Showing papers in "Machining Science and Technology in 2013"
TL;DR: In this paper, the effects of process parameters have been investigated, including thrust force, torque, burr formation, delamination, surface roughness and tool wear on carbon fiber reinforced plastics (CFRP) and titanium.
Abstract: The use of hybrid materials including carbon fiber reinforced plastics (CFRPs) and lightweight metals such as titanium are increasing particularly in aerospace applications. Multi-material stacks require a number of holes for the assembly purposes. In this research, drilling trials have been carried out in CFRP, Ti-6Al-4V and CFRP/Ti-6Al-4V stack workpieces using AlTiN coated tungsten carbide drill bit. The effects of process parameters have been investigated. The thrust force, torque, burr formation, delamination, surface roughness and tool wear have been analyzed at various processing condition. The experimental results have shown that the thrust force, torque, burr formation and the average surface roughness increase with the increased feed rate and decrease with the increased cutting speed in drilling of Ti-6Al-4V. In drilling CFRP, delamination and the average surface roughness has similar tendency with the cutting parameters however thrust force and torque rises with the increased cutting speed. The...
92 citations
TL;DR: In this paper, the authors present a comprehensive review of the USM process for advancement of the process through fundamental insights into the process, and the limitations of USM, gaps observed from the literature review and the directions for future research have also been presented.
Abstract: Ultrasonic machining (USM) is a mechanical material removal process used to erode holes and cavities in hard or brittle workpieces by using shaped tools, high-frequency mechanical motion, and an abrasive slurry. The fundamental principles of stationary ultrasonic machining, the material removal mechanisms involved, proposed models for estimation of machining rate, the effect of operating parameters on material removal rate, tool wear rate, and workpiece surface finish, research work reported on rotary mode USM, hybrid USM, process capabilities of USM have been extensively reviewed in this article. The limitations of USM, gaps observed from the literature review, and the directions for future research have also been presented. Overall, this article presents a comprehensive review of USM process for advancement of the process through fundamental insights into the process.
90 citations
TL;DR: In this paper, the existing and ongoing developments in machining MMCs vis-a-vis tool life, tool wear, machinability and understanding chip formation mechanism have been highlighted Most of the studies discussed in this review will focus on Aluminum matrix composites.
Abstract: Over the last few decades, Metal Matrix Composites (MMCs) have emerged as a material system offering tremendous potential for future applications The primary advantages offered by these materials are their improved mechanical properties, particularly in the areas of wear, strength and stiffness Of the MMCs, Aluminum matrix composites have grown in prominence due to their low density, low melting point and low cost However, machining these materials remains a challenging task mainly due to the high abrasiveness of the reinforcing phases Conventional machining processes such as turning, milling or drilling are adopted for machining MMCs In this article, the existing and ongoing developments in machining MMCs vis-a-vis tool life, tool wear, machinability and understanding chip formation mechanism have been highlighted Most of the studies discussed in this review will focus on Aluminum matrix composites Certain areas of machining studies which have hitherto not been investigated have also been detailed
65 citations
TL;DR: In this paper, the influence of rotational velocity, feed per tooth and two drill bit type on workpiece temperatures and cutting forces when drilling bovine cortical bone has been studied.
Abstract: Surgical procedures that affect the human body's bone structure, often entail cutting, drilling or screwing operations of bone. The post-operative success of these procedures is largely dependent on the degree of damage introduced by the process. In this article, the influence of the rotational velocity, feed per tooth and two drill bit type on workpiece temperatures and cutting forces when drilling bovine cortical bone has been studied. The purpose is to find the optimum cutting conditions that will generate the lower temperatures and cutting forces. The measurement of temperatures has been carried out with an infrared thermography camera, and a piezoelectric dynamometer has been employed to obtain forces. A model has been developed from which heat flow into the drilled bone can be estimated from specific cutting force and the fraction of total heat generated that flows into the bone. This fraction has been shown to depend on the Peclet number for the process, proportional to the drill rotation speed, th...
