Browsing by Keyword "Metals and Alloys"
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Item Advances in Robotic Welding for Metallic Materials: Application of Inspection, Modeling, Monitoring and Automation Techniques(2023-04) Curiel, David; Veiga, Fernando; Suarez, Alfredo; Villanueva, Pedro; Tecnalia Research & Innovation; FABRIC_INTELThe robotic welding manufacturing of metal parts is a very important process, especially in heavy industries such as shipbuilding, oil and gas, automotive, and aerospace. There is a great variety of different techniques for manufacturing by robotic welding, and the welding operations are always in a constant process of evolution, as any advance can be significant to avoid defects during the welding process. Although a great deal of research work has been carried out in recent years, thanks to which results and reviews have been presented on this subject, the main aim of this publication is to define and review works that show the advances in the main inspection, modeling, monitoring, and automated operations during the welding process to avoid, or predictively identify, any possible defect in order to obtain an optimum degree of quality in the welding.Item Aluminium Foam and Magnesium Compound Casting Produced by High-Pressure Die Casting(2016-01-15) Vicario, Iban; Crespo, Ignacio; Plaza, L.M.; Caballero, Patricia; Idoiaga, Ion Kepa; PROMETAL; Tecnalia Research & InnovationNowadays, fuel consumption and carbon dioxide emissions are two of the main focal points in vehicle design, promoting the reduction in the weight of vehicles by using lighter materials. The aim of the work is to evaluate the influence of different aluminium foams and injection parameters in order to obtain compound castings with a compromise between the obtained properties and weight by high-pressure die cast (HPDC) using aluminium foams as cores into a magnesium cast part. To evaluate the influence of the different aluminium foams and injection parameters on the final casting products quality, the type and density of the aluminium foam, metal temperature, plunger speed, and multiplication pressure have been varied within a range of suitable values. The obtained compound HPDC castings have been studied by performing visual and RX inspections, obtaining sound composite castings with aluminium foam cores. The presence of an external continuous layer on the foam surface and the correct placement of the foam to support injection conditions permit obtaining good quality parts. A HPDC processed magnesium-aluminium foam composite has been developed for a bicycle application obtaining a suitable combination of mechanical properties and, especially, a reduced weight in the demonstration part.Item Analysis and comparative study of factors affecting quality in the hemming of 6016T4AA performed by means of electromagnetic forming and process characterization(2011-05-01) Jimbert, P.; Eguia, I.; Perez, I.; Gutierrez, M.A.; Hurtado, I.; COMPOSITE; Tecnalia Research & Innovation; PROMETALHemming is commonly one of the last operations for stamped parts. For this reason it is of critical importance on the performance and perceived quality of assembled vehicles. However, designing the hemmed unión is a complicated task and is deeply influenced by the mechanical properties of the materail of the bent part. Significant problems can arise in this operation when bending aluminum alloys, because cracks can appera due to the localized strain during hemming as a result of the low ductility of automotive aluminum alloys. This paper presents the devlopment of the lectromagnetic forming (EMF) technology for auto body-in-white parts hemming. A relatively simple experimental procedure to perform a hemming operation based on th eprinciple of EMF is presented in order to compare the variation in the quality parameters of a hemmed joint. The achieved results are compared with the corrresponding geometry hemmed utilizing the conventional process. At the same time, the study is completed with the development of a new simulation method for the EMF technology. The results obtained during this study prove the capability of the EMF to obatin quality hem unions simplifying the complicated conventional hemming operation. In this study a loose coupling EMF hemming simulation method has been developed using Maxwell 3D to solve the electromagnetic field computation and Abaqus to solve the mechanical computation. Thsi simulation method shows good agreement with the physiscal experiments. Finally, the EMF hemming process is characterized by analyzing the influence of main input parameters on the quality output parameters.Item Analysis of the behaviour of steel components in contact with AZ91D and AM60 magnesium alloys in HPDC(World Foundry Organization, 2014) Egizabal, P.; Merchán, M.; Corengia, P.; García, C.; Alberdi, M.; Tecnalia Research & Innovation; CIRMETAL; GENERALThe problems encountered in High Pressure Die Casting of magnesium alloys due to the interaction between steel components and the melt alloys are approached. The performance of different steels as well as surface treatments has been compared through a test consisting of the immersion of steel samples in melt AZ91D and AM60. The final objective is to understand the mechanisms of steel degradation through the analysis of the reaction layer and to select the most optimum steel/coating system for magnesium HPDC applications. The materials that are presently used for applications in contact with melt magnesium are usually low carbon stainless steels that do not contain any nickel or copper. Iron reacts with both aluminium and manganese present in magnesium alloys creating an intermetallic reaction layer. Six different steels were selected and tested. It was seen that the main intermetallic layer is composed of Fe2Al5. It is created when AZ91D alloy attacks the Steel and it is thinner in steels with low Mo and V contents. Furthermore the higher the V content the thicker the layer thickness. Subsequently two steels were selected that showed the best performance in the immersion test with the goal of studying different surface treatments that could enhance this performance. The test was repeated with treated samples in both magnesium alloys and a complete microstructural analysis was carried out to understand the reaction mechanisms and select the most appropriate steel alloys. The details of the procedure and results are presented in this work. Following the main conclusions are summarized: It can be said that both PVD and nitriding treatments are capable of minimizing the formation of the intermetallic layer after 3 hours of contact with melt magnesium alloys. The AlCrN coating applied by PVD presents a very good aspect in the case of the 1.2343 steel. It keeps the original thickness and is totally homogeneous all over the surface in contact with the magnesium alloy. The same coating was doped with yttrium and zirconium but no further improvements were appreciated. In the case of the 1.2888 Steel the AlCrN coating presented some cracks after the immersion trial. When doped with Zirconium the cracks did not appear but its thickness diminished and became irregular. Doping with Ytrium did not provide a good behaviour. The coating thickness was irregular and even disappeared in some areas. In the case of the samples treated with the gaseous nitriding process a large porosity was observed into the coatings. This was more evident in the 1.2343 steel. In service conditions these pores could make it possible that Al and Mn diffused through the coating into the substrate with the subsequent formation of the intermetallic layer and loss of properties in the substrate.Item Analysis of the solidification and properties of plaster cast al based composites(2012-03-01) Egizabal, P.; Romero, A.; Torregaray, A.; Tecnalia Research & InnovationThe present work deals with aspects related to the solidification and properties of an Al-Si10Mg/SiC 20p alloy cast in plaster moulds. Several strategies were followed to shorten its solidification time such as embedding copper tubes into the mould to make circulate cooling fluids immediately after the casting step. The analysis of cooling curves provided valuable information on the effect of the particles on solidification events. The precipitation of different phases of the MMC takes place at higher temperatures and earlier than in the case of the non reinforced alloy. Particles affect the solidification pattern of the alloy and play a noticeable role in the precipitation of the phases. This fact should be taken into account to design the filling and feeding systems correctly and for modelling and processing parameters as well as in thermal treatments. Eventually samples were obtained under the highest solidification rate conditions to analyse the microstructure and tensile properties of the MMC material.Item Analysis of the wall geometry with different strategies for high deposition wire arc additive manufacturing of mild steel(2020-07) Aldalur, Eider; Veiga, Fernando; Suárez, Alfredo; Bilbao, Jon; Lamikiz, Aitzol; FABRIC_INTELAdditive manufacturing has gained relevance in recent decades as an alternative to the manufacture of metal parts. Among the additive technologies, those that are classified as Directed Energy Deposition (DED) are characterized by their high deposition rate, noticeably, Wire Arc Additive Manufacturing (WAAM). However, having the inability to produce parts with acceptable final surface quality and high geometric precision is to be considered an important disadvantage in this process. In this paper, different torch trajectory strategies (oscillatory motion and overlap) in the fabrication of low carbon steel walls will be compared using Gas Metal Arc Welding (GMAW)-based WAAM technology. The comparison is done with a study of the mechanical and microstructural characteristics of the produced walls and finally, addressing the productivity obtained utilizing each strategy. The oscillation strategy shows better results, regarding the utilization rate of deposited material and the flatness of the upper surface, this being advantageous for subsequent machining steps.Item Austenite reverse transformation in a q&p route of Mn and Ni added steels(2020-06-29) Arribas, Maribel; Gutiérrez, Teresa; Molino, Eider Del; Arlazarov, Artem; De Diego-Calderón, Irene; Martin, David; De Caro, Daniele; Ayenampudi, Sudhindra; Santofimia, Maria J.; CIRMETAL; PROMETALIn this work, four low carbon steels with different contents of Mn and Ni were heat treated by quenching and partitioning (Q&P) cycles where high partitioning temperatures, in the range of 550 °C–650 °C, were applied. In order to elucidate the effect of applying these high partitioning temperatures with respect to more common Q&P cycles, the materials were also heat treated considering a partitioning temperature of 400 °C. The microstructure evolution during the Q&P cycles was studied by means of dilatometry tests. The microstructural characterization of the treated materials revealed that austenite retention strongly depended on the alloy content and partitioning conditions. It was shown that the occurrence of austenite reverse transformation (ART) in the partitioning stage in some of the alloys and conditions was a very effective mechanism to increase the austenite content in the final microstructure. However, the enhancement of tensile properties achieved by the application of high partitioning temperature cycles was not significant.Item Binder Jetting Of Hardmetals: A Comparative Study Of Microstructures And Properties Of Different Commercial Powders(European Powder Metallurgy Association (EPMA), 2022) Azurmendi, Naiara; Lores, Asier; Agote, Inigo; Fernandes, Cristina; Figueiredo, Daniel; EXTREMATAdditive manufacturing of hardmetals is gaining attention, due to the possibility of fabricating complex shaped parts and new functional designs. Comparing to laser-based AM processes, binder jetting appears to be a more promising technology for hardmetals, due to its low-cost, fast manufacturing process that produces stress and crack-free parts with isotropic properties. In the present work, properties of two different plasma spherodized commercial powders (AMWC701 and AMWC702 grades) have been characterized and printed with binder jetting technology. In addition, final properties of the printed parts sintered in a Sinter-HIP furnace at two different temperatures (1455°C and 1480°C) have been evaluated. Density, shrinkages, microstructure and hardness have been analysed. Best results were obtained with AMWC702 grade sintered at 1455°C, where near full density was obtained (>99%). Measured Vickers hardness was 1227 HV30, which is coherent with the microstructural analysis and close to medium-grained commercial products.Item Binder jetting of high dimensional stability alloy for space applications(European Powder Metallurgy Association (EPMA), 2020) Azurmendi, N.; Lores, A.; Guraya, C.; Agote, I.; EXTREMATBinder Jetting technology provides a new scope in metal additive manufacturing due to its capability to produce high complexity parts in a wide variety of different materials. This work opens a new pathway to fabricate high dimensional stability Invar36 aerospace devices with Binder Jetting technology, for applications where temperature fluctuations directly interfere in the correct performance of high sensibility systems. Since full density part fabrication is one of the main ongoing challenges for Binder Jetting, the leading objective of this work is to study and optimise the main process parameters to increase the final density of Invar36 printed parts. Microstructural analysis and obtained density and CTE values, confirmed the feasibility to fabricate Invar36 parts.Item Binder Jetting Of M2 Tool Steel Metals: Processability And Properties(European Powder Metallurgy Association (EPMA), 2022) Azurmendi, N.; Lores, A.; Agote, I.; Laskurain, A.; EXTREMATBinder Jetting Additive Manufacturing technology permits the processing of a wide range of different metallic alloys which cannot be easily manufactured by other AM means, as they may present undesired microstructures or anisotropic functional properties. For this reason, it has been found that BJ can be a suitable AM technology for processing tool steels and obtaining high quality parts with isotropic properties. In the present work, commercial M2 tool steel powder was studied and processed by Binder Jetting under different processing conditions. After some optimization work, near full density was achieved (>99%), together with MIM-like microstructure and hardness (51 HRC). Therefore, this study