Design And Realize Of The Measure And Control System For Metal Matrix Composites Manufacture By Extrusion Directly Following Vacuum Infiltration Process

Extrusion directly following vacuum infiltration (EDFVI) is proposed based on the Liquid-solid extrusion process for metal matrix composites (MMCs). compare with the Liquid-solid extrusion process , EDFVI is expected to has following advantages:(l) melted metal infiltrate into preform under vacuum environment, so air in MMCs can be decreased, the material will be much more good performance;(2)the effect of vacuum can help the preform crushed;(3)fit to manufacture the magnesium matrix composites. In this paper, Experimental arrangement and the main parameters of EDFVI are presented in details, and a computer measure and control system for EDFVI is developed.According to the character of EDFVI, whole configuration of the measure and control system is designed ,with the hydraulic press as the actuator, a computer analogue control system by closed-loop electro hydraulic proportional valve to the moving speed of sliding block of the hydraulic press is designed, which lays a foundation for the further key parameter control. A data collecting system for EDFVI has been created, which facilitate the further research on the laws of EDFVI, the optimization of the process parameters and the control. Experiments have proved its applicability and precision. Control system for extrusion velocity and infiltration pressure in the process of EDFVI is developed, in which digital PID controller and load compensation algorithm are adopted and realized by software, and the control system is proved viable and effective for EDFVI by the results of simulation on the control system. Finally, a hydraulic machine switching control system has been developed, which has improved the control of EDFVI.Thus, the foundation of experimental research and industrial application has been basically established.