Ultrafine-Grained Microstructure and Improved Mechanical Behaviors of Friction Stir Welded Cu and Cu-30Zn Joints

• 来源期刊: 金属学报（英文版）
• 年，卷（期）: 2018,（8）
• 页码范围: 878-886
• 页数: 9页
• 语种: 英文

摘要

Ultra-strong joints of pure Cu and Cu-30Zn alloy were obtained by friction stir welding under flowing water.The effects of heat inputting condition and material characteristics on the morphologies,microstructures and mechanical properties of welding joints were studied.Defect-free stirring zones of pure Cu and Cu-30Zn were characterized by onion-ringed structure and plastic flowing bands,respectively.Both low stacking fault energy and fast cooling condition contributed to the formation of small recrystallized grains less than 1 μrn in stirring zones.The welding joints in both materials exhibited enhanced mechanical performances due to ultrafine-grained microstructure in stirring zones and disappearance of soft heat-affected-zone.The technique of digital image correlation was used to study the tensile deformation behaviors of welding joints and verify the improved tensile properties.