42 citations
TL;DR: In this paper, a hybrid approach of neural network and fuzzy logic theory has been applied to develop the fuzzy expert system to predict the kerf widths and kerf deviation, which has been compared with the experimental data and found appropriate.
Abstract: Laser cutting is an advanced thermal cutting process of complex nature. It's process behavior drastically changes with slight variation in processing conditions. The prediction of process performance becomes more difficult if cutting materials have non-favorable optical and thermal properties. Titanium (Ti) alloys are characterized by their low thermal conductivity and high chemical reactivity at elevated temperature and hence difficult to cut by laser. It has been found that complex and nonlinear behavior of manufacturing process can better be dealt with the application of artificial intelligence (AI) tools. The aim of present research is to develop a fuzzy expert system for prediction of the laser cutting process behavior of Ti alloy (Ti-6Al-4 V) sheet. A hybrid approach of neural network and fuzzy logic theory has been applied to develop the fuzzy expert system to predict the kerf widths and kerf deviation. The predicted results have been compared with the experimental data and found appropriate. The e...
37 citations
TL;DR: In this article, the effect of cutting speed on machinability of age hardened Inconel 718 with polycrystalline cubic boron nitride (PCBN) tools was explored.
Abstract: Application of polycrystalline cubic boron nitride (PCBN) tools as an alternative for ceramic and cemented carbide tools in machining superalloys has been frequently identified as a solution for enhancing process efficiency but only a limited number of studies has been done in this area. The current study explores the effect of the cutting speed, which was varied in a wide range (2–14 m/s), on machinability of age hardened Inconel 718 with PCBN tools. Performance of binderless PCBN grade and grade with low-cBN content was evaluated in terms of tool life, tool wear, cutting forces and surface quality. Chip formation and process dynamics were analyzed as well. It was found that low-cBN grade provided 70–90% better surface finish and tool life than the binderless at moderate speeds (5–8 m/s). Performance of both grades at low and high speed ranges was non-satisfactory due to notching and flaking respectively. At low cutting speed adhesive wear plays a major role while as the speed increases a chemical wear b...
32 citations
TL;DR: In this article, the frequency domain study showed that the flip bifurcation is a special case of the interaction between modes, and the results of these interactions were verified by comparison with semi-discretization method and time domain simulations, respectively.
Abstract: The productivity of many industrial cutting processes is limited by high amplitude chatter vibrations. An optimization technique based on the use of the stability lobes helps to increase the productivity of these processes, improving the life of machine elements and reducing the tool wear as well. The best-known lobes correspond to Hopf bifurcations. However, in case of interrupted cutting, additional lobes appear due to period doubling or flip bifurcation. When the system has more than one dominant vibration mode, important variations can appear in stability due to interaction between modes. The basic mathematics for the appearance of these new lobes are shown in this article. The frequency domain study shows that lobes related to flip bifurcation are a special case of the interaction between modes. The results of these interactions are verified by comparison with semi-discretization method and time domain simulations, respectively.
32 citations
TL;DR: In this paper, the rotary ultrasonic machining (RUM) of glass BK7 process was investigated and three types of RUM-induced subsurface damage were identified: pulverization, chipping and cracking.
Abstract: The present study aimed to establish an exact comprehension of the subsurface damage patterns generated during rotary ultrasonic machining (RUM) of glass BK7 process. First, the subsurface damage of the specimens produced with and without ultrasonic using three different diamond tools was compared and characterized by means of the bonded interface sectioning technique. Then, the RUM scratching tests were conducted on the polished specimen surfaces with two diamond tools to investigate the subsurface damage formation mechanisms involved in formal RUM process. The damage characteristics of the RUM scratches were investigated with respect to the kinematics principles of the abrasives and the dynamic fracture theory of the brittle material. As a result, three types of RUM-induced subsurface damage were identified: pulverization, chipping and cracking. The pulverization layer characterized by finer debris was just populated near the top surface of the RUM specimen without extending into the interior material. ...
