Papers by Keyword: Micro-Milling

Abstract: The development of micro-products in industry, like aviation, medical equipment, electronics, etc, has been increasing lately. The need for scaling down of product has been increasing to make the product simpler and complex. Micro-milling has capabilities in producing complex parts. In this study, mapping and comparing the result of the machining process of Inconel 718 and Aluminum Alloy 1100 was employed. In this experiment, Inconel 718 was used as workpiece material and the result of Aluminum Alloy taken from recent studies. Then, A cutting tool with a diameter 1 mm carbide coating TiAlN was used in this experiment. The machining process was performed with three varieties of spindle speed and feed rate with a constant depth of cut. After the machining is done, the mapping of the result surface roughness of Inconel 718 and AA1100 performed. It was found that Inconel 718 has poor machinability compared with AA 1100. Inconel 718 also has a high manufacturing cost compared to AA 1100 because the cutting tool was easy to wear.

Abstract: Micro-milling offers high flexibility by producing complex 3D micro-scale products. Weight reduction are one of the optimizations of the product that can make it stronger and more efficient nowadays. Titanium are the most commonly used for micro-scale products especially in biomedical industries because of the biocompatibility properties. Titanium alloys offers high strength with low density and high corrosion resistance that is suitable for weight reduction. This study aims to investigate the influence of high speed cutting parameters to the surface roughness in micromilling of titanium alloy Ti-6Al-4V as high speed cutting offers more productivity since producing more cutting length in the same time. experiments are carried out by micromilling process with variations in high speed cutting parameters of spindle speed and feed rate with a constant depth of cut using a carbide cutting tool of with a diameter of 1 mm. The machining results in the form of a 4 mm slot with a depth as the same as depth of cut, which then measures its surface roughness. It was found that higher feed rate that is followed by higher spindle speed will produce better surface roughness.

Abstract: Vibration assisted machining (VAM) is a method that is widely used in improving the performance of machined products. External vibrations with high frequency to ultrasonic range along with an meso-micrometer amplitude are given to the cutting tool or workpiece. This will result in a periodic separation phenomenon, hence reducing the cutting force which has positive impacts on increasing tool life and machined surface quality. Among the high-precision machining processes, micro-milling which has the ability to produce complex components with 2D and 3D features, can also be applied with the vibration assisted method, known as vibration assisted micro-milling (VAMM). Based on the direction of vibration given in the machining process, there are 1D VAMM with linear vibrations and 2D VAMM with circular or elliptical trajectory vibrations. However to date, neither developed 1D nor 2D VAMM systems are still limited to the research of planar surfaces cutting using linear movement axes, meanwhile vibration assisted in inclination cutting of micro-milling using the rotational movement axes is still very rare. Therefore the purpose of this paper is to present the preliminary model in designing a 2D VAMM system for a 5-axis micro-milling machine. The system is powered using piezoelectric actuators as the vibration-producing actuators.

Abstract: The experimental investigation of process characteristics while performing micro-milling on hybrid aluminium metal matrix composite is discussed in this article. High Speed Steel micro end mill cutters are used for machining of micro-slots on Al6063 metal matrix composite reinforced with zirconia and silicon carbide. The tools are also treated cryogenically at -196°C using liquid nitrogen with a holding time of 24 hours. For this investigation, machining parameters like feed rate, cutting speed and depth of cut are considered as the process parameters. The effect of the process parameters on the material removal rate and surface roughness for hybrid metal matrix composite are analyzed. In addition, tools wear for untreated and cryo-treated single tempered tools are also investigated. The output responses i.e., material removal rate and surface roughness of cryo-treated tools exhibit better results than untreated tool due to increase in strength, hardness and wear resistance.

Abstract: Bioreactor systems for cultivating cells in Life Sciences have been widely used for decades. Recently, there is a trend towards miniaturization, disposables and even micro platforms that fulfill increasing demands strongly aiming for production and testing of novel pharmaceutical products. Miniaturized bioreactors allow low power consumption, portability and reduced space requirements and utilize smaller volumes of reagents and samples [1,2]. A recursive strategy is necessary for optimizing the design and the manufacture of such miniaturized bioreactors. For the fabrication of these prototypes utilized micro-milling. Micro milling is a mechanical process which is commonly applied to create micro-structures in metals, e.g. aluminum and steel, or polymers, e.g. poly carbonate substrates. The structures and geometries are generated by utilizing computer aided design. By means of computer-aided manufacturing, the machining operations are implemented and then transferred to the machine tool. The machine tool moves the cutting tools with certain speeds, feeds and traverse ranges to the substrate. Micro milling has the advantage that the materials are generally not degraded by chemical substances, heating procedures or electromagnetic radiation.

