CBN-WC-10Co复合材料单纤维切削性能  

Cutting Performance of Single cBN-WC-10Co Fiber

作　　者：毛聪[1,2] 卢继[1,2] 梁昶[1,2] 张明军[1,2] 胡永乐[1,2] 

机构地区：[1]长沙理工大学汽车与机械工程学院,长沙410114 [2]长沙理工大学工程车辆轻量化与可靠性技术湖南省普通高等学校重点实验室,长沙410114

出　　处：《机械工程学报》2017年第15期188-200,共13页Journal of Mechanical Engineering

基　　金：国家自然科学基金(51375061);湖南省教育厅科学研究(16A010);湖南省普通高等学校重点实验室开放基金(2016kfjj05)资助项目

摘　　要：利用放电等离子烧结技术和电火花线切割技术制备了尺寸为6 mm×0.8 mm×0.8 mm的CBN-WC-10Co复合材料纤维,刃磨后纤维前角为0°、后角为20°、刃口锋利平直,能够将这种CBN-WC-10Co纤维替代传统CBN磨粒并进行有序排布制备成有序化纤维刀具。开展了单纤维和单颗CBN磨粒在相同条件下单道切削TC4钛合金的对比试验。结果表明,CBN-WC-10Co单纤维的切削力比(Fn/Ft)、切削比能小,且加工质量可与CBN单颗磨粒相媲美;切削时纤维是以零前角对工件进行切削加工,且纤维的两侧面均与加工表面始终保持相互垂直,工件材料受到纤维的挤压作用而向纤维前端及两侧塑性流动大大减少,切削划痕两侧和切出端的材料堆积现象大为减轻;纤维切削划痕沿着切削方向的材料去除率为98.1%~99.1%,材料堆积率为0.9%~1.9%,而磨粒的材料去除率和材料堆积率分别为-54%~86%和10%~160%,表明纤维的材料去除性能比单颗磨粒的好,因此,可以适当地增大纤维的切削参数来实现材料的高效切削加工。CBN-WC-10 Co fibers with macroscopic dimensions of 0.8 mm×0.8 mm×6 mm are fabricated by using spark plasma sintering technique and wire electro-discharge machining. The rake surface and flank surface of the fibers are polished to form a zero rake angle and a 20o clearance angle by using diamond abrasive paper of 3 μm in mesh size. The fibers can be orderly arranged and be prepared oriented fiber cutter through replacing the abrasives in a grinding wheel. A comparative investigation is carried out on the machining mechanisms of TC4 titanium alloy by single c BN-WC-10 Co fiber and by single CBN grit. It is found that both cutting force ratio（Fn/Ft） and specific cutting energy of c BN-WC-10 Co fiber are decreased, and cutting quality is comparable to that for CBN grit. Single c BN-WC-10 Co fiber cuts workpiece with zero rake angle during cutting and the flanks of the fiber are perpendicular to the machining surface. Therefore, the volume of workpiece material flowed to the front and flank of the fiber is small because of smaller squeezing action, and then only a little material accumulate on the sides and the outlet end of the cutting scratch of single c BN-WC-10 Co fiber. The material removal rate along the cutting direction of the scratch formed by the c BN-WC-10 Co fiber is 98.1%~99.1% and the pile up ratio is 0.9%-1.9%. However, the material removal rate and the pile up ratio of the scratch cut by the CBN grit are-54%-86% and 10%-160%, respectively. This indicates that the c BN-WC-10 Co fiber has excellent material removal performance in comparison with the CBN grit, and the high machining efficiency can be achieved by increasing cutting parameters.

关 键 词：单纤维切削 CBN-WC-10Co 切削性能 划痕形貌 切削力 材料去除率 

分 类 号：TG580[金属学及工艺—金属切削加工及机床]