Abstract
In our former papers, machinability of various metals and machining phenomena were investigated to understand the laser machining mechanism. In this paper, machining processes and mechanism of material removal were further investigated to calculate profiles machined with a pulsed YAG laser. The obtained results are as follows.
(1) There are four types of machining processes, namely, heat conduction type, melting only type, mixed type of melt and removal, and removal only type. Some type of the processes will actually take place according to the power density and the irradiated time of laser beam and this information can be used for deciding the machining conditions. (2) The power density of irradiated laser beam decreases with increasing the machined depth and the reduction ratio is estimated by the experimental results of machinability. (3) There are two types of material removal in laser machining; one is the removal as melt and the other is the removal as vapor. And the vapor ratio which is defined as the fraction removed as vapor was estimated from the experimental result.
