Metal Flow Study On Extrusion-spinning Technology Of Magnesium Alloy Cylindrical Pieces With Circinal Inner Ribs

Magnesium alloy is the best materials using in light equipment,parts with inner ribs isthe typical structure of lightweight.Currently magnesium alloy cylindrical pieces with circinalinner ribs produced mainly by casting methods,but it had low performance, inevitable defects.The Internal Power Spinning process within the cylindrical pieces with shallow ribs althoughhave obtained some progress, but the small diameter can be simplified spin, tendons is veryshallow, difficult to meet the practical needs. With the structure characteristics of cylindricalpieces with circinal inner ribs, combined with magnesium alloy plastic deformationcharacteristics,the corresponding extrusion spinning technology was studied. With thistechnology forming cylindrical pieces with circinal inner ribs have the characteristics ofoverall structure, large diameter and high-ribs. Solveing the problems of high forming force,difficulty in forming inner ribs and workpiece out of the mold in the conventional spinforming process,we focus on metal flow law. The process can provide valuable reference forsuch parts in process design.By analyzing the extrusion-spinning process principles, we designed the correspondingextrusion-spinning device. The Extrusion-spinning Wheel on the extrusion-spinning deviceplays a major role in the process,it is the key influence the metal flow and shaping the heightof the ribs. This paper presents three different extrusion-spinning wheel. Using the finiteelement numerical simulation software to simulate the extrusion-spinning process of threedifferent extrusion-spinning wheels.By analyzing the simulation results,we finalized toextrusion-spinning two times using two kinds of wheels. Simulation results show that usingtwo kinds of wheels to extrusion-spinning two times is better than extrusion-spinning onetime using single wheel. After the process of using two kinds of wheels to extrusion-spinning two times isdetermined,combined with metal flow theory to simulate the metal flow of the entireextrusion-spinning process. By equivalent stress and equivalent strain cloud pictures, a pointof stress and strain tracking and damage value changes during the entire extrusion-spinningprocess to illustrate the forming process of circinal inner ribs is actually the process of metalflowing into the rib portion.By simulating the extrusion-spinning process of different billet temperature, radial feedrate and the spindle speed to analyze the equivalent stress,the equivalent strain and the loadconditions under these circumstances. Finally, at about350℃, the work force anddeformation of metal uniform, high-quality parts can be formed. When the extrusion-spinningwheel radial feed rate is0.75mm/s, not only extrusion-spinning efficiency is not low,extrusion-spinning force is not high, theextrusion-spinning forming is relatively stable. Theradial feed rate will not generate the phenomenon of too large metal in front of the wheel.When the spindle speed is3.5rad/s, can not only increase productivity but also improve thethe surface quality of the cylindrical pieces. Reducing the generation of corrugated defects.