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Multiple international organizations and many governments around the world have declared climate emergency. There is a pressing need to minimize the environmental impacts of human activities including manufacturing processes. Machining by mechanical cutting is a fundamental manufacturing process and minimizing and eliminating its environmental impacts is vital. In this keynote paper, sustainability in the context of machining is identified. The resources used in machining have been categorized and the social and environmental impacts and potential methods to reduce them have been identified. The findings are critically discussed and the gaps and challenges for future research direction are highlighted. [ABSTRACT FROM AUTHOR]

This paper aims to enhance the machining characteristics of sinking electrical discharge machining by superimposing an impulse current on a conventional rectangular pulse. The material removal was found to be more significant when the time point of superposition was set earlier after the dielectric breakdown, as the plasma diameter is smaller. However, superimposition immediately after the discharge ignition leads to a higher tool wear ratio. Through experimentation and simulation, it was determined that the optimal time point to increase material removal while keeping tool wear low is approximately 12.5 μs when the rectangular pulse duration was 50 μs. [ABSTRACT FROM AUTHOR]

The advances in electronics, sensors, actuators, smart materials, computers, and communication technologies led to new and improved mechatronics-based smart tooling systems. This paper reviews the sensors and actuators used in tooling systems. The sensor principles to measure force, displacement, and temperature are explained. Actuators based on piezo, magnetorheological fluid, shape memory alloy, and magnetostrictive principles are discussed. Wireless and wire-based power supply and signal transmission techniques to stationary and rotating tools are described. The integration of sensors, actuators, power supply, and microcontrollers to various tooling systems used in boring, milling, turning, and grinding operations are presented along with their process monitoring and control applications in the industry. It is shown that the sensor-actuator tooling systems improve the accuracy, robustness, and productivity of machining which adds intelligence to the machine tools. The current challenges include widening the operating bandwidth of tooling systems, wireless power and high-speed data transmission, miniaturization of actuators and sensors, and onboard processing using embedded micro-controllers. [ABSTRACT FROM AUTHOR]

In this paper the idea of Self-Optimizing Machining Systems (SOMS) is introduced and discussed. Against the background of Industry 4.0, here the focus is the technological level of discrete workpiece production by mechanical machining processes utilizing related machine tools and equipment. Enabling technologies, principles, and methods are described that allow for the implementation of machining systems which are capable of adapting their parameters and settings autonomously, in order to optimize for productivity, quality, and efficiency in manufacturing. Following a description of the meaning and a definition of SOMS as well as a historical retrospection, the required elements of SOMS are discussed and exemplary approaches are presented. Based on sophisticated process planning, monitoring, adaptive control, simulation, artificial intelligence, and machine learning, strategies, state-of-the-art solutions for self-optimization in machining applications are introduced. Several examples showcase how different types of enabling technologies can be integrated synergistically, to improve the manufacturing of parts by SOMS. Finally, the future potential of SOMS as well as challenges and needs are summarized. The paper especially considers the results of the CIRP Cross-STC Collaborative Working Group on SOMS. [ABSTRACT FROM AUTHOR]

To reduce vibration during machining and to avoid re-manufacture or scrap parts, two main methods have been proposed, vibration damping and absorption. In this paper, a novel synergistic integration between both techniques using pillar elements known as flexures (acting as absorbers) and a flexible pneumatic expandable diaphragm (acting as a damper) is presented. Four setups have been compared: the proposed Hybrid Fixture, a traditional solid vice, a flexures fixture, and an expandable diaphragm-only clamp. The Hybrid Fixture was able to reduce the workpiece vibration by 58% and the surface waviness by 74.1% when compared with the traditional solid fixture. [ABSTRACT FROM AUTHOR]

