Surface Layer Dynamics During E-Beam Treatment

Metal surface layers after pulsed electron beam treatment

“…Fig. 4a shows the total target material mass loss per surface area caused by the pulsed electron beam treatment in the beam center [14]. The data of Al alloy and SS fall on each other, while the Cu data stay slightly below.…”

“…Typical profilometer images [13,14] of various targets after treatment with an electron beam of energy density 56 ± 2 J/cm 2 are shown in Fig. 1.…”

“…5, the melting depths are summarized for SS, Cu, and Al alloy at various beam energy densities [14]. Solid symbols represent the values as measured optically from cross-sectional analysis (see Section 4.2.)…”

“…In order to gain knowledge about the interaction of electron beams, with parameters typical for GESA, and metal targets, various fast in situ diagnostic tools were set up and applied in recent years [12][13][14]. From time-and space-resolved surface specular reflectivity measurements, the onset of melting and solidification was determined [12].…”

“…Impact ionization by beam electrons was found to result in a low-density low-temperature target plasma, excluding electric fields in the plasma sheath to be responsible for the growth of the surface features. High-resolution schlieren imaging and a stroboscopic imaging technique allowed the detailed observation of surface irregularities during treatment [14]. Around the onset of melting, bubbles and micro-irregularities were found at the target surface.…”