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The importance of kaffir lime leaf as essential oils (EOs) raw material is starting to get attention because of its commercial value; however, there is no quality reference for kaffir lime leaf EOs, especially in response to various post-harvest handlings. This study aimed to describe the physicochemical characteristics and yield of kaffir lime EOs subjected to different post-harvest. Bogor originated-kaffir lime leaf was prepared to be subjected to several post-harvest treatments, i.e., control/fresh green leaves (P1); milling to produce green leaf flour (P2); drying to produce dry brown leaf (P3), and milling and drying to produce brown leaf flour (P4). The result showed that post-harvest treatment generally decreases an oil yield and increases darkness color, specific gravity and refractive index of tested EOs. Additionally, post-harvest treatment also changes metabolite profile revealed by GCMS analysis. The relative percentage of caryophyllene and citronellol tends to increase, while the linalool and citronellal levels decrease due to tested post-harvest treatment. It was implied that for the benefit of the fragrance industry with a high citronellal requirement, EOs should be made from fresh green leaves and the leaves should be avoided from drying and powdering treatment.

The milling process is the standard method for producing flat tensile test specimens from sheet metal. However, alternative methods employed in the industry for cutting sheet metal include abrasive water jet cutting, laser cutting, punching, and, to a lesser extent, electrical discharge machining. Among these, abrasive water jet cutting stands out for its superior material integrity, versatility, precision, and efficiency, making it a preferred choice. Previous studies consistently show that specimens cut by abrasive water jetting exhibit lower ultimate tensile strength and higher percent elongation than those obtained by milling in standardized tensile tests. This study investigates this behavior across different types of steel and alloys. Both steel types were subjected to milling and water jetting processes, followed by an analysis of their experimental and simulated mechanical behavior to identify discrepancies between the two methods. The findings suggest that milling, influenced by factors such as feed per tooth and cutter diameter, introduces geometric stress concentrators. This relative increase in ultimate tensile strength and decrease in percent elongation are observed consistently in milled tensile specimens compared to those cut by water jet, regardless of material type or thickness. Additionally, the effects of perimeter hardening resulting from superficial plastic deformation caused by the cutting edge, likely due to its small thickness, do not influence the observed trends significantly., Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This research work was supported by the Serra Húnter program (Generalitat de Catalunya)., Peer Reviewed, Postprint (published version)

Machining processes are used in almost every manufacturing company. In many production systems, particularly in the machine building and automotive industries, they even represent the largest proportion of manufacturing processes and therefore have a significant influence on economic and environmental targets. The cutting tools used on NC controlled machine tools are usually made of carbide materials, which are produced with high energy input and the use of critical raw materials. Even so, in mechanical engineering, there are several approaches to substituting carbides with mineral-based materials. These mineral-based materials have interesting mechanical properties such as high strength and good damping and are also highly available and inexpensive. Using the example of an end mill, this paper compares the ecological impact of carbide end mills in comparison to newly developed rock flour-based ones. A comparative life cycle assessment in accordance with the ISO 14040 and ISO 14044 standards is applied. To assess the manufacturing and utilisation phase in the life cycle, several rock flour-based end mills were manufactured and investigated in experimental studies. It is shown that the approach of using rock flour-based end mills is beneficial from an environmental point of view, even considering their lower performance compared to carbide end mills.

Milling influences flour morphology and the molecular structure of biomolecules. Such structure-function interactions are crucial in determining ingredient functionality to develop specific end-products. Laboratory scale X-ray instruments such as X-ray microtomography (µCT), small-angle X-ray scattering (SAXS), and powder X-ray diffraction (PXRD) offer limited brightness and are time-consuming when investigating the flour porosity, starch lamellar structure, and the crystallinity of pulse flours. Herein, synchrotron X-rays (SR) were employed along with laser diffraction, mid-infrared (mid-IR) spectroscopy and scanning electron microscopy (SEM) to non-invasively investigate the molecular changes in roller-milled chickpea, navy bean, green lentil, and yellow pea flours as influenced by milling configurations (termed as flour streams) and flour blending (termed as flour blends). In the realm of this thesis, flour streams comprise break and reduction streams for green lentils and yellow pea flours. However, for chickpeas and navy beans, flour streams combined byproducts streams in addition to the break and reduction streams. Flour blends are a combination of combined break, reduction, and byproduct streams in different proportions. Results indicate that there is a variation in all the measured parameters (particle size distribution (PSD), flour morphology, starch lamellar structure, starch crystallinity, flour porosity, starch and protein secondary structures) in flour streams and blends and within a pulse-type. PSD results from laser diffraction, SR-µCT and SEM revealed multi-modal curve distribution patterns with differences in measured ranges for the same sample. Flour morphology analysis through SEM showcased differences between break and reduction streams, with break streams exhibiting clustered starch granules and reduction streams displaying isolated, deformed granules. Flour blends displayed a mixture of flour morphology analogous to flour streams, reflecting bl

Milling is traditionally the most used machining method when manufacturing complex gas turbine components. In particular those made from nickel-based superalloys. However, for larger free form surfaces, grinding may be an efficient alternative that could be used throughout the complete manufacturing route, from roughing to finishing. Hence, in this work the two processing methods has been compared in regard to surface integrity and productivity. Machining tests have been performed on case plates of heat-treated Alloy 718 using best practise setting for roughing and finishing with grinding and milling. The surface integrity of the work pieces was evaluated regarding surface topography, residual stresses, and deformation. This comparison showed that the main advantage with grinding is the ability to switch between roughing and finishing by just altering the depth of cut. Further, grinding offers lower surface roughness, compressive residual stresses, and significantly lower degree of deformation. From a productivity perspective, deep grinding may offer high material removal rates and ability to machine several work pieces in the same setup. However, grinding is limited to simpler free form geometries and may result in minor surface damages and abrasive surface residue. For selection of machining strategy, advantages and drawbacks shown in this work need to be considered for the application at hand in respect to productivity, surface integrity and requirements on fatigue life., The authors acknowledge VINNOVA for funding this work through the project GrindForm (ref. no. 2019-05833).

