Np-Fe0 addition affects the microstructure and composition of the microwave-sintered lunar soil simulant CLRS-2

Abstract

Microwave sintering is a key technology for future lunar habitats, which has been verified by various lunar soil simulant experiments. However, nanophase iron (np-Fe0), a unique component of the real lunar regolith, has been ignored in previous studies of the microwave sintering of lunar soil simulants. In this study, microwave-sintering experiments of lunar soil simulant CLRS-2 with and without np-Fe0 at different temperatures were conducted. A comparison of the microstructure and chemical composition of sintered products indicates that all products of samples with 1.0 wt% np-Fe0 exhibit better properties than those without np-Fe0 after heating at equivalent temperatures. Adding np-Fe0 to the lunar soil simulant CLRS-2 couples well with microwaves, which may increase the real heating temperature in a sample, resulting in the product being solidified at 700 °C and a relatively dense product forming at 900 °C, thus improving the sintering efficiency. This study suggests that microwave sintering is an effective potential technology for future lunar habitats and road hardening because of the wide distribution of np-Fe0 in the lunar regolith. The technical parameters given in this study can provide an important guide for future lunar construction by microwave sintering.