The paper describes an innovation project aiming to embed sensors into cast metal during the casting process. Important measurands are e.g. elongation, shear, temperature and vibration. In practice this means to turn metal components into also being digital components. This will respond to some of metal industrýs challenges; resource efficient design, increased value added for the casting sector, and general access to different possibilities of digitalization. Technical challenges lie in choices of sensor material to integrate during the casting process that maintains its sensor functionality after casting processing without degrading the mechanical strength of the metal component. Other challenges relate to signal interaction and interference between sensor and metal. To handle the technical challenges the innovation project gathers competence about metal casting and sensor technology. One goal of this innovation project is to develop an innovation platform that elevates the material based casting industry into a wholly or partially value and service based industry. Integration of sensors into cast components makes sensing functionality a natural property of metal, which in turn may turn metal into key components for the industrial digitalization.

The paper presents ongoing research on smart metal castings, meaning the technologicalinnovation of elevating cast metal components into metal components with integratedsensor functionality. Since the innovation targets aim straight at low cost industrial serialproduction, specific high cost and high-end solutions like inclusion of advancedelectronic equipment and after mounted sensors are not part of this innovationdevelopment. Integrating signal carriers inside metal castings to achieve metal castingswith sensor functionality requires robust solutions for connecting the sensor signal to thesensor interrogator and interpreter. The actual transmission of the signal may be donewirelessly or by wire. However, for several reasons there is a challenge with establishingan isolated and distinct connection between the sensor contact, and the contact at theexternal connection, regardless of whether it is to an antenna for wireless transmission orto a wire. This paper presents metallurgical challenges associated with choices ofmaterials, and combinations of metallurgical challenges and production process relatedchallenges, including the high melting temperatures. Aims are to find the rightcombinations of metal alloys, production simplicity, signal stability and robustness. Thepaper will present some of the tests made in the project so far. The project is run in aconsortium of the two Sweden-based industrial companies Husqvarna and SKF, and thetwo Swedish research institutes Swerea SWECAST and RISE Acreo.

Al-Si-Cu alloys are the most widely used materials for high-pressure die casting processes. In such alloys, Fe content is generally high to avoid die soldering issues, but it is considered an impurity since it generates acicular intermetallics (β-Fe) which are detrimental to the mechanical behavior of the alloys. Mn and Cr may act as modifiers, leading to the formation of other Fe-bearing particles which are characterized by less harmful morphologies, and which tend to settle on the bottom of furnaces and crucibles (usually referred to as sludge). This work is aimed at evaluating the influence of sludge intermetallics on the fatigue behavior of A380 Al-Si-Cu alloy. Four alloys were produced by adding different Fe, Mn and Cr contents to A380 alloy; samples were remelted by directional solidification equipment to obtain a fixed secondary dendrite arm spacing (SDAS) value (~10 µm), then subjected to hot isostatic pressing (HIP). Rotating bending fatigue tests showed that, at room temperature, sludge particles play a detrimental role on fatigue behavior of T6 alloys, diminishing fatigue strength. At elevated temperatures (200◦C) and after overaging, the influence of sludge is less relevant, probably due to a softening of the α-Al matrix and a reduction of stress concentration related to Fe-bearing intermetallics. 

Dynamic coarsening of austenite dendrite in lamellar cast iron has been studied for a hypoeutectic alloy. The common morphological parameter to characterize dynamic coarsening, secondary dendrite arm space has been replaced by the Modulus of primary dendrite (MPD) and the Hydraulic diameter of the interdendritic space (DHydIP) to interpret the dynamic coarsening with respect to the local solidification time. The obtained results demonstrate the coarsening process of both the solid and liquid phase. The interdendritic space is increasing as the contact time between the solid and liquid phase increases. The ratio between the DHydIP/MPD is strongly dependent on the precipitated fraction primary austenite indicating clearly the morphology variation during coarsening. The interrupted solidification method demonstrate that the observed coarsening process is not only a combination of the increasing fraction precipitated solid phase and the rearrangement of the solid - liquid interphase curvature but the volume change due to density variation is also contribute to the coarsening process.