Recently, in gear machining, 5-axis machining centers (5X-machine) are gradually being used more often instead of dedicated gear cutting machines especially apparent in the large gear machining industry. From the point of view of improving transmission efficiency and reducing gear noise, there is a demand for high-precision gears. And there is a need for a simple measurement method that can confirm the overall shape, and a high-precision processing technology that uses the results. This paper describes our study of the on-machine profile measurement system using a 5X-machine, a laser scanning probe, and automatic corrective machining based on the measurement results. [ABSTRACT FROM AUTHOR]

Li-Ion batteries are strategic components widely adopted in the e-mobility, electronics and building sectors. Although recycling of Li-Ion batteries has recently received increasing attention, the closed-loop recycling, aiming at supplying high quality materials to the battery manufacturing industry, remains a challenge, due to the inherent complexity in meeting target material specifications. This paper proposes a novel Li-Ion battery mechanical pre-treatment for improved selectivity and pre-concentration of the output streams. Machining processes are employed for battery cell case cutting and size-reduction and separation stages are applied on the isolated active winding. The developed process-chain is validated and benchmarked by experimental analysis. [ABSTRACT FROM AUTHOR]

The paper proposes multi-operation blank localization to fit final product geometries into near net shape blanks. Groups of machining features are located subject to tolerance intervals on their relative positions and a lower bound on the machining allowance which accommodates for uncertainties of measurement and machining. The tolerance error, i.e., the deviation of the resulting dimensions from the center of the tolerance intervals is minimized. The blank localization problem is formulated as a convex quadratically constrained quadratic program that can be solved efficiently for parts with real-life complexity, as demonstrated by a case study from the automotive industry. [ABSTRACT FROM AUTHOR]

Application of additively manufacturing (AM) metals is growing rapidly; however, post-process finish machining is still required to improve dimensional accuracy and surface quality. Determining the high-strain high-temperature behavior of AM metals is critical in simulating finish machining, designing appropriate cutting tools, and predicting surface integrity. This paper investigated the machining characteristics of AM Ti-6Al-4V produced using powder bed fusion. High-strain high-temperature behavior of AM Ti-6Al-4V was determined numerically and used in simulating the process. Machining tests were performed in different directions with respect to the build orientation and chips were collected to examine the mechanic of chip formation. [ABSTRACT FROM AUTHOR]

This paper explores the feasibility of adopting additive manufacturing followed by heat treatment and finish machining to fabricate Nitinol components with enhanced surface integrity and more favourable superelastic characteristics. The most suitable manufacturing approach is demonstrated to achieve these characteristics by establishing appropriate bulk and surface conditioning. New insights are presented on the correlation of process chain parameters and Nitinol superelastic response focusing on the role of the microstructural constituents and surface integrity generated from finish machining with different cooling conditions. The wear behaviour of Nitinol components fabricated by the proposed manufacturing approach is also evaluated to demonstrate bearing applications. [ABSTRACT FROM AUTHOR]

Cutting forces are valuable for monitoring machining processes, as they allow the evaluation of tool wear, process stability, and workpiece quality. This paper presents a new non-intrusive method for monitoring cutting forces using a Kalman filter (KF) and Rauch-Tung-Striebel (RTS) smoothing. The method incorporates structural acceleration measurements as well as feed drive motor currents, thereby achieving wide estimation bandwidth and steady-state (DC) gain preservation. The KF + RTS smoothing are parameterized using spindle speed-sweeping cutting tests, which significantly reduces the experimental effort for model identification. The approach was validated in different machining conditions, which demonstrated good agreement with dynamometer measurements. [ABSTRACT FROM AUTHOR]

The quality requirements of functional parts manufactured by the laser powder bed fusion imply post-processing machining operations. These components include thin walls, hollow and complex shapes that can lead to machining instability. This paper presents a strategy to exploit the inherent crystallographic effect as a tool for stiffening and improving machining stability by considering the orientation of machining bending loads and the crystalline orientation distribution. Three samples were manufactured under the same LPBF parameters but different crystallographic orientations. The results show that the optimal crystalline direction increases static and dynamic stiffness and stability, reducing machining chatter risks. [ABSTRACT FROM AUTHOR]

