Electron Beam Melting (EBM) is an Additive Manufacturing technique to produce functional components. Because of the high temperature during the EBM process, the surface texture of the as-built parts is extremely complex and unique. This distinctiveness of the surface depends on many factors and needs to be well understood to predict final surface properties accurately. Chief among these factors is

Three-dimensional (3D) observations of internal structures are important for evaluating material properties. Serial sectioning with destructive processes is traditionally employed as a 3D observation method. Identifying the boundaries of elements in microscope images and measuring the mechanical properties of each element are required for the evaluation of the mechanical properties of composite materials

An algorithm for solving the problem of local shape errors of optical surfaces correcting by a small-sized ion beam, based on the matrix representation is presented. The algorithm involves searching for points that rise relative to the average height on the surface, where exposure to an ion beam of a given shape will lead to a decrease in the RMS deviation of the surface shape from the calculated one

A large number of drilling have been performed to assemble aircraft parts of carbon fiber reinforced plastic (CFRP). Although high quality is required in machining the holes with high productivity in terms of reliability of parts, delamination often occurs around the holes in drilling. This paper presents a novel drilling method with variable feed rate to machine the delamination-free holes at a high

Additive Manufacturing (AM) has recently attracted increasing attention among manufacturing industries. This class of technologies is capable of creating parts with complex shapes and intricate structures. However, the poor geometric quality of the parts they produced is a major constraint in wide industrial adoption. Currently available analytical techniques based on classic measurement equipment

In-situ SEM nanoindentation and nanoscratch testing methods are commonly used for mechanical characterization and investigation of the deformation and failure mechanisms of coating materials with micro- to nano-scale thicknesses. However, existing SEM-based integrated nanoindentation and nanoscratch instruments have two main limitations. First, the measured mechanical properties of the coating materials

In roll-to-roll continuous printing, given the limitations in the pattern engraving technique and the need for accurate contact angle control between the ink and substrate, printing fine lines in the 10-μm scale is a major hurdle that needs to be addressed to achieve mass production of printed electronic devices. To address this issue, we propose a novel printing method based on gradation engraving;

High precision roll-to-roll processes are believed to be one of the most promising technologies for manufacturing flexible and large-area thin film electronics. However, broadband frictional disturbances caused by the guiding ball bearings affect the precision of the processing roller in the roll-to-roll system, severely hampering the quality of the manufactured products. Conventional feedback control

Multi-wire sawing with a fixed diamond wire is widely used for the mass production of wafers. In this study, a novel electrolyte jet type electroplating method was devised to improve the productivity of these wires. The method is based on increasing the limiting current density (LCD) in the electroplating unit. First, an electrolyte jet type electroplating unit was designed, and the plating characteristics

The triply periodic minimal surface lattice structure is innovatively introduced into the design of flexure hinges in this paper. Four types of triply periodic minimal surface lattices are generated by approximate mathematical expressions. The compliance characteristics of these four lattices are simulated by finite element analysis (FEA), and it is found that the primitive lattice (P-lattice) is the

Bone sawing has been widely used in performing bone surgery. However, thermal necrosis, loss of cutting precision and surface damage may occur in cutting process. The primary objective of this research is to improve cutting performance of bone by advantages of diamond wire sawing. Mechanism of material removal, cutting force, temperature and surface quality are analyzed based on experimental results

This paper is the first in a series of articles which comprehensively discuss the state-of-the-art in microscale additive manufacturing processes and present solutions to challenges impeding their scalability. In this paper, a class of additive manufacturing techniques known as Direct Ink Write/Jet Processes are explored which have been used by researchers for fabrication of microscale parts with varying

This article is the second in a four-part series of articles providing an overview of the challenges and opportunities in microscale additive manufacturing (AM) processes with applications in fabrication of high precision micro/nano-products. Laser-based microscale additive manufacturing processes are discussed this article. Compared to the other AM processes, laser-based processes provide several

The surface finish quality of a machined workpiece is commonly measured using the average roughness parameter, Ra. This parameter, however, is insensitive to the lateral changes undergone by the surface in the feed direction as a consequence of tool wear. In this work, the effectiveness of four methods of workpiece surface analysis, namely autocorrelation, cross-correlation, and two new methods, called

