Abstract
Electron beam drilling is done by sequent removal of molten material. Quantitative measurement of molten layer produced in materials has not been carried out. In the present paper, the temperature rises due to electron penetration into materials are obtained and are compared with those due to a surface heat source. The temperature rise distribution must be obtained from the solution involving electron penetration during a short heating time ; however, for a long heating time, it can be obtained from the solution for a surface heat source. The molten layer remaining at the hole bottom in iron is measured. The layer thickness does not hold constant ; it increases and decreases intermittently. This fact indicates that some quantity of molten layer is required for producing a hole by the ejection of molten metal. The critical quantity depends on the kind of metals.