The demand for miniaturized products and functionalized parts is increasing, and many such products are made of hard and brittle materials machined by abrasive processes. The first part of this keynote paper is dedicated to a discussion of micro parts and micro structures machined – at least in part – by abrasive processes, followed by a discussion of the associated abrasive processes. The strengths and limitations of these processes, among which include dicing, micro grinding, micro abrasive blasting, and vibration and magnet field assisted finishing are discussed. The paper concludes with a discussion of future trends in the field. [ABSTRACT FROM AUTHOR]

This keynote paper mainly focuses on advancements of machining technology and systems for enhanced performance, increased system integration and augmented machine intelligence, critically hinging on new sensors, sensor systems and sensing methodologies being robust, reconfigurable and intelligent, while providing direct adoption and plug-and-play use in industrial practice. One chief novelty is given by the key enabling technologies of Industry 4.0 where integration of sensing systems in manufacturing plants is a cornerstone for transforming conventional manufacturing concepts into digital manufacturing paradigms. Application examples to industrial processes, future challenges and coming trends in machining monitoring are shown. [ABSTRACT FROM AUTHOR]

In this paper, the analysis of surface changes and biocompatibility of Zr-702 additively manufactured bars have been performed. Samples were machined under dry and cryogenic environment at varying cutting speed and feed rate. Afterwards, MC3T3-E1 osteoblast cells were seeded on the as printed and machined surfaces verifying how cells adhesion and proliferation change based on the involved process parameters after 24 h and three days of culture. As a result, a connection between surface characteristics and process cells adhesion and proliferation has been provided and used to assess the potential of machining process to modulate biocompatibility of the investigated material. [ABSTRACT FROM AUTHOR]

This paper presents the results from end milling of Inconel 718 with a newly designed and manufactured minimum quantity lubrication (MQL) delivery system. This involves spraying electrically charged tungsten disulphide (WS 2) nano particles dispersed in vegetable oil through pressurised air as a coolant/lubricant. This method improved the cooling and lubrication during machining. Tool life, surface integrity and cutting forces obtained from end milling Inconel 718 with this new system are compared with conventional flood and MQL cooling/ lubrication. The electrically charged WS 2 nanofluid was found to increase tool life by ≈10% and significantly improve surface integrity. [ABSTRACT FROM AUTHOR]

Long cantilevered high performance milling tools tend to vibrate during machining operation due to process excitation. This impairs the quality of the workpiece surface and limits the achievable material removal rate. An optimisation of the dynamic properties of these tools enables an increased machining performance. This paper introduces a lightweight design of a shell end milling tool with an integrated semi-active damping system based on magnetorheological fluids. The investigations show that this approach allows an adjustment of the dynamic behaviour of the tool. In machining experiments a significant increase of the material removal rates and improved surface quality are achieved. [ABSTRACT FROM AUTHOR]

The paper proposes the prediction of the fatigue strength of additive manufactured Ti6Al4V titanium alloy machined under flood and cryogenic cooling conditions, making use of the approach based on linear elastic fracture mechanics that was used for the first time in the context of such process chains. The role of the machining-generated surface texture, hardening, microstructural characteristics and residual stresses states is discussed in detail, giving new insights about the correlation between surface integrity and fatigue strength when addressing defective metal alloys, as those fabricated through AM. [ABSTRACT FROM AUTHOR]

Accurate prediction of cycle times of machining part programs plays a crucial role in process planning and part flow optimization on shop floors. This paper presents a data-driven approach to model the trajectory generation (interpolation) strategy embedded in the Numerical Control (NC) system of CNC machine tools to accurately predict their machining cycle times. Artificial Neural Networks (ANN) are trained to learn and accurately mimic how the CNC plans its feedrate profile as it accelerates, decelerates, and interpolates along complex part programs. Proposed approach is validated experimentally and shown to predict machining cycle times with >95% accuracy along tested complex machining toolpaths. [ABSTRACT FROM AUTHOR]

