Abstract
Binders composed of polyethylene glycols (PEGs), polymethylmethacrylate (PMMA) and, in some cases, stearic acid have been used to injection mould 316L stainless steel powder having a median particle size of about 25 μm. The effects of changing the molecular weights of the PEGs, of changing the proportions of the PEGs and PMMA in the binders, and of additions of stearic acid on moulding behaviour and on removal of the PEGs from mouldings by water leaching have been investigated. Reducing the PMMA content allows higher solids contents to be moulded and, for a given solids content, lower moulding temperatures to be used and more rapid removal of the PEGs by water leaching. However, reducing the PMMA content lowers the stiffness and strength of the mouldings. Reducing the average molecular weight of the PEGs accelerates the leaching. Introduction of stearic acid allows higher solids contents to be successfully moulded. PM/0796