Influence of Extrusion Speed on the Microstructure Evolution, Interface Bonding and Mechanical Response of Mg MB26/Al 7075 Composite Rod

Yu Chen¹，Rui Zhang¹，Tao Zhou¹，Li Hu¹，Jian Tu¹，Lai-Xin Shi¹，Yan Zhi¹，Li-Wei Lu²，Qiang Chen^3,4，Ben-Hong Liao¹，Lei Liu¹，Wen-Jun Ge¹，Jing Xiao¹，Ming-Bo Yang¹

1. College of Material Science and Engineering, Chongqing University of Technology2. Institute of Light Metal Structural Materials, Hunan University of Science and Technology3. Southwest Technology and Engineering Research Institute4. Precision Forming Integrated Manufacturing Technology of Collaborative Innovation Center

摘 要：The Mg MB26/Al 7075 composite rod,in which Mg MB26 serves as the sleeve and Al 7075 serves as the core,is fabricated via the process of co-extrusion.The influence of extrusion speed on the microstructure evolution,interface bonding and mechanical response of the Mg MB26/Al 7075 composite rod is investigated.The results show that the typical extrusion texture of Mg sleeve does not change during co-extrusion;however,the average grain size in the Mg sleeve slightly changes from 1.57 lm in the case of extrusion speed of 0.3 mm/s to 2.78 lm in the case of extrusion speed of2.1 mm/s.The thickness of interface transition layer increases significantly from 5.5 to 50 lm,and therefore,the interface bonding becomes deteriorative with increasing extrusion speed;in particular,many cavities emerge in the case of 1.2 and2.1 mm/s.

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