Driven by the ever increasing demand in function integration,more and more next generation high value-added products,such as head-up displays,solar concentrators and intra-ocular-lens,etc.,are designed to possess free...Driven by the ever increasing demand in function integration,more and more next generation high value-added products,such as head-up displays,solar concentrators and intra-ocular-lens,etc.,are designed to possess freeform(i.e.,non-rotational symmetric)surfaces.The toolpath,composed of high density of short linear and circular segments,is generally used in computer numerical control(CNC)systems to machine those products.However,the discontinuity between toolpath segments leads to high-frequency fluctuation of feedrate and acceleration,which will decrease the machining efficiency and product surface finish.Driven by the ever-increasing need for high-speed high-precision machining of those products,many novel toolpath interpolation and smoothing approaches have been proposed in both academia and industry,aiming to alleviate the issues caused by the conventional toolpath representation and interpolation methods.This paper provides a comprehensive review of the state-of-the-art toolpath interpolation and smoothing approaches with systematic classifications.The advantages and disadvantages of these approaches are discussed.Possible future research directions are also offered.展开更多
Structured complex silicon components have been widely used in solar cells,biomedical engineering and other industrial applications.As silicon is a typical brittle material,ultrasonic vibration cutting(UVC)is a promis...Structured complex silicon components have been widely used in solar cells,biomedical engineering and other industrial applications.As silicon is a typical brittle material,ultrasonic vibration cutting(UVC)is a promising method to achieve better cutting performance than conventional techniques.High-frequency ID UVC possesses higher nominal cutting speed and material removal rate than many 2D/3D UVC systems,and thus,it has great development potential in industrial applications of structured silicon components.However,few researchers have applied ID UVC to the cutting of structured silicon surfaces,since its main drawback is tool marks imprinted by the vibration on machined surface.In this study,to uncover the key machining characteristics under the condition of ID UVC,a series of tests involving diamond cutting grooves were first performed on the silicon surface.The machined surface and chips were subsequently measured and analyzed to evaluate the critical undeformed chip thickness,surface characteristics,and chip formation.Regarding the main drawback of ID UVC,a novel theoretical model was developed for predicting the length of tool marks and evaluating the impact of tool marks on the surface finish.The results demonstrated that the critical undeformed chip thickness of silicon reached 1030 nm under a certain vibration amplitude and that an array of micro grooves was generated at the plastic region with a surface roughness(7?a)as low as 1.11 nm.Moreover,the micro topography of the continuous chips exhibited discontinuous clusters of lines with diameters of dozens of nanometers,only composed of polysilicon.The novel theoretical model was able to predict the length of tool marks with low error.Thus,the impact of tool marks on the surface finish can be reduced and even eliminated with help of the model.展开更多
基金the support from the UK Engineering and Physical Sciences Research Council (EPSRC) under the program (No. EP/K018345/1)the International Cooperation Program of China (No. 2015DFA70630)
文摘Driven by the ever increasing demand in function integration,more and more next generation high value-added products,such as head-up displays,solar concentrators and intra-ocular-lens,etc.,are designed to possess freeform(i.e.,non-rotational symmetric)surfaces.The toolpath,composed of high density of short linear and circular segments,is generally used in computer numerical control(CNC)systems to machine those products.However,the discontinuity between toolpath segments leads to high-frequency fluctuation of feedrate and acceleration,which will decrease the machining efficiency and product surface finish.Driven by the ever-increasing need for high-speed high-precision machining of those products,many novel toolpath interpolation and smoothing approaches have been proposed in both academia and industry,aiming to alleviate the issues caused by the conventional toolpath representation and interpolation methods.This paper provides a comprehensive review of the state-of-the-art toolpath interpolation and smoothing approaches with systematic classifications.The advantages and disadvantages of these approaches are discussed.Possible future research directions are also offered.
基金The authors would like to express their sincere thanks to the National Natural Science Foundation of China(Grant No.51775482)the Hebei Province Natural Science Foundation of China(Grant No.E2016203372)for their financial support in this research work.
文摘Structured complex silicon components have been widely used in solar cells,biomedical engineering and other industrial applications.As silicon is a typical brittle material,ultrasonic vibration cutting(UVC)is a promising method to achieve better cutting performance than conventional techniques.High-frequency ID UVC possesses higher nominal cutting speed and material removal rate than many 2D/3D UVC systems,and thus,it has great development potential in industrial applications of structured silicon components.However,few researchers have applied ID UVC to the cutting of structured silicon surfaces,since its main drawback is tool marks imprinted by the vibration on machined surface.In this study,to uncover the key machining characteristics under the condition of ID UVC,a series of tests involving diamond cutting grooves were first performed on the silicon surface.The machined surface and chips were subsequently measured and analyzed to evaluate the critical undeformed chip thickness,surface characteristics,and chip formation.Regarding the main drawback of ID UVC,a novel theoretical model was developed for predicting the length of tool marks and evaluating the impact of tool marks on the surface finish.The results demonstrated that the critical undeformed chip thickness of silicon reached 1030 nm under a certain vibration amplitude and that an array of micro grooves was generated at the plastic region with a surface roughness(7?a)as low as 1.11 nm.Moreover,the micro topography of the continuous chips exhibited discontinuous clusters of lines with diameters of dozens of nanometers,only composed of polysilicon.The novel theoretical model was able to predict the length of tool marks with low error.Thus,the impact of tool marks on the surface finish can be reduced and even eliminated with help of the model.