Lost Foam Casting has significant cost and environmental advantages and enables metal casters to produce complex parts often not possible using other methods. The process allows designers to consolidate parts, reduce machining and minimize assembly operations. It also allows foundries to reduce solid waste and emissions. Research co-funded by the U.S. Department of Energy and an industry consortium, and being performed at the University of Alabama at Birmingham Lost Foam Technology Center, has resulted in significant improvements in lost foam process controls. These developments have been, and continue to be adapted for use in industry. The lost foam process consists of first making a foam pattern having the geometry of the desired finished metal part. After a short stabilization period, the pattern is dipped into a water solution containing a suspended refractory. The refractory material coats the foam pattern leaving a thin heat resistant layer that is air dried. When drying is complete, the coated foam is suspended in a steel container that is vibrated while sand is added to surround the coated pattern. The sand provides mechanical support to the thin refractory layer. Molten metal is then poured into the mold, and the molten metal melts and vaporizes the foam. The solidified metal leaves a nearly exact replica of the pattern which is machined as required to produce the desired finished shape. Proper controls must be exercised in each step of the process to assure consistent high quality castings. A lack of in-depth knowledge of the process necessary for proper control measures had slowed adoption of the lost foam casting process.
The overall objective of this program is to advance the theory and application of the lost foam casting technology by increasing the technology transfer to the production floor and to provide methods for solving production problems associated with introducing new products. The two areas that will be the focus of this project are to further reduce casting defects caused by pyrolysis products and to improve the casting accuracy and precision.
Developed in-plant quality assurance procedures to measure coating parameters.
Developed non-contact air gauge for accurate dimensional analysis.
Developed sand density gauge to measure the rate of sand compaction. Companion instrumentation measures casting distortion.
Developed vibrational analysis instrumentation which, when coupled with the density gauge, allows the compaction cycle to be optimized to reduce compaction time and pattern distortion.