Scanning electron beam processing technology based on programmable control

A general vacuum electron beam (EB) machine was equipped with a control system of electron beam scanning, which consisted of two electron beam deflection coils, industrial personal computer (IPC), multifunctional DAQ (data acquisition) card, power amplifiers, programmable logic controller(PLC),virtual instruments (VI) software LabVIEW and so on. The EB scanning track, scanning frequency and energy density distribution at heating zone could be programmed off-line and adjusted on-line. Brazing experiment of stainless steel capillary tube-to-plate structure was carried out by means of the system, and the quality of brazed joints met the technical specification of structure. Dissimilar alloys like niobium and titanium were welded using the scanning heating mode of dissymmetric heat input. The joint was found that melted niobium amount was as much as titanium, and the weld shape was almost symmetric. Dissimilar metals that couldn't be welded directly such as Re-Ti might be welded by using scanning heating technology to prepare the powder metallurgical transition layer.