Study on Characteristics of TC4 Alloy Single Track Prepared by Electron Beam Melting

A series of TC4 alloy single tracks were prepared by electron beam melting, and the effects of the process parameters such as scanning speed, beam current on the surface morphology and geometrical characteristics (re-melt depth, track width, track height, contact angle and aspect ratio) of a single track were investigated. The results show that with the decrease of scanning speed and the increase of beam current, the linear energy input increases and the width and continuity of single tracks are improved. When other parameters are fixed, with the increase of scanning speed, the single track becomes discontinuous and even the balling effect can be observed. The scanning speed, beam current and focus offset all have great influence on the melt pool. With the decrease of the scanning speed and the increase of beam current, the re-melt depth, track width, and track height increase. When the focus offset is 3 mA, the re-melt depth and track width are the maximum while the contact angle is the minimum. For the constant of beam current, with the increase of the scanning speed, the contact angle increases first and then decreases while the aspect ratio decreases.