Preliminary experimental research on micro-milling

4M 2006 - Second International Conference on Multi-Material Micro Manufacture, 2006

Abstract Micro-milling is one of the technologies that is currently widely used for the production of micro-components and tooling inserts. To improve the quality and surface finish of machined microstructures the factors affecting the process dynamic stability should be studied systematically. This paper investigates the machining response of a metallurgically and mechanically modified material. The results of micro-milling workpieces of an Al 5000 series alloy with different grain microstructure are reported. In particular, the machining response of three Al 5083 workpieces whose microstructure was modified through a severe plastic deformation was studied when milling thin features in microcomponents. The effects of the material microstructure on the resulting part quality and surface integrity are discussed and conclusions made about its importance in micro-milling. The investigation has shown that through a refinement of material microstructure it is possible to improve significantly the surface integrity of the micro-components and tooling cavities produced by micro-milling.

Now these days there is a massive requirement in the production of microstructures by a unconventional method. Micro-EDM (µEDM) is a widely accepted unconventional machining option in which material erosion takes place from work-piece using a sequence of electrical spark. This method is used to manufacture micro-parts with the range of 50 μm-100 μm. This paper studied the optimization of various process parameters namely gap voltage, peak current and pulse duration to attain suitable µEDM performance measures such as Material Removal Rate (MRR), low Electrode Wear (EW) and good surface morphology of the microstructure accepted from µEDM machining process.

The International Journal of Advanced Manufacturing Technology, 2018

This work deals with the execution of micro-pockets on two different materials (AISI 316L stainless steel and ZrC+10MoSi2 UHT ceramic) using micro-EDM milling. The experiments were carried out by varying process parameters supposed to influence the surface quality, namely: discharge pulse on time, peak current, voltage and frequency. For both materials, tungsten carbide cylindrical electrodes were used. The investigation focused on the different results obtained in terms of surface roughness (Sa), kurtosis (Sku) and skewness (Ssk) to evaluate the different finishing level of the surface obtained as function of the process parameters. The aim of the present paper is to propose a method for studying the surface characteristics in terms of peaks and valleys shape and distribution with respect to the mean line according to ISO 25178. The results of this analysis can provide important information when designing micro-EDM milling processes.

Advances in Manufacturing, 2020

Micro-milling is a precision manufacturing process with broad applications across the biomedical, electronics, aerospace, and aeronautical industries owing to its versatility, capability, economy, and efficiency in a wide range of materials. In particular, the micro-milling process is highly suitable for very precise and accurate machining of mold prototypes with high aspect ratios in the microdomain, as well as for rapid micro-texturing and micro-patterning, which will have great importance in the near future in bio-implant manufacturing. This is particularly true for machining of typical difficult-to-machine materials commonly found in both the mold and orthopedic implant industries. However, inherent physical process constraints of machining arise as macro-milling is scaled down to the microdomain. This leads to some physical phenomena during micro-milling such as chip formation, size effect, and process instabilities. These dynamic physical process phenomena are introduced and d...

Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science, 2006

Micromilling of metal structures with 'thin' features represents a major challenge towards broadening the use of this technology in a range of microengineering applications, for example in producing multi-channel microstructures, housing for mechanical microdevices, and surgical instruments. The most common thin features seen in microengineering products are ribs and webs.

Micro-milling of metal structures with "thin" features represents a major challenge towards broadening the use of this technology in a range of micro-engineering applications, for example in producing multi-channel micro-structures, housings for mechanical micro-devices and surgical instruments. The most common thin features seen in micro- engineering products are ribs and webs. This research identifies the main factors affecting the reliability of micro-milling technology when employed for the machining of micro-components incorporating thin features. The general principles that should be followed in designing machining strategies for such features are discussed in the paper. Taking these general principles into account, new strategies are proposed to reduce the negative effects of identified factors on part quality and at the same time to overcome some of the problems associated with the use of conventional machining strategies for micro- milling of ribs and webs. To imp...

In micromachining the achievable range of material removal depth is the range of 1 x 10-6 m to 10-3 m. The least count in a normal milling machine is 0.01mm which is greater than 10-3 microns. Normally micro milling is done on specific milling machine which can achieve such micron level of material removal and they involve very high cost. This report is on the experimental procedure done for micro end milling on normal milling machine. During the machining various parameters like speed, feed and depth of cut were varied and surface roughness obtained for each value is noted and an optimum combination value for above is proposed.

Journal of Materials Processing Technology, 2003

Micro-electro-discharge machining (micro-EDM or -EDM) has been gaining popularity as a new alternative method to fabricate micro-structures. The main advantages of the micro-EDM method are its low set-up cost, high accuracy and large design freedom. Compared to etching or deposition techniques, micro-EDM has the advantage of being able to fabricate complex three-dimensional shapes with high-aspect ratio. However, there are many operating parameters that affect the micro-EDM process. The fabrication of micro-electrodes on the machine is also an important process to remove the clamping error to maintain high accuracy in the machined micro-structures.

Electrodes are the most essential component in Micro Electrical Discharge Machining (Micro-EDM). Electrode wear affects the geometry and precision of the components. In present work, a new technique has been adopted to fabricate micro electrodes in rectangular metallic materials using tubular electrodes in EDM process. Micro electrodes with high aspect ratio were generated in rectangular copper block using tubular electrodes of copper in electrical discharge drilling (EDD) process. Machining rate (MR) has been investigated on EDD process using Taguchi's L9 orthogonal array. The process parameters namely Discharge current (Ip), Pulse-on time (Ton) and Pulse-off time (T-off) are used for investigation. In order to optimize process parameters for maximum machining rate, Taguchi's approach has been used in the present research work.

Journal of the Brazilian Society of Mechanical Sciences and Engineering, 2013

Milling is one of the most important processes to manufacture dies and moulds. However, it cannot machine regions with small sizes and difficult access to the cutting tool. Such regions must be machined by electrodischarge machining (EDM). It is known that EDM can damage the integrity of the machined surface, and also requires long processing time, due to both, the necessity to manufacture the electrode and its low material removal rate. The micromilling process, using high-frequency spindle together with cutting tools smaller than 1 mm of diameter has been emerging as an option for machining small regions in dies and moulds. In this context, this paper aims to help the understanding of the cutting phenomenon to manufacture small areas using both machining techniques, in order to identify the adequacy to replace EDM for micromilling in such circumstances. Machining experiments were carried out on AISI P20 (29HRC) and AISI H13 (45HRC) steels. These materials are commonly used in the mould and die industry. Residual stress on machined surface, surface finishing (2D and 3D), SEM images, microstructure and microhardness were accessed. The residual stress was tensile for the EDM pieces and compressive for the milled parts. The material had more influence on the residual stresses values than the process and H13 had higher values than P20. The surface roughness from the EDM machining pieces was not influenced by the material. The EDM caused white layer and microcracks on both materials, but much more intensely on H13. These occurrences were not found on the milled workpieces. Plastic deformation occurred on the micromilled surfaces, but without phase transformation of the material's microstructure. Unexpectedly, the roughness on the hardest material (H13) was worse than P20 for the milling experiments. It was attributed to more intense tool deflection when milling H13. In general, roughness obtained in micromilling was about six times lower than that obtained using EDM and it presented a regular surface topography, unlike the EDM specimens.