1、PDF外文：http:/ 4760 字 出处： Optics & Laser Technology, 1998, 30(2): 95-101 外文翻译 学生姓名 学院名称 机电工程学院 专业名称 机械设计制造及其自动化 指导教师 原文： Laser cutting speeds for ceramic tile: a theoretical-empirical comparison
2、 I. Black * Department of Mechanical and Chemical Engineering, Heriot-Watt University, Riccarton, Edinburgh EH14 4AS, UK Received 21 October 1997； accepted 24 March 1998 Abstract This paper presents a comparison of theoretically-predicted optimum cutting speeds for decorative ceramic tile with exper
3、imentally-derived data. Four well-established theoretical analyses are considered and applied to the laser cutting of ceramic tile, i.e. Rosenthal's moving point heat-source model and the heat balance approaches of Powell, Steen and Chryssolouris. The theoretical results are subsequently compare
4、d and contrasted with actual cutting data taken from an existing laser machining database. Empirical models developed by the author are described which have been successfully used to predict cutting speeds for various thicknesses of ceramic tile. # 1998 Elsevier Science Ltd. All rights reserved. &nb
5、sp;Keywords: CO2 laser Ceramic materials Advanced cutting processes Laser modeling Cutting speeds 1. List of symbols A Absorptivity a Thermal di.usivity (m2/s) C &nb
6、sp; Specific heat (J/kg K) d Cutting depth (mm) Ecut Specific cutting energy (J/kg) k Thermal conductivity (W/m K) J La
7、ser beam intensity (W/m2) L Latent heat of vaporisation (J/kg) l Length of cut (mm) n Coordinate normal to cutting front P Las
8、er power (W) Pb Laser power not interacting with the cutting front (W) Q Heat input (J/s) R Radial distance (mm) r Beam radius
9、 (mm) s Substrate thickness (mm) Scrit Critical substrate thickness (mm) T Temperature ( C ) T0 Ambient temperature ( C ) TP &n
10、bsp; Peak temperature ( C ) TS Temperature at top surface ( C ) t Time (s) V Cutting speed (mm/min) Vopt
11、 Optimum cutting speed (mm/min) w Kerf width (mm) X, Y, Z Coordinate location x, y, z Coordinate distance (mm) Conductive loss function
12、; Radiative loss function Convective loss function Angle between Z-coordinate and x-coordinate (rad) n Coordinate parallel to bottom surface
13、; Angle of inclination of control surface w.r.t. X-axis (rad) v Coupling coe cient Translated coordinate distance (mm) Density (kg/m3 ) &nb
14、sp; Angle of inclination of control surface w.r.t. Y-axis (rad) 2. Introduction Laser cutting of a decorative ceramic tile has its own set of characteristic problems including burnout,striations, dross and out-of-flatness, which all affect the finish quality of a cut edge 1-3. A typical cut may have some or all of these features depending on the type of ceramic tile being processed and on the setting of the various set-up parameters. In a production