Chatter vibrations significantly affect the quality and efficiency of machining operations. Machine learning algorithms for intelligent chatter detection are viable options when there is sensor data available at the machine tool level. Most machine learning methods require a feature engineering phase where the most valuable data should be extracted and prepared as input for a machine learning classifier. The selection of the proper dimensionality reduction method at this early stage enhances the performance of the classifier. This study aims to investigate the effectiveness of several dimensionality reduction methods when using Support Vector Machine (SVM) as a classifier. Vibration signals collected during slot milling are binary labeled as stable (0) and chatter (1). Signals were reshaped to 0.5second segments and 0.1-second segments. Ten-dimensional (10D) statistical time-domain features extracted from signals were reduced to three-dimensional (3D) feature space with Principal Component Analysis (PCA), t-Distributed Stochastic Neighbor Embedding (t-SNE), and Autoencoder (AE) dimensionality reduction methods. Signals were classified by SVM classification with various training distributions. The effectiveness of different dimensionality reduction techniques and different training distributions were compared for chatter detection. Furthermore, it was observed that dimensionally reduced features were classified quicker and more accurately than statistical time-domain features.

Mathematical models play an increasing role in understanding and predicting machining processes, in particular milling. However, despite the considerable efforts that have been dedicated to this problem, a majority of milling models still rely on simplifying assumptions to calculate the chip thickness. In this paper, the chip thickness is determined without these simplifications, based on a surface function that describes the milled surface and on information about the workpiece boundary. By combining the partial differential equation (PDE) governing the evolution of this surface function with the ordinary differential equations (ODE) governing the tool/machine dynamics, a mixed PDE-ODE formulation is proposed to describe the dynamics of the milling process. The coupled system of differential equations is solved using an algorithm that combines finite difference (ODE) and finite volume (PDE) methods. A case study is presented to compare the proposed approach with the classical delay differential equations (DDE) model formulation for milling processes based on a simplified chip thickness model. The PDE-ODE formulation represents an explicit mathematical model for milling process dynamics; it yields a theoretically exact chip thickness and offers a means to assess the validity of models based on DDE formulation. Moreover, the proposed formulation is capable of simulating transient tool behaviors when the tool is milling the outer region of the workpiece, which is in general neglected by the DDE-based models.

The lignocellulosic biomass recalcitrance is the uppermost factor for the utilization of this renewable resource. The development of new pre-treatments, addressed to enhance performance in lignocellulosic biomass conversion into biofuels, fine chemicals, and as potential sources of building blocks for materials, must be focus in two main areas: effectiveness (cost-effective and chemical effective) and green chemistry. In this research, a set of different biomass sources (farmer, harvested wild trees and secondary products) were studied to evaluate the high efficiency of the non-liquid nitrogen (LN) and LN-treated biomass samples’ planetary ball milling performance. The samples have been characterized by particle size distribution, thermogravimetric, FT-IR, statistical chemometric and chemical oxidation analysis. The results have shown a high level on the rupture of the crystallinity and depolymerization degrees of the cellulose and the lignin, for both, non-LN and LN-treated samples. The thermogravimetric analysis showed a clear diminishing in temperature degradation, and a larger amount of biomass degraded at lower temperature, as well as, a high chemical oxidation degree than not milled samples. Finally, the LN-treated samples even exhibited a lower degradation temperature, a larger amount of biomass degraded at lower temperature and a higher oxidation degree, than those non-LN milled.

Chatter vibrations significantly affect the quality and efficiency of machining operations. Machine learning algorithms for intelligent chatter detection are viable options when there is sensor data available at the machine tool level. Most machine learning methods require a feature engineering phase where the most valuable data should be extracted and prepared as input for a machine learning classifier. The selection of the proper dimensionality reduction method at this early stage enhances the performance of the classifier. This study aims to investigate the effectiveness of several dimensionality reduction methods when using Support Vector Machine (SVM) as a classifier. Vibration signals collected during slot milling are binary labeled as stable (0) and chatter (1). Signals were reshaped to 0.5second segments and 0.1-second segments. Ten-dimensional (10D) statistical time-domain features extracted from signals were reduced to three-dimensional (3D) feature space with Principal Component Analysis (PCA), t-Distributed Stochastic Neighbor Embedding (t-SNE), and Autoencoder (AE) dimensionality reduction methods. Signals were classified by SVM classification with various training distributions. The effectiveness of different dimensionality reduction techniques and different training distributions were compared for chatter detection. Furthermore, it was observed that dimensionally reduced features were classified quicker and more accurately than statistical time-domain features.

Accurate prediction of cutting forces is critical in milling operations, with implications for cost reduction and improved manufacturing efficiency. While traditional mechanistic models provide high accuracy, their reliance on extensive milling data for force coefficient fitting poses challenges. The eXtreme Gradient Boosting algorithm offers a potential solution with reduced data requirements, yet the optimal utilization of eXtreme Gradient Boosting remains unexplored. This study investigates its effectiveness in predicting cutting forces during down-milling of Al2024. A novel framework is proposed optimizing its precision, efficiency, and user-friendliness. The model training incorporates the mechanistic force model in both time and frequency domains as new features. Through rigorous experimentation, various aspects of the eXtreme Gradient Boosting configuration are explored, including identifying the optimal number of periods for the training dataset, determining the best normalization and scaling technique, and assessing the hyperparameters’ impact on model performance in terms of accuracy and computational time. The results show the remarkable effectiveness of the eXtreme Gradient Boosting model with an average normalized root mean square error of 14.7%, surpassing the 21.9% obtained by the mechanistic force model. Additionally, the machine learning model could capture the runout effect. These findings enable optimized milling operations regarding cost, accuracy and computation time., Published: 07 November 2023This work was supported by the National Natural Science Foundation of China (NSFC) (Grant numbers 51975288 and 51905270), the National Key Research and Development Plan (Grant number 2020YFB2010605) and by the Hungarian National Research, Development and Innovation Office (Grant number NKFI FK-138500).

