镗削碳纤维复合材料时切削用量对切削力及孔出口撕裂的影响

Influence of Cutting Parameters on Cutting Forces and Hole Exit Tear in Boring CFRP

采用PCD刀具对碳纤维复合材料(CFRP)进行了镗削加工试验,分析了切削用量对切削力、孔出口撕裂因子(撕裂值与孔直径的比值)的影响规律。试验结果表明,三向切削力随背吃刀量、进给量、切削速率的增大而增大。经分析认为,切削速率的增大引起待加工材料的屈服应力增大。由于刀尖圆弧半径较大,试验中出现背向力大于主切削力的现象;撕裂因子与背吃刀量基本无关;进给量与撕裂因子呈线性正相关;当切削速率增大时撕裂因子呈减小趋势,并且减小到一定程度后基本不变;采用PCD刀具镗削加工该材料能够有效地减小孔出口撕裂程度。

In this paper, some experiments were carried out by using PCD tool to bore carbon fiber reinforced plastics （ CFRP ） and the influence of cutting parameters on cutting force and hole exit tear factor（ the ratio of tear size and hole diameter） was analyzed. The testing results showed that 3-D components of cutting forces increase along with the increasing of the cutting depth, feed rate and cutting speed. It is indicated that the raise of cutting speed re- sults in the increasing of yield-stress of the material. Large corner radius causes the highest radial force, followed by the main cutting force and axial force ; Tear factor is almost independent of cutting depth, but there is a linear positive correlation between the factor and feed rate. When increasing the cutting speed the value of tear factor shows a tenden-cy to decrease and then kept essentially constant. Boring CFRP using PCD tool can effectively reduce tear degree of hole exit.