Products with complicated shapes require superior surface finish to perform the intended function. Despite significant developments in technology, finishing operations are still performed semi automatically/manually, relying on the skills of the machinist. The pressure to produce products at the best quality in the shortest lead time has made it highly inconvenient to depend on traditional methods. Thus, there is a rising need for automation which has become a resource to remain competitive in the manufacturing industry. Diminishing return of trading quality over time in finishing operations signifies the importance of having a pre-determined trajectory (tool path) that produces an optimum surface in the least possible machining time. Tool path optimization for finishing process considering tool kinematics is of relatively low importance in the present scenario. The available automation in grinding processes encompass around the dynamics of machining. In this paper we provide an overview of optimizing the tool path using evolutionary algorithms, considering the significance of process dynamics and kinematics. Process efficiency of the generated tool movements are studied based on the evaluation of relative importance of the finishing parameters. Surface quality is analysed using MATLAB and optimization is performed on account of peak to valley height. Surface removal characteristics are analysed based on process variables that have the most likely impact on surface finish. The research results indicated that tool path is the most significant parameter determining the surface quality of a finishing operation. The inter-dependency of parameters were also studied using Taguchi design of experiments. Possible combinations of various tool paths and tool influencing parameters are presented to realize a surface that exhibits lowest errors. / European Horizon 2020 Project SYMPLEXITY

Through the selection of six representative typical Swedish chairs from each era, I present manufacturing techniques and how the craftsmanship has affected the style of the chairs over time. My main source material is the objects themselves. I chose to analyze the constructions and what can distinguish them apart in techniques, material choices, aesthetics and design. The main part of my work has been to find out what are the most occurring damages and its causes. Most damages from renaissance to biedermeier can be linked to the mortise joint. Through interviews with experienced conservators and with my own experiences as a cabinet maker and conservator, I discuss the concept of the ultimate chair design in terms of stability. I have come to the conclusion that the most solid chair is the eight to twelve framed chairs from the Renaissance, but the chair must be adapted to the intended use.

I mitt examensarbete undersöker jag vilken putsmetod som lämpar sig bäst för putsning av infärgat faner utan att infärgat damm fastnar på oönskade områden. Testområdet har varit avgränsat till att undersöka detta problem tillsammans med andra, icke infärgade faner. Frågan är om det finns en metod som på ett effektivt och ergonomiskt sätt garanterar ett bra resultat? Mina tester utgår från om val av material, fiberriktning och snittyta har betydelse för hur det infärgade dammet fastnar på ytan. Min förhoppning är att hantverkare och formgivare ska ta hjälp av denna undersökning för att lättare kunna göra medvetna val där infärgade faner kombineras med andra träslag. Genom intervjuer med andra hantverkare, om deras erfarenheter har ett problemområde kartlagts utifrån vad som är mest relevant för undersökningen. Även litterära studier har gjorts för att bättre förstå träts anatomiska egenskaper. För att uppnå optimala förutsättningar för att infärgat damm inte ska fasta på oönskade områden visar testerna, genom att kombinera infärgat faner med ett bandporigt träslag som har en radiell snittyta tillsammans med en fiberriktning som ligger i samma riktning som putsriktningen, med en putsmetod där direkt sug över putsytan verkar samtidigt som putsningen ger bäst förutsättning för att infärgat damm inte fastnar på oönskade områden.

Additive Manufacturing (AM) is on the verge of causing a downfall to conventional manufacturing with its huge potential in part manufacture. With an increase in demand for customized product, on-demand production and sustainable manufacturing, AM is gaining a great deal of attention from different industries in recent years. AM is redefining product design by revolutionizing how products are made. AM is extensively utilized in automotive, aerospace, medical and dental applications for its ability to produce intricate and lightweight structures. Despite their popularity, AM has not fully replaced traditional methods with one of the many reasons being inferior surface quality. Surface texture plays a crucial role in the functionality of a component and can cause serious problems to the manufactured parts if left untreated. Therefore, it is necessary to fully understand the surface behavior concerning the factors affecting it to establish control over the surface quality. The challenge with AM is that it generates surfaces that are different compared to conventional manufacturing techniques and varies with respect to different materials, geometries and process parameters. Therefore, AM surfaces often require novel characterization approaches to fully explain the manufacturing process. Most of the previously published work has been broadly based on two-dimensional parametric measurements. Some researchers have already addressed the AM surfaces with areal surface texture parameters but mostly used average parameters for characterization which is still distant from a full surface and functional interpretation. There has been a continual effort in improving the characterization of AM surfaces using different methods and one such effort is presented in this thesis. The primary focus of this thesis is to get a better understanding of AM surfaces to facilitate process control and optimization. For this purpose, the surface texture of Fused Deposition Modeling (FDM) and Laser-based Powder Bed Fusion of Metals (PBF-LB/M) have been characterized using various tools such as Power Spectral Density (PSD), Scale-sensitive fractal analysis based on area-scale relations, feature-based characterization and quantitative characterization by both profile and areal surface texture parameters. A methodology was developed using a Linear multiple regression and a combination of the above-mentioned characterization techniques to identify the most significant parameters for discriminating different surfaces and also to understand the manufacturing process. The results suggest that the developed approaches can be used as a guideline for AM users who are looking to optimize the process for gaining better surface quality and component functionality, as it works effectively in finding the significant parameters representing the unique signatures of the manufacturing process. Future work involves improving the accuracy of the results by implementing improved statistical models and testing other characterization methods to enhance the quality and function of the parts produced by the AM process.

