29 research outputs found
A Rotating-Tip-Based Mechanical Nano-Manufacturing Process: Nanomilling
We present a rotating-tip-based mechanical nanomanufacturing technique, referred to here as nanomilling. An atomic force microscopy (AFM) probe tip that is rotated at high speeds by out-of-phase motions of the axes of a three-axis piezoelectric actuator is used as the nanotool. By circumventing the high-compliance AFM beam and directly attaching the tip onto the piezoelectric actuator, a high-stiffness arrangement is realized. The feeding motions and depth prescription are provided by a nano-positioning stage. It is shown that nanomilling is capable of removing the material in the form of long curled chips, indicating shearing as the dominant material removal mechanism. Feature-size and shape control capabilities of the method are demonstrated
Nanogrids and Beehive-Like Nanostructures Formed by Plasma Etching the Self-Organized SiGe Islands
A lithography-free method for fabricating the nanogrids and quasi-beehive nanostructures on Si substrates is developed. It combines sequential treatments of thermal annealing with reactive ion etching (RIE) on SiGe thin films grown on (100)-Si substrates. The SiGe thin films deposited by ultrahigh vacuum chemical vapor deposition form self-assembled nanoislands via the strain-induced surface roughening (Asaro-Tiller-Grinfeld instability) during thermal annealing, which, in turn, serve as patterned sacrifice regions for subsequent RIE process carried out for fabricating nanogrids and beehive-like nanostructures on Si substrates. The scanning electron microscopy and atomic force microscopy observations confirmed that the resultant pattern of the obtained structures can be manipulated by tuning the treatment conditions, suggesting an interesting alternative route of producing self-organized nanostructures
Three-Dimensional Nanofabrication Utilizing Selective Etching of Silicon Induced by Focused Ion Beam Irradiation
Optimization and fabrication of curvilinear micro-grooved cutting tools for sustainable machining based on finite element modelling of the cutting process
Nanogrooving by using multi-tip diamond tools
This chapter introduces nano-grooving approach by using multi-tip diamond tools to generate nanostructures such as nano-gratings/nano-grooves on large substrates. It starts by briefing the work principle and history of this nanofabrication approach. It then introduces the machining mechanism, influences of processing parameters, and tool wear on the machined nanostructures. It concludes with a summary of research challenges, current research achievements, and future research directions to systematically establish this nanofabrication approach
Experimental study on cutting comparison of structured cutting tools in dry cutting of EN19 alloy steel
One of the promising and emerging techniques used to improve the tool chip contact phenomenon is to create micro- and/or nanostructures on the surfaces of cutting tools. The rake face structuring of the cutting tool has been the focus of research, and its benefits are well documented in literature. The effects of structures applied on different faces of the cutting tool have been studied in detail, yet there is a scope on cutting performance comparison of structured tools. This study looks into the cutting performance comparison of three fabricated cutting tools: a cutting tool with the rake face structure, a cutting tool with flank face structure and a tool with both the rake and the flank face structure. Structures on the cutting tools were created with a femtosecond laser system. Orthogonal machining of EN19/AISI/SAE4140 was performed to assess the cutting performance of the fabricated structured tools. Machining performance of structured tools was measured against cutting performance of unstructured tool. Results suggest that structured tools deliver better machining performance. However, improvement in certain machining parameter (forces, compression ratio, contact length, etc.) is linked to the structures created on a specific face of the cutting tool, although each structured side of the tool has a counter effect. Structured cutting tools reduce sticking contact from 52% to 42%–45%. Also, structured cutting tools lower the energy consumption due to decreased compression ratio. Precisely this research classifies the preference on the application of tool structuring for improved performance.</p