ARB 가공된 순동에서 소량의 잔류원소가 인장 거동에 미치는 영향

With the rapid advancement in electronic industries, there is a great interest on the nano grain sized, high-purity copper, which possesses both high-strength and high-conductivity, produced by severe plastic deformation (SPD). The nano grain sized materials, in general, show the unconventional mechanical behavior as a result of extremely high density of grain boundary area causing a rapid dynamic recovery during deformation. The commercially available, high-purity copper usually contains a small amount of trace phosphorous, and the presence of such element is believed to affect the rate of dynamic recovery, and eventually tensile behavior of pure copper. In the present study, the effect of trace phosphorous on the tensile behavior of accumulative roll bond (ARB)ed high-purity copper was examined. Both 99.99% pure oxygen-free copper (OFC) and 99.9% pure deoxidized high phosphorous copper (DHP) were used for the present study. It was found that the tensile strength of OFC ceased to increase after 2 ARB process cycles, while that of DHP increased continuously with ARB process up to 8 cycles, suggesting that the presence of trace phosphorous affected the rate of dynamic recovery significantly. Finally, it was discussed how the trace phosphorous affected the tensile behavior of ARBed, high-purity copper, based on the SEM, TEM and DSC(differential scanning calorimeter) observations. (Received February 17, 2004)