Studies on surface wettability have received tremendous interest due to their potential applications in research and industrial processes. One of the strategies to tune surface wettability is modifying surface topogra...Studies on surface wettability have received tremendous interest due to their potential applications in research and industrial processes. One of the strategies to tune surface wettability is modifying surface topography at micro-and nanoscales. In this research, periodic micro-and nanostructures were patterned on several polymer surfaces by ultra-precision single point diamond turning to investigate the relationships between surface topographies at the micro-and nanoscales and their surface wettability. This research revealed that single-point diamond turning could be used to enhance the wettability of a variety of polymers, including polyvinyl chloride(PVC), polyethylene 1000(PE1000), polypropylene copolymer(PP) and polytetrafluoroethylene(PFTE), which cannot be processed by conventional semiconductor-based manufacturing processes. Materials exhibiting common wettability properties(θ≈ 90°) changed to exhibit "superhydrophobic" behavior(θ > 150°). Compared with the size of the structures, the aspect ratio of the void space between micro-and nanostructures has a strong impact on surface wettability.展开更多
Single-point diamond turning (SPDT) is widely used in the machining of infrared materials and metal-based mirrors. Diamond tips can scratch material, replicate the shape of the tip, and create annular turning marks on...Single-point diamond turning (SPDT) is widely used in the machining of infrared materials and metal-based mirrors. Diamond tips can scratch material, replicate the shape of the tip, and create annular turning marks on optical surfaces, which can have unpredictable adverse effects on imaging. In order to predict the effect of turning marks diffraction on the degradation of imaging quality, a model of the influence of SPDT processing parameters on the reduction of system imaging MTF under the influence of ideal grating turning marks diffraction was established. The results show that the depth of the turning mark will lead to the decline of MTF, especially the low frequency information. Finally, a method is proposed to reduce the effect of turning marks diffraction through changing the processing parameters. .展开更多
A fast tool servo (FTS) system is developed for the fabrication of non-rotationally symmetric micro-structured surfaces using single-point diamond turning machines.The constructed FTS employs a piezoelectric tube actu...A fast tool servo (FTS) system is developed for the fabrication of non-rotationally symmetric micro-structured surfaces using single-point diamond turning machines.The constructed FTS employs a piezoelectric tube actuator (PZT) to actuate the diamond tool and a capacitive probe as the feedback sensor.To compensate the inherent nonlinear hysteresis behavior of the piezoelectric actuator,Proportional Integral (PI) feedback control is implemented.Besides,a feed-forward control based on a simple feed-forward predictor has been added to achieve better tracking performance.Experimental results indicate that error motions in the performance of the system caused by hysteresis can be reduced greatly and the micro-structured surface is successfully fabricated by implementing the FTS.展开更多
铝反射镜在航空航天和空间遥感卫星领域中广泛应用,为了提高铝反射镜的轻量化率,降低民用商业遥感卫星的发射成本,设计了一种背部开放式、三角形孔结构和三点支撑形式的轻量化铝反射镜。在此结构基础上,首先以质量最小为优化目标,以反...铝反射镜在航空航天和空间遥感卫星领域中广泛应用,为了提高铝反射镜的轻量化率,降低民用商业遥感卫星的发射成本,设计了一种背部开放式、三角形孔结构和三点支撑形式的轻量化铝反射镜。在此结构基础上,首先以质量最小为优化目标,以反射镜背部加强筋的厚度和加强筋的布局为优化对象,以柔度最小为响应约束,应用有限元法对反射镜背部加强筋的厚度进行尺寸优化和加强筋的布局进行拓扑优化,得到的铝反射镜轻量化率超过63%;然后设计了工装夹具进行单点金刚石车削加工试验;最后使用激光干涉仪检测反射镜的面形精度。检测结果表明:反射镜的面形值PV(peak to valley)为1.48μm,能够满足民用商业遥感卫星的使用要求。展开更多