Monolithic optics are rapidly developing to fulfil the increasing demand for smart imaging. The complexity of such optics makes it almost impossible to fabricate directly using multi-axis machining. The industry is urging for a versatile solution, despite various techniques tailored for specific microstructures. In this paper, a novel multi-axis approach is proposed to directly develop maximum fill-factor complex lens arrays with intricate features, by reconfiguring the multi-axis to expand flexibility to develop these functional surfaces. The effectiveness of this approach is experimentally verified. This study paves a way towards versatile solutions to address any complex surface currently considered "impossible to machine". [ABSTRACT FROM AUTHOR]

Electrical discharge machining (EDM) is a versatile unconventional machining process allowing high precision manufacturing. Due to the thermal main active principle, the process-induced heat affected rim zone always needs to be particularly considered regarding its characteristics as the resulting surface integrity has to fulfill the needed functional properties for advanced applications. Today, no deterministic model is available especially for the residual stress prediction. As consequence, current process design is based on experience and heuristic optimization. The paper therefore mechanistically links the material modification and the process-induced load. Inversion of the according process signature component finally allows model-based process design. [ABSTRACT FROM AUTHOR]

Blasting erosion arc machining (BEAM) introduces a high-efficiency and low-cost machining technique in dealing with difficult-to-cut materials. Despite its high machining efficiency, the machined surface is quite rough. It leads to an excessive allowance for subsequent processing. This paper presents an optimized tool electrode design that enables an enhanced hybrid arc breaking mechanism. Both flow field simulation and machining test verify that the optimized electrode can guarantee a much better gap flow field and debris expelling effect. The corresponding machined surface is significantly improved in aspects of surface roughness, smoothness, uniformity, recast layer as well as heat affected zone. [ABSTRACT FROM AUTHOR]

In the past few decades, there has been considerable advancement in developing and testing structured and textured cutting tools for different machining operations. This paper not only presents a review of the state-of-the-art in manufacturing processes to structure and texture surfaces of cutting tools for machining applications but also identifies the strengths and weaknesses of utilizing structured or textured rake and flank faces as well as other important functional surfaces of cutting tools. This includes an assessment of the relevant texture geometries and microscale structures and their applicability and/or limitations for the improved chip material flow and contact at the chip-tool interface, reduced forces, dynamic deflections, and friction, improved anti-adhesion and tool wear, and enhanced debris management, lubricant, and coolant utilization. This manuscript includes contributions from many research groups in academia who closely work with industry and the content presented herein is expected to provide an organized and comprehensive narrative on current advances, capabilities, and challenges in developing and implementing optimum texture and structure design on cutting tool surfaces with some guidance for future directions. [ABSTRACT FROM AUTHOR]

One of the effective strategies to improve dry machining processes is the implementation of micro-textured cutting tools. Micro-textures decrease the chip-tool contact length and thus reduce friction and heat which lead to better surface quality and longer tool life. However, micro-cutting of the bottom side of the chip, known as derivative cutting, is an issue when using textured tools. Derivative cutting increases the cutting forces, heat, and ultimately tool wear. This paper investigates the effect of micro-texture design parameters on the occurrence of derivative cutting and offers design recommendations when preparing micro-grooves to eliminate/reduce the severity of this phenomenon. [ABSTRACT FROM AUTHOR]

Wear assessment is an essential feature within the Industry 4.0 framework to optimise machining and control durability of components made of innovative materials. Complex topographies often make wear measurement a challenging task. Literature tackles it by comparing the final topography with the unworn state, either by empirical methods or by registration via machine vision algorithms. This paper develops a framework to evaluate the related measurement uncertainty, so far lacking, by exploiting instruments metrological characteristics and statistical modelling. This framework is applied to an industrially relevant case study to compare the performances of accredited methods for wear measurement available in literature. [ABSTRACT FROM AUTHOR]

