摘要
目的研究切屑形成机理对加工过程的影响。方法超声振动辅助车削技术通过刀具振动的拟间歇切削特征控制切屑尺寸和切屑形态,从而提高了加工表面质量。针对SiCp/Al复合材料的切屑形成机理,探究常规车削和超声振动辅助车削的切屑形成过程。研究了颗粒分布对第一变形区变形阶段的影响,以及不同加工方式下切削参数对切屑形态的影响。最后,描述了切屑自由表面和刀-屑接触界面的颗粒损伤形式,以直观地描述常规车削与超声振动辅助车削SiCp/Al复合材料加工中切屑的形成过程。结果通过测试加工后工件表面形貌发现超声振动辅助车削的切屑更加连续、切屑尺寸较小的加工表面粗糙度更小,常规车削的表面粗糙度为0.805μm,超声振动辅助车削的表面粗糙度为0.404μm,超声振动辅助车削比常规车削的表面粗糙度降低了49.8%。结论与常规车削相比,超声振动辅助车削有利于减小切屑厚度。超声振动辅助车削得到的切屑更加连续,避免了切屑碎裂,促进了切屑的顺利排出。通过对切屑形态进行研究,选择最优切削参数可以有效提高工件表面质量。
SiCp/Al is a metal matrix composite.It has excellent properties such as wear resistance,high temperature resistance,and fatigue resistance,and is widely used in fields such as aerospace,automobiles,electronics.The excellent physical and chemical properties of SiCp/Al composite materials have attracted widespread attention from the industry.With the application of SiCp/Al composite materials in these fields,there is an urgent demand for their precision machining technology,as well as research on machining methods and cutting mechanisms to improve surface quality.In the processing of SiCp/Al composite materials,the smooth discharge of chips and the prevention of chip fragmentation and adhesion on the processed surface can effectively improve the surface quality of the work piece.The effect of chip formation mechanism on the machining process was explored.Ultrasonic vibration assisted cutting technology improved the chip size and shape through the quasi-intermittent cutting characteristics of tool vibration,thereby improving the surface quality of machining.The chip morphology of SiCp/Al composite materials was analyzed through comparative experiments of conventional cutting and ultrasonic vibration assisted cutting.The particle distribution in the shear deformation zone stage and the effect of cutting parameters on chip morphology were studied.The chip morphology of conventional and ultrasonic vibration assisted cutting was compared from three aspects:feed rate,cutting depth and rotational speed.Due to the presence of SiC particles in SiCp/Al composite materials,the material began to deform along the boundaries of the particles,and the effective stress reached the material yield strength for the first time.During the deformation process,the increase of stress might cause particle movement and fracture.Therefore,during the cutting process,due to the continuous changes in the position of the particles cut by the tool,the angle of the boundary line at the beginning of deformation changed,leading to fluctuations in the shear angle within a certain range.And the chip segmentation degree Gs was introduced for quantitative comparison between conventional cutting and ultrasonic vibration assisted cutting experiments.It was found by comparison that the sawtooth degree of conventional cutting was 0.264-0.685,and the sawtooth degree of ultrasonic vibration assisted cutting was 0.085-0.364.The sawtooth shaped chips formed by ultrasonic vibration assisted cutting were not obvious,which avoided the fracture of the free surface of the chip at the crack.Finally,the particle damage forms of the chip free surface and the tool chip contact interface were described to visually describe the chip formation process in conventional cutting and ultrasonic vibration assisted cutting of SiCp/Al composites.Ultrasonic vibration assisted turning with more obvious elastic recovery was beneficial for reducing chip thickness.The chips obtained by ultrasonic vibration assisted cutting are more continuous,avoiding chip fragmentation and promoting the smooth discharge of chips.By observing the surface morphology of the work piece after processing,it is concluded that the smaller and more continuous the chip size,the smaller the surface roughness of the machined surface,while the surface roughness for conventional cutting is 0.805μm.The surface roughness of ultrasonic vibration assisted turning is 0.404μm.Compared with traditional turning,ultrasonic vibration assisted turning can reduce surface roughness by 49.8%.By observing the morphology of chips and selecting the optimal cutting parameters,the surface quality of work piece processing can be effectively improved.
作者
林洁琼
于行
周岩
谷岩
周晓勤
LIN Jieqiong;YU Hang;ZHOU Yan;GU Yan;ZHOU Xiaoqin(College of Electrical Mechanical Engineering,Changchun University of Technology,Changchun 130000,China;School of Mechanical and Aerospace Engineering,Jilin University,Changchun 130000,China)
出处
《表面技术》
EI
CAS
CSCD
北大核心
2024年第6期144-156,共13页
Surface Technology
基金
国家自然科学基金(U19A20104)
吉林省高性能制造及检测国际科技合作重点实验室(20220502003GH)。