Machining is an essential part of modern manufacturing. During machining, the wear of cutting tools increases, eventually impairing product quality and process stability. Determining when to change a tool to avoid these consequences, while still utilizing most of a tool's lifetime is challenging, as the tool lifetime can vary by more than 100% despite constant process parameters [1]. To account for these variations, all tools are usually changed after a predefined period of time. However, this strategy wastes a significant proportion of the remaining lifetime of most tools. By monitoring the wear of tools, all tools can potentially be used until their individual end of life. Research, development, and assessment of such monitoring methods require large amounts of data. Nevertheless, only very few datasets are publicly available. The presented dataset provides labeled, multivariate time series data of milling processes with varying tool wear and for varying machine tools. The width of the flank wear land VB is used as a degradation metric. A total of nine end milling cutters were worn from an unused state to end of life (VB ≈ 150 µm) in 3-axis shoulder milling of cast iron 600–3/S. The tools were of the same model (solid carbide end milling cutter, 4 edges, coated with TiN-TiAlN) but from different batches. Experiments were conducted on three different 5-axis milling centers of a similar size. Workpieces, experimental setups, and process parameters were identical on all of the machine tools. The process forces were recorded with a dynamometer with a sample rate of 25 kHz. The force or torque of the spindle and feed drives, as well as the position control deviation of feed drives, were recorded from the machine tool controls with a sample rate of 500 Hz. The dataset holds a total of 6,418 files labeled with the wear (VB), machine tool (M), tool (T), run (R), and cumulated tool contact time (C). This data could be used to identify signal features that are sensitive to

The manufacturing industry faces customer demands for increased product quality and individuality to be economically successful. Established processes on the shop floor cannot overcome resulting challenges. Due to the increased quality requirements, potentially more products must be checked regarding their requirement fulfilment. In addition, customer individuality increases the number and rate of product releases. During product releases, the quality of the product is checked. Coordinate measuring machines are usually used for the quality assessment of milling processes. However, these are only suitable in the area of high quantities per batch due to downtimes of the milling machine while assessing product quality. On-machine inspection systems show particular strengths when a high proportion of the manufactured products have to be inspected and potentially reworked. These systems are criticized for their poor accuracy compared to coordinate measuring machines. This paper demonstrates the accuracy and repeatability of a tactile system in a field test at a tool manufacturer. Based on the test results, the tactile on-machine inspection system is compared with conventional coordinate measuring machines. Finally, the application area and its limits are identified for tactile on-machine inspection systems.

Syftet med denna uppsats är att undersöka vad som skiljer de lämningar åt från kvarnverksamhet som inte finns i Fornsök från de som är registrerade som kulturlämning. Historiskt kartmaterial har studerats för att försöka få en uppfattning om det är så att de inte platsar i ramen för en forn- kulturlämning, dvs tillkommen efter år 1850 och om det är därför de inte finns i registret. Alla lämningarna från kvarnar i Forshälla socken går att återfinna på kartor före år 1850. Uppsatsen önskar också öka uppmärksamheten på denna typ av lämningar i skog och mark så att de erhåller ett starkare skydd när skogen ska avverkas. En analys har gjorts gällande var och en av lämningarna och miljön runt dessa och om de riskerar att skadas vid en avverkning av skogen., The purpose of this essay is to investigate what distinguishes the remains from mill activities that are not found in Fornsök from those that are registered as cultural remains. Historical map material has been studied to try to get an idea of whether it is the case that they do not fit within the framework of an ancient cultural relic, i.e., added after the year 1850 and if that is why they are not in the register. All the remains from water mills in Forshälla parish can be found on maps before the year 1850. The essay also wishes to increase attention to this type of remains in forest and land so they can receive stronger protection when the forest is cut down. An analysis has been made of each of the remains and the environment around them and whether they are at risk of damage when the forest is harvested.

Fräsning och annan intermittent skärande bearbetning ger upphov till termisk utmattning av skärverktyg. Problemet med termiska sprickor blir större vid bearbetning av värmehållfasta material som austenitiskt rostfritt stål eftersom värmeväxlingarna i skärverktyget blir mer extrema. Detta fenomen förvärras ytterligare vid användning av traditionell kylning. Fräsning av rostfritt stål utförs därför torrt. Den torra bearbetningen är inte oproblematisk eftersom höga temperaturer uppstår i skärzonen vilket påverkar verktygets livslängd och i vilken utsträckning avverkningshastigheten kan höjas med högre skärhastighet eller matning. Detaljer som tar lång tid att tillverka är negativt för både företagens ekonomi och miljön till följd av större energiåtgång.Minimalsmörjning är en metod som går ut på att små mängder smörjmedel i form av aerosol fokuseras mot skäreggen och smörjer kontakten mellan arbetsstycke och skär, vilket minimerar friktionsvärmen. På detta sätt kan den totala värmeutvecklingen reduceras samtidigt som värmeväxlingarna hålls på en lägre nivå jämfört med traditionell kylning. Syftet med arbetet var att undersöka och jämföra planfräsning av austenitiskt rostfritt stål, 1.4301, under torr bearbetning och bearbetning med minimalsmörjning.Centralt för studien var hur verktygsförslitningen och ytjämnheten hos bearbetat material påverkas då minimalsmörjning appliceras gentemot vid torr bearbetning.En fråga som togs upp var om avverkningshastigheten kunde ökas med minimalsmörjning utan att få negativ inverkan på verktygsförslitning och ytjämnhet av bearbetat arbetsstycke.Fullfaktorförsök upprättades och jämförelsen mellan torr bearbetning ochminimalsmörjning gjordes med planfräsning med PVD-belagda hårdmetallskär. Ett optiskt mätmikroskop användes för att analysera förslitningen på skärverktygens spån- och släppningssidor efter ca 3 minuter i ingrepp. Ytjämnhet på bearbetad ytamättes med ytjämnhetsmätare och temperaturen i arbetsstycket mättes med termoelement.Re, Milling and other intermittent metal cutting operations often cause thermal fatigue in the cutting tools used. This type of wear is more severe during machining of heat resistant alloys such as austenitic stainless steel because of more extreme temperature variations during the cutting procedure. This phenomenon is further accelerated by employing flood cooling. Milling of stainless steel is therefore usually performed dry. Dry cutting is, however, not without its share of problems, since high temperatures develop in the cutting zone which adversely affect tool life and to which extent the productivity can be increased via higher cutting speeds or feed rates. Parts that take longer to manufacture are not only bad for business economics, but also for the environment due to higher energy consumption.Minimum quantity lubrication is a method that uses minimal quantities of oil dispersed as aerosol toward the cutting edge. This lubricates the tool-workpiece interface which minimizes frictional heat. This way, the total heat during cutting can be reduced while also avoiding the extreme temperature variations associated with flood cooling. The purpose of this thesis is to study and compare the performance of dry cutting and minimum quantity lubrication during face milling of austenitic stainless steel, 1.4301.The tool wear rates of the cutting tools and surface quality of the machined workpiece were compared for the two cutting environments. Of particular interest was the question whether the material removal rate could be increased with the usage of minimum quantity lubrication without adversely impacting the tool life or workpiece surface quality.A full factorial design of experiments was created, and the comparison of dry machining and minimum quantity lubrication was done by face milling with PVDcoated carbide inserts. An optical stereo microscope was used for the analysis of rake and flank wear after roughly 3 minutes of cutting tool engagement. Surface roughness of m

