Profiling the quality of bentonite clay with dilatometry
Bentonite, Foundry Clays, Green Sand Binder, Molding Binders, Sand Additives
73rd World Foundry Congress "Creative Foundry", WFC 2018 - Proceedings
Bentonite clay (Montmorillonite) is one of the basic components of a green sand system. The bentonite clay serves as a sand binder that is both cost effective and abundant. The green sand process is currently used in the production of more castings than any other molding method. The quality of the clays used has been historically evaluated using standard tests including CEQ, (Cation Exchange Quotient), chemical analysis, swelling index, and test casting results. The University of Northern Iowa Metal Casting Center has developed a method of determining clay quality using the thermal expansion profile determined by dilatometry. This method can quickly predict not only the quality of the castings the clay will produce but also the durability of the clay in a green sand system over several casting cycles. The method can also be used to determine how sand additives will affect the performance of the clay in the system.
Metal Casting Center
Original Publication Date
UNI ScholarWorks, Rod Library, University of Northern Iowa
Thiel, J.; Ravi, S.; and Lafay, V., "Profiling the quality of bentonite clay with dilatometry" (2018). Faculty Publications. 772.