抄録
This paper deals with the forced removal of molten part in drilled hole by vapor pressure of backing material with low evaporating temperature. The following results were obtained by a thermal analysis and experiments. (1) The backing material with lower evaporating temperature than that of workpiece and with high thermal conductivity enables to remove molten part of workpiece by its vapor pressure. (2) The thermal properties of backing material for removing molten part in drilled hole can be analytically estimated for given workpiece. (3) The range of machining conditions to obtain clogless holes becomes much wider and amount of molten rock in both surfaces around hole is reduced by using backing material. (4) Backing material has the effect to increase outlet diameter of workpiece without changing inlet diameter. This effect is more remarkable in backing material with high thermal conductivity.
