| 摘要 |
PURPOSE:To provide a means of drilling by setting laser beam power density to an optimum value for boring process in accordance with variable conditions including physical properties of a work, laser beam's pulse band and spot diameter, etc. CONSTITUTION:Laser beam's power density Pv is sought from an equation, that is, Pv=Tb' K (pi)<v2>/a fan<-1>(4R t/a2) 1/2. Whereas, K is heat conductivity of a work; R is the work's heat diffusion rate; t is laser beam's pulse band; a is the laser beam's spot diameter; Tb is revised boiling point of the work and this is shown by an equation, that is, Tb=Tb+(Lm+Lb)/C, and Tb signifies boiling point, Lm fusing heat, Lb steaming heat and C specific heat. Laser beam is to be utilized for drilling process by setting its power density to a value larger than Pv sought from the above equation. |
