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Cutting tool materials are the backbone of machining and play a vital role in the manufacturing industry. Innovation in cutting tools is important for customized and demanding applications. This state-of-the-art review is focused on innovations and future research directions for cutting tools covering i) tool materials/microstructure/property relationships, ii) coatings and their effect on tool performance, iii) cutting edge and functional surface preparation and effect on tool performance, iv) tool geometry for high performance and stable machining considering rapid machining, sustainability, and circularity aspects. The vision is to identify tool material/coating/geometry/functional surface relationships for significant improvement in machining performance. This paper includes perspectives from several research groups with a detailed discussion on current advances, capabilities, and challenges in engineered design of cutting tools, materials, coatings, structures and sets a new agenda for future tooling and research directions. [ABSTRACT FROM AUTHOR]

Six-axis robots are increasingly employed in manufacturing due to their excellent volume on cost ratio and extensive reach, facilitating the machining of large components, including those made of composites. However, this enhanced volume on cost ratio often compromises rigidity. This study investigates the effect of cutting conditions on surface integrity and robotic drilling forces when machining Aluminum 6082-GFRP stacks using 6 mm solid carbide drills and a 6-axis Sta¨ubli TX200 robot. Two distinct drill geometries are assessed in various drilling sequences. Feed rate emerges as a pivotal parameter affecting drilling forces and hole quality. Comprehensive testing encompasses a range of feed rates and drilling strategies in both individual materials and stack sequences. The analysis includes cutting forces and hole quality, considering surface integrity and standard quality indicators such as delamination, arithmetic roughness, and burr height. The research seeks to propose optimal cutting conditions, specifically feed rate and cutting speed, essential for advanced industrial applications. These conditions ensure hole quality and surface integrity, which is particularly important for riveting processes and ensuring effective sealing. [ABSTRACT FROM AUTHOR]

Thin-walled aluminium components used in the structure of aircrafts are subjected to fatigue loads. Fatigue performance of those components is affected by the surface integrity generated in the last machining step. This paper proposes an analytical model to identify the fatigue crack initiation site considering the surface topography, residual stresses (RS) and mechanical properties induced by machining. To validate the model fatigue samples of aluminium 7050-T7451 were prepared by face milling. Machining-induced RS were measured by hole-drilling and the surface topography of the gauge region of the fatigue samples was characterised using a confocal microscope. Then, uniaxial fatigue tests were done at R = 0.1 and subsequently the fracture was analysed. The model predicted nucleation of cracks at the surface when the stress amplitude was above 290 MPa. Fatigue tests done at an amplitude of 350 MPa confirmed crack initiation at the points with the highest stress concentration predicted by the model. By contrast, the cracks were nucleated at the side of the samples when the stress amplitude was below 290 MPa. In fact, compressive RS induced by face milling protected the surface from crack nucleation at lower applied stresses as predicted by the model. [ABSTRACT FROM AUTHOR]

Titanium alloy Ti6Al4V is of great importance to the aeronautical and medical sectors due to its mechanical properties such as a high strength-to-weight ratio and corrosion resistance. On the downside, machining Ti6Al4V can lead to accelerated tool wear and poor surface finish of the machined part due to its low heat dissipation capacity. Traditionally, oil and water based metalworking fluids (MWFs) have been used to overcome such issues. However, new regulations and eco-friendly manufacturing trends suggest that conventional MWFs should be minimised, as they are hazardous to the environment and workers' health. Additionally, titanium prostheses contaminated with oil can cause severe integration problems on the patient. This article researches the feasibility of replacing conventional emulsions with sustainable liquid carbon dioxide (LCO 2) cooling. For this purpose, an optimisation of the tool geometry (helix angle, clearance angle and cutting edge geometry) for LCO 2 assisted milling of Ti6Al4V was carried out, taking into account parameters such as cutting forces, surface roughness and the microstructure of the machined surface. This research contributes to the development of environmentally friendly and work safe manufacturing processes that meet the challenges of machining Ti6Al4V for aerospace and medical applications. [ABSTRACT FROM AUTHOR]