30 citations
TL;DR: In this article, an attempt has been made to monitor the tool condition (in-process) using acoustic emission (AE) sensor in microendmilling of different materials such as aluminum, copper and steel alloys.
Abstract: Recently researchers and manufacturers have shown keen interest in fabricating micro-components through tool based mechanical micromachining processes namely micromilling, microdrilling, microturning, etc. In this scenario, microendmilling is used in the manufacture of micro-molds, micro-dies, micro-channel, micro-gear, etc. The major issue in microendmilling process is the unpredictable life of the micro-tool and its premature failure during operations. Therefore in this work, an attempt has been made to monitor the tool condition (in-process) using acoustic emission (AE) sensor in microendmilling of different materials such as aluminum, copper and steel alloys. From this study, it is observed that there is a strong relationship between the tool wear (flank wear) and acoustic emission (AERMS) signals, surface roughness (Ra) as well as chip morphology. In order to understand the mechanism of tool wear, SEM and EDAX analyses were carried out on the microendmill after machining. Scanning Electron Microscope...
28 citations
TL;DR: In this article, an analysis of variance (ANOVA) and regression analysis were performed to investigate effects of cutting conditions on cutting and thrust forces based on a full factorial design, and the applicability of Merchant's analysis for calculating cutting force with respect to rake angle and feed was evaluated by comparison with experiments.
Abstract: In orthopedic operations, no sound solutions exist to avoid conditions like tool breakage, bone fracture/cracks and thermal necrosis for lacking understanding of the mechanics of the bone cutting process. In this work, analysis of variance (ANOVA) and regression analysis were performed to investigate effects of cutting conditions on cutting and thrust forces based on a full factorial design. Then applicability of Merchant's analysis for calculating cutting force with respect to rake angle and feed was evaluated by comparison with experiments. Finally, the friction coefficient was evaluated by calculation. ANOVA shows that forces are much more sensitive to feed, cutting direction and rake angle than to cutting speed. Regression equations including all four factors were obtained by introduction of dummy variables. Cutting forces from experiments and from Merchant's analysis are partially comparable (maximum relative error = 34%) when feed and rake angle are changed. Friction coefficient was affected by rake...
28 citations
TL;DR: In this article, a rational model for simulating the process of core drilling in geomaterials is proposed, considering a fundamental kinematical constraint to the rotary drilling process, namely the helicoidal trajectories of the cutters.
Abstract: A new, rational model is proposed for simulating the process of core drilling in geomaterials. The model describes in a consistent manner the complicated process of core drilling in quasi-brittle materials. After reviewing a model from the literature, based only on the balance of forces at the cutting edge, a new approach is introduced, considering a fundamental kinematical constraint to the rotary drilling process, namely, the helicoidal trajectories of the cutters. At the same time, the mechanical balance of engine power supply and drilling energy consumption must hold. The concept of drilling strength, i.e., the energy consumed to remove the unit volume of base material, is discussed, showing that the expression of the drilling strength depends on the fracture mechanisms occurring in the base material, and thus depends also on the shape of the indenters (back rake angle, wear-flat). A simple estimate of the wear effects at the cutting edges, based on experiments, is proposed. In conclusion, a global fo...
TL;DR: In this article, the experimental and analytical results of an investigation of additional factors that affect the dimensional accuracy and surface finish of turned parts besides the three major factors mentioned above are reported.
Abstract: This article reports the experimental and analytical results of an investigation of additional factors that affect the dimensional accuracy and surface finish of turned parts besides the three majo...
TL;DR: A deep understanding of the material's machinability is of p... as mentioned in this paper. But it has not yet been explored in many engineering fields due to its attractive specific strength and corrosion resistance.
