Gelcasting of Alumina and Alumina-cBN

Gelcasting is a promising technology for manufacturing of advanced structural ceramic components. This forming process was developed to overcome some of the limitations of other complex- shape forming techniques such as injection molding and slip casting. Gelcasting is a new near net shaping technique, which has rapidly evolved from a laboratory invention towards industrial application. In this work, a highly loaded but very fluid slurry consisting of ceramic powder(Al2O3, Al2O3-cBN), water, dispersant (Ammonium poly acrylic acid) and gelformer(2-hydroxyethyl methacrylate), is poured into a mold and subsequently gelled. Once gelation has taken place, the part is strong enough to retain its shape and can be demolded, dried, calcined and sintered. The industrialization of gelcasting technique has been prevented to some extent because the main component of the gel, acrylamide, is a neurotoxin. Therefore a low-toxicity gel casting system is highly more desirable in this field. Feasibility of using a non- toxic gel-former (2-hydroxyethyl methacrylate) is studied.