This work aims to investigate and assess the beneficial function and feasibility of nanofluids in minimum quantity lubrication (MQL) assisted machining. The goal is to develop newly generated CNT based nano hybrid cutting fluid and demonstrate its effect on surface roughness of Al alloy. Moreover, the fabricated nano hybrid cutting fluid will eventually reduce cutting fluid consumptions and maintain an eco-friendly environment. Three conditions were used to perform the machining process such as dry condition, conventional oil and Al_2O_3/CNT nanoparticle with EVO oil as base fluid. The lowest surface roughness achieved for nanofluid and the maximum surface roughness for the dry condition. In terms of looking for optimum parametric combination, Artificial Neural Network (ANN) and Response Surface Methodology (RSM) have been used. The ANN technique has proved its efficiency since its correlation coefficients, mean prediction errors (MPEs), and root mean square errors (RMSEs) are small compared to the RSM approach.

The deterioration of the cutting edge during machining influences production cost and productivity. The adhesion is one of the main wear mechanisms. This study delves into the adhesive mechanism in the context of turning, milling, and drilling, focusing on three different cutting materials: 34CrNiMo6, 1.437 stainless steel, and ductile iron. Building upon previous research on the adhesive process in turning, a dynamic model was developed to understand the mechanism further. The results showed that adhesion is a general phenomenon occurring in all tested work materials, but with varying intensity levels. Intermittent cuts did not greatly impact the adhesive mechanism, and cutting data, coolant, and chip breaking also showed little effect. However, the presence of graphite in ductile iron temporarily inhibited adhesion. The source of the adhesive sound was found to be the pivoting movement of the chip as it binds and rips off the cutting tool, leading to a frequency shift upon detachment. The adhesive wear was found to be a thermal mechanism, where chemical reactions between the SiO2 in the work material with the cutting tool caused thermal cracks and low-frequency fatigue.

This paper presents a comprehensive cross-functional analysis of machining operations for ductile cast iron components in the automotive industry, focusing on the problem of chip carryover and its impact on downstream processes. The research aims to understand the role of machining and identify the source of the issue, by analyzing different machining sequences and the chips that affect the final product or subsequent production stages. To achieve this, the study initially focuses on a 5-axis machining production cell, evaluating the current choice of tooling systems and peripheral processes such as cooling, lubrication, and chip removal solutions. Based on empirical findings, the study presents newly developed solutions to address and minimize the problem of chip carryover in the current production context. These solutions include implementing new sequences of operations and optimizing peripheral processes to prevent chip buildup and reduce the need for manual intervention. The results of the study demonstrate the effectiveness of the proposed solutions in reducing production costs and improving product quality. Overall, this research highlights the importance of a broad and cross-functional approach for developing and implementing improved production strategies. By providing an alternative to a costly manufacturing issue, this study contributes to the ongoing efforts to improve the efficiency and sustainability of manufacturing processes in the automotive industry., This paper presents a study focused on addressing the issue of chip carryover in machining operations for ductile cast iron components in the automotive industry. Chip carryover occurs when the metal chips resulting from a machining process such as drilling or milling, are not correctly removed from the workpiece. Hence, these small parts of metal remain with the part and get carried over to later stages of the manufacturing process, potentially causing problems. To achieve this, the study conducts a comprehensive and cross-functional analysis of machining operations and their impact on downstream processes. A specific focus is placed on a milling center, evaluating tooling systems, cooling, lubrication, and chip removal solutions. By analyzing empirical findings, the research proposes innovative solutions to minimize chip carryover, ensuring improved product quality and reduced production costs. The newly developed solutions involve implementing optimized sequences of operations and peripheral processes to prevent chip accumulation, thereby reducing the need for manual intervention. Through the implementation of these solutions, the study demonstrates their effectiveness in enhancing the efficiency and sustainability of the manufacturing processes conducted at this site. This research underscores the significance of a holistic and cross-functional approach in developing and implementing improved production strategies. By providing an alternative to costly manufacturing issues, this study contributes to the ongoing efforts to enhance the efficiency and sustainability of manufacturing processes in the automotive industry, benefiting both the industry and the broader public.

In this study, Al2O3-TiB2 coating was successfully deposited on steel substrates by in situ plasma spraying (IPS) using H3BO3, Al, and TiO2 reactants. Beside TiB2 and Al2O3, Al18B4O33 was formed as a by-product with ratio of about 13 wt%. The effect of milling time of reactant and the reaction behavior was also explored. Milling process for at least 10 h can promote efficiency of reaction and milling for efficient production of Al2O3-TiB2 composite. Wear behavior was examined in terms of hardness, wear track width, and wear rate of the coatings with respective measured values of 797.6 HV, 1061.3 µm, and 4.2 × 10−3 mm3/N.m. Based on the FESEM observations, the thickness of abrasive coating was 417 µm, delamination and adhesion were the main wear mechanisms in Al2O3-TiB2-coated specimens., Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Materials and Environment

The effect of pure Ni addition (5 wt.%) in MgH2 powder was investigated mechanochemically for short milling times (15, 30, and 45 min). Obtained MgH2-Ni system was characterized by XRD, SEM-EDS, PSD, DSC, and TPD. Compared to pure MgH2, uniform distribution of nickel reduces the temperature of H2 desorption by more than 100 °C. It is shown that influence of two important processes, grinding and catalysis, may be followed separately. We can conclude that the catalysis of H2 desorption by Ni particles on MgH2 matrix is the dominant effect for the investigated short milling times.

