Browsing by Author "Vicario, Iban"
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Item Adjustment of a High Pressure Die Casting Simulation Model against Experimental Data(2015-12-25) Anglada, Eva; Meléndez, Antton; Vicario, Iban; Arratibel, Ernesto; Aguillo, Idoia; CIRMETAL; Tecnalia Research & Innovation; PROMETALIn addition to the typical difficulties associated with the numerical simulation of metal casting processes, the special characteristics of the high pressure die casting (HPDC) increase the difficulty of obtaining reliable results. The process followed to define and adjust one HPDC simulation model against experimental measurements by means of inverse modelling, is presented together with information related with the test campaign. This knowledge may be of interest for other researchers interested in the HPDC simulation and/or in the simulation models adjustment. The case of study corresponds to the specific case of one variation of the alloy AlSi9Cu3 (in-house developed) and one variation of the H13 steel (in-house developed), used for the mold manufacturing. The simulation models include the mold thermal evolution during the consecutive cycles of the manufacturing process, together with the cavity filling and the later cooling of the alloy.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 Compound Formation and Microstructure of As-Cast High Entropy Aluminums(2018-03-09) Sanchez, Jon Mikel; Vicario, Iban; Albizuri, Joseba; Guraya, Teresa; Koval, Natalia; Garcia, Jose; CIRMETAL; PROMETALThe aim of this work is to study the microstructure of four high entropy alloys (HEAs) produced by large scale vacuum die casting. Al40Cu15Mn5Ni5Si20Zn15, Al45Cu15Mn5Fe5Si5Ti5Zn20, Al35Cu5Fe5Mn5Si30V10Zr10, and Al50Ca5Cu5Ni10Si20Ti10 alloys formed a mixture of different structures, containing intermetallic compound (IC) and solid solution (SS) phases. The phases observed in the casting alloys were compared with the equilibrium phases predicted by Thermo-Calc. The measured densities varied from 3.33 g/cm−3 to 5.07 g/cm−3 and microhardness from 437 Hv to 887 Hv. Thus, the microhardness and estimated strength/density ratios are significantly higher than other lightweight high entropy alloys (LWHEAs).Item Design, Microstructure and Mechanical Properties of Cast Medium Entropy Aluminium Alloys(2019-12-01) Sanchez, Jon Mikel; Vicario, Iban; Albizuri, Joseba; Guraya, Teresa; Acuña, Eva Maria; CIRMETAL; PROMETALIn this work, the design, microstructures and mechanical properties of five novel non-equiatomic lightweight medium entropy alloys were studied. The manufactured alloys were based on the Al65Cu5Mg5Si15Zn5X5 and Al70Cu5Mg5Si10Zn5X5 systems. The formation and presence of phases and microstructures were studied by introducing Fe, Ni, Cr, Mn and Zr. The feasibility of CALPHAD method for the design of new alloys was studied, demonstrating to be a good approach in the design of medium entropy alloys, due to accurate prediction of the phases, which were validated via X-ray diffraction and scanning electron microscopy with energy dispersive spectroscopy. In addition, the alloys were manufactured using an industrial-scale die-casting process to make the alloys viable as engineering materials. In terms of mechanical properties, the alloys exhibited moderate plastic deformation and very high compressive strength up to 644 MPa. Finally, the reported microhardness value was in the range of 200 HV0.1 to 264 HV0.1, which was two to three times higher than those of commercial Al alloys.Item The Determination of Dendrite Coherency Point Characteristics Using Three New Methods for Aluminum Alloys(2018-07-26) Vicario, Iban; Viteri, Ester; Montero, Jessica; Djurdjevic, Mile; Huber, Gerhard; Gómez, Iban Vicario; PROMETALThe aim of this work is to give an overview of existing methods and to introduce three new methods for the determination of the Dendrite Coherency Point (DCP) for AlSi10Mg alloys, as well as to compare the acquired values of DCP based on a thermal analysis and on the analysis of cooling curves working with only one thermocouple. Additionally, the impact of alloying and contaminant elements on the DCP will be also studied. The first two proposed methods employ the higher order derivatives of the cooling curves. The DCP was determined as the crossing point of the second and third derivative curves plotted versus time (method 1) or that of the temperature (method 2) with the zero line just after the maximum liquidus temperature. The third proposed method is based on the determination of the crossing point of the third solid fraction derivative curve with the zero line, corresponding to a minimum of the second derivative. A Taguchi design for the experiments was developed to study the DCP values in the AlSi10Mg alloy. The DCP temperature values of the test alloys were compared with the DCP temperatures predicted by the previous methods and the influence of the major and minor alloying elements and contaminants over the DCP. The new processes obtained a correlation factor r2 from 0.954 and 0.979 and a standard deviation from 1.84 to 2.6 °C. The obtained correlation values are higher or similar than those obtained using previous methods with an easier way to define the DCP, allowing for a better automation of