Twin-screw Whip Produce Aluminum Alloy Semi-solid Billet

There are many kinds of preparation methods of Semi-Solid billet, for examples: mechanical stirring method, Strain -Induced Melt Activation (SIMA) process, spray sediment process, ultrasonic wave treatment, powder metallurgy process etc. But these tradition process have some unconquerable disadvantages or the area that alloy apply is very small, and the dimension of billets that were prepared by tradition processes is so small that can not be used in the industry production. To overcome these problems, we make use of new process of screw propulsion and cooling controlled by slope to obtain bigger diameter billet and homogeneous microstructure.Semi-Solid billets preparation process of screw propulsion and cooling controlled by slope is a new technology. Under near solid phase condition, propelled by screw, semisolid slurry passing through slope-cooling barrel get into billet mould and crystallize quickly. Mould is cooled by water , which ensure that the microstructure is homogeneous and fine. Under cooling inclined barrel and gravitational shearing and screw shearing and stirring, nucleation rate is high and coarse dendrite is broken up. In this case, the microstructure of semisolid alloy gradually evolves from dendrites to fine spherical grains.The main aim of present work is to design and manufacture equipment, simulate the two screw whisk flow field and the semi-solid billets preparation. This equipment mainly includes power equipment, transmission equipment, working equipment and other equipments. Among them, the key point is to design and manufacture barrel and screw. Using combined barrel ensure the suitable processing technology and high work efficiency. Using self-wiping and intermeshing screw can make the screw clean., screw geometry is derived under the principle of relative motion, is the basis of designing screw. Using intermeshing co-rotating twin-screw provides higher shear rate and grain refinement. This article is to simulate the intermeshing co-rotating twin-screw extruder slurry flow in three-dimensional non-Newtonian isothermal flow. The math model of screw is founded by two-screw geometry, apply the software of ANSYS to carry through the finite element solution, and gain results of the velocity field, pressure field, viscosity field, shear stress field, slurry flow velocity field. Results show that under different screw rotating speed, maximum velocity concentrate in the spiral roof area, pressure gradually increase along axis, and viscosity decrease with the increase of screw rotating speed, and maximum shear stress is in the spiral roof area and it increase with the increase of screw rotating speed, and slurry in the barrel flows as"∞"shape. Analyzed the warm-up temperature of barrel, the temperature of the liquid poured into the barrel and the speed of electric machine affect the result of experiment in produce LY12 aluminum alloy semi-solid billet by two-screw whip, and make sure the conformable craftwork parameter of preparation methods of Semi-Solid billet by a series of experiment.