The microstructure and mechanical properties of friction stir welded Cu-30Zn brass alloys

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:589

Article

Sun, Y. F.¹  Xu, N.¹  Fujii, H.¹ 

[1] Osaka Univ, Joining & Welding Res Inst, Ibaraki 5670046, Japan

关键词: Friction stir welding;    Dynamic recrystallization;    Mechanical properties;    Cu-Zn brass alloy;   

DOI  :  10.1016/j.msea.2013.09.094

来源: Elsevier

【 摘 要 】

The optimized processing map for the friction stir welding of commercial 2 mm-thick single phase Cu-30Zn brass alloy plates was obtained, which included a welding speed that ranged from 200 to 800 mm/min, a rotation speed that ranged from 750 to 1200 rpm and a constant applied load of 1000 kg. A remarkably refined microstructure was formed in the stir zone. The average grain size ranged from 6.4 to 9.6 mu m depending on the different welding conditions, which is much smaller than the 282 pm of the base metal. Compared with the base metal, the dislocation cells, annealing twins with a smaller twin lamellar width, are easy to form in the stir zone. All the sound welds fractured on the base metal during the tensile tests, indicative of improved mechanical properties in the stir zone. Miniature tensile tests of the stir zone revealed that the highest tensile strength of the stir zone can reach about 380 MPa, much higher than the 340 MPa of the base metal. The mechanism for the mechanical property improvement in the brass alloy joints are discribed and clarified from the viewpoint of microstructural evolution. (C) 2013 Elsevier B.V. All rights reserved.

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