The aim of this work was to investigate how accurately residual stresses can be simulated in a cast component. The reason why this is important is that a simulation that also considers residual stresses can be used to design cast components more weight- and cost-efficient. The verification was done by comparing simulated results with physical measurements on cylinders made of ductile iron. The measurements were performed with two methods, sectioning and holedrilling. These methods were applied on both as-cast and machined cylinders. The simulations were based on process data from casting trials and material data from the simulation software database. The material data for the heat conductivity of the molding sand was fitted to get a good conformity between measured and simulated temperatures. This was done to ensure that the residual stress simulation used a relevant temperature history. It turned out that the simulation was in good agreement with results from the sectioning measurements of the axial stress while results from the hole-drilling measurements were contradictive. These results were contradictive for both as-cast and machined cylinders. It can therefore be concluded that residual stresses measured by the sectioning method resulted in good conformity with the simulated σz stresses. It was also concluded that the feeders, acting as extra heat sources, affects residual stresses locally and contributes to differences in stresses beneath the feeders, compared to corresponding areas between the feeders. It was also found that the resolution of the mesh needs to be finer to take into account changes in the stresses with increments in depth when using the hole drilling method.

The paper describes a project with the aim to develop communicating and functional cast iron components in smart systems. The concept is based on sensors integrated into cast iron components; this will influence not only the component but also the casting process. Among the technical challenges is how to choose a sensor solution that cost-efficiently and with minimal environmental impact can be integrated into the component during the casting process, and especially without being damaged during mold filling and the high pouring temperature. Another challenge is how the iron will interact and interfere with sensor signals and whether an insulating intermediate material is needed or not. Integrating the sensors into the casting makes sensors a natural part of the component, which in turn can lead to more resource efficient designs, increased value added for the casting sector, and a general access to different possibilities of digitalization. The integrated sensors can be used for effective control and monitoring of components when in service and give information about for example how the component is used and what conditions it is exposed to. In other words, the component can tell when maintenance is needed or in worst cases, indicate that something is wrong before a failure will happen. Important measurands can e.g. be elongation, shear, temperature and vibration. Different combinations of sensor materials and insulating materials and their interaction with the cast iron have been investigated. It is shown how the interaction at the interface affects the microstructure and consequently the properties of the cast iron. In the case of insulating materials it is e.g. shown how air gaps are formed and in the case of sensor materials it is shown how a diffusion zone is formed and how this zone depends on the sensor material. How this diffusion zone affects the microstructure is discussed.

The paper describes work done using synchrotron light to investigate the microstructure and how it behaves in 3D when a load is applied. Two different cast iron materials with different matrix structures and graphite morphologies were investigated; SiMo51, which is basically a spheroidal iron (SGI) alloyed with Si and Mo, and a lamellar graphite iron (LGI). The tensile test specimens were loaded in steps, at which x-ray tomography as well as 3DXRD measurements were made to characterize the microstructure. The result shows how the crack propagates and which path it takes through the materials. DVC was applied to analyze the strain fields. This work also shows how useful synchrotron experiments can be in the study of the mechanical behavior of cast iron.

The primary precipitation of Fe-rich intermetallics in AlSi9Cu3(Fe) type alloys is studied for different Fe, Mn, and Cr contents and cooling rates. Differential scanning calorimetry, thermal analysis, and interrupted solidification with a rapid quenching technique were used in combination in order to assess the nucleation temperature of sludge particles, as well as to follow their evolution. The results revealed that the sludge nucleation temperature and the release of latent heat during sludge formation are functions of Fe, Mn, and Cr levels in the molten alloy (i.e., the sludge factor, SF) and cooling rate. Moreover, it can be concluded that sensitivity to sludge formation is not affected by cooling rate; i.e., a decrease in the SF will reduce sludge nucleation temperature to the same extent for a higher cooling rate as for a lower cooling rate. The sludge formation temperature detected will assist foundries in setting the optimal molten metal temperature for preventing sludge formation in holding furnaces and plunger systems.

