碳化硅颗粒增强铝基复合材料微细电火花线切割加工材料去除率研究

Research on Material Removal Rate of SiC /Al Particulate Metal Matrix Composite by Micro-wire Electrical Discharge Machining

碳化硅颗粒增强铝基(SiCp/Al)复合材料微细电火花线切割加工材料去除过程受多种因素交互影响,难以获得有效的材料去除率数学模型,而在多约束条件下试验研究不失为解决该问题的一种有效方法。采用中心复合设计(CCD)实验方法,设计三因素五水平的SiCp/Al复合材料微细电火花线切割加工实验方案。利用响应曲面法建立材料去除率与主要电源参数(开路电压、电容和脉宽)的二阶模型,通过对实验数据的多元二次拟合,获得材料去除率的二次回归数学模型。进一步分析了实际加工条件对工艺参数的约束,并以提高SiCp/Al复合材料微细电火花线切割加工材料去除率为目标建立工艺参数优化模型。设计粒子群优化(PSO)算法及其流程进行优化问题求解,其结果显示PSO算法可以快速有效地获得满足多约束的最佳工艺参数。

The material removal of SiC/AI particulate （SiCp/Al） metal matrix composite by micro-wire electrical discharge machining （micro-WEDM） is influenced by many factors, which makes it difficult to obtain the mathematical model of material removal rate （MRR） effectively. To solve this problem, an ex- perimental study method is conducted under the constraint conditions. A central composite design （CCD） testing with 3-factor and 5-level is carried out, SiCp/A1 metal matrix composite machining test scheme is designed, and then a second-order relational model is established between MRR and main power parame- ters （ open-circuit voltage, discharge capacitance, and pulse duration） by using response surface methodology. Through multiple quadratic fitting, a quadratic regression mathematical model of MRR is obtained.Constrains of actual machining condition upon the parameters are analyzed further. With the goal of improving MRR of SiCp/Al metal matrix composite by micro-WEDM, a parameters optimization model is established. Particle swarm optimization algorithm and its procedure are designed to solve the model. The result shows that the algorithm could be used to achieve optimized process parameters which satisfy multiple constraints rapidly and effectively.