基于可编程控制的扫描电子束加工技术

Scanning electron beam processing technology based on programmable control

在通用真空电子束焊机的基础上配置两对电子束偏转线圈、工控机多功能数据采集卡、功率放大器、可编程控制器以及虚拟仪器软件LabVIEW等,构建一个电子束扫描控制系统。利用该系统可对电子束扫描轨迹、扫描频率以及加热区域电子束能量密度的分配进行离线编辑和在线调节。使用该系统进行了不锈钢毛细管板结构的钎焊试验,钎焊接头质量满足结构技术规范。对铌钛异种合金采用不对称热输入的扫描加热方式进行焊接,获得了铌、钛熔化量相当,焊缝形状对称的焊接接头。对于不能直接焊接的异种金属(如Re-Ti),可使用该系统的扫描加热技术,通过粉末冶炼制备中间过渡层。

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.