demonstrates that good quality M2 parts can be obtained by means of BJ, opening new design and manufacturing possibilities for more complex and advanced tooling applications.Item Binder jetting process effects on metal powder reusability(European Powder Metallurgy Association (EPMA), 2019) Agote, I.; Azurmendi, N.; Guraya, C.; Lores, A.; EXTREMATDue to its high cost and its direct impact in final part properties, the reuse of metal powders for additive manufacturing purposes is being a trending subject of study. In order to reduce production costs, ensure a robust process quality management, and consolidate a widespread industry adoption of Additive Manufacturing (AM) technology, the analysis and control of the effect that multiple process cycles have on powder raw material is crucial. To this aim, a starting virgin 316L powder was subjected to a number of Binder Jet printing and curing cycles, simulating large size production lots. The powder particle size distribution, oxide content and powder contamination was analysed along with the sinterability of some control specimens printed between certain number of process cycles. Results showed that, unlike in other powder bed based AM technologies, the reuse of powder material in Binder Jetting process has a minimum influence on raw powder and final part density.Item Biointegration of corneal macroporous membranes based on poly(ethyl acrylate) copolymers in an experimental animal model(2015-03-01) Del Barrio, Jorge L.Alió; Chiesa, Massimo; Ferrer, Gloria Gallego; Garagorri, Nerea; Briz, Nerea; Fernandez-Delgado, Jorge; Valls, Maria Sancho Tello; Botella, Carmen Carda; García-Tuñón, Ignacio; Bataille, Laurent; Rodriguez, Alejandra; Arnalich-Montiel, Francisco; Ribelles, Jose L.Gómez; Antolinos-Turpín, Carmen M.; Gómez-Tejedor, Jose A.; Alió, Jorge L.; De Miguel, Maria P.; Tecnalia Research & Innovation; SGCurrently available keratoprosthesis models (non-biological corneal substitutes) have a less than 75% graft survival rate at 2 years. We aimed at developing a model for keratoprosthesis based on the use of poly(ethyl acrylate) (PEA)-based copolymers, extracellular matrix-protein coating and colonization with adipose-derived mesenchymal stem cells. Human adipose tissue derived mesenchymal stem cells (h-ADASC) colonization efficiency of seven PEA-based copolymers in combination with four extracellular matrix coatings were evaluated in vitro. Then, macroporous membranes composed of the optimal PEA subtypes and coating proteins were implanted inside rabbit cornea. After a 3-month follow-up, the animals were euthanized, and the clinical and histological biointegration of the implanted material were assessed. h-ADASC adhered and survived when cultured in all PEA-based macroporous membranes. The addition of high hydrophilicity to PEA membranes decreased h-ADASC colonization in vitro. PEA-based copolymer containing 10% hydroxyethyl acrylate (PEA-HEA10) or 10% acrylic acid (PEA-AAc10) monomeric units showed the best cellular colonization rates. Collagen plus keratan sulfate-coated polymers demonstrated enhanced cellular colonization respect to fibronectin, collagen, or uncoated PEAs. In vivo implantation of membranes resulted in an extrusion rate of 72% for PEA, 50% for PEA-AAc10, but remarkably of 0% for PEA-HEA10. h-ADASC survival was demonstrated in all the membranes after 3 months follow-up. A slight reduction in the extrusion rate of h-ADASC colonized materials was observed. No significant differences between the groups with and without h-ADASC were detected respect to transparency or neovascularization. We propose PEA with low hydroxylation as a scaffold for the anchoring ring of future keratoprosthesis.Item Case Study to Illustrate the Potential of Conformal Cooling Channels for Hot Stamping Dies Manufactured Using Hybrid Process of Laser Metal Deposition (LMD) and Milling(2018-02) Cortina, Magdalena; Arrizubieta, Jon; Calleja, Amaia; Ukar, Eneko; Alberdi, Amaia; FABRIC_INTELHot stamping dies include cooling channels to treat the formed sheet. The optimum cooling channels of dies and molds should adapt to the shape and surface of the dies, so that a homogeneous temperature distribution and cooling are guaranteed. Nevertheless, cooling ducts are conventionally manufactured by deep drilling, attaining straight channels unable to follow the geometry of the tool. Laser Metal Deposition (LMD) is an additive manufacturing technique capable of fabricating nearly free-form integrated cooling channels and therefore shape the so-called conformal cooling. The present work investigates the design and manufacturing of conformal cooling ducts, which are additively built up on hot work steel and then milled in order to attain the final part. Their mechanical performance and heat transfer capability has been evaluated, both experimentally and by means of thermal simulation. Finally, conformal