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]

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This article emphasizes the importance of threat agnostic epidemiology and surveillance in US public health agencies for ensuring health security. It discusses the need for investments in the applied epidemiology workforce, training, and public health data systems to implement new scientific technologies and methods. The article highlights various approaches to threat agnostic surveillance, including syndromic surveillance, electronic laboratory and case reporting, and wastewater surveillance. It also discusses the challenges and potential of home testing, genomic surveillance, and data modernization in public health practice. The article concludes by emphasizing the need for continued investment in public health data infrastructure to strengthen the nation's biodefense capacity and enhance health security. The document further discusses the importance of modernizing public health data systems and building capacity in the epidemiology workforce to effectively respond to future public health threats. It emphasizes the need for collaborative efforts and the adoption of standards to improve data exchange and interoperability. The document also highlights the gaps in the epidemiology workforce and the need for ongoing training and flexible funding models. It concludes by providing recommendations to support threat agnostic public health surveillance, including increasing diagnostic capabilities, developing methods for integrating non-traditional laboratory test results, and providing sustainable funding for data modernization and workforce development. [Extracted from the article]

The wear of milling tools used for finishing green ceramics shaped by pellet additive manufacturing can be challenging. This article aims to evaluate the tool life of a tool, initially dedicated to thermoplastics, when used for milling green zirconia and seeks to confirm the influence of the build direction on the cutting forces. The tool can withstand 30 minutes of milling without reaching the tool life criteria of ISO 8688. The generated surfaces exhibited a shiny finish, no material pull out and a Ra < 1.6 µm. The cutting forces were low with maximal values of 15 N. [ABSTRACT FROM AUTHOR]

A novel aerosol evaluation cell was employed to measure particle number and mass concentration, with a size distribution from nano to micro scale. Different cooling/lubrication and airflow extraction scenarios were tested on a CFRP/Ti6Al4V case study, and the particle concentrations were measured to evaluate their effect on productivity and cost per hole, if current occupational exposure limits are respected. Aspects to achieve sustainable machining like tool life, consumption of coolant and energy, and standby time required to safely open the machine-tool doors were considered. LCO 2 delivered the best productivity and cost results as it improved the tool life by 40 % compared to MQL, while eliminating the need for standby time to evacuate particles. [ABSTRACT FROM AUTHOR]

The development of cutting tools requires the knowledge of tribological phenomena at the tool – workpiece contact area. This knowledge is in dearth particularly for difficult-to-cut alloys like gamma titanium aluminide (gamma – TiAl alloys). Therefore, this article is an attempt to plug the gap and aid the development of cutting tools for gamma – TiAl alloys. To this end, friction, adhesion, and coating wear between AlTiSiN coated cemented carbide tool and Ti-48Al-2Cr-2Nb (Near lamellar), Ti-48Al-2Cr-2Nb (Duplex), and the most used titanium alloy of Ti-6Al-4V (alpha – beta) were experimentally derived. A Pin-on-Cylinder (PoC) tribometer with contact conditions corresponding to commercial machining conditions was used with dry, flood(EML), and two MQL lubricants. Additionally, the heat generated and partitioned between the pin and workpiece was quantified to assess the thermal exposure to the coatings. The results showed that Ti-6Al-4V had approximately 50% higher apparent friction coefficient than the Ti-48Al-2Cr-2Nb alloys. Interestingly, the friction coefficients of Ti-48Al-2Cr-2Nb alloys were nearly consistent across the entire test matrix. Notably, the change in the microstructure from near lamellar to duplex did not elicit any qualitative or quantitative change in the friction profile of Ti-48Al-2Cr-2Nb alloys. The contact pressure proved to be the statistically significant property influencing friction evolution inversely for Ti-6Al-4V alloy and directly for Ti-48Al-2Cr-2Nb alloys. The results showed higher probability of coating wear in dry conditions as opposed to the flood and MQL lubricants. [Display omitted] [ABSTRACT FROM AUTHOR]