the accuracy of DCP determination. The use of derivative curves plotted versus temperature employed in the last two proposed methods, where the test samples did not have an influence over the registration curves, is proposed to have a better accuracy than those of the previously described methods.Item Determination of Solidification of Rigidity Point Temperature Using a New Method(2020-04-03) Villanueva, Ester; Vicario, Iban; Sánchez, Jon Mikel; Crespo, Ignacio; PROMETAL; CIRMETALThis work aims to calculate the rigidity point temperature of aluminum alloys by three new methods and compare them with currently employed methods. The influence of major and minor alloying elements over the rigidity point temperature is also discussed. Until now it has been difficult to determine the exact temperature of the rigidity point, since small variations in the data obtained give variable results, making it difficult to automate the process with high accuracy. In this work we suggested three new mathematic methods based on the calculation of higher order derivatives of (dT/dt) with respect to time or temperature compared to those currently employed. A design of experiments based on the Taguchi method was employed to compare the effect of the major and minor alloying elements for the AlSi10Mg alloy, and to evaluate the accuracy of each developed method. Therefore, these systems will allow better automation of rigidity point temperature (RPT) determination, which is one of the most important solidification parameters for solidification simulators. The importance of the correct determination of this parameter lies in its relation to quality problems related to solidification, such as hot tearing. If the RPT presents very low-temperature values, the aluminum casting will be more sensitive to hot tearing, promoting the presence of cracks during the solidification process. This is why it is so important to correctly determine the temperature of the RPT. An adequate design of chemical composition by applying the methodology and the novel methods proposed in this work, and also the optimization of process parameters of the whole casting process with the help of the integrated computational modeling, will certainly help to decrease any internal defective by predicting one of the most important defects present in the aluminum industry.Item Development of a Squeeze Semisolid High-Pressure Die Casting Process for Magnesium Structural Parts(2019-07-15) Vicario, Iban; Crespo, Iñigo; Val, D.; Weiss, U.; Cao, D.; Martinez de la pera, Ignacio; Sanchez, Jon Mikel; PROMETAL; CIRMETALHigh-pressure die casting is the most common method used to produce magnesium castings, due to the excellent balance of cost and properties for high production volumes with limitations in terms of final mechanical properties. A newly developed process based on employing low injection speeds, in a range slightly over the standard semisolid speeds with a modified die, with thick gates and high die temperatures has been developed. Despite working with speeds that are not in the lamellar flow, the obtained parts present very low porosity, allowing the use thermal treatments to increase the ductility without producing blisters. The demonstration has been performed in a AM60B magnesium body joint produced by the squeeze casting process. Finally, the microstructure and the mechanical properties of as-cast and T4 heat-treated samples were studied. The results indicate the improvement of the mechanical properties in T4 heat-treated parts; specifically, a 40% improved deformation-to-failure, 40-60% improved penetration force and 90% of energy absorption were possible to obtain employing the newly developed SC + T4 process.Item Effect of Material and Process Atmosphere in the Preparation of Al-Ti-B Grain Refiner by SHS(2015-09) Vicario, Iban; Poulon-Quintin, Angeline; Lagos, M.A.; Silvain, JF; PROMETAL; EXTREMATAl-Ti-B master alloys are widely used in the aluminum industry as grain refiners for the control of the microstructure of the aluminum alloys. The SHS (self-propagating high-temperature synthesis) is an ex situ method that uses exothermic reactions to sustain the chemical reaction in a combustion wave. The advantages of SHS are the low energy requirement, simplicity and product purity. However, the raw material used has to be very pure, with a very small size leading to the necessity of a reactor with a protective gas to produce the reaction. The purpose of this investigation is to fabricate SHS master alloys with commercial standard raw materials, with lower purity and higher grain size without a reactor or protective gas in order to (1) decrease the price and (2) improve the productivity of master alloy manufacturing. The possibility of using cheap borated salts instead of expensive pure boron has been studied. Different compositions of aluminum master alloy have been developed. Bigger TiB2 grain size has been obtained when using bigger commercial raw materials. Larger titanium powder can produce an aluminum master alloy with a maximum of 30% of aluminum without reactor. In comparison, SHS reaction is much more difficult when using finer titanium powder.Item ESR Processing of a New HighPressureDieCasting Steel(2021) Dubberstein, T.; Hengst, A.; Caballero, Patricia; Vicario, IbanSchmiedewerke