TAILIEUCHUNG - Effects of guiding chamber on welding pressure in hollow extrusion die design of AA7075
This paper aims at the development of an extruding seam square tube of AA7075 high strength aluminum alloy. In order to increase the welding pressure of the hollow AA7075 tube in extrusion process, a special die feature has been created. Several different proportions of chamber structure in outlet of extrusion die have been designed. | Journal of Science and Technology 54 (5A) (2016) 191-200 EFFECTS OF GUIDING CHAMBER ON WELDING PRESSURE IN HOLLOW EXTRUSION DIE DESIGN OF AA7075 Do Anh Tuan1, Nguyen Nhu Tung2 1 Department of Mechanical Engineering, Hung Yen University of Technology and Education, Dan Tien-Khoai Chau-Hung Yen, Vietnam. 2 Hung Vuong University, Phu Tho-Vietnam. Nong Trang Ward, Viet Tri City, Phu Tho * Email: airgun631@ Received: 15 June 2016; Accepted for publication: 12 December 2016 ABSTRACT Porthole die extrusion has a great advantage in the forming of hollow section of aluminum alloy tube. This paper aims at the development of an extruding seam square tube of AA7075 high strength aluminum alloy. In order to increase the welding pressure of the hollow AA7075 tube in extrusion process, a special die feature has been created. Several different proportions of chamber structure in outlet of extrusion die have been designed. The finite element analysis software DEFORM 3D to analyze various design parameters on the load – displacement and the welding pressure have been studied. In this study, a different high proportion in material guiding chamber has been defined. The results showed that if a suitable material guiding chamber has been built then welding pressure can be increased rapidly. When the ratio of chamber height and length is 2:1 the increased welding pressure is the best. Keywords: extrusion, aluminum, welding pressure, die design. 1. INTRODUCTION Porthole, bridge or spider die are currently used in the seamless hot extrusion of hollow or complex profiles of aluminum and light alloys. The metal flowing through these die has to split and then rejoin around the mandrel supports (webs) thus creating in the profile a longitudinal extrusion weld (seam) corresponding to the location of each web. The quality of the obtained roles is strictly affected by the effectiveness of the material joining inside the welding chamber. Welding occurs at the solid state if proper .
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