In manufacturing, different costs must be considered when selecting the optimal manufacturing configuration. Costs include manufacturing costs, material costs, labor costs, and overhead costs. Optimal manufacturing configurations are those that minimize production criteria, such as costs, production speed, and flexibility, while still meeting the required production levels and quality standards. To find the optimal manufacturing configuration, manufacturers often use a combination of traditional techniques, e.g., mathematical modeling, simulation, and optimization, to evaluate the tradeoffs between different cost factors and identify configurations that provide the best balance between cost and performance. However, these techniques may require long development and simulation time, and/or may require expert knowledge. This paper presents a method for selecting the optimal manufacturing configuration, focusing on cost optimization, using a reinforcement learning (RL) approach for sequential decision-making. The proposed method involves developing a RL environment, requiring lower development and simulation times than traditional techniques, that captures the incurred costs, recurring costs, production rates, and setup times of manufacturing configurations. The problem is then solved using the Proximal Policy Optimization algorithm to identify the configuration that minimizes costs while still meeting the required production levels and quality standards. The effectiveness of the proposed method is validated through a machining process planning case study with multiple cost factors and production constraints. In particular, the machining process plan was developed for an industry-relevant product prototype. The results show that the proposed method can find solutions that are robust to stochastic noise, providing valuable insights for manufacturers looking to optimize manufacturing operations. [ABSTRACT FROM AUTHOR]

Copyright of Revista Española de Sociología is the property of Federacion Espanola de Sociologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Broaching is widely used for the manufacturing of complex geometries which requires high dimensional accuracy and surface finishing (e.g., fir tree, dovetail). A software development for force prediction in complex shape broaching is presented. The software automatically extracts the local uncut chip section along each tooth of the tool and based on the empirical specific cutting forces of the material the total force per tooth is calculated. The software was validated experimentally. For that purpose, fir trees of Inconel 718 were broached. Predicted forces showed an average relative error of 6% when compared to the experimental results. [ABSTRACT FROM AUTHOR]

The identification of input parameters for funite element modelling of the cutting process is still a complex task as the experimental testing equipment cannot reach its combined levels of strains, strain rates and temperatures. Inverse identification using Artificial Intelligence method provides a relevant alternative. In this paper, material constitutive and friction models parameters identified with an Efficient Global Optimization algorithm and an ALE orthogonal cutting model are introduced in a CEL model. Assessment of the differences in the results due to the formulation and dependence of parameters identification to the finite element model are then performed. [ABSTRACT FROM AUTHOR]

Surface errors in contour milling due to force induced tool deflections have a direct impact on the dimensional and geometrical accuracy of the finished part. In this sense, virtual manufacturing systems provide the capability to predict the errors generated at the final surface aiming to reduce production ramp-ups. Effects of working conditions on the surface error imprinted by the tool during a stable milling process along the whole tool path are studied at different radial and axial depths of cut. The developed process model was validated experimentally, showing good agreement in the prediction of the resulting dimensional surface error for when a single tooth is involved in the cut. [ABSTRACT FROM AUTHOR]

The use of multidirectional composite-metal stacks employing glass fibre reinforced plastics (GFRP), is gaining traction in many industrial applications. However, finishing operations in these materials (e.g. drilling), often present problems such as delamination and burrs, which are mainly due to mechanical loads. This paper presents a hybrid approach to predicting drilling cutting forces based on mechanistic drilling models coupled with a 2D Finite Element Analysis (FEA). A comprehensive mechanical characterization of the GFRP that was used, to validate the new material constitutive model of the composite was carried out, and an accurate prediction of cutting forces was obtained. [ABSTRACT FROM AUTHOR]