Modern manufacturing systems are becoming increasingly complex, dynamic, and connected, and their performance is being affected by not only their constituent processes but also their system-level interactions. This paper presents an integrated modelling method based on a graph neural network (GNN) and multi-agent reinforcement learning (MARL) collaborative control for adjusting individual machining process parameters in response to system- and process-level conditions. The structural and operational dependencies among process machines are captured with a GNN. Iteratively trained with MARL, machines learn to adaptively control local process parameters, e.g., machining speed and depth of cut, while achieving the global goal of improving production yield. [ABSTRACT FROM AUTHOR]

Waterjet guided laser (WJGL) cutting is a relatively new technology for high-precision machining of difficult-to-cut materials. However, its material removal mechanism presents some unique features because of the interaction between laser, waterjet and workpiece. This paper investigates the surface formation mechanism in WJGL cutting of Ni-based superalloy and its influence on the fatigue performance. Two different microstructures have been found on the surface layer, i.e. recast crystals and redeposited amorphous oxide, resulting from solidification of melt and plasma respectively under the laser-waterjet interaction. Mechanical twinning structures were also revealed in the substrate due to the waterjet confined plasma shockwave impact. [ABSTRACT FROM AUTHOR]

This paper presents an overview of recent developments in simulating machining and grinding processes along the NC tool path in virtual environments. The evaluations of cutter-part-geometry intersection algorithms are reviewed, and are used to predict cutting forces, torque, power, and the possibility of having chatter and other machining process states along the tool path. The trajectory generation of CNC systems is included in predicting the effective feeds. The NC program is automatically optimized by respecting the physical limits of the machine tool and cutting operation. Samples of industrial turning, milling and grinding applications are presented. The paper concludes with the present and future challenges to achieving a more accurate and efficient virtual machining process simulation and optimization system. [ABSTRACT FROM AUTHOR]

Broaching is a unique machining process with high accuracy and surface quality, which is employed in mass and batch production for the manufacture of components with highly complex geometries. It involves the use of multiple-edged complex tools in which the cutting edges are arranged with an offset also known as "rise per tooth" that determines the depth of cut per tooth. This paper presents the state-of-the-art of both the experimental and modelling aspects of broaching, and identifies the most important features related to this machining process. This includes a critical assessment of specifically designed broaching setups and their applicability and/or limitations compared to the machines used in industry. Contributions from academia and industry are included to support a comprehensive report of recent advances, as well as a roadmap for future developments. [ABSTRACT FROM AUTHOR]

In the machining of material compounds, materials with differing properties must be identified during the process and process parameters must be controlled accordingly. Structure integrated strain gauges in feeling machines are a promising approach for providing signals for monitoring and control tasks. This paper presents the first investigation and implementation of this technology for a turning machine turret. Firstly, the simulation based positioning of the sensors is discussed. Secondly, disturbance variables such as cooling temperature and assembly tolerances of machine components, which affect the strain measurement, are investigated. Finally, the successful material-specific machining based on the feeling machine is presented. [ABSTRACT FROM AUTHOR]

Demand for generating functional micro patterns on a curved surface such as molds has increased in various industrial sectors. In order to meet the demand, it is important to develop advanced micro machining technology to generate curved form and fine patterns, simultaneously and efficiently. This paper presents a newly developed machining system equipped with a fast tool servo mechanism for milling process driven by a giant magnetostrictive actuator and evaluation of its basic machining performance. The results confirmed that the developed system has capability to position the end mill precisely during machining and to generate patterned curved surface. [ABSTRACT FROM AUTHOR]

