Manufacturing Of Microcomponents Research Articles

Prediction of Burr Formation in End Micro Milling Poly methyl Methacrylate (PMMA) and Polycarbonate (PC) Substrates Using Convolutional Neural Network (CNN)

Polymer microfluidic device is growing in the fields of disease detection, drug synthesis, and environmental monitoring because of the benefits of the miniaturized platforms that provides rapid high-throughput analysis at small sample volumes. A machining technique called micro milling is employed in the manufacture of micro components (micro fluidic devices) such as poly methyl methacrylate (PMMA) or polycarbonate (PC). Micro milling has the advantage of being a quicker, more affordable, and more effective method for fabricating more complex structures. PMMA has been used as the substrate in this study for micro milling followed by factor analysis. This aim of this study is to understand the influence of each micro milling parameter to the surface quality. This paper includes 450 microscopic images of the micro-milling substrate by different parameters like spindle speed, depth of cut and Surface quality. The microscopic images are divided to test, train and Val dataset, using three datasets and a Convolutional Neural Network (CNN) is designed.

Manufacturing of micro components on amorphous alloy with a high-aspect-ratio characteristic structure by multistage forming method

Manufacturing of micro components on amorphous alloy with a high-aspect-ratio characteristic structure by multistage forming method

An experimental analysis of minimum chip thickness in micro-milling of two different titanium alloys

Micro-milling is a micro-mechanical cutting method used to obtain complex and three-dimensional micro geometries. Micro-cutting tools are used in the manufacturing of micro-components and the type of workpiece is also important for good surface quality and minimum burr. In this study, micro machinability of Ti6Al4V alloy which is used most frequently in micro-component production is compared with Ti5553 alloy. Micro-milling of Ti5553 alloy and comparison of the minimum chip thickness with Ti6Al4V were performed for the first time in this study. Using different cutting parameters, the variation of surface roughness, burr width, and cutting forces were investigated. The cutting tests were carried out on a specially designed and high-precision micro-milling test system using a TiCN-coated two-flute end mill of 0.6 mm diameter. According to the results, minimum chip thickness is approximately 0.3 times the edge radius of the cutting tool and does not vary with the alloy type. At feed rates smaller than the minimum chip thickness, both the cutting forces increase and the surface quality decreases. For both alloys, reduced feed rate and increased depth of cut lead to increased burr width. The burr widths in Ti6Al4V alloy are higher. At the end of the study, the limits of the cutting parameters where plowing occurred for the both alloys are clearly determined. In addition, the limits of the cutting parameter causing plowing have been confirmed by cutting forces, surface roughness, and burr formation.

Worn tool geometry–based flank wear prediction in micro turning

Mechanical micromachining techniques have gained much popularity in the manufacturing of microcomponents with complex shapes in the past couple of decades. Machining at the microscale poses several challenges such as size effect, which highly influences the material deformation mechanism resulting in a nonlinear variation in specific cutting energy, which accelerates the tool wear. Since micromachining is associated with micro-features, high precision and tight tolerances, the prediction of tool wear in advance is essential. Calibrated tool-wear models are generally used for the prediction of tool wear in the macro machining regime, whereas the applicability of these tool-wear models in the microscale machining is not explored much in the past. In the present work, Usui tool-wear model and worn tool geometry–based Malakizadi model are calibrated for the tool flank wear prediction during micro turning of Ti-6Al-4V alloy, using a hybrid approach involving both finite element simulations and cutting experiments. The validation experiments show that both the models can satisfactorily predict the tool-wear rate during micro turning with a percentage error of less than 15%. Results indicate that the worn tool geometry–based tool-wear model outperforms the conventional Usui model as it incorporates the instantaneous tool geometry, which also makes it suitable for different tool geometries.

Microscale laser flexible dynamic forming of Cu/Ni laminated composite metal sheets

Currently, the forming processes employed on formation of laminated composite metal sheets belong to quasi-static loading either in macroscale or microscale. Innovative forming processes are requested to meet the challenges in manufacturing of micro components produced by new materials. A new process that employing microscale laser flexible dynamic forming (MLFDF) on formation of laminated composite metal sheets was adopted in this paper. The feasibility of this new process was verified firstly. The research results showed that, the forming depth of Cu/Ni laminated composite metal sheets under MLFDF increased with laser energy increasing, number of laser pulse increasing and thickness of soft punch decreasing. Surface roughening happened in formed parts and the roughness increased with laser energy increasing. Deformation of Cu/Ni laminated composite metal sheets was dominant by external layer. Unlike conventional forming processes, it was found stacking sequence didn’t have considerable effect on forming behavior of Cu/Ni laminated composite metal sheets under MLFDF. Another advantage of MLFDF was discovered that Cu/Ni laminated composite metal sheets were formed without any delamination till fracture under this forming process. The experiment revealed that MLFDF could be a promising alternative of conventional microscale forming processes for formation of laminated composite metal sheets.

A method for monitoring and diagnosing the circular trajectory error in micromilling

In CNC manufacture of micro components the manufactured product dimensional quality is strongly influenced by the machine tool movements accuracy. Trajectory curves and axis displacement speed values interfere in the machine positioning error. This situation is not considered in the traditional tests of a machine tool positioning accuracy performance. In this work micromilling machine performance assessment is proposed by means of monitoring and forecasting of positioning errors during a circular trajectory. Data monitored by grid encoder were used for drafting a method structured with experimental planning for monitoring and forecasting positioning errors. Trials with different feed rate and radius for a circular trajectory were carried out for assessment and validation of the method proposed.