Copyright of Education Policy Analysis Archives / Archivos Analíticos de Políticas Educativas / Arquivos Analíticos de Políticas Educativas is the property of Educational Policy Analysis Archives & Education Review and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The transfer of global education policies occurs unevenly across contexts and fails to consider local identity and characteristics. These policy practices are wrapped up in political interests, power relations and ideological implications. Transferring global policies of inclusion in education to national education systems is a relevant example of this. Drawing on empirical data from 39 semi-structured interviews conducted with policymakers and bureaucrats from 17 regions in Spain, this article examines the transfer of UNESCO guidelines for inclusive education in favour of cultural diversity to national contexts. The analysis reveals that policymakers and bureaucrats recognise international guidelines and highlight education policies aimed at promoting access and participation for all in schools, in line with the UNESCO Framework for Action. However, they also consider local traditions based on compensation through policy structures that favour segregation. The analysis suggests that the transfer of international discourses to national contexts wrapped up in political interests, power relations and ideological implications and reinforce structures of inequality. [ABSTRACT FROM AUTHOR]

Lightweight materials like Carbon Fiber Reinforced Polymers (CFRPs) present certain challenges, mainly regarding the resultant surface integrity of the holes. Different techniques such as optimized tool geometries, machining techniques and cooling/lubricating techniques have been tested for improving surface integrity on CFRPs. Unfortunately using coolants presents certain challenges when machining CFRPs, as the moisture absorption can degrade the mechanical properties of the composite, on top of the environmental and health hazards created by water and oil based metalworking fluids. Therefore, this study aims to evaluate the influence of environmentally friendly liquid carbon dioxide (LCO 2) based cooling/lubricating conditions and Polycrystalline Diamond (PCD) drill bit geometries (point angle) on the delamination when drilling CFRP composites. The results showed significant influence of the tool geometry and cooling condition on the surface integrity of CFRPs, especially in the case of the former. [ABSTRACT FROM AUTHOR]

Drag finishing is one of the mass finishing processes that enhances surface roughness on complex and rough parts produced by additive manufacturing. This paper proposes a model to simulate abrasive media flowing around the part at a macroscopic scale based on an original rheological model inspired by civil engineering techniques. The correlation between the evolution of the surface roughness and numerical results reveals the high sensitivity of the process to media's rheological behaviour and the surface orientation of the surface regarding media flow. This model provides a better understanding of the physical mechanisms (chip formation or plastic deformation) induced at the surface during polishing, and it helps choosing the optimal finishing conditions. [ABSTRACT FROM AUTHOR]

Although drilling of FRP - metal stacks is the most widely used machining operation for these materials, it remains challenging in many aspects (tool wear, vibrations, delamination, poor surface finish, etc). In this context, this paper presents an analysis of drilled AISI 304-GFRP stacks using a 6 axis Stäubli TX200 robot, which is a technology increasingly used in applications such as aeronautics due to the advantages it offers (spatial accessibility, productivity, flexibility). This study focuses on hole quality based on appropriate criteria (burrs, surface roughness, roundness and delamination measurements) depending on a large range of cutting parameters. [ABSTRACT FROM AUTHOR]

Transmission shafts used in the automotive sector must have a good tribological performance, and therefore an enhanced surface integrity. This paper aims to study the effect of eco-friendly innovative finishing operations (belt finishing, cryogenic grinding and dry grinding) on the surface integrity and tribological performance of steel grade 27MnCr5, and compare to the behavior of components produced by conventional wet grinding process. For that purpose, a total of seven finishing conditions were analysed: wet grinding as reference, two dry grinding conditions, two cryogenic grinding conditions and two hard turning+belt finishing conditions. The surface integrity (roughness, residual stresses, hardness and microstructural defects) of samples was assessed. Finally, the step-loading test method was used to determine the scuffing resistance of the samples. Tested innovative finishing operations led to higher scuffing resistance than conventional wet grinding. Results demonstrate that higher surface hardness and roughness leads to higher scuffing resistance, while the effect of surface residual stresses is not significant. [ABSTRACT FROM AUTHOR]