Industrial robots, used for milling processes, have to execute highly dynamic and accurate movements. External static and dynamic process forces lead to static deflections and dynamic excitations. In this paper, we present a coupled offline simulation and planning strategy of the machine-process interaction with online adaptation mechanisms for increased system robustness. The process planning, optimization and milling force prediction are executed offline, while the online compensation and adaptation accounts for static deflections and unmodeled disturbances. The benefits of the combined offline and online approach are demonstrated by stabilizing machining processes and accurate deflection compensation with unmodeled changes in spindle speed and feed rate for the machining of aluminum workpieces. [ABSTRACT FROM AUTHOR]

This paper presents results of both oxidation and tool wear tests concerning the couples consisting of Ni-and Ti-based alloys and TiAlN coating to determine its oxidation behaviour. Firstly, oxidation tests are performed in a special chamber at temperatures ranging from 700°C to 1000°C in air atmosphere. Secondly, the wear tests were carried out keeping the same temperature range. The surface morphologies, chemical elements and produced phases were analysed with SEM, EDS and XRD techniques. The results show that protective Al 2 O 3 films are formed on the TiAlN coating surface. The prediction methodology for oxidation process and corresponding tool wear is proposed. [ABSTRACT FROM AUTHOR]

Wire Arc Additive Manufacturing (WAAM) is a fusion- and wire-based additive manufacturing technology which has gained industrial interest for the production of medium-to-large components with high material deposition rates. However, in-depth studies on performance indicators that incorporate economic and environmental sustainability still have to be carried out. The first aim of the paper has been to quantify the performance metrics of WAAM-based manufacturing approaches, while varying the size and the deposited material of the component. The second aim has been to propose a multi-criteria decision-analysis mapping to compare the combined impacts of products manufactured by means of the WAAM-based approach and machining. [ABSTRACT FROM AUTHOR]

Abstract: During the last few decades, there has been significant progress in developing industry-driven predictive models for machining operations. This paper presents the state-of-the-art in predictive performance models for machining, and identifies the strengths and weaknesses of current models. This includes a critical assessment of the relevant modelling techniques and their applicability and/or limitations for the prediction of the complex machining operations performed in industry. This paper includes contributions from academia and industry, and is expected to serve as a comprehensive report of recent progress, as well as a roadmap for future directions. Process models often target the prediction of fundamental variables such as stresses, strains, strain-rates, temperatures etc. However, to be useful to industry, these variables must be correlated to performance measures: product quality (accuracy, dimensional tolerances, finish, etc.), surface and subsurface integrity, tool-wear, chip-form/breakability, burr formation, machine stability, etc. The adoption of machining models by industry critically depends on the capability of a model to make this link and predict machining performance. Therefore, this paper would identify and discuss several key research topics closely associated with predictive model development for machining operations, primarily targeting industry applications. [Copyright &y& Elsevier]

Abstract: This paper presents a review of the latest research activities and gives an overview of the state of the art in understanding changes in machine tool performance due to changes in thermal conditions (thermal errors of machine tools). The topics are focused on metal cutting machine tools, especially on turning and milling machines as well as machining centres. The topics of the paper thermal issues in machine tools include measurement of temperatures and displacements, especially displacements at the tool centre point, computations of thermal errors of machine tools, and reduction of thermal errors. Computing the thermal errors of machine tools include both, temperature distribution and displacements. Shortly addressed is also to avoid thermal errors with temperature control, the influence of fluids and a short link to energy efficiency of machine tools. The paper presents the summary of research work in the past and current. Research challenges in order to achieve a thermal stable machine tool are discussed. The paper apprehend itself as an update and not a substitution of two published keynote papers of Bryan et al. in 1990 and Weck et al. in 1995. [Copyright &y& Elsevier]

This paper aims to visualize spatio-temporal phenomena in electro physical and chemical processes in order to understand machining mechanisms and to achieve a technological breakthrough. In situ measurement methods to visualize the time evolution of stress, strain, temperatures, fluid velocities, and species density distributions, together with 2D or 3D images of the workpieces being processed are summarized. Applications of these methods to fundamental studies on electrical discharge machining, electrochemical machining, laser processing and additive manufacturing are introduced. Signal recording and processing technologies and real time monitoring enabling closed-loop feedback control are also discussed. [ABSTRACT FROM AUTHOR]