Abstract: Titanium alloy Ti6A14V has been widely used in many engineering fields due to its attractive specific strength and corrosion resistance. A deep understanding of the material's machinability is of p...
TL;DR: In this paper, a new method for discrimination of various types of pulses generated during an electrical discharge machining process in presence of a rotating electrode is presented, which involves simultaneous comparison of the gap voltage and current signals with various thresholds.
Abstract: This article presents a new method for discrimination of various types of pulses generated during an electrical discharge machining process in presence of a rotating electrode. Existing pulse discrimination methods do not perform efficiently in an electrical discharge machine with rotating electrode, as arcs rarely occur during the machining process. Our method involves simultaneous comparison of the gap voltage and current signals with various thresholds. The main advantage of our proposed method is its efficient computation and significantly better accuracy in discriminating between various pulse classes for electrical discharge machining devices with rotating electrode. Experimental studies demonstrate a superior performance of our method in distinguishing normal pulses from harmful arcs, open circuit and short circuit pulses, compared with the state-of-art methods.
TL;DR: In this article, a comprehensive experimental study on the cutting force differences between rotary ultrasonic machining (RUM) and conventional diamond side grinding, drilling and face grinding is conducted on K9 glass.
Abstract: A comprehensive experimental study on the cutting force differences between rotary ultrasonic machining (RUM) and conventional diamond side grinding, drilling and face grinding is conducted on K9 glass. By analyzing the experimental results and the kinematics of diamond grits, it can be seen that the reasons for the cutting force differences between with and without ultrasonic vibration are not same for the three machining processes. The cutting force difference of conventional diamond side grinding and RUM can be explained by analyzing the trajectory of diamond grits, while the cutting force difference of conventional diamond drilling and RUM is mostly dependent upon the difficulty level of removing chips. As a transitive form, the cutting force difference between conventional diamond face grinding and RUM is affected by both the diamond grits' trajectory and the difficulty level for removing chips. In addition, it is also noticed that different cutting tools have different reduction percentages of cutti...
TL;DR: In this paper, an axisymmetric finite element method-based thermal model has been developed for the determination of the transient temperature distribution in the aluminum sheet, which is further used for determination of hole profile, hole taper and extent of heat affected zone during laser beam percussion drilling.
Abstract: Determination of hole taper and extent of heat affected zone is a challenging task for manufacturing engineers from the quality and accuracy point of view of the laser-drilled hole especially in reflecting materials like aluminum. In this article, an axisymmetric finite element method-based thermal model has been developed for the determination of the transient temperature distribution in the aluminum sheet, which is further used for determination of hole profile, hole taper and extent of heat-affected zone during laser beam percussion drilling. Simulation results showing the effect of pulse width, pulse frequency, and peak power on hole taper and extent of heat affected zone incorporating the temperature dependent thermal properties and phase change have been presented. The developed model is also capable of predicting the hole profile through the isotherm generated along the depth of hole due to repeated laser pulses. The predicted values of hole taper are compared with the experimental results. It is f...
TL;DR: In this article, a novel tool was created by depositing amorphous diamond coating (AD) on a stainless steel tip, which was used to improve the surface finish and surface hardness of Nitronic-50 HS stainless steel workpieces.
Abstract: Burnishing is a cold working process that can be used to improve surface finish and surface hardness of workpieces. Conventionally, diamond or hard metal burnishing tools are used. In the present work, a novel burnishing tool was created by depositing amorphous diamond coating (AD) on a stainless steel tip. This tool was used to improve the surface finish and surface hardness of Nitronic-50 HS stainless steel workpieces. Nitronic-50 HS is used in a wide range of applications in industry. The burnishing process was carried out at different burnishing parameters (force, revolution speed, feed and number of tool passes). Burnishing parameters had a significant effect on the finishing process and they had to be optimized to achieve the best results. Remarkable improvements in surface finish (70% decrease in roughness) and hardness (25% increase) could be achieved with this tool and process in the surface finishing of Nitronic-50 stainless steel workpieces. From the tribological point of view, the AD-coated ti...