The present work provides validation of the ultimate tensile strength computational models, based on full-scale lamellar graphite iron casting process simulation, against previously obtained experimental data. Microstructure models have been combined with modified Griffith and Hall–Petch equations, and incorporated into casting simulation software, to enable the strength prediction for four pearlitic lamellar cast iron alloys with various carbon contents. The results show that the developed models can be successfully applied within the strength prediction methodology along with the simulation tools, for a wide range of carbon contents and for different solidification rates typical for both thin-and thick-walled complex-shaped iron castings.

Varying the carbon contents, chemical composition and solidification rate greatly influences the microstructural morphology in lamellar graphite iron resulting in large variations in material properties. Traditionally, ultimate tensile strength (UTS) is used as the main property for the characterisation of lamellar graphite iron alloys under static loads. The main models found in the literature for predicting UTS of pearlitic lamellar graphite iron are based on either regression analysis on experimental data or on modified Griffith or Hall-Petch equation.In pearlitic lamellar graphite iron the primary austenite transformed to pearlite reinforces the bulk material while the graphite flakes which are embedded in an iron matrix reduce the strength of the material. Nevertheless a dominant parameter which can be used to define the tensile strength is the characteristic distance between the pearlite grains defined as the maximum continuous defect size in the bulk material, which in this work is expressed by the newly introduced parameter the Diameter of Interdendritic Space. The model presented here covers the whole spectrum of carbon content from eutectic to hypoeutectic composition, solidified at different cooling rates typical for both thin and thick walled complex shaped castings.

Investigation of dynamic coarsening in lamellar cast iron is extended over a wide interval ranging from hypoeutectic to eutectic composition. The dendrite morphology is defined on as-cast samples produced under various cooling rates. The as-cast morphology is considered being close to the one at the end of solidification. The obtained relations describing the coarsening process as a function of local solidification time and fraction austenite are compared to results obtained from interrupted solidification experiments. By using the Modulus of primary dendrite (MPD) and the Hydraulic diameter of the interdendritic space (DHyd IP) become possible to characterize the coarseness of a wide range of lamellar cast irons solidified under various cooling rates.

Traditionally, ultimate tensile strength (UTS) is used as the main property for the characterization of lamellar graphite iron (LGI) alloys under static loads. The main models found in the literature for predicting UTS of pearlitic lamellar graphite iron are based on either regression analysis on experimental data or on modified Griffith or Hall-Petch equation. In pearlitic lamellar graphite iron the primary austenite dendritic network, transformed to pearlite, reinforces the bulk material while the distance between those pearlite grains, defines the maximum continuous defect size in the bulk material. Recently the novel parameter of the Diameter of Interdendritic Space has been used to express the flow length in a modified Griffith equation for the prediction of the UTS in LGI. Nevertheless this model neglects the strengthening effect of the pearlite lamellar spacing within the perlite grains. A model based on modified Hall-Petch equation was developed in this work. The model considers the effect of both microstructure parameters and covers a broad spectrum of microstructure sizes typical for complex shape castings with various wall thicknesses.

This study focuses on abrasion resistance of Lamellar Graphite Iron (LGI) using microscratch test under constant and progressive load conditions. The interactions between a semi-spherical abrasive particle, cast iron matrix and graphite lamellas were physically simulated using a sphero-conical indenter. The produced scratches were analysed using LOM and SEM to scrutinise the effect of normal load on resulting scratch depth, width, frictional force, friction coefficient and deformation mechanism of matrix during scratching. Results showed a significant matrix deformation, and change both in frictional force and friction coefficient by increase of scratch load. Furthermore, it was shown how abrasive particles might produce deep scratches with severe matrix deformation which could result in graphite lamella's coverage and thereby deteriorate LGI's abrasion resistance.

