Feedforward control of droplet transition in electron beam freeform fabrication based on dual beam spot method

Abstract

In this paper, a feedforward control method of droplet transition based on dual beam spot in electron beam freeform fabrication is proposed. A deflection coil is used to form two beam spots on the surface of the workpiece. Images containing the prepositive spot are taken, the height information of the workpiece surface is obtained through image processing method, and feedforward control is performed accordingly. The experiment result shows that the proposed method has excellent detection accuracy. It can keep the droplet transition distance and state stable when the height of the surface to be deposited fluctuates, and achieve uniform and stable deposition morphology.