Aerostructures withstand cyclic mechanical loads and therefore, their design must fulfil surface integrity and fatigue strength requirements. This paper studies the effect of pneumatic machine hammer peening on surface integrity of 7050-T7451 aluminium alloy. Specimens were hammer peened using two different stepover distances (0.07 and 0.35 mm) and initial offset (0.3 and 0.5 mm). A Kistler dynamometer was used to measure the forces generated by hammer peening. Then, the surface topography, residual stresses and microstructural damage of the specimens were characterised. The results demonstrate that the magnitude of residual stresses and the thickness of the affected layer increases when reducing the stepover distance, while surface roughness reduces. Additionally, none of the tested conditions produced microstructural defects. These findings suggest that pneumatic hammer peening is an additional process to manufacture thin-walled structural aluminium alloy components. [ABSTRACT FROM AUTHOR]

Drilling is a continuous cutting process where two or more cutting edges remove the material, to obtain the desired feature. During the chip evacuation, it generally rubs against the generated surface. Thus, the roughness obtained differs from other machining processes such as turning or milling. Therefore, surface roughness can be different from the analytically expected one. In this research work, an analysis of the cutting conditions where a level of roughness is expected to meet specific requirements has been carried out. 600 holes were made with two different tool geometries on steel without modifying the cutting conditions. When analysing the surface generated, certain variability in the roughness profiles obtained can be observed. External signals to the machine tool were acquired with sensors (cutting forces, vibrations, and acoustic emissions) as well as internal signals (spindle power, spindle torque in the Z-axis, spindle current and positions, speeds, accelerations, and jerk of the tool tip in the three axes of the machine). The most representative statistical features of the signals regarding roughness were selected using correlation analysis. Besides that, the hierarchical clustering of statistical features of the external and internal signals of the process was compared with clusters obtained using roughness parameters. Results show that clusters appear using signals highly related to the roughness parameters obtained from the measured profiles, confirming a mapping between the acquired signals during the machining process and the roughness of the holes. [ABSTRACT FROM AUTHOR]

Surface topography irregularities generated by broaching are analysed. Experimental tests were carried out on three workpiece materials: AISI 1045, Ti-6Al-4V, and Inconel 718, varying the cutting speed, rise per tooth, and rake angle. The experimental results combined with numerical simulation demonstrate that surface topography irregularities result from mechanical rather than thermal effects. Higher surface topography variations are obtained when the force magnitude increases, and when its direction is more perpendicular to the machined surface. Additionally, the Young's modulus of both the workpiece and tool materials plays a fundamental role in topography quality, reducing irregularities when the Young's modulus is increased. [ABSTRACT FROM AUTHOR]

This article introduces a non-intrusive method to estimate facial muscle activity from images, diverging from conventional electrode-based approaches. Our methodology capitalizes on an inclusive set of features encompassing a diverse range of facial muscles, often overlooked in research, thus significantly expanding the scope of analyzing muscle activity within facial expressions. Our method is based on the standard 68-point face landmark and extends it by identifying the interactions of these muscles when a person performs a specific facial expression. These interactions are recorded in a feature vector, which is used by three classifiers, Linear Discriminant (LD), Support Vector Machine (SVM) and Multi-layer Perceptron (MLP) to classify six facial expressions (anger, disgust, fear, happiness, neutrality, and sadness). The method's validation is conducted with three databases: FACES, KDEF, and JAFFE. These databases present different challenges; the first contains faces of individuals from three age ranges and both genders displaying facial expressions. On one hand, the KDEF database contains images of both genders but only within the range of young adults, whereas JAFFE comprises solely female faces. Additionally, JAFFE presents another drawback, representing only 10% of the images contained in FACES. In all these cases, our method yields excellent results, occasionally achieving 100% classification, especially in the young category. It is also noteworthy that the best results were obtained in the classification of facial expressions in female faces, suggesting that women tend to be more expressive. The method was thoroughly evaluated, and the results demonstrate the robustness of the approach, showcasing its good performance across three different databases and also for faces of individuals across various age groups. Numerical metrics, including accuracy, precision, recall, and F1 score, are presented along with confusion matrices. • A novel, image-based non-intrusive method for estimating facial muscle activity. • Inclusive set of features encompassing diverse facial muscles. • Efficient measurement with standard facial landmarks, ensuring computational ease. [ABSTRACT FROM AUTHOR]