Robotic machining centers offer diverse advantages: large operation reach with large reorientation capability, and a low cost, to name a few. Many challenges have slowed down the adoption or sometimes inhibited the use of robots for machining tasks. This paper deals with the current usage and status of robots in machining, as well as the necessary modelling and identification for enabling optimization, process planning and process control. Recent research addressing deburring, milling, incremental forming, polishing or thin wall machining is presented. We discuss various processes in which robots need to deal with significant process forces while fulfilling their machining task. [ABSTRACT FROM AUTHOR]

Machining of biocompatible materials is facing the fundamental challenges due to the specific material properties as well as the application requirements. Firstly, this paper presents a review of various materials which the medical industry needs to machine, then comments on the advances in the understanding of their specific cutting mechanisms. Finally it reviews the machining processes that the industry employs for different applications. This highlights the specific functional requirements that need to be considered when machining biocompatible materials and the associated machines and tooling. An analysis of the scientific and engineering challenges and opportunities related to this topic are presented. [ABSTRACT FROM AUTHOR]

Surface generation in machining processes is affected by a complex interaction between cutting edge and workpiece material, leading to surface artefacts, so that the surface topography deviates considerably from the kinematic one. This paper shows how to model such interaction, taking into account cutting edge topography, material deformation and cutting edge trajectory errors to achieve a reliable prediction of surface topography generation in ball end milling. The model is experimentally validated in upward raster ball end milling of copper and tool steel. [ABSTRACT FROM AUTHOR]

Additive Manufacturing has proved to be suitable for supporting or even replacing traditional manufacturing approaches in some industrial contexts. Among the various processes that can be used to produce metal parts, Wire Arc Additive Manufacturing (WAAM) is known to be an economically convenient, welding-based direct energy deposition technique for large parts with reduced complexity. The present paper proposes a structured modelling framework to assess whether WAAM could successfully substitute machining processes. The costs, manufacturing times, energy demand and carbon footprint are considered. A case study is presented to clarify and demonstrate the applicability of the proposed methodology. [ABSTRACT FROM AUTHOR]

In the context of Industry 4.0, data management is a key point for decision aid approaches. Large amounts of manufacturing digital data are collected on the shop floor. Their analysis can then require a large amount of computing power. The Big Data issue can be solved by aggregation, generating smart and meaningful data. This paper presents a new knowledge-based multi-level aggregation strategy to support decision making. Manufacturing knowledge is used at each level to design the monitoring criteria or aggregation operators. The proposed approach has been implemented as a demonstrator and successfully applied to a real machining database from the aeronautic industry. [ABSTRACT FROM AUTHOR]

Abstract: Creating three-dimensional micro scale features in hard ceramics is challenging. This paper presents the results of an experimental study of a two-step laser-assisted microgrinding process that has the potential to meet this challenge. The process works by locally weakening the ceramic material via laser irradiation and subsequently microgrinding the weakened material to create a finished micro scale feature. The paper presents the results for laser-assisted microgrinding of silicon nitride. In particular, the differences in grinding force, surface finish, tool condition, and material removal rate obtained with and without laser assist are compared and discussed. Physically based explanations for the experimental observations are given. [Copyright &y& Elsevier]

Abstract: Due to the lack of coolant in dry machining processes, there is an increase of heat input into workpieces during the cutting process. As a result, an inhomogeneous temperature distribution occurs, which can lead to problems concerning compliance with critical tolerances, because of distortions of the workpiece. Using the FEM simulation it is possible to calculate and handle these distortions. This paper contains a mathematical model developed to calculate the surface heat flux as input data for FEM simulation. In comparison to former publications, this paper deals not only with single results, but rather with an overview of the results of the past two years. [Copyright &y& Elsevier]