正弦调制靶是瑞利-泰勒(Rayleigh-Taylor,R-T)不稳定性研究的重要实验用靶。从国内外实验用靶的需求出发,采用金刚石车削技术,在紫铜表面完成了振幅为10μm、波长为100μm等一系列正弦曲线的加工。采用直线插补原理编制数控加工程序,利...正弦调制靶是瑞利-泰勒(Rayleigh-Taylor,R-T)不稳定性研究的重要实验用靶。从国内外实验用靶的需求出发,采用金刚石车削技术,在紫铜表面完成了振幅为10μm、波长为100μm等一系列正弦曲线的加工。采用直线插补原理编制数控加工程序,利用超精密金刚石车床,设计了合理的加工工艺过程,分析了对正弦曲线轮廓加工及测量的主要影响因素及误差,通过Form Talysurf series 2型触针式轮廓仪对正弦曲线轮廓进行测量。结果表明:正弦曲线轮廓平滑,波长和振幅数值上与理论值基本相同。通过SPDT技术制备的正弦曲线图形基本满足R-T不稳定性实验需求。展开更多
基金financial support from Heriot-Watt University (Edinburgh)the Engineering and Physical Sciences Research Council (EP/K018345/1) for this study
文摘Studies on surface wettability have received tremendous interest due to their potential applications in research and industrial processes. One of the strategies to tune surface wettability is modifying surface topography at micro-and nanoscales. In this research, periodic micro-and nanostructures were patterned on several polymer surfaces by ultra-precision single point diamond turning to investigate the relationships between surface topographies at the micro-and nanoscales and their surface wettability. This research revealed that single-point diamond turning could be used to enhance the wettability of a variety of polymers, including polyvinyl chloride(PVC), polyethylene 1000(PE1000), polypropylene copolymer(PP) and polytetrafluoroethylene(PFTE), which cannot be processed by conventional semiconductor-based manufacturing processes. Materials exhibiting common wettability properties(θ≈ 90°) changed to exhibit "superhydrophobic" behavior(θ > 150°). Compared with the size of the structures, the aspect ratio of the void space between micro-and nanostructures has a strong impact on surface wettability.
文摘Single-point diamond turning (SPDT) is widely used in the machining of infrared materials and metal-based mirrors. Diamond tips can scratch material, replicate the shape of the tip, and create annular turning marks on optical surfaces, which can have unpredictable adverse effects on imaging. In order to predict the effect of turning marks diffraction on the degradation of imaging quality, a model of the influence of SPDT processing parameters on the reduction of system imaging MTF under the influence of ideal grating turning marks diffraction was established. The results show that the depth of the turning mark will lead to the decline of MTF, especially the low frequency information. Finally, a method is proposed to reduce the effect of turning marks diffraction through changing the processing parameters. .
基金Funded by the National High-tech R&D Program ("863" Program) of China (No.2006AA04Z314)
文摘A fast tool servo (FTS) system is developed for the fabrication of non-rotationally symmetric micro-structured surfaces using single-point diamond turning machines.The constructed FTS employs a piezoelectric tube actuator (PZT) to actuate the diamond tool and a capacitive probe as the feedback sensor.To compensate the inherent nonlinear hysteresis behavior of the piezoelectric actuator,Proportional Integral (PI) feedback control is implemented.Besides,a feed-forward control based on a simple feed-forward predictor has been added to achieve better tracking performance.Experimental results indicate that error motions in the performance of the system caused by hysteresis can be reduced greatly and the micro-structured surface is successfully fabricated by implementing the FTS.
文摘铝反射镜在航空航天和空间遥感卫星领域中广泛应用,为了提高铝反射镜的轻量化率,降低民用商业遥感卫星的发射成本,设计了一种背部开放式、三角形孔结构和三点支撑形式的轻量化铝反射镜。在此结构基础上,首先以质量最小为优化目标,以反射镜背部加强筋的厚度和加强筋的布局为优化对象,以柔度最小为响应约束,应用有限元法对反射镜背部加强筋的厚度进行尺寸优化和加强筋的布局进行拓扑优化,得到的铝反射镜轻量化率超过63%;然后设计了工装夹具进行单点金刚石车削加工试验;最后使用激光干涉仪检测反射镜的面形精度。检测结果表明:反射镜的面形值PV(peak to valley)为1.48μm,能够满足民用商业遥感卫星的使用要求。
文摘正弦调制靶是瑞利-泰勒(Rayleigh-Taylor,R-T)不稳定性研究的重要实验用靶。从国内外实验用靶的需求出发,采用金刚石车削技术,在紫铜表面完成了振幅为10μm、波长为100μm等一系列正弦曲线的加工。采用直线插补原理编制数控加工程序,利用超精密金刚石车床,设计了合理的加工工艺过程,分析了对正弦曲线轮廓加工及测量的主要影响因素及误差,通过Form Talysurf series 2型触针式轮廓仪对正弦曲线轮廓进行测量。结果表明:正弦曲线轮廓平滑,波长和振幅数值上与理论值基本相同。通过SPDT技术制备的正弦曲线图形基本满足R-T不稳定性实验需求。