MicroMachining

Topics: Machining, Electrical discharge machining, Numerical control Pages: 17 (3736 words) Published: February 17, 2015
At this time, unfortunately, a convergence in terminology has not been forthcoming and, hence, a definition of the term Micro-Machining to be implied in the context of this assessment is in order. In principle, one may take two viewpoints:(1) The first viewpoint may define Micro-Machining as the collection of all cutting operations that are performed on micro/meso-scale components and products that fall into the 100 μm to 10,000 μm size range as shown in the figure below. The Micro-Machining regime is characterized by the requirement of producing high accuracy complex geometric features in a wide variety of materials in the above-defined size range. These requirements impose the use of considerably downsized tooling (micro-tools, e.g. endmills in the 50 to 500 micron diameter range), small undeformed chip thicknesses and feedrates (submicron to a few microns) and speed settings (50K to 200K RPM might not be uncommon) that would be considered technologically infeasible at the conventional macro-scale. As a consequence, the principal distinction between Macro and Micro-Machining operations emerges and manifests itself as the dominance of ploughing and rubbing phenomena at the cutting edge over shearing and the necessity to take micro-structural effects into consideration. (2) The second viewpoint approaches the definition of the Micro-Machining regime from the standpoint of the magnitude of the undeformed chip thickness being removed in the cutting process. It is difficult to define a clear-cut value of the undeformed chip thickness that would differentiate the macro-, micro/meso- and nano-scale cutting regimes since other factors such as grain-structure, cutting edge radius, etc., also come into play. The authors of this report would suggest the following classification: Miniaturization is the order of the day. Until recently a decade ago traditionally watch parts were considered to be the micro components one can think off. Recent changes in society’s demand have forced us to manufacture variety of micro components used in different fields starting from entertainment electronics to bio medical implants. We are all familiar with the phrase “the world is getting smaller.” However, it is not just that the world is getting smaller, practically everything we use is getting smaller. Manufacturing technology has advanced to higher levels of precision to satisfy the increasing demand to reduce the size of parts and products in the electronics, computer, and biomedical industrial sectors. New processing concepts, procedures and machines are thus needed to fulfill the increasingly stringent requirements and expectations. Micromachining refers to techniques for fabrication of 3D structures on the micrometer scale. Until recently watch parts were considered to be the micro components produced for the purpose of making watches. Recent demands for micro parts have required us to manufacture variety of micro components used in different fields from entertainment electronics to biomedical implants. The convenience and value of many products can be substantially increased with reduced size and weight. With the trend toward miniaturization, micromachining becomes increasingly important in fabricating micro parts1. In the medical field, diagnosis and surgery without pain is possible through miniaturization of medical tools. The convenience and value of many products can be substantially increased with reduced size and weight. With the trend towards miniaturization, micromachining becomes increasingly important in fabricating micro parts. Micro parts may have overall size of few millimeters but it has many features that falls in micro range from 1 μm to 500 μm features size of 100 μm is common in micromachining. This means small as hair size, the average hair diameter is about 100 μm1-5. The design and construction of tools, tool holders, cutting tools, and electrodes need to evolve as greater demands are placed on them for machining these...
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