Transmission error is one of the most important performance indicators for evaluating harmonic drives, and can have crippling effects on positioning accuracy and stability of industrial robots. However, most of the existing error analysis methods focus on a single factor, and do not consider the uncertainty of dynamic parameters, leading to evident limitations. In the present study, static transmission

In this paper, we propose a practical texture design on the tool flank face for suppressing chatter vibration and flank adhesion. To avoid chatter vibration during cutting, the process damping phenomena can be utilized, where the tool flank face contacts the surface of a finished workpiece to provide a damping effect. As a new technology for an effective process damping, the tool flank texture-assisted

In this paper, a static multi-longitudinal mode laser self-mixing absolute angle measurement system is developed to accurately monitor the deflection angle. The experimental results show that this multi-longitudinal mode laser angle sensor is capable of effectively measuring the deflection angle of the vertical dihedral mirror. The angle-measurement range and resolution of the self-mixing experimental

Spindle speed variation (SSV) is one of the effective methods which suppresses regenerative chatter. However, regenerative chatter can grow even if SSV is applied. In the previous work, the chatter growth characteristics in SSV were clarified. The chatter frequency changes proportionally to the varying spindle speed, and it causes the change of the magnitude of the dynamic compliance. Hence, chatter

Harmonic positioning errors can negatively affect the positioning accuracy of the ball screw drive system. This paper addresses the problem of harmonic positioning error suppression in ball-screw drives using Adaptive Feedforward Cancellation (AFC). AFC method is integrated with the dual (i.e., rotational and translational) feedback structure used in ball-screw drives. The ability of AFC to quench

Microscale additive manufacturing is one of the fastest growing areas of research within the additive manufacturing community. However, there are still significant challenges that exist in terms of available materials, resolution, throughput, and ability to fabricate true three-dimensional geometries. These challenges render commercialization of currently available microscale additive manufacturing

Nanofibers are used in various fields and applications, such as medical care, environment protection, apparel, and agriculture; it is believed that they will continue to show substantial growth in the future. In this study, we focused on the filtration application of nanofibers. The filtration performances achieved polymeric nanofiber mass production by a melt-blowing method. First, the filtration

The Part III of the four-part series of articles discusses the challenges and opportunities in microscale additive manufacturing processes, specifically focusing on energy-induced deposition and electrochemical processes. Compared to the direct ink write (DIW) and laser-based processes, the energy-induced deposition methods can fabricate high-resolution, high aspect ratio and complex parts, while the

The three-probe method for separating the spindle rotation error and the specimen form error is extensively described in the literature. An attractive feature is its application in in-process measurement. However, the resulting uncertainty is studied far less extensively. In this paper, an evaluation and propagation method for the uncertainty, as well as for an uncertainty reduction, is given based

A 50 N dead-weight type force standard machine (DWM) was developed by the National Metrology Institute of Japan to expand the lower end of calibration force from 10 N to 1 N. The weights of the DWM consisted of a loading frame and a linkage-weight stack. The loading frame applied a gravitational force of 1 N to a force transducer under calibration. The calibration and measurement capability of the

The gap between two mating surfaces has a direct influence on sealing performance. However, traditional surface metrology rarely characterizes the gap between two mating surfaces. To solve this problem, a novel concept of surfaces complementarity is proposed in this paper. Surfaces complementarity measures how well two rough surfaces fit into each other. To make this concept applicable in engineering

This note addresses the high-speed, high-precision point-to-point motion control of an air-bearing planar stage. The custom-designed stage uses four air-bearings to levitate the stage for the high-speed frictionless operation. Because of the floating nature, the controller for the system needs to overcome the nonlinear free-moving dynamics of the stage and achieve the required performance. To fulfill

Wavelength-modulation Fourier interferometry has been employed to measure the thickness of a glass plate. However, nonlinear phase-modulation error causes a DC error in the evaluated phase distribution. In this study, a 5 N–2 phase-extraction algorithm was derived for the simultaneous measurement of the thickness and surface shape of a glass plate with eliminating the DC phase error. First, the condition