Rapid prototyping technology has emerged as one of the most significant technologies that enable the reduction of the product development and production times. The novel low-cost desktop multifunctional machine tool, able to support additive and subtractive manufacturing of symmetrical and asymmetrical cylindrical parts, is presented. The core of the invention is the new concept of the machine tool with a horizontal rotating device chuck (3-axis rotary CNC) as a multifunctional rapid prototyping machine. The specific concept of the machine’s geometry enabled reconfigurability, i.e., the simple change of tools for the unique combination of three production technologies on one desktop machine: milling, laser engraving, and rotary 3D printing. Open-source control infrastructure enables end-user customization and machine upgradeability and achieves cost-effectiveness. Innovative design enables additional technological advantages in the desktop rapid prototyping machine tools domain, such as: 1) the possibility of the production of a single cylindrical part completely in one clamping by using a combination of additive and subtractive manufacturing (which achieves effective use of material, energy, and reduced time consumption, increased productivity, increased accuracy); 2) modularity and the open architecture control structure which allows for upgradeability and further development of the machine according to end-user needs (possibility to add supplementary axes per users’ demands; 3) digital twin technology. MultiProDesk is a valuable production tool for SMEs in various production technologies where it allows users to adopt mass customization concepts and to reach mass personalization production (as a step to Industry 4.0).

The project is situated in the neighbourhood of Bressoux in the post-industrial city Liege in Belgium. Bressoux felt at first as a deserted place. It gave the impression that only people live here because of financial necessity. The people with better jobs move away, the ones left behind seem forgotten and neglected. “The winner takes it all!” is the attitude of our economy (Brugmans, 2016, p.6). What is left for the ‘others’? Are they the ones hidden behind the facades of Bressoux? What will their future perspective be? In order to explore the lives of the people in multicultural neighbourhoods like Bressoux, a common ground had to be found. I believe it is food. And to be more specific: bread. Bread is used in almost every cuisine of every culture. Therefore the research follows the journey of bread trough time, space and the everyday life: Daily bread. The historical and social-cultural research of the production and consumption of bread, also led to an extended research on milling and (communal) wood-fire ovens. The research gave awareness of the importance of how we deal with our primary needs of food, warmth and community. They should be more visible and more directly involved in our daily lives. The conclusion of the research is translated into the design. The design contains a communal oven within a living room for the neighbourhood, connected with a mill factory using the traditional stone-milling. This is situated in an existing building and surrounded by seven new-built apartment blocks. The apartment blocks consists of three or five apartments, all connected with the chimney of a tile-stove which provides most of the warmth and is located on the ground floor in a shared space. The mill gives the neighbourhood the opportunity to buy local produces and healthy flour and the communal wood-fire oven a place to make their own bread or other food and share it with their neighbours in a warm space. The housing is based on the principle of sharing, Architecture, Urbanism and Building Sciences | Urbanism

In models for the dynamics of the milling process, the characterization of the chip thickness plays a central role. In this abstract, we develop an alternative model for the computation of the chip thickness. The chip thickness is computed using (i) a surface function describing the evolution of the milled surface and (ii) the information about the shape of the workpiece. Combining a partial differential equation (PDE) governing the surface function with the ordinary differential equations (ODE) governing the tool dynamics, a mixed PDE-ODE model formulation is proposed to describe the milling process dynamics. Compared with the classical delay differential equation (DDE) formulation for milling dynamics, this novel formulation is more accurate because less assumptions have been made to compute the chip thickness. Case studies show that the two formulations generally agree well with each other. However, a sizable difference on predicted limit cycles, characterizing the periodic tool motion, occurs when the axial depth of cut is relatively large. This PDE-ODE formulation brings a novel perspective for analyzing milling processes as well as a means to assess the validity of models that based on DDE formulation.

This study analyses the factors that contributed to the collective behaviour of the mob at the January 6th Capitol riot and which factors were most influential. Previous studies have primarily relied on motive and justification in explaining prevention means and in part the actions of crowds during riots. However, have been unable to provide an in-depth understanding of a crowd’s collective behaviour and the process that occurs when individuals are placed in a crowd setting. Data was collected through reports and articles to accumulate information on the event, those involved and relevant theories, these were placed in a coding agenda through deductive content analysis that was followed, throughout the study. The results found that baiting, milling, norms and SIDE were crucial influential factors that contributed to the mob’s collective behaviour. Furthermore, the collective behaviour can be deemed as normative for the situation and that in turn collective behaviour contributes to the violence at the Capitol riots.

Porcelain tile manufacturing is an energy-intensive industry that is in dire need of increasing productivity, minimizing costs, and reducing CO2 emissions, while keeping the product quality intact to remain competitive in today’s environment. In this contribution, alternative processing parameters for the porcelain tile production sequence were proposed based on simulation-based process optimization. Flowsheet simulations in the Dyssol framework were used to study the impact of the milling and firing process parameters on the electrical and thermal energy consumption, final product quality, and productivity of the entire processing sequence. For this purpose, a new model of gas flow consumption in the sintering stage was proposed and implemented. During optimization, the primary condition was to maintain the product quality by keeping the final open porosity of the tile within the specified industrial range. The proposed simulation methodology proved to be effective in predicting the influence of the processing parameters on the intermediate and final products of the manufacturing sequence, as well as in estimating the production costs for the Brazilian and Spanish economic conditions. This approach has shown great potential to promote digitalization and establish digital twins in ceramic tile manufacturing for further in-line process control., Porcelain tile manufacturing is an energy-intensive industry that is in dire need of increasing productivity, minimizing costs, and reducing CO2 emissions, while keeping the product quality intact to remain competitive in today’s environment. In this contribution, alternative processing parameters for the porcelain tile production sequence were proposed based on simulation-based process optimization. Flowsheet simulations in the Dyssol framework were used to study the impact of the milling and firing process parameters on the electrical and thermal energy consumption, final product quality, and productivity of the entire processing sequence. For this purpose, a new model of gas flow consumption in the sintering stage was proposed and implemented. During optimization, the primary condition was to maintain the product quality by keeping the final open porosity of the tile within the specified industrial range. The proposed simulation methodology proved to be effective in predicting the influence of the processing parameters on the intermediate and final products of the manufacturing sequence, as well as in estimating the production costs for the Brazilian and Spanish economic conditions. This approach has shown great potential to promote digitalization and establish digital twins in ceramic tile manufacturing for further in-line process control., Deutscher Akademischer Austauschdienst (DAAD)