TL;DR: In this article, the machinability of A319 and A356 under T0 and T6 conditions was evaluated during the dry drilling machining process, with the chip form, chip breakability, and the cutting forces.
Abstract: Aluminum alloys are widely used in several applications. Cast alloys are usually considered to be brittle materials leading to short chip formation during machining. Although they can be produced near net shapes, products made of these alloys very often require some machining. The purpose of this study is to evaluate the machinability of A319 and A356 under T0 and T6 conditions. The machinability was assessed during the dry drilling machining process, with the machinability indexes including the chip form, chip breakability, and the cutting forces. It was found that A319 and A356 exhibit different machinability behaviors, especially under the T6-condition in terms of force requirements, chip breakability, and chip segmentation. The chip grain size obtained by X-ray diffraction techniques was also studied and correlated to the machining conditions. It was also found that both the microstructure of the workpiece materials and the machining conditions significantly affect the chip formation mechanism, and so...
TL;DR: In this paper, the effects of shaping the micro-discontinuities of the active surface of a grinding wheel were investigated in the internal deep traverse grinding process, and it was determined that the implementation of micro discontinuities extends the grinding wheel dura.
Abstract: The article depicts the kinematic parameters of micro-discontinuities and how their shaping methods impact upon the active surface of grinding wheels. It also details the construction of a special device which makes it possible to obtain micro-discontinuities with specific and defined surface configurations and shapes. Experimental research into the effects of shaping the micro-discontinuities of the grinding wheel active surface was realized in the internal deep traverse grinding process. Grinding wheels with a ceramic bond, made from micro-crystalline sintered corundum grains, were utilized in the research. The research investigated the duration of the durability period of the grinding wheels. It also looked at the grinding power, as well as the machined surface roughness, when using grinding wheel with or without micro-discontinuities shaped upon the active surface. As a result of the research undertaken, it was determined that the implementation of micro-discontinuities extends the grinding wheel dura...
TL;DR: In this article, the authors focused on the machined surface integrity of Ti-6Al-4V alloy using polycrystalline diamond (PCD) tools under wet milling condition and investigated the surface integrity in terms of surface roughness, surface topography, microhardness, microstructure, and metallurgical alternations.
Abstract: This study is focused on the machined surface integrity of Ti-6Al-4V alloy using polycrystalline diamond (PCD) tools under wet milling condition. The surface integrity in terms of surface roughness, surface topography, microhardness, microstructure, and metallurgical alternations is investigated. The observations and conclusions are primarily focused on the effect of cutting speed (250–2,000 m/min) on the surface and subsurface of the machined Ti-6Al-4V. Experimental results show that machined surface integrity of Ti-6Al-4V alloy is sensitive to the variation of cutting speeds. Obvious machining (feed) marks can be found on the machined surfaces. Micro hardness examinations showed 5–20% hardening of the top machined surfaces than the bulk material. The analyses of microstructure and metallurgical alternations reveal that slight subsurface microstructure alteration such as plastic deformation on the subsurface and no phase transformation were observed. The evolution of crystallographic texture induced by t...
TL;DR: In this article, a laser pre-scan process is designed to preheat the workpiece before laser-assisted machining to overcome the laser power constraint, and the machinability of highly alloyed wear resistant materials of 27% and 35% chromium content is evaluated in terms of tool wear, cutting forces, and surface integrity through LAM experiments using cubic boron nitride (CBN) tools.
