Identification And Control Of The Process For Composite Forming By Liquid-Solid Extrusion

Liquid-solid extrusion of composite material is a new kind of metal forming process, which has been developed in recent years with a promising practical application prospect for its simple working procedure, low cost and good workpiece performance.Through a lot of experiments,The optimization and chosing method of key process parameters(pouring temperature, mold warm-up temperature, impregnating pressure, impregnating time)has been mastered.Under the precondition of appropriate chosing these parameters, the effective control of extrusion velocity is the key of mading good workpiece.But the control of extrusion velocity remains a handwork,and it is heavily affected by such uncertainties as a handler's knowledge and skill about the process.In order to solve the problem, the automatic control of the extrusion velocity is studied,and a computer control system is also designed under existing condition.The control of extrusion velocity in the process is not only involved in the process equipment,but also related to the process itself. So,in the paper,proceeding from the automatic control of extrusion velocity and based on the basic control strategy presented firstly,the relation among parameters of the process such as pressure,temperature and displacement is investigated,and the model of the process has been built using system identification method.Then, a corresponding controller is designed together with its control algorithm,and the control system is proved viable and effective by the results of simulation on the control system.In the end,the problem of the realization of the control system is discussed by using modularization method.The hardware of the control system is designed and a sofeware with a perfect manmachine interface is developed,too.Thus, the problem of the control of extrusion velocity during the process has been basically solved, which establishes a base for the application of the process.