Active aerostatic bearings, the main advantage of which is their ability to provide negative compliance, are gradually being used in metal-cutting machines as load-bearing structures and as automatic compensators for the deformation of their technological system. The disadvantages of such bearings are an increased tendency to instability and poor dynamics quality. The article proposes a new design

The modeling accuracy of feed drive is mainly affected by two factors: the accuracy of model form and the completeness of sample data which is used to identify the parameters of the established model form. One of the main works of this study is to construct the experimental trajectories which are used to obtain the sample data. Different from the trajectories selected based on the researcher's experience

This paper presents a novel design method of the anisotropic structure to attain infinite dynamic stiffness to avoid chatter vibration in boring operations. Because a long and slender tool is used for boring operations, the stiffness of the tool holder is likely to decrease, resulting in low chatter stability. Although it is difficult to improve the stiffness of the boring holder itself, the nominal

Nickel based single crystal alloys have excellent properties such as heat resistance, corrosion resistance and creep resistance, which are widely used in aerospace and other national defense fields. Severe work hardening occurs in the process of cutting nickel based single crystal alloy. How to improve the machining quality and grasp the cutting deformation mechanism has become the research focus.

In this study, we developed prototypes of boring tools with anisotropic dynamic stiffness, and their chatter stability was investigated analytically and experimentally. In Part 1, a novel design of boring tools with an anisotropic structure was proposed to improve the nominal stiffness in boring operation, thus resulting in higher chatter stability in simulation. In this part (Part 2), anisotropic

Gallium liquid metal ion source focused ion beam (FIB) instruments are widely used for cross-sectional sample preparation of specific areas of interest for scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Most FIB instruments are equipped with a metal needle for manipulation of the sample in the sample chamber most commonly as a micro-sampling probe for preparing TEM samples

Additive manufacturing (AM) is a rapidly developing technology that has attracted considerable interest in industry because of its tremendous advantages. However, the inferior surface quality of AM components, particularly the partially melted powders adhering to the surface, restricts the functionality of the as-printed parts. In particular, the internal hole is more challenging to finish because

A new high-precision two-dimensional (2D) micro-accelerometer is proposed in this study to measure low-frequency vibration. A flexure hinge with low crosstalk and high axial stiffness is used as a spring, and a 2D optical angular displacement sensor is used to detect the motion of the inertial mass. The accelerometer is calibrated using a homemade one-dimensional horizontal micro-vibration calibration

The objective of this research is to demonstrate the capability of a long stroke linear ferrofluid (FF) stage. This stage is a passive alternative to existing linear aerostatic stages and can be used in low loaded CNC devices, pick and place machines, microscopy or scanner applications. To compete with aerostatic stages the bearing must be repeatable and achieve sufficient stiffness for the application

To reduce the cost, complexity and stroke loss due to sensing components in analog charge control, a digital charge control (DCC) strategy for reducing the hysteresis in piezoelectric actuators (PEAs) is presented. In this solution, a current sensor built into the amplifier is used to derive the charge by numerical integration instead of series sensing components. In such an approach the PEA can be

The lever-type mechanism is one of the most widely used compliant mechanisms in precision engineering applications. To achieve large amplification ratios, the lever-type mechanisms are often connected in series. However, overstress during the deformation process of the mechanism appears frequently, resulting in the undesired deformation and the distortion of amplification ratios. Also, the enveloping

A major modification has been made to the conventional mode-locked femtosecond laser autocollimator so that the apex angle of a small prism, which is a transparent object difficult to be measured by the conventional optical methods, can be measured. In the oblique-incidence optical setup, a collimated mode-locked femtosecond laser is at first made incident to a target prism, and the laser beam reflected

A quantitative analysis of the surface and subsurface damage to gallium nitride (GaN) substrate from precise mechanical polishing with diamond abrasives and characterizations of their removal by the chemical mechanical polishing (CMP) process with colloidal silica slurry was performed. The cross-sectional transmission electron microscopy showed that the highly-defected regions were approximately 200 nm

In order to apply UV nanoimprinting method to fabricating fine hairs, which imitates those on sole of a gecko's foot, the shape of hair was designed as straight, making it easy to be released from the mold. The length of hairs which branch off at the tip was designed to be short, preventing them from aggregating. Under these restrictions, considering the asperities due to roughness of objective surface

