聚晶立方氮化硼刀具电火花放电磨削分析

摘要

Polycrystalline cubic boron nitride (PCBN) compact samples with different grain size are processed.Electrode running speed,open-circuit voltage,peak current,pulse width and pulse interval were selected as the main process parameters.The material removal volume and electrode loss were set as the evaluation index of production efficiency;workpiece surface roughness value was set as evaluation standard of processing quality.By electrical discharge grinding experiments,combined with scanning electron microscopy observation,energy spectrum analyzer and roughness tester,the influences of main process parameters on electrical discharge grinding were analyzed.So were polycrystalline cubic boron nitride compact electrical discharge grinding technics & mechanism.The research indicated that PCBN machining in EDG process was to melt bond at high temperatures,which resulted in PCBN particles falling off and realized material removal.This process was accompanied by element replacement and oxidation.PCBN particle size has less effect on efficiency and quality of electrical discharge grinding than electrical discharge process parameters.With the increase of the electrode rotation speed or open-circuit voltage,material removal volume of the workpiece and electrode loss both increased.With the increase of the peak current, material removal volume and surface roughness value of workpiece increased,but electrode loss decreased.%以国产不同粒度的聚晶立方氮化硼复合片试样作为研究对象，选取电极转速、开路电压、峰值电流、脉冲宽度和脉冲间隔作为主要工艺参数，以材料去除量、电极损耗作为加工效率的评价指标，以试样表面粗糙度值作为加工质量评价标准，结合扫描电镜观测、能谱分析、粗糙度仪测试，分析主要工艺参数对放电磨削加工的影响。实验结果表明：研究表明：PCBN 电火花放电磨削加工的机理是高温熔化黏结剂，从而导致聚晶立方氮化硼颗粒脱落而实现磨削去除，过程中还伴随着元素间的置换和氧化；PCBN 粒度对电火花放电磨削加工效率和质量的影响不如放电加工工艺参数的影响显著；材料去除量、电极损耗随着电极旋转速度的增加、开路电压的增大均有不同幅度的增加；随着峰值电流的增加，材料去除量增加，电极损耗减小，工件材料的表面粗糙度值增大。