Hard chrome exhibit hardness of about 70 HRC and lubricity that prevents seizing and galling and is therefore the common first choice for engineers to reduce friction and minimize wear. These properties enable engineering applications such as cutting and drilling, especially in manufacturing, production and consumer good industries. Hard chrome has a wide set of functions as being decorative, corrosion resistant and ease cleaning procedures. Hence, electroplating is a common process to synthesize hard chrome butthis process is banned by EU due to the rise of hazardous components. However, the need for alternative material is at rise but, fundamental issues for hard chrome are yet to be solved. The purpose of the work is to develop atomic structures for two systems using different programs such as OpenMX, VESTA and Ovito. The goal is to identify atomic wear mechanisms of hard chrome in an ideal system (Al2O3- Cr) and a real system (Al2O3 - Cr2O3) using density functional theory (DFT). These two systems are analyzed since every surface oxidises in air (real system) and under increased mechanical loads the pristine surface of hard chrome (ideal system) can be exposed to the counter body (Al2O3). DFT based molecular dynamics simulations are carried out at a temperature of 300 K and a sliding speed of 10 ms−1. The simulation interval is 0-15000 fs and radial distribution function (RDF) is employed to analyse the atomic wear mechanisms. Both systems start to show adhesive wear due to amorphization, mixed with signs of abrasive wear on the atomic scale. The systems are further analyzed using electron density distribution (EDD), that plots electronic structures enhancing the analyse of different type of bondstaking place. The bulk structures mainly show covalent bonds with ionic and metallic bonds less represented. Furthermore, same observations have been made for the interfaces of the ideal and real system. / Hårdkrom uppvisar hårdhet på ungefär 70 HRC och en smörjförmåga som förhindrar nötning och är därför det vanliga första valet för ingenjörer att minska friktionen och minimera slitaget. Dessa egenskaper möjliggör tekniska tillämpningar, såsom skärning och borrning, särskilt inom tillverknings, produktions och konsumentvaruindustrin. Hårdkrom har ett brett användningsområde och flera egenskaper såsom att vara dekorativ, korrosionsbeständig och underlätta rengöringsprocedurer. Därav är galvanisering en vanlig process för att syntetisera hårdkrom, men denna process är förbjuden av EU på grund av utsläpp av farliga komponenter. Behovet av alternativt material är vid uppgång men, de grundläggande problemen för hård krom är ännu inte lösta. Syftet med arbetet är att ta fram atom strukturer för två system med hjälp av olika program, såsom OpenMX, VESTA och Ovito. Målet är att identifiera vilken typ av nötning som sker på hårdkrom i ett idealt system (Al2O3- Cr) och i ett verkligt system (Al2O3- Cr2O3) genom att använda täthetsfunktionalteorin (DFT). Dessa två system analyseras eftersom varje yta oxiderar i luften (verkligt system) och under ökade mekaniska belastningar kan den orörda ytan av hårtkrom (idealiskt system) exponeras för motkroppen (Al2O3). DFT simuleringar är skapade med en temperatur på 300 K och en glidningshastighet på 10 ms−1. Simulerings intervallet är från 0-15000 fs och med hjälp av radiell fördelningsfunktion (RDF) analyseras de atomiska nötnings mekanismerna. Båda systemen börjar visa adhesiv nötning på grund av amorfisering, samt ett tecken på abrasiv nötning på en atomisk skala. Systemen analyseras vidare med användning av elektrondensitetsfördelning (EDD) som plottar elektroniska strukturer vilket förbättrar analysen av olika typer av bindningar som äger rum. Bulkstrukturerna visar huvudsaklig en kovalent bindning med joniska och metalliska bindningar mindre representerade. Samma observationer har gjorts för gränssnitten mellan det ideala och verkliga systemet.

