电子束熔丝增材随行退火系统及均匀面热源扫描

在电子束熔丝沉积增材制造过程中,采用电子束对零件成形区域进行扫描并控制热输入,可以改善零件的温度分布,实现随行退火,达到减小应力和控制变形的目的。采用工控机、波形发生卡、扫描线圈及其驱动电路,以及动态聚焦线圈及其驱动电路搭建了电子束高速扫描系统,实现了电子束高速扫描及动态聚焦等功能。基于LabVIEW开发了随行退火扫描控制系统,提出了基于像素点阵定位和动态聚集的控制方法,实现了电子束扫描的精确定位和热输入控制;研究了不同扫描路径对面热源温度均匀性的影响,并采用多点同步测温电路对扫描区域的温度进行了测量。试验结果表明,该电子束随行退火系统可以实现扫描位置和热输入的精确控制,通过扫描路径优化显著提高了面热源温度分布的均匀性。

Real Time Annealing System of Electron Beam Freeform Fabrication and Scanning of Uniform Surface Heat Source

In the manufacturing process of electron beam freeform fabrication,the temperature distribution of the part can be improved by scanning the forming area of the part with electron beam and controlling the heat input,and the annealing along the part can be realized to reduce the stress and control the deformation.The high-speed scanning system of electron beam is built by using industrial computer,waveform generator,scanning coil and its driving circuit,and dynamic focusing coil and its driving circuit.The functions of high-speed scanning and dynamic focusing of electron beam are realized.Based on LabVIEW,the control system of real time annealing scanning is developed,and the control method based on pixel lattice positioning and dynamic aggregation is proposed to realize the precise positioning and heat input control of electron beam scanning;The influence of different scanning paths on the temperature uniformity of the heat source is studied,and the temperature of the scanning area is measured by using multi-point synchronous temperature measurement circuit.The experimental results show that the scanning position and heat input can be accurately controlled by the electron beam real time annealing system,and the uniformity of the temperature distribution of the surface heat source can be significantly improved by optimizing the scanning path.