This research paper is concerned with the experimental study of high-feed end milling of 1.4541 (X6CrNiTi18-10) stainless steel with replaceable cermet plates. Several machining operations were performed under different cutting conditions. The variable values were depth of cut, feed per tooth and cutting speed. The results were analyzed, and cutting forces were evaluated for dependence on cutting conditions (cutting speed, depth of cut, feed per tooth). The obtained data were statistically processed and plotted in graphs. It was found that the percentage distribution of cutting forces changed as the tool load increased. The ratio of forces acting in individual axes also changed with varying trends. An increasing trend was recorded in the x and y axes, while a decreasing trend was recorded in the z axis. Measured change, approximately 10%, can no longer be neglected as it can significantly influence the clamping stability of a part.

Milling is a complex and versatile process employed to produce parts by material removal, especially in the aerospace industry. However, two phenomena—tool wear and chatter—limit the process's quality and production rate by reducing machining efficiency, accuracy and precision. As a result, industries aim to monitor these conditions in realtime. Furthermore, early identification of chatter is essential for advanced manufacturing of metal components, as it has a significant effect on surface finish and tool lifetime presenting a major limitation in increasing the material removal rate. These two challenges are frequently faced in the machining of hard-to-cut materials such as titanium alloys, which are widely used in various industries because of their high strength-to-weight ratio, exceptional corrosion resistance, and other physical and mechanical properties that are highly desired for broad applications. However, titanium alloys have low machinability, which is characterised by great variations in the cutting forces. This accelerates chatter occurrence and tool wear progress. Literature reports a variety of investigations for tool wear and chatter monitoring, but they have mostly been studied as separate and unrelated phenomena. Scholars have modelled and predicted the co-occurrence of both events, but there are some discrepancies among the findings. Therefore, to improve the quality and production of titanium alloy workpieces, this experimental study investigates the simultaneous occurrence and correlation of tool wear and chatter in milling the most employed titanium alloy, Ti6Al4V. This research aims to determine whether tool wear progress has a significant effect on chatter during the milling of Ti6Al4V., Thesis (PhD Doctorate), Doctor of Philosophy (PhD), School of Eng & Built Env, Science, Environment, Engineering and Technology, Full Text

This chapter discusses the maize production in the world is mostly attributed to the development of technology and the seed industry, increased agro-efficiency, innovative maize food, and technical maize products, and, principally, innovation and increased production of bioethanol and biodiesel. The physical properties of maize grains are a group of important quality attributes, in addition to the chemical composition and cellular structure of the grains. Besides the proportion of glassy versus floury endosperm, hardness is also affected by the endosperm cell structure and pericarp thickness. Cellular compactness, cell sizes, and cell wall thickness all affect the kernel hardness but the most important is the endosperm cell structure: starch granules are surrounded with continuous protein matrix which is thinner and weaker in floury endosperm. Density is defined as a ratio of weight and volume and expresses the weight of unit volume i.e. specific weight. It is expressed as bulk density or true density.

[EN] Synthetic gibbsite (Al(OH)3) was mechanically activated by attrition milling for 24 h, with various grinding ball-to-powder weight ratios (0, 5, 10, and 20), and characterized by thermal analysis (TG-DSC). Further, we determined the corresponding kinetic parameters using the model-free and model-fitting methods from the Thermogravimetric Analysis (TG) data set. We found that the activation energies provided by both models agree very well. At temperatures higher than 350 °C, the milled samples (GB5, GB10, and GB20) lose mass very slowly, while the unmilled sample (GB0) decomposes faster. In addition, we demonstrated that the decomposition mechanism of each sample engages multi-step reactions, and the corresponding activation energies change with the increasing milling conditions., [ES] Se ha activado mecánicamente gibbsita sintética, Al(OH)3, mediante molienda por atrición durante 24 h. Se han empleado diversas relaciones de bolas de molienda a polvo (0, 5, 10 y 20, en peso) y se caracterizó mediante análisis térmico (TG-DSC). Con estos resultados se determinaron los correspondientes parámetros cinéticos a través de los análisis sin modelo y con modelo de ajuste del conjunto de datos de análisis termogravimétrico (TG). Se ha encontrado que las energías de activación proporcionadas por ambos modelos concuerdan muy bien. A temperaturas superiores a 350 °C las muestras molidas (GB5, GB10 y GB20) pierden masa muy lentamente, mientras que la muestra sin moler (GB0) se descompone más rápido. Además, se demuestra que el mecanismo de descomposición de cada muestra involucra reacciones con varias etapas, y las correspondientes energías de activación cambian con el incremento de la energía de molienda.

Attrition-milling process has been applied to Ce-doped CaMnO3 precursors to obtain small grain-size powders. The use of Ce4+ as dopant instead a Rare Earth3+ has allowed decreasing by 50% the atomic proportion of dopant, to obtain equivalent charge carrier concentration, which is required for attaining promising properties for thermoelectric applications. An impressive decrease in thermal processing time was achieved, together with an increase in thermoelectric performances, when compared to classically prepared materials. XRD and SEM analysis have confirmed that the final material is nearly single phase. Moreover, grain sizes and density increase with the sintering duration. These microstructural differences are reflected in a significant decrease in electrical resistivity, when compared to the samples prepared from ball-milled precursors (used as reference), without drastically modifying the Seebeck coefficient values. On the other hand, despite of their high electrical conductivity, thermal conductivity is decreased for short time sintered materials, leading to the highest ZT values at 800 °C (∼0.27) in samples sintered for 1 h at 1310 °C. These values are among the best reported in the literature, but they have been obtained in very short time using a simple, and easily scalable process. The suggested approach presented in this work appears particularly promising for large-scale production of oxide-based thermoelectric modules for power generation.

