Papers by Author: X.J. Wu

Abstract: Microwave printed circuit board (MPCB) is a typical difficult-to-machine material because the ceramic particle bonded with polytetrafluoroethylene (PTFE) has high strength and hardness in its insulation layer. Research on MPCB milling parameter optimization is carried out in this paper. The maximum material removal rate is selected as the objective function, considering the constraints of machine tool, cutting tool and processing requirements. An optimization program is compiled by Matlab and the genetic algorithm (GA) toolbox (gatbx). A cutting database is set up by Access software. An optimal milling parameters database management system (DBMS) based on Browser/Server (B/S) structure is developed by ASP technique and Dreamweaver software.

Abstract: Chemical vapor deposited (CVD) diamond film has a series of outstanding properties. However, it can not be easily machined by conventional technologies available currently for its high hardness and stability. Laser processing diamond film method can be an efficient way to process diamond film because of its high energy density. The mechanisms of laser processing diamond film are thermal oxidation, graphitization and evaporative ablation of graphite. Temperature distribution is of great importance to understand these complex phenomena taking place during the process because different temperatures lead to different physical and chemical changes of diamond. In this paper, the finite element method (FEM) software ANSYS is applied to calculate the temperature distribution. The relation between etching depth and laser machining parameters (laser power and scanning speed) is presented. The proper parameter ranges of laser power and scanning speed for a certain etching depth is also investigated with this method.