Laboratory Tests of Selective Laser Melting of Simulants of Lunar Regolith with Various Granulometric Properties

The paper presents the results of laboratory tests of selective laser melting (SLM) of powder compositions of lunar regolith simulants from the terrestrial rocks of gabbro-diabase and labradorite, which have different ranges of fractionality. It is shown that compositions with narrow ranges of fractionality of either 50–100 or 100–140 μm make it possible to produce the samples with rather good properties: relatively low porosity and rather good compliance with the requested geometric shape. Experimental dependences of the porosity of tested samples on the energy density of melting are obtained. For both cases of powder compositions from gabbro-diabase with the narrow fractions, either 50–100 or 100–140 μm, the dependences on the energy are practically the same: with increasing energy density up to 20 J/mm 3 and greater, the porosity approaches 30–35%. On the other hand, experimental tests shown that SLM technology for a powder composition with a broad range of fractions, from 0 to 100 μm, does not allow testing samples with acceptable properties to be produced—either with low porosity and with reasonable consistency with the specified geometry.