Abstract: The machinability of high chromium wear resistant materials is poor due to their high hardness with a large amount of hard chromium carbides. This study is focused on improving the machinability of high chromium wear resistant materials with different microstructures and hardness levels via laser-assisted machining (LAM). A laser pre-scan process is designed to preheat the workpiece before LAM to overcome the laser power constraint. A transient, three-dimensional LAM thermal model is expanded to include the laser pre-scan process, and is validated through experiments using an infrared camera. The machinability of highly alloyed wear resistant materials of 27% and 35% chromium content is evaluated in terms of tool wear, cutting forces, and surface integrity through LAM experiments using cubic boron nitride (CBN) tools. With increasing material removal temperature from room temperature to 400°C, the benefit of LAM is demonstrated by 28% decrease in specific cutting energy, 50% improvement in surface roughne...
TL;DR: In this paper, Bayesian inference is applied to predict tool life for milling/turning operations using the random walk/surface methods, and the results are used to update the probability distribution of tool life using a probability distribution.
Abstract: According to the Taylor tool life equation, tool life reduces with increasing cutting speed. The influence of additional factors can also be incorporated. However, tool wear is generally considered a stochastic process with uncertainty in the model constants. In this work, Bayesian inference is applied to predict tool life for milling/turning operations using the random walk/surface methods. For milling, Bayesian inference using a random walk approach is applied to the well-known Taylor tool life model. Tool wear tests are performed using an uncoated carbide tool and AISI 1018 steel work material. Test results are used to update the probability distribution of tool life. The updated beliefs are then applied to predict tool life using a probability distribution. For turning, both cutting speed and feed are considered. Bayesian updating is performed using the random surface technique. Turning tests are completed using a coated carbide tool and forged AISI 4137 chrome alloy steel. The test results are applie...
TL;DR: In this paper, the macro-geometry (run-out, shape, profile, etc) and the micro geometry (density, distribution, and shape of the grains) of a grinding wheel are measured after both truing and dressing, and the effectiveness of the truing is studied by analyzing the topography of the wheel to characterize the tool and its effect on workpiece surface quality during the grinding process.
Abstract: The macro-geometry (run-out, shape, profile, etc) and the micro-geometry (density, distribution, and shape of the grains) of a grinding wheel are measured after both truing and dressing The effectiveness of the truing is studied by analysing the topography of the wheel to characterize the tool and its effect on workpiece surface quality during the grinding process Using wheel replicas, the surfaces are analyzed with a non-contact interference microscope and the measurements are processed with MountainsMap Software For different truing and dressing conditions, the dressing efficiency, the grain density, and its effects on the roughness and wear of the wheel in the grinding process are investigated
TL;DR: In this paper, two kinds of coated carbide inserts, which were obtained by the methods of physical vapor deposition and chemical vapor deposition (CVD), were used for face milling of titanium alloys TC11 and TC17.
Abstract: Advanced coatings on cutting tools play an important role in improving the machinability of difficult-to-cut materials (e.g., titanium alloys, nickel-based superalloys, and ultra high strength steels). In this article, two kinds of coated carbide inserts, which were obtained by the methods of physical vapor deposition (PVD) and chemical vapor deposition (CVD), were used for face milling of titanium alloys TC11 and TC17. The wear mechanism and the performance of the coated inserts have been investigated when machining titanium alloys in the present work. The coated inserts were observed by scanning electron microscope (SEM) and energy dispersion spectrometer (EDS). Both tool failure modes and wear mechanisms were analyzed. The results indicate that PVD-(TiN + TiAlN)-coated carbide insert (Tool-A) is suitable for machining TC17 alloy under dry condition, and CVD-(TiN + Al 2 O 3 + TiCN)-coated insert (Tool-B) is useful for milling TC11 alloy. When face milling TC17 alloy without coolant, the crater with chip...
TL;DR: In this paper, the authors highlight the utilization of the EDM process using multi-thin tool-electrodes with diameters of 0.3, 0.5 and 1.0mm and different lateral spaces (3.0 to 0.8mm).