Groditz (SWG) is among the global players of special re-melted steel alloys production. Within the RFCS project n⁰ 751360 HPDCSTEEL (High Pressure Die Casting Steel) a new ESR steel grade has been developed. At SWG the steel grade was produced using an open ESR unit. During re-melting the master alloy has been continuously added into the liquid slag bath and a modified ESR ingot of 20t has been manufactured. The ESR process was modified to increase the quality and performance of the steel, maintaining a constant distribution of synthetic carbides into the obtained ingot. A master alloy was placed on the bottom of the ESR machine before starting with the pre-charge. Furthermore, during re-melting the master alloy has been fed continuously using an installed balance system. No problems in the steel processing were detected, with a standard ESR melting and permanent feeding of the new alloy. The chemical composition of the alloy and of the liquid ESR slag was measured several times during the re-melting process, to determine if the master alloy was correctly dissolved in the melt.Item How Simulation and Model Adjustments Helps Metal Casting Processes(NAFEMS, 2017) Anglada, Eva; Meléndez, Antton; Vicario, IbanThe use of numerical simulation in the metal casting industry has experienced a significant increase during last years.Item Microstructure and Phase Formation of Novel Al80Mg5Sn5Zn5X5 Light-Weight Complex Concentrated Aluminum Alloys(2021-12-01) Sanchez, Jon Mikel; Pascual, Alejandro; Vicario, Iban; Albizuri, Joseba; Guraya, Teresa; Galarraga, Haize; CIRMETAL; PROMETALIn this work, three novel complex concentrated aluminum alloys were developed. To investigate the unexplored region of the multicomponent phase diagrams, thermo-physical parameters and the CALPHAD method were used to understand the phase formation of the Al80Mg5Sn5Zn5Ni5 , Al80Mg5Sn5Zn5Mn5 , and Al80Mg5Sn5Zn5Ti5 alloys. The ingots of the alloys were manufactured by a gravity permanent mold casting process, avoiding the use of expensive, dangerous, or scarce alloying elements. The microstructural evolution as a function of the variable element (Ni, Mn, or Ti) was studied by means of different microstructural characterization techniques. The hardness and compressive strength of the as-cast alloys at room temperature were studied and correlated with the previously characterized microstructures. All the alloys showed multiphase microstructures with major α-Al dendritic matrix reinforced with secondary phases. In terms of mechanical properties, the developed alloys exhibited a high compression yield strength up to 420 MPa, high compression fracture strength up to 563 MPa, and elongation greater than 12%.Item A novel procedure for the evaluation of new refractories for aluminium furnaces(Cenertec, 2015-04) Vicario, Iban; de Landía, Leonor; Mendizabal, Gorka; Toledo, Nagore; Anglada, Eva; Rodriguez, PatxiRefractory materials for aluminium industry are designed to be resistant to different degrees of thermal, mechanical and chemical wear. The refractory wall thickness reduction during service life increases the heat losses through walls, decreasing the thermal efficiency of the furnace. Last developments are focused on obtaining refractories with better performance and improved insulation properties. On this regard, a novel procedure has been developed to compare the thermal and chemical performance of different refractories. This procedure includes comparing the resistance of the refractory to molten aluminium, determining corundum and cracks appearance, and measuring the internal and external wall temperatures of a testing furnace using thermography. These temperature measurements make possible to estimate the wall thermal conductivity together with its evolution in time and also validate its simulation modelling in order to be used in future furnace designs. Two refractories have been tested by this procedure for comparative purposes; a commercial alumina castable and an improved alumina castable with better insulation propertiesItem Phase prediction, microstructure and high hardness of novel light-weight high entropy alloys(2019-01) Sanchez, Jon Mikel; Vicario, Iban; Albizuri, Joseba; Guraya, Teresa; Garcia, Jose Carlos; CIRMETAL; PROMETALGuided by CALPHAD modeling, low-density and multiphase three novel High Entropy Alloys (HEAs), Al40Cu15Cr15Fe15Si15, Al65Cu5Cr5Si15Mn5Ti5 and Al60Cu10Fe10Cr5Mn5Ni5Mg5 were produced by large scale vacuum die casting. A mixture of simple and complex phases was observed in the as-cast microstructures, which demonstrates good agreement with CALPHAD results. The measured densities varied from 3.7 g/cm3 to 4.6 g/cm3 and microhardness from 743 Hv to 916 Hv. Finally, the hardness of all the light-weight HEAs (LWHEAs) with densities below 4.6 g/cm3 manufactured to date were reviewed. The hardness of Al40Cu15Cr15Fe15Si15 and hardness to density ratio of Al65Cu5Cr5Si15Mn5Ti5 are the highest of all LWHEAs reported up to date.Item Prediction and validation of shape distortions in the simulation of high pressure die casting(2018-06) Anglada, Eva; Meléndez, Antton; Vicario, Iban; Idoiaga, Jon Kepa; Mugarza, Aitz; Arratibel, Ernesto; CIRMETAL; Tecnalia Research & Innovation; PROMETALThe use