Background: Distortion arises during machining of metallic parts from two main mechanisms: 1) release of bulk residual stress (BRS) in the pre-form, and 2) permanent deformation induced by cut tools. Interaction between these mechanisms is unexplored. Objective: Assess this interaction using aluminum samples that have a flat surface with variations of BRS, where that surface is subsequently milled, and we observe milling-induced residual stress (MIRS) and distortion. Methods: Plate samples are cut from two kinds of large blocks, one kind stress-relieved by stretching and a second kind solution heat treated, quenched and aged. The BRS field in the plates is known from a recent series of measurements, being small in the stress relieved plates (within ±20 MPa) and large (±100 MPa) in the quenched plates, varying from tension to compression over the surface that is milled. MIRS is measured following milling using hole-drilling. Distortions of thin wafers cut at the milled surfaces are used to elucidate BRS/MIRS interactions. A finite element (FE) model and a strength of materials model are each used to assess consistency between wafer distortion and measured MIRS. Results: Milling in samples with high BRS magnitude changes the directions of MIRS and distortion relative to the milling direction, with the direction of maximum curvature rotating toward or away from the milling direction depending on the sign and direction of BRS. High magnitude BRS was also found to increase the wafer peak arc height, nearly doubling the amount found in low BRS samples. Conclusion: Measured residual stress and observed wafer distortion both show interactions between MIRS and BRS. Stress analysis models show that the differences in measured MIRS are consistent with the differences in observed distortion.

Studiens syfte avsåg att möjliggöra 5-axlig bearbetning med 3D- uppriktning i en existerande fräsmaskin, för framtida automatisering av en bearbetningsprocess kallad hybridbearbetning. Projektet innefattade även utvärdering av mätresultat och lösningen krävde säkerställning av mätningar med hög precision. Genom litteraturundersökningar och observationer av avdelningens maskiner och processer kunde relevant information inhämtas. Utförandet bestod av analyser och modellering i Siemens NX, jämförelsetester av positioneringsmatriser, felsökning, implementering av mätresultat till fräsmaskin och statistisk analys av data. Planering och koordinering blev även en vital del då många parter ingick i projektet. Projektet presenterar jämförelsetester som bekräftat mätningar av testdetaljer. Möjligheter för att teoretiskt hämta mätresultat har identifierats. En CAD-modell där mätresultat kan analyseras och bekräftas har skapats, den kan även användas av avdelningen för framtida analyser av mätningar. Utveckling har medfört lyckad 3-axlig bearbetning med 3D-uppriktning. Däremot blev 5-axlig bearbetning med 3D-uppriktning inte genomförbart, på grund av dess oförväntade komplexitet. Projektet har medfört mycket information som kan vara användbart för fortsatt utveckling av lösningen, om företaget avser projektet ekonomiskt försvarbart., The purpose of the study was to enable 5-axis machining with 3D alignment in an existing milling machine, for future automation of a process called hybrid machining. The project also included evaluation of measurement results and the solution required ensuring measurements with high precision. Through literature surveys and observations of machines and processes, relevant information could be obtained. The execution consisted of analyzes and modeling in Siemens NX, comparison tests of positioning matrices, troubleshooting, implementation of measurement results to the milling machine and statistical analysis of data. Planning and coordination also became a vital part as many parties were involved in the project. The project presents comparative tests that have confirmed measurements of test products. Opportunities for theoretically retrieving measurement results have been identified. A CAD-model where measurement results can be analyzed and confirmed has been created, it can also be used by the company for future analyzes of measurements. Development has led to successful 3-axis machining with 3D-alignment. However, 5-axis machining with 3D alignment was not feasible, due to its unexpected complexity. The project has provided a lot of information that can be useful for further development of the solution, if the company intends the project financially defensible., 2022-07-01

The aim of this study was to improve the machinability of wood-plastic composites by exploring the effects of different wood-plastic composites on machinability. In particular, the effects of milling with cemented carbide cutters were assessed by investigating cutting forces, cutting temperature, surface quality, chip formation, and tool wear. The cutting parameters determined to yield an optimal surface quality were rake angle 2°, cutting speed 9.0 m/s, feed per tooth 0.3 mm, and cutting depth 1.5 mm. In these optimized milling conditions, the wood-plastic composite with polypropylene exhibited the highest cutting forces, cutting temperature, and tool wear, followed by polyethylene and polyvinyl chloride wood-plastic composites. Two wear patterns were determined during wood-plastic composite machining, namely chipping and flaking. Due to the different material composition, semi-discontinuous ribbon chips and continuous ribbon chips were generated from the machining process of wood-plastic composites with polypropylene and polyethylene, respectively. The wood-plastic composite with polyvinyl chloride, on the other hand, formed needle-like chips. These results contribute to a theoretical and practical basis for improved wood-plastic composite machining in industrial settings., Validerad;2022;Nivå 2;2022-02-11 (hanlid);Part of special issue: Manufacturing and Mechanics of Materials;Funder: National Natural Science Foundation of China (31971594); Natural Science Foundation of the Jiangsu Higher Education Institutions of China (21KJB220009), Technology Innovation Alliance of Wood/Bamboo Industry (TIAWBI2021‐08); Self‐Made Experimental and Teaching Instruments of Nanjing Forestry University in 2021 (nlzzyq202101); International Cooperation Joint Laboratory for Production, Education, Research and Application of Ecological Health Care on Home Furnishing