I den första delen av studien tillverkades och bestämdes värmeledningsförmågan för samtliga provkroppar i olika kvarts/fältspatsander från Baskarpsand. Sanderna skiljer sig åt i medelkornstorlek och kornstorleksfördelning. Två olika självhärdande bindemedel, alfaset och furan, användes. I studiens senare del tillverkades och bestämdes värmeledningsförmågan för provkroppar också i sander baserade på andra mineraler. Dessutom undersöktes ytterligare ett bindemedel, nämligen Coldbox. Resultat för Coldbox redovisas i rapporten, då den inte kommer att ingå i någon publikation. Resultaten från de övriga försök kommer att publiceras i en vetenskaplig tidskrift inom något av områdena gjuteriteknik eller mineralogi. För att tillgodose de tilltänka tidskrifternas publiceringsregler, redovisas inte resultaten för dessa i denna rapport.

The casting processes are characterized by complex relationships between predictors and responses. It is the fundamental understanding of these complex relationships that often involves hundreds of factors, which improves quality without losing productivity and raising cost. In this work, cast solid solution strengthened ferritic spheroidal graphite irons GJS-500-14 and GJS-600-10 (EN 1563:2012) have been evaluated. These materials offer stronger components with good machinability owing to their even hardness properties. In this case the predictors are chemical composition, gating layout, foundry set-up, testing procedure and equipment etc. and the responses are the tensile properties (Rp0.2, Rm, A5). Here 200 tensile specimens compiled from industrial foundry melts from over 30 years of research have created a state-of-the-art platform for statistical engineering in order to perform Exploratory Data Analysis (EDA) and data visualization. This statistical platform has provided new insight on how foundries should treat complex relationships between predictors and responses in order to identify sources of variation and interaction effects.

Binders present an important part of the powder metallurgy technology as they are vital to provide efficient powder agglomeration and/or lubrication during shaping. At the same time, they have to be easily removed from the compacts during initial stages of sintering without any harmful effect for the base material, as well as for the environment. Therefore, behavior of gelatin as a binder for stainless- and tool-steel gas-atomised powder compacts was studied by thermal analysis and electron microscopy. Thermal analysis showed that peak mass-loss occurred in the range between 340 and 370 °C, depending on the base powder and heating rate. Risk for base powder oxidation at temperatures below 425 °C was detected. Based on the obtained results, it is recommended to perform debinding at ~425 °C after applying a heating rate of around 7.5 °C min-1. Only in this way efficient enough binder removal can be obtained concurrently to avoiding base powder oxidation.

Projektet ACDC syftar till att vidareutveckla Swerea SWECASTs Test- ochdemonstrationsanläggning för utveckling av gjutprocesser och gjutna prototyperoch produkter i riktning mot det övergripande målet att strukturen ska utformas såatt en långsiktig och hållbar drift av anläggningen kan genomföras.T&D-anläggningen är en viktig resurs för forsknings- och uppdragsverksamhetenpå SWECAST. Grunden utgörs av en pågående verksamhet i försöksgjuteriet somtidigare fokuserat på utbildning av gjuterioperatörer och praktiska provgjutningar,men som under en följd av år successivt har breddats till att även inkludera såväldesign- och beredningsprocess som efterkontroll av material och komponenter.Verksamheten inkluderar även en 3D-printer för sandformar och kärnor. På siktär strävan att även inkludera utvärdering av den färdiga komponentens prestandagenom exempelvis utmattningsprovning, korrosionstester och fälttester.Denna delrapport beskriver det arbete som bedrivits under första halvan avprojektet ACDC för att omvandla det tidigare utbildningsjuteriet till en effektivoch funktionell försöksanläggning, hitta nya samverkansformer internt på Swecastsamt ta fram en bärkraftig metodik för framställning av gjutna koncept inomprojekt och uppdrag.Inom projektet ACDC återstår flera viktiga punkter att slutföra under 2017. Enkonkret vision om långsiktig hållbarhet för T&D-anläggningen ska formuleras.Examensarbetet om virtuella modeller ska slutföras och utvärderas. Slutligen ärambitionen att dessutom utforma en modell för Framtidens Gjuteri.

