The Influence of Modified Inorganic Binders Intended for 3D Printing on Selected Properties of Thermally Cured Moulding Sands – Conventionally and with Microwaves

Abstract

This study determined the impact of thermal curing on the basic properties of moulding compounds made with commercial inorganic binders and binders based on them, modified for use in 3D printing technology (Binder Jetting). Two inorganic binders based on sodium silicate and a binder based on aluminosilicates were tested. As part of the work, the parameters for thermal curing of the mixtures were selected: for curing in a dryer, the best properties were obtained for mixtures containing 2.0 p.p.w. of binder cured for 10 min at 160°C. In the case of microwave curing, the best properties were obtained for moulding sands containing 2.0 p.p.w. of binder cured for 6 min at a device power of 800 W. The tests showed that the basic properties of moulding compounds with binders developed on the basis of commercial binders for use in 3D printing technology, thermally cured in a dryer, do not differ significantly from the properties of compounds with commercial binders. In the case of microwave curing, a reduction in the strength of compounds with new binders was observed in relation to compounds with classic binders. Thermal deformation tests of compounds with classic and modified binders confirmed the typical behavior observed for inorganic systems. It was proven that new, modified inorganic binders developed for 3D printing of moulds and cores using Binder Jetting technology can be used as binding materials in thermally cured moulding sands. Both thermal curing methods were assessed as suitable for curing moulding compounds with new binders.