影响PCD刀具刃磨质量因素研究

Study on factors influencing grinding quality of PCD tools

本文采用合理的腐蚀清洗方法对PCD试样进行腐蚀,获得了清晰真实的PCD磨削表面。在此基础上借助扫描电镜,通过观察PCD刀具磨削表面和刃口的微观形貌,系统研究了磨床转速、磨削压力及磨削液等因素对PCD刀具刃磨质量的影响。研究结果表明:磨床转速越高,磨削表面质量越好,但过高或过低的转速会使刃口锯齿度增大;较大的磨削压力对磨削表面质量和刃口质量都有负面影响;同时,无论转速高与低,磨削压力大或小,干磨后的PCD磨削表面质量均好于湿磨。细砂轮低速干磨PCD时,磨削表面由于疲劳应力的作用出现了一些垂直于磨削表面的裂纹。

Using a new etching method with aqua regia （HNO3 ＋ 3HCt）, very clear morphology of PCD ground surface was revealed, and then the mierographs of ground surface and cutting edge of etched PCD samples were studied using SEM. The investigation results showed that, a higher grinding speed can make the ground surface smoother. But with a too high or too low grinding speed, the quality of the cutting edge will deteriorate. Grinding forces have negative impact on both ground surface and cutting edge＇ s quality. No matter what grinding speed and grinding forces are used, the quality of ground PCD tools is better when grinding fluid is not used. If PCD tools are ground with fine-grained wheel and at low speed, some fractures will appear on the ground area because of the fatigue stress of PCD.