Incremental hole drilling for residual stress measurement are widely used in industrytoday and is considered to be a cheap and fairly reliable method for stress measurements. Eventhough the method assumes isotropic material, it has been expanded to orthotropic materials suchas composite laminates. With heterogeneous material like grey cast iron, the reliability andaccuracy of the method still often fails to provide residual stress data valid for analysis. Cast ironmicrostructural aspects that complicate the analysis are the graphite and its morphology,variations in matrix structures and casting defects. These features can extend over differentlength scales and give cast iron highly localised mechanical properties. Global engineeringparameters, such as Young’s modulus and Poisson’s ratio, are used together with the locallymeasured strains to calculate the residual stresses. Utilizing global material parameters whilemeasuring locally can provide false stress results. Grey cast iron exhibits a non-linear elasticbehaviour and the Young’s modulus can change significantly and can therefore result in verydifferent calculated residual stresses. Experiments were conducted on cast stress lattices utilizingincremental hole drilling to measure strains. To calculate the residual stresses, global materialparameters and standard evaluation procedures in accordance to ASTM E837 were used. Resultsshow that the method is questionable for grey cast iron but can be used for ductile iron. Lack ofmaterial properties knowledged are suggested to be the main obstacle for residual stressevaluations on grey cast iron as the accuracy of the method decreases as hole depth approaches 1mm.

The higher mechanical strength of Compacted Graphite Iron (CGI) than Flake Graphite Iron (FGI) makes it very useful material for several commercial components. The knowledge of microstructure and hence the mechanical properties and machinability is very important for the CGI to used efficiently in manufacturing. The complex geometry of cast components makes it difficult to produce adequate microstructure in the whole component. Adequate material properties can be achieved by having good knowledge about the correlations between the casted geometry, graphite morphology and pearlite content. In the presented paper, 18 different model materials have been analysed extensively, concerning the effect of chemical composition, solidification and cooling rate on the nodularity, pearlite content, interlamellar spacing in pearlite, hardness and mechanical properties. Later, the cutting force measurement tests were performed on some of the materials and it was found that the forces have a strong positive correlation with pearlite content and the tensile strength of the materials.

In order to design and produce high-quality castings with reliable performance, the effect of the melt handling and melt quality during different processing stages needs to be understood and controlled, and numerical methods to provide correct input data to structural analyses of castings enabled. This paper aims to investigate tensile properties, in particular tensile toughness, of a secondary high-pressure die casting (HPDC) aluminium alloy with different levels of defects and imperfections. The melt, which was transported in liquid state from the smelter to the foundry, has been sampled after different holding times by casting into Y-blocks. Tensile testing was performed, and the levels of defects and imperfections were characterized using measurements of porosity, bifilm index, density index, sludge factor and the amount of iron-rich intermetallics. Two different quality indices have been evaluated, and a method to apply the results in simulations of damage in a casting, containing defects, subjected to load is demonstrated.

The effect of pore drag on grain growth is one of the most frequent effects encountered in the last stage of sintering. Therefore, the understanding of the effect of microstructure and pore location, pore morphology on grain growth is essential. Here a migrating grain boundary interacts with pores and other grain boundaries such that its structure and energy vary during grain growth. Consequently, it is of great interest to see whether the grain boundary energy decreases or increases during the interaction between migrating grain boundaries and pores. In this paper, the conditions for grain boundary migration and pinning are related to pore curvature and illustrated theoretically and experimentally.

