电镀金刚石钻头加工碳化硅陶瓷的试验研究

Drilling SiC ceramic with electroplated diamond bits

碳化硅陶瓷硬度高,断裂韧性低,孔加工较为困难。通过正交试验设计分析电镀金刚石钻头的结构参数对孔加工效率的影响,采用控制变量法分析加工工艺参数对孔加工效率的影响,通过施加预紧力装置分析预紧力对孔加工质量的影响。结果表明:钻头结构参数满足壁厚为0.4 mm,金刚石质量浓度为0.88 g/cm^3、粒度为500/425μm、外径为20 mm,加工工艺参数满足轴向压力为780~820 N及主轴转速为2 500~2 700 r/min时,碳化硅陶瓷的孔加工效率较高;预紧力为15.8~16.2 k N时,孔口没有出现明显的裂纹和崩豁现象,孔加工质量较好。

SiC ceramic with high hardness and low fracture toughness is difficult to be drilled. The effect of structural parameters of electroplated diamond bits on hole-drilling efficiency of Si C ceramic was analyzed through the orthogonal experiment. The effect of processing parameters on hole-drilling efficiency was analyzed through controlling variable method. The effect of prestressing force on hole-drilling quality was analyzed with prestressing force device. The results show that,when structure parameters of electroplated diamond bit satisfy the following conditions that the wall thickness is 0.4 mm,diamond concentration is 0.88 g/cm3,diamond grit is 500/425 μm,outer diameter is 20 mm,and when processing parameters meet axial pressure in the range of 780-820 N and spindle speed in the range of 2 500-2 700 r/min,the hole-drilling efficiency of Si C ceramic is higher. When prestressing force is in the range of 15.8-16.2 k N,there are no obvious cracks and breakdowns at orifice and holedrilling quality of Si C ceramic is better.