Smooth Particle Hydrodynamics Simulation of Micro-Cup-Extrusion Using a Graphit-ic Coating

Microextrusion is becoming increasingly important for the manufacturing of microcomponents. However, this reduction in scale to a microlevel means that the influence of friction and the need for suitable lubrication are greatly increased. This study therefore looks at the use of a low-friction and highly wear resistant Graphit-ic coating on the mold-forming section of a microextrusion mold, this coating being applied by a closed-field unbalanced magnetron sputter ion plating technique. A microcup of CuZn33 brass alloy was then extruded, with a wall thickness of 0.45 mm, outside diameter of 2.9 mm, and an internal diameter of 2 mm. The experimental results in which extrusion uses the mold coating with Graphit-ic film are compared against the experimental results in which extrusion uses the mold uncoating with Graphit-ic film. This showed that the load was decreased a lot and the self-lubricating solid coating facilitates a smooth extrusion process. As the extrusion rate was quite high, smoothed particle hydrodynamics method simulations of the extrusion process were conducted, these being then compared with the experimental results. These result showed that the SPH simulation can be applied to show the deformation of materials and predict the load trend.

Compact machining module for laser chemical manufacturing

The size of machines for the manufacture of micro-components commonly stands in gross disproportion to the component size. The achievable accuracy is limited by inaccuracies of mechanical positioning elements and external disturbances. Micro-machining of metals can be realised in manifold ways by laser processes. In this paper, a compact module for laser chemical processing using continuous wave laser radiation is presented. For the laser-induced chemical machining the material removal is a result of thermochemical reactions between an etchant and the surface of a metallic workpiece at low laser power densities. Laser-induced chemical machining results in improved surface quality of the machined workpiece and it also avoids stress and strain of the material. Through the use of a micro-mirror array (DMD) for flexible beam shaping a 2-dimensional machining of the workpiece is possible. The laser chemical machining method now allow for the first time to connect the DMD technology with laser-based micro-machining for compaction of the machining module.

Optimisation of Micro Injection Moulding Process through Design of Experiments

The paper presents the optimisation of Micro Injection Moulding (MIM) process through Design of Experiments (DoE). MIM is a relatively new technology which is used for the rapid manufacture of micro components. In order to meet the quality and reliability constraints it is important to reduce variability during its operation due to changes in process parameters. In this study, an understanding of the MIM process and consequently its optimisation is carried out by DoE based on six parameters which influence the surface quality, flow length and the aspect ratio. Significant single process parameters and interactions between them were determined through statistical analysis. For the 2-level test, an aspect ratio of 20, 21, and 20 were achieved respectively for Polypropylene (PP), Acrylonitrile-Butadiene-Styrene (ABS) and Polyoxymethylene (POM).

Investigation of recast layers generated by a powder-mixed dielectric micro electrical discharge machining process

The use of powder-mixed dielectrics in micro-electrical discharge machining (micro-EDM) is an important technological development with the potential to improve machined surface quality and impart functional properties to machined surfaces. These process capabilities are vital in the manufacture of microcomponents since enhancing machined surface characteristics can extend their service life and improve their functionality. While studies have been conducted on gap enlargement and surface roughness, there is limited work on subsurface characteristics. The present study assessed the recast layer thickness, given the potential of applying powder-mixed dielectrics to recast layer reduction and surface modification. Moreover, its process characteristics under specific micro-EDM process parameters, such as low powder concentrations, nano-sized powder granularities, and sub-microsecond pulse-on time durations, which have received limited coverage, have been elucidated. The study has revealed evident changes in recast layer thickness under different machining conditions. The reductions in recast layer thickness at a powder concentration of 0.1 g/l were found to range between 15 per cent and 35 per cent for pulse-on time durations between 166 ns and 606 ns. Furthermore, flushing effects from tool electrode rotation have been shown to exert an influence on recast layer thickness as well as on the amount of powder particles within the discharge gap.

Friction stir microforming of superplastic alloys

The last decade has witnessed a strong technological thrust for manufacturing of micro-components. Polymers and ceramics have been replicated using micromolds, and are commercially used to produce microcomponents in large numbers. On the other hand, for demanding microsystems applications, metals are an attractive choice, for their mechanical and wear properties. Microforming of superplastic alloys has been investigated with good success. This paper discusses a novel technique of microforming using friction stir technology and superplastic materials science. Superplastic Al-7075 and Al-Mg-Zr alloys have been microformed and characterized in this study.

NEW MACHINING CONCEPT FOR MANUFACTURING MICROSTRUCTURES WITH EXCIMER LASERS

The manufacturing of microcomponents with excimer lasers, especially for small series and batch production, is an alternative to other established micromanufacturing methods associated with etch-technology. To avoid long nonproductive times, a general and flexible machining concept is presented, which is based on the mask projection of the excimer laser beam. Beginning the process chain with the workpiece design, a developed preprocessor is able to calculate the overall removal volume from computer-aided design (CAD) data and to break down into elementary volumes that are able to be processed with single laser pulses. Moreover, based on the restrictions of the excimer laser process, a set of NC data is generated to automatically start the production process. The reliability of the system is proven with different geometries such as micro-gear wheels and microlenses.