Mechanism of High-Power-Density Electron Beam Penetration in Metal

Publisher Website
Google Scholar
Abstract
Electron beams of approximately 2 kW power and acceleration voltages in the range about 100 kV are focused on metal surfaces in spots of 15 to 250 μ so that maximum power densities of more than 1013 W/m2 can be achieved. Such electrons penetrate several orders of magnitude deeper into the solid or liquid materials than the classical penetration depth of 100 keV electrons would allow for. A high‐speed movie (2500 frames per second) of the process shows that the surface is closed by a liquid film most of the time and that it only ruptures during very short intervals. The temperatures at the surface and in the interior of the welds have been determined during the process, experimentally and theoretically, respectively. Also, the dislocation of the metal within the weld has been studied with an electron‐probe x‐ray microanalyzer and with radio‐active tracing. Measurements of mass density show that it decreases after the material has been affected by the electron beam. In the discussion, a tentative explanation of the effect is offered.

This publication has 3 references indexed in Scilit: