超声椭圆振动切削SiCp/Al复合材料仿真研究

Simulation Study of Ultrasonic Elliptical Vibration Cutting SiCp/Al Composites

SiCp/Al复合材料具有优异的物理性能,但颗粒的存在导致其加工困难。颗粒材料的超硬性和耐磨性、加工表面的损伤以及刀具的磨损被认为是该类颗粒复合材料加工的主要障碍。目的 针对SiCp/AI复合材料难加工特性,通过对比常规切削(CC)与超声椭圆振动切削(UEVC)来研究其加工机理,分析两种加工方式下颗粒的损伤对切屑形成以及表面质量的影响。方法 基于Si Cp/Al复合材料的实际微观结构建立切削模型,采用有限元仿真的方法从微观层面展现其切削过程,能够直观呈现两种加工方式下颗粒损伤对切屑形成、刀具磨损以及表面质量的影响,进而预测复合材料在实际加工过程中可能遇到的问题,提出相应的解决方案。结果CC加工为锯齿状切屑,切削过程中主要为颗粒对刀具的两体滑动摩擦以及铝基体粘着摩擦,加工中导致的地下损伤严重。而UEVC加工时切屑易成段分离,切削过程中主要为颗粒对刀具的三体滚动摩擦,切屑根部聚集的颗粒相较CC加工过程较少,弱化了对加工表面的损伤。在两种加工方式下,加工表面存在以下缺陷:颗粒破碎、颗粒凸起、大空腔、凹坑以及沟槽等。结论 总体来说,UEVC加工有利于断屑,导致的损伤缺陷更少,颗粒破损程度更小,能大幅降低切削力,对改善SiCp/Al复合材料加工表面质量有一定效果。

SiCp/Al composites have excellent physical properties,but it is difficult to process SICP/Al composites due to the presence of particles.The superhardness and wear resistance of particle materials,damage to the machined surface,and tool wear are considered to be main obstacles to the processing of such particle composites.Objective To address the challenging machinability of SiCp/AI composites,the machining mechanism was studied by comparing conventional cutting(CC)with ultrasonic elliptical vibration cutting(UEVC),and the effects of particle damage on chip formation and surface quality under the two machining methods were analyzed.Methods The cutting model was established based on the actual microstructure of SiCp/Al composites,and the finite element simulation method was used to show the cutting process from the microscopic level,which was able to intuitively show the effects of particle damage on chip formation,tool wear,and surface quality under the two machining methods,so as to predict the problems that may be encountered in the actual machining process of composite materials and to propose corresponding solutions.Results CC machining is serrated chips,the cutting process is mainly two-body sliding friction of particles to the tool and adhesion friction of the aluminum matrix,and the underground damage caused by the machining is serious.However,during UEVC machining,the chips are easily separated into segments,the cutting process is mainly three-body rolling friction of particles to the tool,and particles gathered at the root of the chip are less compared with the CC processing,weakening the damage to the machined surface.Under the two machining methods,the machined surface has the following defects:particle breakage,particle protrusion,large cavities,pits,and grooves.Conclusion Overall,UEVC machining is beneficial to chip breaking,resulting in fewer damage defects and smaller particle damage,and can significantly reduce cutting force,which has a certain effect on improving the machining surface quality of SiCp/Al composites.