cooling conduits are evaluated and compared to traditional straight channels. The results show that LMD is a proper technology for the generation of cooling ducts, opening the possibility to produce new geometries on dies and molds and, therefore, new products.Item Cermets development by Ers process: Effect of the mould on the material properties(2017) Agote, I.; Lagos, M. A.; Da Costa, E.; EXTREMATWC-Co is known for its excellent characteristics such as hardness and wear resistance, for machining and wear resistant applications. Today, both the W and the Co are considered critical materials by the European Union and, in addition, the Co is particularly toxic. This fact makes that alternatives to replace these elements are gaining importance in recent years. This work presents the study of the processing Fe-TiC system by non-conventional sintering process as a potential alternative to some WC-Co compositions. The electrical resistance sintering (ERS) process has been used to obtain fully dense Fe-TiC compositions. ERS is based on Joule heating which allows conducting extremely fast sintering cycles. The Fe-TiC system with different binder content phase was studied and analysed (microstructure, hardness and fracture toughness). The effect of the die used during the sintering process has been studied. It was found that the thermal characteristics of the die play an important role in the obtained materials properties.Item CFD Modelling and Comparison among DifferentConfigurations of Parallel Plates Iron Electrowinning Cells(2009-10) Serna, M.; SGWithin the ULCOS project, a pilot cell for iron electrowinning is being designed. Electrical energy is used to transform iron ore particles (hematite) suspended in a sodium hydroxide solution into iron metal and oxygen. The work developed by Labein-Tecnalia is focused on the study of the fluid flow for different electrolytic cell configurations to get knowledge of the interaction between the oxygen bubbles generated during the process and the electrolyte flow. The numerical algorithm used is the finite volume used in the commercial Computational Fluid Dynamics code FLUENT. The work developed is focused on vertical and horizontal parallel plates configurations, to analyze the removal of oxygen bubbles from the gap between anode and cathode, and the access of iron ore particles to the cathode. A user subroutine has been developed for the CFD code to compute the mass flow rate of oxygen bubbles generated at the anode, as a function of the local current density. A methodology has been developed to analyze the accessibility of the iron ore particles to the cathode. The knowledge obtained from this work has helped for the design of the pilot cell within the ULCOS project.Item Characterization of a Medium Mn-Ni Steel Q&P Treated by a High Partitioning Temperature Cycle(2022-03-13) Arribas, Maribel; Del Molino, Eider; Gutiérrez, Teresa; Arlazarov, Artem; Martin, David; De Caro, Daniele; Ayenampudi, Sudhindra; Santofimia, Maria J.; CIRMETAL; PROMETALIn this work, a medium Mn-Ni steel was treated through Quenching and Partitioning (Q&P) with a partitioning temperature (PT) of 650 °C, which corresponded to the start of the austenite reverse transformation (ART) phenomenon. The influence of the quenching temperature (QT) and partitioning time (Pt) on austenite stabilization and mechanical properties was investigated. A strong influence of the quenching temperature was observed. Results were compared with those obtained after a Q&P treatment with 400 °C partitioning temperature. The Q&P cycle with quenching to room temperature and a high partitioning temperature produced a steel with a high retained austenite (RA) volume fraction and exceptional strength–ductility balance. The analysis of the mechanical stability of the retained austenite revealed a significant stress-induced transformation. Nevertheless, the austenite, which was stable at stresses above the yield stress, provided significant TRIP-assisted ductility. Bending, hole expansion and post-stamping properties were also evaluated for the most promising conditions.Item Characterization of Inconel 718® superalloy fabricated by wire Arc Additive Manufacturing: effect on mechanical properties and machinability: effect on mechanical properties and machinability(2021-09) Alonso, Unai; Veiga, Fernando; Suárez, Alfredo; Gil Del Val, Alain; Tecnalia Research & Innovation; FABRIC_INTELWire and Arc Additive Manufacturing has the potential to become an appropriate technique to produce large complex-shaped metallic parts. However, a post-processing machining operation is necessary to reach the final geometry. In this work, Inconel 718 walls were manufactured in a monitored environment and their microstructure and mechanical properties were characterised. Then, slot milling operations were performed to investigate the influence of cutting