of the thermomechanical simulation is very infrequent in the metal casting industry although the associated results are really useful for the manufacturing process. The main reasons are the complexity, the long calculation times and the difficulties to interpret the results. The parts manufactured by metal casting processes cool from its filling temperature to ambient, which causes a certain stress-strain state. Although the stress levels might be significant, the main worry of the foundrymen is usually the shape distortion. That is, the mismatches between the desired dimensions and the real ones. The problem is that the results obtained from numerical simulation are not directly useful to cover this industrial necessity. This work presents the prediction obtained using the thermomechanical simulation for the final dimensions of a component manufactured in aluminium alloy by high pressure die casting (HPDC) and its validation with the final dimensions of the manufactured component. The methodology established to forecast the mismatches with the reference geometry is also detailed, as it may be useful to encourage the use of this type of simulation in the metal casting industry.Item Rapid simulation models for aluminium furnaces design(2017-07-04) Anglada, Eva; Vicario, Iban; de Landia, Leonor; Mendizabal, Gorka; Toledo, Nagore; CIRMETAL; PROMETALThe minimisation of energy consumption in aluminium metal casting industries requires an appropriate design of the furnaces to reduce as possible the heat losses through the walls. Detailed simulation models have been developed that allow the in-depth study of furnace behaviour, but these models are too complex and slow for some industrial necessities. To make possible a fast evaluation during preliminary phases more agile models are needed. This agility may be achieved by simplified models, but the results could be affected by a lack of accuracy. The work presented hereafter shows how the steady state analysis of the furnace walls with simplified models of finite elements may give sufficiently accurate and fast results. The simulation models have been validated against experimental results, thus confirming their ability to adequately reproduce the thermal behaviour of the walls of several furnaces regardless of their composition or heating system.Item Simplified Models for High Pressure Die Casting Simulation(2015) Anglada, Eva; Meléndez, Antton; Vicario, Iban; Arratibel, Ernesto; Cangas, Gaizka; CIRMETAL; Tecnalia Research & Innovation; PROMETALThe simulation of the High Pressure Die Casting (HPDC) process is a complex type of simulation. The industrial procedure is based on consecutive manufacturing cycles that must be taken into account in the simulation. Moreover the part geometries use to be complex and the alloy is injected at really high velocities. All of that usually implies long calculation times that in complex cases can lead to several days. Sometimes, the circumstances require to have available a fast solution despite involve a loss of accuracy. The work presented hereafter discusses different possibilities to simplify the HPDC simulation models together with their benefits and drawbacks. The simplified simulation models have been validated against a detailed 3D simulation model, previously correlated with experimental results. The comparative, shows that the use of simplified models may be a solution that makes possible a big reduction in calculation times maintaining a reasonable level of accuracy.Item Solid Fraction Determination at the Rigidity Point by Advanced Thermal Analysis(2021-12-27) Villanueva, Ester; Vicario, Iban; Sánchez, Jon Mikel; Albizuri, Joseba; Montero, Jessica; PROMETAL; CIRMETALThe aim of this work is to determine the Solid Fraction (SF) at the rigidity point (FRP) by applying advanced thermal analysis techniques. The variation of the FRP value is important to explain the solidification behavior and the presence or absence of defects in aluminum alloys. As the final alloy composition plays a key role on obtained properties, the influence of major and minor alloying elements on FRP has been studied. A Taguchi design of experiments and a previously developed calculating method, based on the application of high rank derivatives has been employed to determinate first the rigidity point temperature (RPT) and after the corresponding FRP for AlSi10Mg alloys. A correlation factor of r2 of 0.81 was obtained for FRP calculation formula in function of the alloy composition.Item Vidrios metálicos y high entropy alloys… ¿es el desorden la clave de los materiales del futuro?(2018-07) Sánchez, Jon Mikel; Vicario, Iban; Meléndez, Antton; CIRMETAL; PROMETAL; Tecnalia Research & InnovationLas aleaciones metálicas tradicionales han consistido en la mezcla de un elemento mayoritario con otros elementos en menores proporciones, que actúan de solutos en la estructura cristalina del elemento principal mejorando las propiedades del metal base. En el acero, los átomos de carbono de un tamaño mucho menor se encuentran insertados en los huecos intersticiales de la microestructura del hierro. A pesar de que se mejoran las propiedades de los elementos puros, las aleaciones siguen manteniendo unas determinadas propiedades derivadas del elemento mayoritario.