Control System And Experimental Study Of 3D Printing Metal Powder Prepared By Wire Electrical Explosion

3D printing technology is widely used in aerospace,defense electronics,medical dentistry,energy and power and other fields.Metal powder,as the most important raw material for 3D printing of metal parts,restricts the development of metal 3D printing technology to a large extent.At present,the spherical metal powder for 3D printing is mainly monopolized by foreign manufacturers.The domestic production of 3D printing metal powder has problems such as insufficient preparation methods,reliance on imported equipment.The metal powder prepared by the wire electrical explosion method has good sphericity,less satellite powder,high purity,easy particle size control,etc.Therefore,the study of preparing metal powder for 3D printing by the wire electric explosion method is of great significance.Based on the characteristics and requirements of pulse power control,an automatic system designed for preparing 3D printing metal powder by wire electrical explosion,which adopted the mode of gas discharge leading in large current.It mainly includes two parts: process control and data acquisition.To a large extent,it solves the problems that the process of wire electric explosion is difficult to control and the high-frequency current is difficult to collect in a short time.According to the in-depth exploration of the process parameter requirements and work flow for preparing 3D printing metal powder by wire electrical explosion,the electrical control schematic diagram with PLC as the control core is designed,including the high-voltage charging and discharging part and the low-voltage control part,and it is built and debugged.The 3D printing metal powder system is prepared by wire electrical explosion,which can run safely and stably for a long time.In the process of preparing 3D printing metal powder by wire electric explosion,the choice of electrical parameters directly affects the amount of energy deposited by the metal wire,which in turn affects the effect of the prepared metal powder.Only when the parameters reach the matching mode can the metal powder with the best effect be prepared.In this thesis,two methods of circuit simulation and experimental research are used to study the influence of electrical parameters on the process of electric wire explosion.In the circuit simulation,based on the RLC circuit and the specific action model,the wire resistance model and the wire electric explosion discharge circuit model were established.By changing the initial charging voltage or the wire resistance for simulation,it is found that the initial charging voltage is increased and the metal is reduced.The wire resistance can increase the current peak value during the electric explosion process of the wire,thereby increasing the energy deposited on the wire;In the experimental study,the initial charging voltage,the resistance of the wire,and the inductance of the discharge loop have been studied through the inductive analysis in the experimental study with the influence of electrical explosion energy deposition and metal powder particle size and distribution.Using wire electrical explosion to prepare 3D printing metal powder device to test refractory metal tantalum and non-refractory metal aluminum and nickel.The voltage and current signals are recorded and stored during the wire electrical explosion process.The size and distribution of the particles are observed.The experimental results show that the automatic system for preparing 3D printing metal powder by wire electric explosion can produce relatively pure and spherical micron spherical tantalum powder,aluminum powder and nickel powder,which provides a new way for the preparation of 3D printing metal powder and lays a good foundation for the development of additive manufacturing.