Research on the Novel Energy-Containing Alloy Skeleton Based on Triply Periodic Minimal Surface

Abstract

Herein, a triply periodic minimal surface energy-containing alloy (TPMS-EA) skeleton is prepared and placed inside solid propellant pillars using the selective laser melting (SLM) process. To ensure optimal combustion performance of the skeleton, the combustion characteristics of three types of alloy powders—AlMg, AlSiMg, and AlMgZr—suitable for SLM are compared using scanning electron microscope, X-ray diffraction, and thermogravimetry-differential scanning calorimetry (TG-DSC). The AlMgZr alloy powders exhibit the best combustion properties. The skeleton model is analyzed through finite element simulation, and AlMgZr alloy powder is processed into three types of triply periodic minimal surface energy-containing metal (TPMS-EM) skeletons (Gyroid, Diamond, and Schwarz) with varying porosities. The results indicate that the measured mass combustion enthalpy of the AlMgZr alloy powder is 28 587 ± 110.95 J g⁻¹. The combustion efficiency is 94.33%, and the weight gain ratio due to oxidation is 81.3%. This alloy powder demonstrates superior performance compared to AlMg and AlSiMg alloy powders. The gyroid structure, which boasts 95% porosity, exhibits a yield strength of 57.80 ± 1.26 MPa among the pillars. This enhancement results in a 34.04% improvement in the mechanical properties of the pillars compared to those without a skeleton, as well as an increase in the combustion completeness of the pillars.