Gelcasting of metal powders in nontoxic cellulose ethers system

A nontoxic gel system for gelcasting complex-shape metal green body was investigated. The process was based on the heat-initiated gelation characteristic of water-soluble cellulose ether (CE) or its hydroxyalkyl derivative in hydrotropic solution. In gelcasting, a highly loaded but very fluid suspension consisting of iron powder, water, antioxidant, dispersant and gelformer, was poured into a non-porous mould and gelled at 60 °C. The apparent viscosity of the suspension and factors influencing it were analyzed. The green bodies with bending strength of about 2.5 MPa had a smooth surface and homogeneous microstructure. After sintering, dense and uniform iron parts were successfully obtained.