Simulation tools have improved significantly and are now capable of accurately predicting mould filling behavior. The quality of prediction is highly dependent on material properties and set-up of boundary conditions for the simulation. In this work material properties were measured and casting conditions were analyzed to accurately replicate the casting process in simulation. The sensitivity of the predictions to minor process variations commonly found in foundries was evaluated by comparing simulation and cast samples. The observed discrepancies between simulation and cast samples were evaluated and discussed in terms of their dependency on process variations. It was concluded that the simulation set-up was capable of reasonable predictions and could replicate the asymmetry of the filling however did not accurately predict the absolute value of the unfilled area. It was discovered that asymmetric flow due to variations in the orientation of the casting mould during filling could have greater influence on the predictions than the actual variation in fill time. The quality of simulation is dependent on equipment and techniques used in the foundry as well as the metallurgical model to simulate the process. © 2017, The Author(s).

Improving the mechanical properties of high pressure die-cast (HPDC) components through T6 heat treatment is still a challenge due to surface blistering. In the current study, theoretical formulation of porosity growth in cast aluminum, EN AC 43100, has been developed along with differential scanning calorimetry and wave dispersive spectrometry to determine temperature ranges of phase transformations and Al-matrix enrichment of solutes. Optimal combinations of time and temperature for maximum possible Mg dissolution in the Al-matrix without blistering as well as tensile testing on samples extracted from HPDC components and samples from the gradient solidification technique that offers samples with low porosity levels have been performed. The results demonstrate that even if the Mg level in the Al-matrix increases and no blisters on component surface are apparent, the strength outcome is limited and can be degraded. Consequently no guarantees are granted that with a seemingly well performed T6 treatment, strength improvement will be realized.

The effect of in-situ precipitating particles on the grain size of Al-Ti-treated and untreated Hadfield steel cast in a pilot scale environment was studied. Hadfield steel was melted in an induction furnace and cast in Y-Block samples. Light Optical Microscopy (LOM) and the intercept method were utilized for the grain size measurements. Additionally, Thermo-Calc Software TCFE7 Steels/Fe-alloys database version 7 was used for thermodynamic equilibrium calculations of the mole fraction of particles. The planar disregistry values between the austenite and the precipitating particles were calculated. It was observed that increasing oxide content in samples with low Ti(CN) content resulted in a finer microstructure, while increasing the Ti(CN) content under similar oxide content levels led to a coarser microstructure. The potency of each type of particle to nucleate austenitic grains was determined. Spinel (MnAl2O4, MgAl2O4) particles were characterized as the most potent, followed by olivine (Mn2SiO4), corundum (Al2O3, TiO2), and finally Ti(CN), the least potent particle.

A quantitative analysis of the amount, size and number of particles that precipitate in situ in titanium- and aluminium-treated Hadfield steel cast during pilot-scale experiments has been performed. SEM with EDS and automated particle analysis abilities was utilized for the analysis. Additionally, Thermo-Calc was used for thermodynamic calculations and Magma 5 for solidification and cooling simulations. Predicted particles sizes calculated with a model based on the Ostwald ripening mechanism were compared with the experimental data. The effect of solute availability, cooling rate and deoxidation practice on the particle population characteristics was determined. It was concluded that the amount, size and number of precipitating particles in Hadfield steel castings is possible to be controlled according to certain requirements by a careful selection of proper additives in proper amounts and also by the optimization of the casting process in aspects of deoxidation timing and control of the cooling rate of the castings.

Projektet är en fortsättning och avrapportering av 3 års G-projekt inom högpresterande Al-legeringar, HPAL.

Arbetet har fokuserat på att få ökad kunskap framförallt inom två områden; hur man kan öka hållfasthet respektive seghet hos kommersiella Al-Si-legeringar vid förhöjda temperaturer resp. rumstemperatur. En litteraturstudie har visat hur man genom tillsats av olika legeringstillsatser och användning av mer specialanpassade legeringar kan uppnå mycket goda egenskaper. I detta projekt har utgångspunkten varit konventionella legeringar. Bättre egenskaper skulle åstadkommas både genom optimering av legeringselement hos dessa och genom att minimera defektnivåer med förbättrad ingjutsteknik.