Abstract: Fast and high-quality machining operations require high dynamic path accuracy of the machine tool in use. Complementary to the work done on NC path planning and mechatronic simulation, in this paper a device is introduced for direct 3D measurements of dynamic path deviations at the tool center point (TCP). With it, linear as well as rotary axes can be tested in one setup, thus dynamic parameters such as jerk and acceleration limits can be set homogeneously for obtaining the required dynamic path accuracy. Relevant Eigenfrequencies of the machine can be identified. Measurement method, uncertainty estimation and result evaluation are explained in this paper. [Copyright &y& Elsevier]

Abstract: There is a need for developing hybrid micro-manufacturing processes capable of generating three-dimensional micro-scale features in hard-to-machine materials. This paper deals with the development of the laser assisted micro-milling process for which a novel 4-axis machine has been designed and built. This paper presents the results of experiments on laser assisted micro-milling of hardened A2 tool steel (62 HRc). The dimensional accuracy of the micro-milled feature and surface finish obtained with and without laser heating are compared and discussed. Scientific explanations for the different observations are given. [Copyright &y& Elsevier]

Abstract: The functions of metal cutting machine tools have been increasing to meet the demands of high productivity and high accuracy in machining complicated and difficult parts on one machine. This paper presents a comprehensive survey of multi-functional machine tools used for metal cutting, and their kinematic configurations, control and programming technologies. Design principles and assessment of multi-functional machine tools are discussed mainly taking examples of 5-axis machining centers. The paper also presents examples of latest multi-functional machine tools as well as current status of related supporting technologies. [Copyright &y& Elsevier]

Abstract: For measuring machines and machine tools, geometrical accuracy is a key performance criterion. While numerical compensation is well established for CMMs, it is increasingly used on machine tools in addition to mechanical accuracy. This paper is an update on the CIRP keynote paper by Sartori and Zhang from 1995 [Sartori S, Zhang GX (1995) Geometric error measurement and compensation of machines, Annals of the CIRP 44(2):599–609]. Since then, numerical error compensation has gained immense importance for precision machining. This paper reviews the fundamentals of numerical error compensation and the available methods for measuring the geometrical errors of a machine. It discusses the uncertainties involved in different mapping methods and their application characteristics. Furthermore, the challenges for the use of numerical compensation for manufacturing machines are specified. Based on technology and market development, this work aims at giving a perspective for the role of numerical compensation in the future. [Copyright &y& Elsevier]

Abstract: Among the industrial gear grinding processes, continuous generating grinding allows the highest material removal rates due to its kinematics. The process capabilities can be further increased by using CBN as a more efficient abrasive material. The research work described in this paper proves the high potential of vitreous bonded CBN grinding worms. Compared to corundum worms, the CBN tools offer significantly better behavior with regard to process stability, gear quality and residual stress on the machined gear tooth flanks. The results also show that a well adapted dressing technology is not only an important prerequisite for the efficient application of CBN worms but it also offers excellent and further possibilities to increase the grinding process performance. Dressable CBN grinding worms have not yet been introduced to industrial gear grinding processes. The paper gives an insight into the preparation and application of these innovative tools not only for academia but also for industry. [Copyright &y& Elsevier]

This paper summaries advancements in fixed abrasive machining of non-metallic materials, which include reinforced concretes, stones, rocks, carbon fiber reinforced plastic, metal and ceramic matrix composites, wood, wood-fiber plastic composite, biomaterials (bone, plaque, and enamel), and structural and electronic ceramics. The broad impacts, diverse applications, and innovations of fixed abrasive machining processes are presented. Benefits of the engineered deterministic distribution of abrasive grain grinding tools are demonstrated. Industrial perspectives and future research on innovative fixed abrasive machining technologies that enable new processes and improve the productivity are highlighted. [ABSTRACT FROM AUTHOR]