Abstract
High pressure die casting (HPDC) is a recently popular manufacturing method which deals with high veloci-ty injection of liquid metal into the molds. Although the process is fast and secures mass production, porosity is one of the challenging defects in final product and might be influenced by jet breakup as well as atomization during molten metal injection phase. In the case of atomization a large number of droplets with high velocity impinges the colder confining walls of the casting mold and might solidify consecutively. In this study an Eu-lerian-Lagrangian hybrid approach (previously developed by authors) is used to model the general flow behav-ior, liquid sheet breakup, droplet formation and droplet-turbulence interaction during the injection phase. A hypothetical model is presented to correlate the atomization phenomenon and the consequent droplets behavior with the porosity formation near the surface of the final product. In this model, highly frequent non-isothermal droplet impacts at the mold walls are considered as the main source of heterogeneous microstructure formation. Accordingly, the model is able to estimate the probability of porosity formation based on the process parameters, frequency of droplet impingement and the time scale of solidification. This model is applied to the injection of molten aluminum into a lab-scale casting mold. The simulation results show relatively good agreements with the experimental results for both liquid jet breakup and porosity formation.
| Original language | English |
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| Title of host publication | Proceedings of Proceedings of the ICLASS 2015, 13th International Conference on Liquid Atomization and Spray Systems, 2015 |
| Number of pages | 11 |
| Publication status | Published - 2015 |
Fields of science
- 203 Mechanical Engineering
JKU Focus areas
- Computation in Informatics and Mathematics
- Mechatronics and Information Processing
- Engineering and Natural Sciences (in general)