Table 6. Shrinkage (mm) of Coated and Dried Cores
factors that can affect final casting dimensions, but it is potentially significant and should be included in calculating tooling dimensions.
Acknowledgements
Many thanks to Greg Tordoff of Fairmont Minerals for pro- viding both knowledge and materials to the Team’s efforts. Also special thanks to Greg Sturtz of Ashland and James Lapeus of Ford for their contributions to the team.
REFERENCES
1. Foundry Trade Journal. “Multiple Advantages with New Sand System: A New Mineral Core and Mould Sand Process,” vol. 177, No. 3606, pp 21-22 (2003). Press release. Retrieved from http://www.
allbusiness.com/primary-metal-manufacturing/ foundries/
648620-1.html
2. Baker, S.G, Werling, J.M., “Versatile Core Sand Test Method”, AFS Transactions, vol. 112, pp 663-669 (2004).
Technical Review & Discussion
Re-Evaluating Core Dimensional Changes R. Showman, M. Nocera and J. Madigan; Ashland Performance Materials, Dublin, OH, USA G. Baltz, T. Hajduk and J. Wohleber; Ford Motor Company, Cleveland, OH, USA
Reviewer: Overall the paper covers a topic not well ex- plored, but data is lacking to fully understand the phenom- ena that is being investigated. The conclusions are basically observations, and don’t offer much explanation about the mechanisms or reasons why core shrinkage occurs. More emphasis on why the observations are occurring would be welcomed.
Author: We agree that much more could be done on this topic and that more rigorous testing and data analysis
would likely provide answers to some of the puzzles pre- sented in the paper and to questions raised by the re- viewers. However, the primary initial focus was to solve a problem at the casting plant. The core shrinkage test- ing was intended to addresses the plant’s issues rather than to thoroughly investigate a phenomenon that is not well understood. Once the testing showed that shrink- age was stable and that it was likely not the root cause of the casting dimensional problems, the focus shifted elsewhere. The paper was intended to show the value of using proven problem solving methods and of teamwork between foundries and suppliers as much as it was about test methods and core shrinkage. We had hoped that this message would have as much value to the industry as the actual shrinkage data. We agree that there are still many questions to be answered and hope that by pointing out these questions, more interest will be raised and testing can continue within the industry.
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International Journal of Metalcasting/Summer 10
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