speed and machining direction. The conclusions drawn from this article can be used as a guide for a correct definition of strategies and milling parameters. It was observed that at higher cutting speeds a better surface quality and lower torques are obtained. Moreover, the main novelty of this work is that is shows the influence of the anisotropy of WAAM-Inconel 718 on its machinability. Milling along the torch's travel direction offers better dimensional tolerance values with lower cutting torques, being more favourable than machining in the building direction.Item Characterization of nanostructured Ti–B–(N) coatings produced by direct current magnetron sputtering(2007-02-26) López-Cartes, C.; Martínez-Martínez, D.; Sánchez-López, J.C.; Fernández, A.; García-Luis, A.; Brizuela, Marta; Onate, J.I.; TECNOLOGÍAS DE HIDRÓGENO; INGENIERÍA DE SUPERFICIES; Tecnalia Research & InnovationA series of Ti–B–(N) coatings prepared by dc magnetron sputtering using TiB2 targets in Ar/N2 gas mixtures has been chemically and structurally characterized by transmission electron microscopy, X-ray diffraction, electron energy-loss spectroscopy, and X-ray photoelectron spectroscopy. The influence of synthesis parameters such as applied heating power and nitrogen flow on the structure and chemical composition of the coatings has been studied. Independently of the experimental conditions employed during the synthesis, hexagonal TiB2 is the main crystalline phase present in the coatings. The use of N2 leads to the formation of an amorphous mixture of BN/TiN phases, as well as a diminution of the TiB2 crystalline phase. The influence of the composition and structure of the coatings on their hardness is also discussed.Item A comparative study of the feasibility of cellular MAX phase preforms formation by microwave-assisted SHS and SPS techniques(2020-05) Dmitruk, Anna; Lagos, M.A.; Naplocha, Krzysztof; Egizabal, Pedro; EXTREMAT; Tecnalia Research & InnovationTwo methods were evaluated in terms of manufacturing of MAX phase preforms characterized with open porosity: microwaveassisted self-propagating high-temperature synthesis (SHS) and spark plasma sintering (SPS). The main purpose of fabrication of such open-porous preforms is that they can be successfully applied as a reinforcement in metal matrix composite (MMC) materials. In order to simulate the most similar conditions to microwave-assisted SHS, the sintering time of SPS was significantly reduced and the pressure was maintained at a minimum value. The chosen approach allows these two methods to be compared in terms of structure homogeneity, complete reactive charge conversion and energy effectivity. Study was performed in Ti-Al-C system, in which the samples were compacted from elemental powders of Ti, Al, C in molar ratio of 2:1:1. Manufactured materials after syntheses were subjected to SEM, XRD and STEM analyses in order to investigate their microstructures and chemical compositions. As was concluded, only microwave-assisted SHS synthesis allows the creation of MAX phases in the studied system. SPS technique led only to the formation of intermetallic secondary phases. The fabrication of MAX phases’ foams by microwave-assisted SHS presents some interesting advantages compared to conventional manufacturing methods. This work presents the characterization of foams obtained by microwave-assisted SHS comparing the results with materials produced by SPS. The analysis of SPS products for different sintering temperatures provided the better insight into the synthesis of MAX phases, supporting the established mechanism. Dissimilarities in the heating mechanisms that lead to the differing synthesis products were also discussed.Item Comparison of hard metals fabricated by electrical resistance sintering (ERS) and sinter-HIP(European Powder Metallurgy Association (EPMA), 2016) Schubert, Thomas; Weißgärber, T.; Lagos, M. A.; Agote, I.; Gallardo, J. M.; Montes, J. M.; Prakash, L.; Oikonomou, P.; Andreouli, C.; EXTREMATThis work presents the microstructural characterization and properties of WC-Co hardmetals obtained by ERS (Electrical Resistance Sintering) compared to conventionally sintered material. The new ERS method to obtain cutting tools is being developed within the EFFIPRO project. Thanks to the short processing time, this novel sintering technology will enable an important reduction of energy consumption contrary to traditional furnace sintering methods. In order to study the microstructures and homogeneity of the WC-Co materials, optical and electron microscopy combined with X-ray and magnetic measurements were performed. In addition, mechanical properties (hardness and toughness) of the materials were analysed at different parts of the samples. The results show that relevant parts of ERS processed samples reveal finer microstructures and higher hardness than the conventionally sintered ones.