Abstract: Ceramic material is widely used industrial products due to excellent physical and mechanical properties, which in turn post challenge to shape ceramic material into desired shape and accuracy. A feasible method is to process ceramic material in its pre-sintered state. However, the interior of pre-sintered ceramic body contains a lot of high hardness particles which causes serious tool wear, especially in the three-dimensional micro-milling. In this paper, a theoretical model of calculating tool average volume wear rate is proposed based on abrasive wear mechanism and fatigue wear mechanism in alumina ceramic micro-milling. Experiments under various processing parameters are carried out to verify this model. The results indicate that theoretical values of the tool wear rates agree with experimental results. Most of the deviations are within 10%.

Abstract: The development of industry in the last ten years has caused the production of parts with relatively small dimensions. This has led to intensive development of efficient micro-technologies through research of processes, machines and tools. This paper presents the research of machinability, channels micro-milling in AISI D2 tool steel (X155CrVMo-5), hardened to 62 HRc. As the tool is used micro-milling cutter with diameter of 0.6 mm and relatively large working length of 5 mm. Analysis of surface roughness, burr on workpiece edges and reduction of cutter diameter due tool wear was performed.

Abstract: Single crystal Ni₃Al-based superalloy has excellent comprehensive performance.To study the micro-milling surface quality of Ni₃Al-based superalloy, this article used two-edged carbide alloy micro-milling tool with 0.8mm diameter, then orthogonal experiment of three factors and five levels was implemented to the micro-milling of typical single crystal Ni₃Al-based superalloy IC10. The primary and secondary factors of the impact on the micro-milling surface quality were found from spindle speed, feed rate, milling depth by range analysis, and the ideal cutting process parameters combination was optimized and obtained, then its cutting mechanism and the reason of affecting the surface quality were analyzed. The experiment result has certain guiding significance to the micro-milling mechanism of single crystal superalloy.

Abstract: This study is carried out to investigate the influence of pulsed magnetic treatment on wear of carbide micro-end-mill. To analyze the friction behavior of micro-end-mill with workpiece, the special micro-end-mill with a chisel is fabricated and used in micro-milling experiments. A paramagnetic material aluminum alloy is employed as workpiece material. The experimental results indicated 17% and 27 % reductions in maximum minor flank wear width and chisel edge wear area of micro-end-mill after pulsed magnetic treatment, respectively. However, the surface roughness and morphology of machined aluminum alloy have no obvious changes with or without pulsed magnetic treatment. Consequently, the reduction of tool wear during milling aluminum alloy can be mainly attributed to the improvement of mechanical properties of carbide tool materials after pulsed magnetic treatment.

Abstract: This paper is aimed at evaluating the micro-machinability of the Ti-6Al-4V titanium alloy made by the means of two different Additive Manufacturing (AM) technologies. AM comprises promising technologies, widely used especially to produce parts made of difficult-to-cut materials, such as the titanium alloys. Titanium alloys represent one of the most widely used materials in the biomedical field, thanks to the high biocompatibility and excellent mechanical characteristics. Even if near-net-shape parts can be produced through AM, semi-finishing and/or finishing machining operations may be necessary to obtain the required surface finish and geometrical tolerances. Micro-milling technique is a soliciting solution for this kind of application due to its high flexibility, elevated material removal rate and direct contact between the tool geometry and work piece. Nevertheless, there are deficiencies in the literature regarding the study of micro-machinability of materials produced by means of AM technologies. In this paper, the micro-machinability of the Ti-6Al-4V alloy obtained by two different AM technologies, namely Electron Beam Melting (EBM) and Direct Metal Laser Sintering (DMLS), was studied and compared in order to assess the influence of the material as-delivered condition. Micro-milling tests were conducted on a high-precision 5-axis Kugler™ micro-milling centre under dry cutting conditions, by using uncoated, two fluted, flat-end-square, tungsten carbide tools with a diameter of 300 microns. The full immersion slotting strategy was chosen under full factorial design of experiments with two factors (cutting speed and feed per tooth). The micro-machinability was evaluated in terms of burr formation, surface integrity (surface topography and surface defects), tool damage and microstructure alterations.