Powder Forming Process Of Computer Simulation

Foamed metals are new materials which are made up of metal and gas pores. Foamed metals can be made by P/M method, but the relative density and its distribution, defects, crack in the foam will have significant effect on its cell struture, porosity and performance. Studies on Aluminum powder forming are in the beginning, to study this process is of important significane. In this paper two processes, powder compaction and powder extrusion , are studied. In addition, traditional powder plastic working process, method of trial and error, is used to determine the process and die design and it costs much time, CAD/CAE based on powder forming theory can be used to reduce research period and save the costs.In this paper, theoretical research, physical experiment and numerical simulation are combined to systematically study the Aluminum powder forming discipline and compacting mechanism. Yield criteria of powder or sintering materials are analyzed. Mechanical parameters are obtained by physical experiment, then proper finite element model is constituted to modle the process.As to the powder compaction process, finite element software MSC.MARC is used to model the process. Shima modle of powder material module in MARC is used. The parameters can be gained by going through documents, handlets and doing experiment. Then one-directional and two-directional compacting process are studied under different load. The relative density and distribution of the billet and strain and stress varying and distributing principle are gained. After comparision, bi-directional compacting under 400MPa pressure is a good process to get billet with good performance.As to the P/M billet's extruding process, finite element software DEFORM is sleeted to simulate the process. Referring to the compacting result, sintering billet whose relative density is 0.9 and correlative parameters are used. Rigid-plastic variation calculus theory of compressible materials is utilized to model the extruding process. Then the extruding die dimension is determined. Finally the compacting principle of the billet, strain and stress distribution and powder particle flowing rule are analyzed in detail under this condition.