10:20 a.m. - 10:50 a.m. Fluid Flow Modeling Validation of Complex Geometries Alan Druschitz, Virginia Tech The purpose of this project is to determine the accuracies and limitations of ProCast simulation software as it relates to metal casting techniques available at the Virginia Tech (VT) foundry. Simulation software is becoming a valuable tool in the metal casting industry that optimizes current casting processes by virtually modeling the outcome of a casting. Simulation and physical casting trials of a complex geometrical shape (turbine blade) were evaluated to fully understand the capabilities of the software. The simulations illustrated combinations of the various parameters: mold preheat temperature, metal superheat temperature, and gating system design. Most of the simulations filled completely and uniformly with the exception of the extreme parameter conditions (no mold preheat or metal superheat). The physical castings of the blades, however, did not fill completely, leading to the conclusion that there is some discrepancy between the simulation software and the physical casting capabilities of the VT foundry.
10:50 a.m. - 11:20 a.m.
Introduction and Experiences in Self-Monitoring, Adaptive, Recalculating Treatment Technology Degassing Brian Began, Foseco Rotary impeller degassing, or rotary degassing for short, is a well- established practice for removing hydrogen from molten aluminum alloys.
inert or active gasses within the aluminum melt.
11:20 a.m. - 11:50 a.m. Using Computer Simulation to Drive the Design of Feeding Systems for Investment Castings David Schmidt, Finite Solutions, Inc.
Investment foundries use a variety of methods for design of feeding systems. Many of these methods are based on non-scientific principles, or principles which neglect the actual behavior of the cast metal during solidification. There is now a set of tools and principles available which, if applied correctly, will reduce or eliminate the vast majority of feeding problems encountered in investment casting. Application of these techniques to a given casting may often require only 20 or 30 minutes of human and computer time, yet this may eliminate years of problems in subsequent production of the castings. Considerable cost savings in terms of reduction of scrap and customer returns can be realized. This paper will explain the principles and the use of computerized tools, as well as present multiple examples where these methods have been successfully applied in actual foundries to improve quality and reduce defects.
The principle behind rotary degassing is to disseminate The dissolved
hydrogen seeks to equilibrate with the purge gas bubbles, which rise to the melt surface, carrying hydrogen out of the melt and into the atmosphere. The principle is effective and time trusted. However, the effectiveness of the degassing process is greatly influenced by a variety of variables including the ambient conditions, the rotary degasser parameters, and the melt properties. Hence, a specific degassing process may work brilliantly one day, but may fail to deliver the required quality the next day even if the degassing parameters are maintained strictly due to a change in ambient conditions or minor fluctuations in the alloy composition (such as adding a little more Mg or Sr). Often degassing procedures are designed to negate these fluctuations by adding degassing time, increasing purge flow rates or the elimination of potentially helpful alloy additions. This paper will document efforts to create a model that incorporates the aforementioned variables and uses them to capably predict rotary degassing or upgassing effectiveness under the various realizable scenarios. It will briefly discuss the process for generating and validating the model and will include graphical illustrations of the various variable interactions derived from the model. Finally, the paper will document experiences in incorporating the model into a Metal Treatment Station (MTS) unit used at an actual production foundry verification trials. The successful implementation of the degassing model into a production Model is a process coined Self-Monitoring Adaptive Recalculation Treatment Technology or SMARTT, for short.
Technical Questions?
Ask the Experts
Our panel of experts is here to help.
All posted questions are anonymous and made available to all Institute members.
FOR MEMBERS ONLY
A member service from... the Investment Casting Institute
Visit our website for more details
www.investmentcasting.org
October 2017 ❘ 31 ®
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64