This study presents an analytical model of a flextensional actuator comprised of a piezoceramic rod or stack transducer integrated into a flexible mechanical structure. It converts and amplifies the longitudinal in-plane strains in the transducer into the out-of-plane bending of metal beams. Two curvilinear beams mounted by means of two hinged links with an offset to a centrally located piezoceramic

The primary concern with micro-positioning systems is to achieve precise positioning, coupled with the broad stroke of actuation. Over the past few years, the advancement in piezoelectric technology has adequately fulfilled the purpose of precision positioning applications. The advantages of accurate control and positioning accuracy, compactness, minimum wear and tear, enhanced stiffness in conjunction

The prediction of cutting forces is critical for the control and optimization of machining processes. This paper is concerned with developing prediction model for cutting forces in micro-grinding. The approach is based on the probabilistic distribution of undeformed chip thickness. This distribution is a function of the process kinematics, properties of the workpiece, and micro-topography of the grinding

To enhance the machining efficiency, curved thin-walled parts in the aerospace and automobile industries are often formed to the near-net shapes and then subtractive manufactured to their design shapes. The billets for the manufacturing process may lack of the removal material in some regions due to low forming accuracy, which would increase the rejection rate of these parts. However, there is a chance

Subsurface damage (SSD) introduced from abrasive machining significantly degrades the reliability and lifetime of glass ceramics. In this work, nanoindentation tests were performed on the cross section near the lapped surface to determine the nanomechanical properties of subsurface layer of a lapped BK7. Remarkable differences were found between SSD layer and its bulk counterpart in terms of load-displacement

The microstructural and mechanical anisotropy of metallic additive manufactured parts is well-established as the nature itself of the process induces the formation of columnar grains along the build-up direction. However, the effect of this anisotropy on the alloy machinability is rarely considered and a deeper understanding is needed. In the current study, Ti6Al4V prisms were fabricated by laser powder

One advantage of a femtosecond laser is that it enables the processing of materials that are otherwise difficult to process via conventional methods such as cutting, grinding, electric discharge machining, etc. However, it is difficult to predict a three dimensional shape processed by the laser. To achieve required three-dimensional shapes using femtosecond lasers with high accuracy and efficiency

For in-line surface inspection of microfluidic devices, optical measurement techniques with sub-micrometer resolution and a long working distance (W.D.) objective lens are needed. Structured illumination microscopy (SIM) is a good candidate to achieve high resolution. In micro-structured surface inspection, however, measurement needs to be carried out through coherent imaging, and thus conventional

Injection moulding is ubiquitous in the production of plastic optical components, the functionality of which depends on minimising residual stress and on precisely replicating surface forms. In this study, variotherm-assisted microinjection moulding is used to manufacture a practical microlens array designed for light-field applications in order to achieve satisfactory geometric accuracy, surface quality

With the increase in machine tool types, including multi-axis control and multi-function machine tools, it can be difficult to select the appropriate machine tools for targeted parts machining. This study aims to automate machine tool selection by evaluating and comparing machining processes on a variety of machine tools. A system to analyze machining process based on the functional description of

In optical coordinate measurement using cameras, the number of images, and positions and orientations of the cameras, are critical to object accessibility and the accuracy of a measurement. In this paper, we propose a technique to optimise the number of cameras and the positions of these cameras for the measurement of a given object using visible point analysis of the object's computer aided design

Ti–6Al–4V is considered to be the most important and useful alloy in the aerospace industry and many other fields. The growing demand for high productivity in machining requires a novel technique for drilling this material efficiently. In this article, a novel grinding technique for drilling with a combination of ultrasonic-assisted grinding and plasma electrolytic oxidation is proposed. The technique

The combined application of a conventional photoresist masking process and microslurry-jet (MSJ) mechanical removal process was studied for microstructuring the surface of glass. Masking patterns made of a photocurable resin (SU-8) were created on the glass, and both the SU-8 patterns and exposed glass surface were simultaneously removed using the MSJ. When the sacrificial patterns of the SU-8 were