Browsing by Keyword "HPDC"
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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 Metamodels’ Development for High Pressure Die Casting of Aluminum Alloy(2021-10-31) Anglada, Eva; Boto, Fernando; García de Cortazar, Maider; Garmendia, Iñaki; CIRMETAL; Tecnalia Research & Innovation; FACTORYSimulation is a very useful tool in the design of the part and process conditions of high pressure die casting (HPDC), due to the intrinsic complexity of this manufacturing process. Usually, physics-based models solved by finite element or finite volume methods are used, but their main drawback is the long calculation time. In order to apply optimization strategies in the design process or to implement online predictive systems, faster models are required. One solution is the use of surrogate models, also called metamodels or grey-box models. The novelty of the work presented here lies in the development of several metamodels for the HPDC process. These metamodels are based on a gradient boosting regressor technique and derived from a physics-based finite element model. The results show that the developed metamodels are able to predict with high accuracy the secondary dendrite arm spacing (SDAS) of the cast parts and, with good accuracy, the misrun risk and the shrinkage level. Results obtained in the predictions of microporosity and macroporosity, eutectic percentage, and grain density were less accurate. The metamodels were very fast (less than 1 s); therefore, they can be used for optimization activities or be integrated into online prediction systems for the HPDC industry. The case study corresponds to several parts of aluminum cast alloys, used in the automotive industry, manufactured by high-pressure die casting in a multicavity mold.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 Research on Coatings and Infiltration to Strengthen Ceramic Lost Cores Used in High-Pressure Die Casting Processes(2019-07-15) Merchán, Mikel; García de Cortázar, Maider; Galarraga, Haize; Bárcena, Jorge; Artola, Antxon; CIRMETAL; EXTREMATLost cores used to manufacture complex aluminium components through high-pressure die casting (HPDC) processes need to withstand very high injection velocities and pressures. The conventional sand cores used in other casting processes, such as sand casting or low-pressure die casting, do not support the aggressive process parameters of the HPDC, so advanced ceramic cores must be used. These cores must be strong enough not to get broken during the casting process, but, at the same time, they must have a minimum porosity to be easily removed from the casting to obtain the finished part. Due to this porosity, the aluminium penetrates the core surface during the casting process. So, the criterion here is to find the necessary compromise between strength and porosity and to protect the core surface from the aluminium penetration. In this work, two research lines have been followed to address these challenges. On the one hand, different refractory coatings have been applied to the ceramic core surface with the aim of sealing it. Amongst the coatings analysed, boron nitride-based one has been found to be the most suitable and cost-effective solution to avoid aluminium penetration. On the other hand, silica has been proved to be a suitable infiltration agent to increase the strength of the core.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.