Alvian Toto Wibisono, Andika Akbar Wicaksono, Andromeda Dwi Laksono, Fasih Bintang Ilhami, Muhammad Qomaruz Zaman, Budi Agung Kurniawan
Truncated octahedron (TO) lattice structure is complex geometry for lightweight and mechanically efficient structure application. This study proposes feasibility for hybrid Fused deposition modelling-investment casting (FDM-IC) manufacturing route to produce Al 7075 lattice structures with TO geometry. TO pattern with 4.6–5.0 mm strut diameters were fabricate by FDM using PLA material, followed by thermal removal, mold sintering, and IC of Al 7075 at mold cavity. IC performed by gravity IC and vacuum assisted IC. The results show TO lattice with 5.0 mm strut diameter successfully fabricated. The strut diameter is smaller than target with reduction of 4–10.9% due to shrinkage. The TO lattice has α Al matrix grain phase, MgZn phase at grain boundary, C and SiO2 as residual phase from mold. Increasing strut diameter enlarged grain size (up to 301 μm) while decreasing hardness (to 78.3 HV), confirming strong geometry–property relationships. © 2026 Elsevier B.V.
Department of Materials and Metallurgical Engineering, Faculty of Industrial Technology and Systems Engineering, Institut Teknologi Sepuluh Nopember, Surabaya, Indonesia; Study Program of Materials and Metallurgical Engineering, Faculty of Engineering and Industrial Technology, Institut Teknologi Kalimantan, Balikpapan, Indonesia; Department of Natural Science, Faculty of Mathematics and Natural Science, Universitas Negeri Surabaya, Surabaya, Indonesia; Department of Electrical Engineering, Faculty of Intelligent Electrical and Informatics Technology, Institut Teknologi Sepuluh Nopember, Surabaya, Indonesia