed. Systematic evaluation of the variables governing the longitudinal crystal growth of individual copper crystals in a 16 mil fiber was carried out. Single crystals approximately 40 mils in length were obtained by a 1010° C. anneal, specimen velocity of 0.005 mm./second through a 10 cm. furnace, with 2.5 grams of tension on specimen. Specimen had undergone 92% diameter reduction by cold-drawing prior to anneal.