E-Thesis 574 views 238 downloads
Numerical and Experimental Verification of Investment Casting Process / VICTORIA THOMAS
Swansea University Author: VICTORIA THOMAS
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PDF | E-Thesis
Copyright: The Author, Victoria U. Thomas, 2023 Distributed under the terms of a Creative Commons Attribution 4.0 License (CC BY 4.0).
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DOI (Published version): 10.23889/SUthesis.63706
Abstract
Vacuum induction melting investment casting is a process used to produce metal components.The procedure comprises of induction melting of a billet under vacuum conditions, followed bydirect pouring into a casting mould. Castings made by this method are prone to defects suchas misrun, inclusions and...
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Swansea, Wales, UK
2023
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| Institution: | Swansea University |
| Degree level: | Doctoral |
| Degree name: | EngD |
| Supervisor: | Lavery, Nicholas P. and Brown, Stephen G. R. |
| URI: | https://cronfa.swan.ac.uk/Record/cronfa63706 |
| Abstract: |
Vacuum induction melting investment casting is a process used to produce metal components.The procedure comprises of induction melting of a billet under vacuum conditions, followed bydirect pouring into a casting mould. Castings made by this method are prone to defects suchas misrun, inclusions and porosity. In this work, the impact of piping defects within IN713Cbillets is examined, specifically their size and location on flow characteristics during pouring anddefect occurrence in finished castings. Manufactured holes were introduced in concast billets asa controlled method of exploring the effect of piping on alloy pouring flow characteristics. Usinga Design of Experiments approach, an L9 array of two-piece billets was used to investigate theimpact of disc height, hole diameter and hole position. A bespoke vacuum induction meltingchamber was designed and fabricated with viewing ports which enable non-contact temperaturemeasurements and high-speed images to be recorded during the heating and pouring processes,respectively. The L9 array was reproduced in numerical models of electromagnetic inductionheating, and thermal fluid flow during alloy pouring, created using the in-development EMAGmodule for ESI ProCAST. Thermal results from electromagnetics models were used as initialconditions for alloy pouring, and additional mould filling and solidification simulations.The experimental data served as validation for numerical models and demonstrates that themodelling approach delivers representative results, while minimising computational demand.Knowledge of the temperature distribution within the billet from electromagnetic simulations isfound to be key for accurate defect prediction. By interrogating defect criteria in post-processing,the impact of piping on defect occurrence is understood. Using a 15 mm disc, or ‘penny’,resulted in a reduction of defect instances, consistent with anecdotally reported improvementsobserved in the casting industry. Through this modelling, this is explained by reductions inthe maximum alloy pouring temperature. |
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| Keywords: |
Vacuum Induction Melting, Investment Casting, Numerical Modelling, Experimental Verification, Casting, Design of Experiments, Industrial Experiments |
| College: |
Faculty of Science and Engineering |