Laser beam welding has been widely applied in different industrial sectors due to its unique advantages. However, there are still challenges, such as beam positioning in T-joint welding, and gap bridging in butt joint welding,especially in the case of varying gap width along a joint. It is expected that enabling more advanced control to a welding system, and obtaining more in-depth process knowledge could help to solve these issues. The aim of this work is to address such welding issues by a laser beam shaping technology using a novel deformable mirror together with computer vision methods and also to increase knowledge about the benefits and limitations with this approach. Beam shaping in this work was realized by a novel deformable mirror system integrated into an industrial processing optics. Together with a wave front sensor, a controlled adaptive beam shaping system was formed with a response time of 10 ms. The processes were monitored by a coaxial camera with selected filters and passive or active illumination. Conduction mode autogenous bead-on-plate welding and butt joint welding experiments have been used to understand the effect of beam shaping on the melt pool geometry. Circular Gaussian, and elliptical Gaussian shapes elongated transverse to and along the welding direction were studied. In-process melt pool images and cross section micrographs of the weld seams/beads were analyzed. The results showed that the melt pool geometry can be significantly modified by beam shaping using the deformable mirror. T-joint welding with different beam offset deviations relative to the center of the joint line was conducted to study the potential of using machine learning to track the process state. The results showed that machine learning can reach sufficient detection and estimation performance, which could also be used for on-line control. In addition, in-process and multidimensional data were accurately acquired using computer vision methods. These data reveal weaknesses of current thermo-fluid simulation model, which in turn can help to better understand and control laser beam welding. The obtained results in this work shows a huge potential in using the proposed methods to solve relevant challenges in laser beam welding. / Lasersvetsning används i stor utsträckning i olika industrisektorer på grund av dess unika fördelar. Det finns emellertid fortfarande utmaningar, såsom rätt positionering av laserstrålen vid genomträngningssvetsning av T-fogar och hantering av varierande spaltbredd längs fogen vid svetsning av stumfogar. Sådana problem förväntas kunna lösas med avancerade metoder för automatisering, metoder som också förväntas ge fördjupade kunskaper om processen. Syftet med detta arbete är att ta itu med dessa problem med hjälp av en teknik för lasereffektens fördelning på arbetsstycket, s.k. beam shaping. Det sker med hjälp av en ny typ av i realtid deformerbar spegel tillsammans med bildbehandling av kamerabilder från processen. För- och nackdelar med detta tillvägagångssätt undersöks.Beam shaping åstadkoms med hjälp av ny typ av deformerbart spegelsystem som integreras i en industriell processoptik. Tillsammans med en vågfrontsensor bildas ett adaptivt system för beam shaping med en svarstid på 10 ms. Processen övervakas av en kamera linjerad koaxialt med laserstrålen. För att kunna ta bilder av svetspunkten belyses den med ljus av lämplig våglängd, och kameran är försedd med ett motsvarande optiskt filter. Försök har utförts med svetsning utan tillsatsmaterial, direkt på plåtar, svetsning utan s.k. nyckelhål, för att förstå effekten av beam shaping på svetssmältans geometri. Gauss fördelade cirkulära och elliptiska former, långsträckta både tvärs och längs svetsriktningen har studerats. Bilder från svetssmältan har analyserats och även mikrostrukturen i tvärsnitt från de svetsade plåtarna. Resultaten visar att svetssmältans geometri kan modifieras signifikant genom beam shaping med hjälp av det deformerbara spegelsystemet. Genomträngningssvetsning av T-fogar med avvikelser relativt foglinjens centrum genomfördes för att studera potentialen i att använda maskininlärning för att fånga processens tillstånd. Resultaten visade att maskininlärning kan nå tillräcklig prestanda för detektering och skattning av denna avvikelse. Något som också kan användas för återkopplad styrning. Flerdimensionell processdata har samlats i realtid och analyserats med hjälp av bildbehandlingsmetoder.  Dessa data avslöjar brister i nuvarande simuleringsmodeller,vilket i sin tur hjälper till med att bättre förstå och styra lasersvetsning.Resultaten från detta arbete uppvisar en god potential i att använda de föreslagna metoderna för att lösa relevanta utmaningar inom lasersvetsning. / <p>Till licentiatuppsats hör 2 inskickade artiklar, som visas inte nu.</p>

