碳纤维增强复合材料T型齿槽加工缺陷的形成机制

针对平纹编织碳纤维增强复合材料(CFRP)T型齿槽切出侧最外层纤维在切制过程中产生的缺陷,建立齿槽切出侧最外层纤维的切削模型,采用T型铣刀展开切制齿槽的试验,研究缺陷的形成机制。在切出侧最外层纤维的切削过程中,存在A、B两种情形,分别为纬向纤维的切削有经向纤维的支撑和无经向纤维的支撑。结果表明: 随着每齿进给量的增大,齿槽切出侧最外层纤维的残余因子基本呈减小趋势,而分层因子呈增大趋势,且残余因子主要经历2次减小,依次包括A情形残余纬向纤维的减少和残余经向纤维的减少;B情形的残余纬向纤维普遍存在于每次试验中,但在A情形纤维被切除的适当每齿进给量区间内,部分B情形纤维能有效被切除;此外,采用细晶粒硬质合金刀具进行齿槽加工的每齿进给量选择在11.22 μm/z~15.62 μm/z区间内较为合适。试验结果与理论推导所反映的规律基本一致,该研究对每齿进给量的选取和缺陷的抑制具有指导意义。

Formation mechanism of T-slotting machining defects of carbon fiber reinforced plastics

In view of the T-slotting defects on the outermost layer at the cut-out side on plain-woven carbon fiber reinforced plastics (CFRP), the cutting models on the outermost layer of fibers at the cut-out side were established.The slotting tests, using a T-slot cutter, were carried out to study the formation mechanism of the T-slotting defects.In the cutting process of the outermost layer at the cut-out side, there are Case A and Case B, for respectively the cutting of fill fibers with the support of warp fibers and the cutting of fill fibers without the support of warp fibers.The results show that when the feed per tooth increases, the residual factor of the outermost layer at the cut-out side basically decreases while the delamination factor increases.And residual factor mainly experiences 2 times of decreasing in succession, including the reducing of residual fill fibers of Case A and the reducing of residual warp fibers.Residual fill fibers of Case B are ubiquitous in each test, but some of them can be removed effectively when the feed per tooth region is appropriate, in which Case A fibers are removed.Using a fine grain cemented carbide cutter for slotting, the appropriate feed per tooth region is between 11.22 μm/z and 15.62 μm/z.The changing rules reflected by the theoretical derivations are in good agreement with the test results.The study has guiding significance for the selection of feed per tooth and the inhibition on the T-slotting defects.