Peer Reviewed, Objectius de Desenvolupament Sostenible::7 - Energia Assequible i No Contaminant, Objectius de Desenvolupament Sostenible::7 - Energia Assequible i No Contaminant::7.2 - Per a 2030, augmentar substancialment el percentatge d’energia renovable en el con­junt de fonts d’energia, Objectius de Desenvolupament Sostenible::7 - Energia Assequible i No Contaminant::7.3 - Per a 2030, duplicar la taxa mundial de millora de l’eficiència energètica, Objectius de Desenvolupament Sostenible::7 - Energia Assequible i No Contaminant::7.b - Per a 2030, ampliar la infraestructura i millorar la tecnologia per tal d’oferir serveis d’energia moderns i sos­tenibles per a tots els països en desenvolupament, en particular els països menys avançats, els petits estats insulars en desenvolupament i els països en desenvolupament sense litoral, d’acord amb els programes de suport respectius, Postprint (published version)

In this project the objective is to understand how to design a braiding machine capable of automated production of Omnifibre in a research environment. Automated production of Omnifibre is the key issue for the researchers as they want to increase the weaveabilty of the fibers and make it more suitable for use in active textiles. To achieve the necessary knowledge when designing a braiding machine, an extensive literature study was performed which focused on braids, braiding machines, and CNC manufacturing. An Interview with a researcher and with a manufacturing expert was conducted. Simulations of different braiding machine configurations were performed in TexMind braiding machine configurator. Solidworks was used to estimate the size of the braiding machine. A large amount of the machine’s parts were manufactured on a CNC mill and lathe to test manufacturability and to aid in designing optimal subsystems. The result is a proposed design for a braiding machine in the form of a 3-D model and a partially completed prototype used for testing and design evaluation. The conclusion is that Omnifibre is much like other ultra-fine braided threads, and the research on its applicability has a big impact on the braiding machine’s design, especially on flexibility in thread material and braiding patterns.

High strength aluminum alloys have for a long time been a popular material utilized in the automotive and aerospace sector due to coveted mechanical properties in terms of weight, strength, fatigue, and corrosion. However, tribological mechanisms such as tribo-film formation and material transfer during the metal cutting manufacturing process of aluminum impose significant reduction of machining and tool-life performance. Additionally, environmental aspects associated with metal cutting manufacturing has got more interest and pushed cutting tool development in new directions to meet increased customer demands. One possible way of achieving this, is the implementation and utilization of diamond based cutting tools which has been shown to perform well in machining of high strength aluminum. However, in depth knowledge regarding the tribological properties of diamond based cutting tools is currently lacking. Thus, the aim of this master thesis has been to investigate the refined tribological characteristics and properties of WC-Co cemented carbide cutting tools coated with synthetically grown CVD diamond. Tribological testing methods, such as frictional scratch/sliding, pin-turning, contact-zone temperature measuring, and longitudinal turning have been conducted to acquire extensive amount of research material in the form of test samples and data information. Furthermore, pin-turning tests were performed using a newly developed Tribojan pin-turning equipment and the performance of this was evaluated as a subgoal task. Specimen sample analysis have primarily been performed through LOM and SEM/EDS microscopy techniques. The results acquired from testing, microscopy analysis and data set evaluation have showed promising results in terms of frictional characteristic and material transfer properties regarding CVD diamond coated surfaces. The average CoF of CVD diamond sliding against an Alumec 89 aluminum alloy surface were somewhat lower as compared with similar sliding of, Höghållfasta aluminiumlegeringar har länge varit ett populärt material inom bil- och flygindustrin på grund av deras eftertraktade mekaniska egenskaper när det gäller vikt, styrka, utmattning och korrosion. Däremot medför tribologiska fenomen, så som tribofilmbildning och materialöverföring under metallskärande tillverkningsprocesser för aluminium, en betydande minskning av prestanda hos utrustning och skärverktygens livslängd. Dessutom har miljöaspekterna i samband med metallskärande tillverkning fått ökat intresse och därmed drivit utvecklingen av skärverktyg i nya riktningar för att uppfylla kundernas ökade krav. Ett möjligt sätt att uppnå detta är att införa och använda diamantbelagda skärverktyg, vilka har visat sig fungera bra vid bearbetning av höghållfast aluminium. Dock saknas det för närvarande djupgående kunskaper om de tribologiska egenskaperna hos dessa diamantbaserade skärverktyg. Syftet med detta examensarbete har därför varit att undersöka de förfinade tribologiska egenskaperna hos WC-Co skärverktyg av hårdmetall belagda med syntetiskt odlad CVD-diamant. Tribologiska testmetoder, så som friktionsskrapning/glidning, pinnsvarvning, temperaturmätning i kontaktzonen samt longitudinell svarvning, har genomförts för att samla in analysmaterial i form av prover och datainformation. Dessutom utfördes pinnsvarvningstesterna med hjälp av en nyutvecklad så kallad Tribojan-utrustning, vars prestanda har utvärderats som ett delmål i projektet. Analyser av provexemplar har huvudsakligen utförts med hjälp av mikroskopitekniker så som LOM och SEM/EDS. Resultaten från provning, mikroskopianalys och utvärdering av data har visat lovande resultat när det gäller friktions och materialöverföringsegenskaper för CVD-diamantbelagda ytor. Den genomsnittliga CoF för CVD-diamant som glider mot en yta av aluminiumlegeringen Alumec 89 var något lägre jämfört med motsvarande glidning av konventionellt WC-Co hårdmetallmaterial. Dessutom verkar friktionsbeteendet hos CVD-diamant va

Although much research has been carried out in the field of the milling of GFRP (Glass Fibre Reinforced Polymer) composites, the complexity of the process is such that it is still not mastered in many industrial cases. The current work is aimed at studying the influence of three different geometries of PCD (PolyCrystalline Diamond) and cemented tungsten carbide cutting tools during the up-milling of GFRP composites at fixed cutting conditions (vc = 502 m/min and vf = 420 mm/min). Delamination, cutting forces and tool wear are compared at the fresh and worn states, and the correlation between the lifespan and the cost of the cutting tool is analysed. The main wearing phase of the tools was performed under the conditions of production in the facilities of a company (Sobelcomp, Loncin, Belgium). The results indicate that the PCD tool with the straight edge, inclined peripheral tooth shape produces the smallest total cutting force and less delamination (shortest and lowest number of delaminated fibres) at both fresh and worn states. Moreover, the grinding ability of PCD makes the cutting tool cost per part lower than for cemented carbide. The PCD tool is therefore the best option to mill GFRP parts.