Abstract: In the electrical discharge machining (EDM) process, thin tool-electrodes are constantly gaining much importance due to the growing demand for manufactured parts with more functional characteristics and with small geometrical dimensions for applications in many work fields. This article highlights the utilization of the EDM process using multi-thin tool-electrodes with diameters of 0.3, 0.5 and 1.0 mm and different lateral spaces (3.0 to 0.8 mm). This machining technology requires using more than one tool-electrode in the same time for fabrication of microholes with high process performance and productivity. One of the principal aims of the experimental investigations of this article is to determine the minimum lateral spacing required between tool-electrodes for reducing process costs under acceptable conditions related to the surface of the machined workpiece. Tool-electrode wear and material removal rate are investigated as result of these experiments under adjustment of different process parameters. T...
TL;DR: In this article, a numerical model was developed to predict the roughness profile along a line in the feed direction, in contour milling operations with cylindrical milling tools.
Abstract: A numerical model was developed to predict the roughness profile along a line in the feed direction, in contour milling operations with cylindrical milling tools. From the model, average roughness Ra and maximum peak-to-valley roughness Rt were calculated for families of tools defined by 100,000 random combinations of radius values. Radii were selected by means of the Monte Carlo Method. Each family is defined by an average radius and a standard deviation of radius, assuming normal behavior. Histograms, roughness variation intervals, medians and modes, were calculated at different feeds. The model was validated through experimental tests. Effect of standard deviation of radius, number of teeth and tool diameter were studied. Although radius values were randomly selected according to a normal law, roughness values did not follow a normal distribution. At low standard deviations, intervals of roughness values, medians and modes vary only slightly with feed, except at very low feeds where intervals are narro...
TL;DR: In this article, the authors propose a model of machine tool behavior for a tool path with linear and circular interpolations and machining cycle time prediction, which involves subdividing the trajectories into elementary geometries according to the type of interpolation (circular or linear).
Abstract: In the context of high-speed milling (HSM), during the machining process dynamic machine response has to be identified. To achieve this, we have to calculate the feed rate evolution in linear and circular interpolation according to dynamic performance of machine. In addition to that, actual trajectory for transition passages between two interpolations must be estimated with take into account of specific machining tolerances. This article proposes a model of machine tool behavior for a tool path with linear and circular interpolations and machining cycle time prediction. The method involves subdividing the trajectories into elementary geometries according to the type of interpolation (circular or linear). At points where different trajectories meet, there is often a discontinuity in curvature or in tangency, which decreases the feed rate. At the points of discontinuity in tangency, a fillet radius is inserted. In this article, the influence of the geometry for elementary trajectories was determined. Then, ...
TL;DR: In this paper, a laser cutting of large diameter hole in aluminum foam is carried out and morphological changes in the cutting section are examined using scanning electron microscopes, energy dispersive spectroscopy and X-ray diffraction.
Abstract: Laser cutting of large diameter hole in aluminum foam is carried out and morphological changes in the cutting section are examined using scanning electron microscopes, energy dispersive spectroscopy and X-ray diffraction. The thermal stress fields in the cutting section are computed in line with the experimental conditions. Finite element code is incorporated in the numerical simulations. It is found that the cut section is free from defects such as large size burrs and dross attachments. The thermal stress predicted is less than the yielding limit of the workpiece. The presence of air trapped within the pores prior to laser irradiation in the workpiece results in the formation of oxide compounds at the cut sections.
TL;DR: In this article, the precision cutting of a molding die is realized using a square end mill on a 5-axis control machine, and the tool setting errors are analyzed and the compensation method of the errors is proposed.
Abstract: The precision cutting of a molding die is realized using a square end mill on a 5-axis control machine. In this study, first the tool setting errors are analyzed and the compensation method of the errors is proposed. The effectiveness of compensation in precision cutting is confirmed. Next, the form accuracy of the spiral tool pass is compared with contour one in precision cutting of a spherical surface. Finally, the molding die with spherical surface is manufactured using a square end mill made out of single-crystal diamond based on the results of the compensation of the errors and the comparison of the two tool passes, and the form accuracy and surface roughness of the molding die are measured.