Hardware-in-the-loop (HiL) is a concept for testing physical equipment by connecting itto a mathematical representation (model) of the physical process. HiL-testing reduces thecost and saves time before testing the physical equipment (hardware) on the real (physical)process. The physical process chosen for this study is wire+arc additive manufacturing(WAAM), an advanced additive manufacturing (AM) technology that deposits metalbased material layer-by-layer. In this study, simulations of the robot path are carried outwhile the physical robot performs a physical process (additive manufacturing). In robotadditive manufacturing, the desired CAD model is currently sliced down into layers usingslicer software, and the layers are then translated into a path. The robot then moves alongthe path of these pre-defined layers to produce a three-dimensional structure. The heightof the produced structures and desired CAD models have deviations because of processinstabilities and temperature variations among other factors. The robot path should beupdated every time a layer is printed to compensate for the height differences. This isachieved by parametrizing the CAD model, i.e., the CAD model of the structure to beprinted is replaced by a mathematical equation (model). In this study, the mathematicalmodel is updated for each layer in real-time with feedback data from sensors that monitorthe additive manufacturing process. The concept of updating a mathematical model andexecuting it in real-time is called real-time simulation (RTS). In this study, a HiL-basedreal-time simulation setup has been developed, which predicts the required printing layerheight and the number of layers (based upon the latest feedback data from the monitoringsensors), and the required height of the structure. By combining hardware and software,a cyber-physical system has been created, enabling the transition from automation toautonomous robotics and contributing to Industry 4.0.

Magnesium with two-thirds of the density compared to aluminium and one-quarter of steel, intrigues product developers and material scientists due to the light metal’s excellent combination of strength to weight ratio as well as their capability of being produced as a High Pressure Die Cast component compared to other ferrous or light metal alloys.   However, a magnesium alloy inherits some concerning drawbacks, limiting the exploitation in structural applications and mechanical design such as automotive, heavy machinery and aerospace components. The need for a magnesium alloy that could withstand a sufficient amount of wear, temperature and corrosive environment, leads towards the investigation and evaluation of a suitable, functional coating as a solution to exploit the evident advantages a magnesium alloy exhibits. A substantial amount of research is required in order to reduce an existing knowledge gap that is the ongoing development in the search for a sufficient functional coating and adherence capability to the highly reactive substrate that is a magnesium alloy.   This industrial master thesis is an early stage investigation to evaluate how the currently used aluminium substrate with an electrodeposited coating relate and compares to a heat-treated electroless deposited coating through tribological and thermophysical induced stresses. These properties are tested with proven industrial standard methods resulted in a comprehensive conclusion and discussion regarding the feasibility of applying the coating onto a commercial magnesium alloy closely related to the Mg-alloy developed by Husqvarna and thereby contributing to technological advances to the highly relevant topic within product development in materials engineering.

