Numerical Simulation Study Of Molybde Metallic Powder Warm Compaction Process

In the last decade of 20th century, powder metallurgy with these dominances including saving energy and materials, higher efficiency, lower pollution and cost was considered as a most creative processing technology and has been widely used in the kinds of industrial departments. For example, warm compaction technology was used to product high melting-point and hard alloys such as wolframium, molybdemum and cuprum. Stress condition of particles was researched in the course of metallic powder warm compaction process based on both domestic and oversea research. And the course was simulated on with finite element method in molybademum. Main contents are followed as:Firstly the dissertation reviewed the research methods and mechanical models of powder metal compaction process put forward by many famous scholars such as Shima, Oyane, Gurson, Doraivelu, Drucker. And their merit and demerit are analyzed further.Secondly by building and solving I-D and II-D models based on characters of particles flowing, stress functional equation was obtained in the green body. And the equation can be used to predict distribution of density and densification effect.Warm compaction process of three-dimensional cylinder was simulation on by finite element method. Further some key problems including the model parameters, contact detection method, loading condition were done with suitablely. The data including distribution of density, temperature, stress and laws of particles flowing were got from simulation results. And warm compaction experiment on Molybdenum was carried in order to prove that situation including density measured by Archimedes law and specific conductivity.According to FEM model, laws that parameters including press, velocity, temperature, friction effect on densification were researched on and carried orthogonal test on. Subsequently, evaluation criterion suit for FEM simulation was presented and used to study influence on densification with visualization analysis.Finally the commonly flaws existing in green body were simulated on. And some...