Microstructural and mechanical analysis of TiCN-reinforced AlMgScZr composites fabricated via laser powder bed fusion: Insights into triple periodic minimal surface lattice structures

The additive manufacturing of ceramic-reinforced AlMgScZr composites via laser powder bed fusion (LPBF) and their application in triply periodic minimal surface (TPMS) architectures remain underexplored, despite their potential for lightweight high-performance components. This research pioneers the integration of micron-scale TiCN particles into an AlMgScZr alloy through LPBF process, revealing critical microstructure-property relationships. The incorporation of TiCN fundamentally alters the consolidation dynamics of the AlMgScZr alloy matrix, promoting the transition from columnar to equiaxed grains of the matrix, and resulting in a superior matrix grain refinement. Post-aging treatment enhances the mechanical properties of 5 vol.% TiCN-AlMgScZr composite, achieving an ultimate tensile strength of 683 MPa, a yield strength of 654 MPa, and an elongation rate of 4.1%, which are among the highest values reported for LPBF processed aluminum matrix composites and alloys to date. Building on these findings, the study further assesses the compressive performance of TPMS structures fabricated from LPBFed 5 vol.% TiCN-AlMgScZr composite. This assessment combines experimental testing with Finite Element (FE) simulation, with a particular focus on a TPMS structure inspired by the Douglas fir (D-F structure). The results demonstrate that TiCN reinforcement markedly improves the compressive behavior of TPMS structures, with the D-F structure showing superior compressive strength compared to other TPMS structures. Additionally, the D-F structure fabricated from TiCN-AlMgScZr composite exhibits exceptional vibration damping capabilities. This study, by integrating material performance, structural design, and potential damping application, offers valuable insights into the fabrication of advanced aluminum matrix composites through additive manufacturing, contributing to the development of high-performance materials for industrial applications.