Ökad användning av byggtekniken massivträ kan ge ett positivt bidrag till hållbart byggande. Utvecklingen inom datornavigerad bearbetning ger massivträ möjligheten att rationalisera byggproduktionen inom trä. Tekniken ligger rätt i tiden och kommer att värderas allt högre då den tillvaratar materialets karaktäristiska egenskaper. Utvecklingen av massivträ har resulterat i teknikvarianter av hur virke kan sammanfogas till solida element. Ett behov har funnits av en marknadsjämförelse mellan befintliga principer där studien förtydligar grundläggande skillnader för intresserade byggaktörer. Problemfrågan för denna studie har varit: vilka principer för sammanfogning av trä till plattelement inom massivträ är mest fördelaktiga? Detta sett utifrån faktorerna produktionskostnad, hållfasthet och ekologiska övervägningar. För att förtydliga den undersökta byggmetodens nytta i ett vidare perspektiv har det presenterats en allmän beskrivning av massivträ. Studien är jämförande och grundar sig på en litteraturstudie samt företagskontakter med 27 företag i 6 länder. Följande tekniker för tillverkning av plattelement i massivträ har behandlats i rapporten:  Limning  Spikning  Klamring  Skruvning  Tvärspänning  Dymling: vertikal-, horisontal- och diagonalgående samt med skruvar i trä  Laskning  Träsvetsning Studien visar att teknikerna inom massivträ skiljer sig åt. Högst bedömning får korslimmat trä (CLT) när det gäller kostnad och hållfasthet. Med hänsyn till ekologin värderas laskat trä högst. Vid en sammanvägning av hållfasthet och ekologi är den skruvformade trädymlingen fördelaktigast. Dessa alternativ ger valfrihet i synlig yta samt ett effektivt resursutnyttjande av lågvärdigare virkeskvalitéer och lämpar sig inom bostadsbyggnation. CLT är mest kostnadseffektivt, inte patentskyddat samt det mest etablerade alternativet på marknaden dock är utvecklingen av ett sunt lim fortfarande under arbete. I pågående forskning finns ett annat alternativ där tekniken träsvetsning visat ge en starkare fog än lim. Ur ekologisk synpunkt är plattelement genomgående i trä är att föredra, då det ger en sund konstruktion i full skala, eftersom inga kemikalier eller lagerresurser används. Forskning har visat att massivträ har en positiv och hälsofrämjande effekt på de boende i motsats till effekterna av icke naturliga material. / The increasing use of solid wood construction methods can have a positive impact on the sustainability of constructions. The development of computer-controlled processing techniques enables the solid wood timber industry to rationalize the construction of buildings. The solid wood techniques come at time and will be higher valued in the future due to the natural characteristics of this material. The improvement of solid wood methods has resulted in various techniques to join wood into solid prefabricated parts. There is a need for a comparative market study of the different principles of solid wood construction to widen the knowledge and to explain interested builders the viability of these techniques. The key question for this study is: Which techniques of combining solid wood elements to whole boards are the most favorable ones concerning wood construction buildings – leaving apart questions of production costs, durability and ecological considerations? To point out the utility of these construction techniques and give them a broader understanding a general study of solid wood construction has been presented. The comparative study is based as well on studies of literature as on reviews of 27 companies in 6 countries. The following techniques for the production of boards made of solid timber elements are considered in this report:  Laminating  Nailing  Stapling  Screwing  Stress laminating  Doweling: vertically, horizontally, diagonally and with wooden screws  Dovetailing techniques  Wood welding techniques The study shows that the techniques of solid wood construction are very different in itself. CLT of cross-laminated timber scores highest in terms of cost and durability, but if one considers ecological factors, dovetailing is best. Taking into account both durability and ecological considerations, doweling is best. These alternatives give some freedom of choice regarding the visibility of surfaces and the efficient use of lower qualities of timber and they are therefore suitable for residential construction buildings. CLT is the most cost-effective, not patented and well established option in the market; the development of more health-friendly adhesives is still going on. Current researches demonstrate an alternative: Wood welding joins the parts better together than gluing them. Considered from the ecological viewpoint, boards made exclusively of wood, are preferable since no chemicals or not renewable resources are used. Recent researches show, that solid wood constructions have positive effects on the health of the residents of these buildings in comparison of buildings using non-natural materials. / <p>ORCID-id: 0000-0001-7091-6696</p>

Much study has been carried out to determine the properties of Lamellar Graphite Iron (LGI) or grey iron and their relations to factors such as the cooling rate, the dendrite morphology, the pouring temperature, and so on. However, there hasn’t been much comprehensive study on the properties of LGI outside the generally used and accepted composition, with 1 to 3% Silicon. The scope of this study is to measure and evaluate the thermal conductivity and tensile strength of LGI, for a higher concentration of  Si and different carbon contents. The concentration of Si aimed for was 4% but the concentration obtained after spectroscopy was between 4.1% to 4.15%. There are two hypereutectic, one near-eutectic and three hypoeutectic samples considered and these six chemical compositions were cast under different cooling conditions . The cooling time has been varied by providing different molds of 30mm, 55mm, and 80mm diameter cylinders respectively, for all the six sample compositions. The microstructure analysis carried out studies the segregation of Si, the graphite morphology, primary austenite morphology. These factors are then compared to the thermal and tensile behavior measured in this study. It can be observed that the thermal conductivity studied in the present work has a direct correlation for a higher Si content and tends to be greater than the thermal conductivity values observed from other studies with lower content Of Si. However, the conductivity shows an inverse relation with the cooling rate and is maximum for the samples with the lowest cooling rate. The tensile strength, on the other hand, seems to have a lower value than that observed in previous studies for LGI with 1 to 3% Si, but shows a direct correlation with the cooling rate. The mean area fraction of dendrites obtained and the mean interdendritic hydraulic diameter is also measured and their influence on the properties are also studied. The addition of more Si has greatly favored the thermal behavior positively but has also reduced the tensile strength.