Study On Fluidity Of ZL101 In Semi-solid Micro-Extrusion

As an advanced metal forming technology, micro-forming technology plays a very important role in industry production. In this paper, ZL101 in semi-solid micro-extrusion is studied by combing the good forming feature of semisolid metal with micro-forming technology, fluidity in Semi-solid Micro-extrusion is discussed, which is very useful for micro-forming application of semi-solid metal.The micro-die for experimental study based on the micro-extrusion of semisolid metal was designed and manufactured. The heating device used to reheat together with the temperature controlling system to control the temperature accurately was redesigned. Experiment for reheating and micro-extrusion based on semisolid ZL101 billets was taken. The relationship between the forming temperature, extrusion diameter, extrusion ratio, die bearing and the micro-formability of semisolid metal is studied with the results showing as below: (1) semi-solid forming under the micro-forming condition can reduce the extrusion load to 30%-60%;(2) a phenomenon which is similar to scale effect happens during semi-solid micro-forming process; (3) die bearing can affect the metal flow rate under micro-forming conditions , metal flow rate is closely related to temperature.The theory for microstructure evolvement based on semisolid metal ZL101 alloy during reheating process and micro-hardness were discussed in this paper and some laws of the relationship between some extrusion parameters and the microstructure evolvement were primarily studied with the results showing as below: (1) The grains become larger and the grain boundaries become more apparent under the extrusion diameter 0.5mm compared with the other larger extrusion diameters, which means the micro-dimension extrusion diameter can affect the evolvement of the microstructure.(2) Under the conditions of micro-forming, hardness is closely related to temperature and extrusion diameter.The study results of this paper are useful in the process design, die design , and the application of semi-solid technique.