Microstructures and Mechanical Properties of Friction Stir Welds of Oxygen Free Copper

Park, Hwa-Soon; Lee, Byung-Woo

Journal of KWJS 2005;23(1):77-85.
Published online April 29, 2005.

[연구논문] FSW에 의한 무산소동 접합부의 조직 및 기계적 성질

Microstructures and Mechanical Properties of Friction Stir Welds of Oxygen Free Copper

Abstract

The structures and mechanical properties of friction stirred welds of oxygen free copper(OFC) sheet were investigated. Defect-free welds were obtained in a relatively wide range of the welding conditions from 1000 to 2000 rpm, and welding speed from 500 to 2000 mm/min. The microstructure of the stirred zone(SZ) showed recrystallized grains, and the grain size varied largely with the welding conditions. The SZ hardness values including those of all the optimum welding conditions were slightly lower than that of the base metal, and increased with decreasing heat input. The tensile strength of the all-SZ increased with increasing the hardness values. The Hall-Petch relationship was confirmed between the yield strength of the all-SZ and the recrystallized grain size of the SZ.