16-17#11 Alternative Granular Media for Green Sand Casting
Principal Investigator: Dr. Sam Ramrattan, Western Michigan University
Steering Committee Chair: James Furness, Furness Newburge Inc.
Foundry engineers have long known that certain AFS standard green sand properties tests provide limited information for green sand control. This limitation is especially apparent when strict casting dimensional control and a superior casting surface is required. Green sand control is a conundrum because water, clay, additive and sand grain surface area changes dynamically during the metal casting process. Test that rapidly measures these deviations simultaneously in a green sand system are required. New and non-standard dynamic green sand tests such as the modified cone jolt toughness test (MCJT) and the thermal erosion test (TET) are able to differentiate among various compactability levels (moisture content) and clay levels.
The objective of this project was to determine the green properties for five alternate molding media, evaluate the finish at the mold metal interface, and to evaluate the durability of the alternate molding media for molding and reclamation.
Library Paper Number: 19-121
17-18#01 Effects of Metallurgical Factors on Micro-Porosity in Ductile Iron Castings
Principal Investigator: Dr. Simon Lekakh, Missouri University of Science and Technology
Steering Committee Chair: George Kokos, CAT
Cast iron with spherical graphite (SGI) has a unique combination of high strength with good melt fluidity allowing metal casting industry to produce complicated geometry castings. SGI has less solidification shrinkage than steel; however, it is significantly higher than in gray iron. Currently, foundries use effective techniques to prevent formation of macro-shrinkage defects in hot spots; however, increasing complexity of ductile iron castings makes it difficult to produce sound castings without more widely distributed micro-porosity. Intensive risering helps with the elimination of large shrinkage pores but does not always warranty absence of micro-porosity.
The objective of this project was to study metallurgical factors that effected micro-porosity formation in SGI casting using novel experimental and simulation methods.
Library Paper Number: 19-157
17-18#02 Heat Treatments to Develop High-Strength Ferritic Ductile Iron
Principal Investigator: Richard Gundlach, Gundlach Consulting Services
Steering Committee Chair: Scott Lammers, American Foundry Society
Past research has shown that heat treatment can produce a fine-grained ferritic structure in ductile iron with tensile properties competitive with solution-strengthened ferritic ductile iron.
The objective of this project was to demonstrate that grain refinement, through heat treatment, can substantially increase the strength of ferritic ductile iron. As well as to determine how grain refinement affects impact toughness and the ductile-to-brittle transition temperature.
Library Paper Number: 19-142
17-18#05 Prediction and Control of Distortion in Permanent Molds
Principal Investigator: Lynn Ferguson, DANTE Solutions Inc.
Steering Committee Chair: David Neff, Consultant
Permanent molds are subjected to high thermal stresses and are prone to distortion. Each casting cycle introduces heat into local areas of the mold, increasing the temperature and creating severe thermal gradients. Most of the mold material stays in the elastic deformation region and returns to the original dimensions upon cooling. However, in some parts of the mold the compressive surface stresses may exceed yield, resulting in permanent, plastic deformation. Other metallurgical events are also in play as the mold distortion occurs over many casting cycles where time at temperature is an issue.
This is primarily a computational effort supported by experimental data. In this study, finite element modeling was used to identify the sources of mold distortion and also to explore methods to minimize mold distortion. Computer software will be used to assess both thermal stress and the change in microstructure that will occur due to time and temperature for the hot face of the mold cavity.
Library Paper Number: 19-209