Inför arbetet togs en ny provstavsmodell fram i CAD. För att visa flödets inverkan på defekter, och därmed hållfasthet, gjordes modellen i två versioner; bra resp. mindre bra ingjutssystem. Sandformarna togs fram med hjälp av 3D-skrivare. Resultaten av dragprovningen blev oväntade; skillnaden mellan grupperna var mycket liten.

I arbetet med legeringar med förbättrad duktilitet valdes en legering från litteraturen, där man använt Cr för att till viss del ersätta Mg. Som utgångsmaterial valdes AlSi7Mg. Prover togs fram med hjälp av en gradientugn, där en kontrollerad stelning bidrar till att minimera defekter. Resultatet visar att Cr-tillsatsen gav en ganska liten ökning av segheten, däremot fick man efter konventionell åldring en ordentlig sänkning av brott- och sträckgräns. Åldring vid längre tider gav hållfasthet jämförbara med grundlegeringen utan Cr, men lägre än legeringen från litteraturen.

Gradientstelningsförsök har visat att kisel bidrar starkt till varmhållfastheten vid 230 C för legeringen STENAL 460. En ökning av kiselhalten från 9,1 till 12,4 % ger bättre mekaniska egenskaper(R

m, Rp0.2 och A5) vid såväl rumstemperatur som vid 230 C. Jämfört med baslegeringen erhölls förbättring av sträck- och brottgräns vid 230 C med 49 respektive 17 % samtidigt som brottförlängningen ökade med 20 %. Motsvarande förbättring av sträck- och brottgräns samt brottförlängning vid rumstemperatur var 16, 22 respektive 69 %. Ett examensarbete utfört vid JU visar intressanta resultat hur kisel, cobolt och nickel var för sig och tillsammans bidrar till varmhållfastheten för Al-Si-legeringar.

Heat treatment of cast ductile iron (DI) to ausferritic ductile iron (ADI) is known to increase fatigue properties. However, the surface roughness of the cast material is also of significant importance. In this investigation, test rods with seven different surface qualities were cast from the same melt i.e. with same chemical composition. The surfaces of the test rods were varied by a number of parameters; grain size of the moulding sand, coated or non-coated mould surfaces, as-cast or machined and polished, shot peened or not. In addition, a reference material in conventional DI was cast and tested. All eight series were subjected to high-cycle fatigue bending tests. The results show that surface defects, such as micro porosity and minor inclusions drastically decrease the fatigue properties. For some ADI materials the stress amplitude limit was actually lower compared to the non-heat treated DI. The machined, polished and shot-peened material demonstrated the best fatigue properties, which is as expected.

Improved energy efficiency is one of the most effective strategies for achieving energy sustainability and independence locally, regionally and globally. Industry accounts for 40% of global energy usage each year, which suggests its potentially significant impact on overall energy use. The rapid development of standards for more efficient equipment and components are pushing manufacturers towards further improvements on a component level. However, it has been shown that the largest efficiency potential is actually found in higher system levels in which components serve, such as production processes, ventilation or hydraulic systems. Even though the importance of increasing energy efficiency at a systemic level has been widely acknowledged in recent years, practical approaches are seldom discussed in the literature. This gap between aspiration and achievement calls for the development of new approaches to foster system efficiency in industrial systems. This paper presents a systems analysis and corresponding model to increase the energy efficiency of industrial processes that involve intensive usage of electric motor systems. The model originates from traditional value stream mapping. Three case studies representing three different industrial processes were conducted to develop and validate the model. In total, 31 energy efficiency measures were identified, 29 of which address actions beyond component levels. Alongside identifications of energy efficiency measures, the model promotes the creation of conditions for cross-functional worker participation. By applying this model, the knowledge and skills gained by industrial personnel working with improved energy efficiency, maintenance and production processes can be used immediately to generate improvement suggestions. The paper concludes that this model, based on a simplified energy-focused value stream mapping, could broaden the scope of energy efficiency actions, engage a larger group of workers within the organisation and increase systems efficiency. This can be further used as a practical tool for finding continuous improvement possibilities that will result in strengthened competitiveness and more cost-effective and sustainable manufacturing.