碳纤维/树脂基复合材料铣削表面粗糙度及表面形貌研究

目的研究了CFRP材料铣削加工过程中,部分主要工艺对CFRP材料加工表面质量的影响规律,为工艺参数优化,提高此类零件的表面质量提供依据。方法设计了CFRP材料铣削中的切削参数、刀具结构、加工方法与加工表面粗糙度及表面形貌之间的单因素试验。通过单调改变一个切削参数而其余切削参数不变,得到了工件表面粗糙度和表面形貌随切削参数、刀具结构、加工方法的变化规律。结果当铣削速度增大时,工件的表面粗糙度变化不大,表面微坑缺陷的数量却有所增加,但变小、变浅。当进给速度增大时,工件表面粗糙度呈上升趋势,表面缺陷也随之增加。无涂层多齿刀具铣削后的工件表面粗糙度最大,其次是金刚石涂层多齿刀具铣削的工件,最小的是金刚石涂层交错齿刀具铣削的工件。多齿刀具加工后的表面有较多的微坑缺陷,但普遍深度较浅且面积较小。交错齿刀具对分层缺陷的抑制作用最明显,但在左旋和右旋刀齿交错处容易出现较严重的加工缺陷。与普通机械加工方法相比,超声振动加工方法得到的工件表面质量较好,可以有效减少表面微坑缺陷,改善CFRP铣削加工表面质量。结论 CFRP材料铣削加工时,为了获得较好的加工表面质量,切削参数应选用较高的切削速度和较低的进给速度,切削刀具宜选用多齿带涂层刀具。和普通机械加工方法相比,超声振动铣削加工方法更为有利于获得好的表面质量。

Surface Roughness and Surface Morphology of Milled Carbon/Epoxy Composite Surface

As a kind of excellent polymer matrix composite, carbon fiber reinforced polymer (CFRP) is widely used in manufacturing of aircraft and spacecraft components. CFRP components are usually near net shape, but they also shall be subject to second cutting after demoulding to ensure size of the assembly. This work aims to investigate rule of effects of some main processes on surface quality of CFRP during milling process, so as to provided basis for optimizing cutting parameters and further improving surface quality of such parts. A single-factor experiment was designed among cutting parameters, tool structure, machining method, finished surface roughness and morphology of CFRP. Law of change in surface roughness, cutting parameters, tool structure and machining method was obtained by adjusting one of the cutting parameters and reserving the rest of cutting parameters. As the mil-ling speed increased, surface roughness of the workpiece changed slightly, surface micro-pit defects increased but diminished and shallowed. As the feeding speed increased, both the surface roughness and surface defects increased. Uncoated multitooth cutter exhibited the maximum workpiece surface roughness, followed by multitooth cutter with diamond coating, and finally staggered tooth cutter with diamond coating. In addition, surface processed by the multitooth cutter had more micro-pit defects, which were generally shallow and small. The staggered tooth cutter had inhibition most significant effects on delamination defect, but serious processing defects might be present in joints of left- and right-hand cutter teeth. Compared with common mechanical machining, workpiece acquired in ultrasonic vibration machining method exhibited better surface quality of the CFRP, less surface micro-pit defects and better CFRP milling surface quality. In order to obtain a better surface quality during CFRP milling, higher milling speed and lower feed speed as well as multitooth coated cutter shall be selected. Compared with common machining method, the ultrasonic vibration machining method may contribute to better surface quality.