基于粉末本构模型和多体力学仿真的模架集成式粉末成形设备的设计

Design and Manufacture of the Mould-frame Integrated Powder Forming Equipment Based on Constitutive Model of Powder and Simulation of Multi-body Dynamics

研制出一种新型的低成本、小体积、高精度的专用模架集成式粉末成形设备。以MSC.Marc与MSC.Adams软件相结合提出基于数值模拟的1 MN压机设计方法,即根据粉末压制试验构建末材料流动应力本构模型;通过该模型在MSC.Marc软件数值计算出所设计压机压制过程的模冲载荷;在分析模架集成式粉末成形设备各个模板在压制工过程运动特点的基础上,建立多体运动学数学方程;将所得模冲载荷作为边界条件加载到对模架集成式粉末成形设备在压制过程的模拟仿真;并在MSC.Adams软件中分析各个模板在压制过程中力学状态,从中分析该设备在实际工况下的可靠性。研制出电液比例阀和光栅尺相结合的控制系统,实现对缸同时驱动,解决不同模板之间的动作协调的问题,所研制试验样机实现零件轴向压制精度为±0.02 mm。实际压制过程所得各模冲载荷与模拟结果相一致,从而验证粉末成形设备设计所采用的本构模型是准确的,基于数值模拟进行粉末成形设备设计的方法的正确性。

The special powder molding machine integrating mould frame is designed and manufactured with the feature such as low-cost, small size and high-precision. During the course of the design and manufacture for the special powder molding machine, the flow stress constitutive model of powder and the multi-body dynamics model are construct. Furthermore, the 1 MN powder metallurgy press is put forward based on the numerical simulation by combining the software of MSC.Marc and MSC.Adams. The numerical result of punch load is computed by software of MSC.Marc and the obtained result is exerted as a boundary condition for simulating the pressing process of the special powder molding machine, From the numerical result, the mechanical state of each pattern plate is analyzed in software of MSC.Adams so that the reliability of the special powder molding machine is obtained at the actual working condition. The control system combining the electro-hydraulic proportional valve and grating ruler is developed which makes the two contrapositive hydro-cylinders drive at the same time. And the movement coordination of different mould plates is resolved. The axial pressing accuracy of the formed part is ：L0.02 mm manufactured by the test prototype. There is consistentency between the measured punch load and the numerical result during the compaction which demonstrates that the constitutive model used for powder forming equipment design is accurate and the method based on numerical simulation is correct for powder forming equipment design.