Study On Fabrication Of Ordered Micro-nano Structures Based On Nanoindentation

The ordered micro-nano structures on the material surface can effectively change or enhance the surface properties.Therefore,it has a wide range of applications in many fields,such as changing the optical characteristics of the optical element,and improving the wear resistance of the mechanical part.Researchers have developed a variety of fabrication techniques of the ordered micro-nano structures,such as photolithography,electron beam etching,and nanoimprinting.However,the resolution of photolithography is limited by the wavelength;the electron beam etching technology has low fabrication efficiency,which can not be used in large areas;the rigid template in nanoimprint technology is difficult to manufacture.These disadvantages make their application limited.Nanoindentation technology is widely known as a testing method for measuring the mechanical properties of materials at the micro-nano scale,which greatly promotes the development of materials science.In this paper,nanoindentation technology is used as a novel machining technology for the fabrication of the ordered micro-nano structures.The main research work carried out are as follows:Firstly,a set of force controlled module with nanoindentation processing capability is developed and a three-dimensional micro-nano processing platform based on the module is built.The module uses a micro diamond probe as a tool,a piezoelectric ceramic transducer as an actuator,a flexible hinge mechanism as a force-sensitive element and high-precision displacement sensors to realize the closed-loop control of the normal force between the workpiece surface and probe and to record the press-in depth of probe in real time.Moreover,the index of the module and the processing capability of the platform are tested.Secondly,the finite element simulation method was used to study the processing mechanism of the ordered micro-nano structures based on nanoindentation.The single indentations of different probes and different loads was simulated by a three-dimensional finite element simulation model,and the rationality of the model was verified.Simulations of multi-indentations was conducted to investigate the effects of indentation pitch and angle on the ordered micro-nano structures based on nanoindentation.Finally,the ordered micro-nano structures are fabricated based on nanoindentation.Vickers,Berkovich and Conical probes are used to process single-row indentations and indentation arrays of different pitch and angles to form ordered micro-nano structures,and the influence of these parameters are explored.The surface-enhanced Raman scattering effect of the ordered micro-nano structures based on nanoindentation is studied.The enhancement factor of R6 G Raman spectra was used to characterize the surface-enhanced Raman scattering effect.