钎焊金刚石磨粒钻钻削C/SiC陶瓷基复合材料孔时切屑对钻削过程的影响

Effect of chips on drilling process when drilling C/SiC ceramic matrix composite holes with brazed diamond abrasive drill

钎焊金刚石磨粒钻适合钻削碳纤维增强碳化硅陶瓷基复合材料孔,但大量切屑会对孔的钻削过程产生不利影响。为此,针对切屑排出过程,分析切屑形貌,研究钻削时切屑对轴向钻削力、孔加工质量、钻头磨损的影响。结果表明:切屑对轴向钻削力有影响,尤其钻削深孔时影响显著。切屑对孔进口的加工质量几乎没有影响,只表现为孔进口处的轻微崩边;切屑对孔出口的加工质量影响显著,可引起严重的纤维断裂、撕裂缺陷以及基体的大区域脱落。同时,切屑加剧钻头磨损,使钻头不仅出现崩刃、微裂纹等轻微磨损,而且还产生基体剥落、金刚石剥落等严重磨损行为。

Brazed diamond abrasive drill was suitable for drilling holes in carbon fiber reinforced silicon carbide ceramic matrix composites,but a large amount of chips could adversely affect the drilling process of the holes.Therefore,according to the chip discharge process,the chip morphology was analyzed,and the effects of chips on the axial drilling force,the hole processing quality and the drill wear during drilling were studied.The results show that the chips have an effects on the axial drilling forces,especially when drilling deep holes.The chips have little effects on the machining quality of the hole inlet,only a slight edge collapses at the hole inlet.The chips have a significant impacts on the processing quality of the hole outlet,which can cause serious fiber breakage,tear defects,and large areas of the matrix shedding.At the same time,the chip intensifies the drill wear,which not only causes slight wear such as edge collapse and micro crack,but also produces serious wear behaviors such as matrix peeling and diamond peeling.