Primary Study On Forming Method Of Semisolid Micro-extrusion

With rapid development of Micro-electromechanical Systems, the demand of subminiature parts becomes more and more urgent. As an advanced micro-process technology, micro-forming technology not only has excellent feature such as high material utilization and good product performance, but also plays a very important role in micro-part forming accurately and efficiently. Obvious size effects will appear if submillimetre parts are produced in plastic forming, and size effects limit micro-forming technology extensively using. Therefore, to research and develop micro-forming technology has profound theoretical meaning and wide perspective.Based on the research and development of micro-forming in domestic and aboard, in this paper, the feasibility of thixo-extrusion used in micro-part forming was studied. The ring-shaped heating device used to reheat and temperature control system was designed. Based on technological parameters, such as extrusion temperature, speed and ratio, the semisolid aluminum alloy was used in experimentation to study forming property. The results showed that temperature is one of the most important parameters for extrusion; low temperature and extrusion speed are good in forming micro-parts; extrusion ratio has little influence on forming property; the load of semisolid extrusion fluctuated in a certain rang which is lower than that in routine high-temperature extrusion, and material flowed stably.Visco-plasticity finite element analysis technology was introduced in this paper. Material model of ZL101 aluminum alloy at semisolid state was defined on the platform of DEFORM -3D, and the micro-part by thixo-forming was analyzed. Because the extrusion is intensive plastic deforming and...