Compressive Properties of Al-Si Alloy Lattice Structures with Three Different Unit Cells Fabricated via Laser Powder Bed Fusion.

Tetsuya Yamada,Naoki Takata,Makoto Kobashi,Keito Sekizawa,Asuka Suzuki,Xiaoyang Liu

doi:10.3390/ma13132902

Abstract

In the present study, in order to elucidate geometrical features dominating deformation behaviors and their associated compressive properties of lattice structures, AlSi10Mg lattice structures with three different unit cells were fabricated by laser powder bed fusion. Compressive properties were examined by compression and indentation tests, micro X-ray computed tomography (CT), together with finite element analysis. The truncated octahedron- unit cell (TO) lattice structures exhibited highest stiffness and plateau stress among the studied lattice structures. The body centered cubic-unit cell (BCC) and TO lattice structures experienced the formation of shear bands with stress drops, while the hexagon-unit cell (Hexa) lattice structure behaved in a continuous deformation and flat plateau region. The Hexa lattice structure densified at a smaller strain than the BCC and TO lattice structures, due to high density of the struts in the compressive direction. Static and high-speed indentation tests revealed that the TO and Hexa exhibited slight strain rate dependence of the compressive strength, whereas the BCC lattice structure showed a large strain rate dependence. Among the lattice structures in the present study, the TO lattice exhibited the highest energy absorption capacity comparable to previously reported titanium alloy lattice structures.

Highlights

Cellular lattice structures, consisting of a periodic arrangement of strut-based unit cells, exhibit numerous high-performance features, including ultra-light weight, high specific stiffness, thermal insulation and good energy absorption capability
The present study aims to investigate the effect of unit cell type on compressive behavior of lattice structures
In order to elucidate the reason for the higher plateau stress, the body centered cubic-unit cell (BCC), truncated octahedron (TO), and Hexa unit cells simulated by the FEM analysis

Summary

Introduction

Cellular lattice structures, consisting of a periodic arrangement of strut-based unit cells, exhibit numerous high-performance features, including ultra-light weight, high specific stiffness, thermal insulation and good energy absorption capability. These structures are of interest for the application in biomedical, automobile and aerospace fields [1,2,3]. Vilardell et al reported Ti-6Al-4V lattice structures designed for implant applications with stiffness and density close to the host bone [4]. Cuadrado et al [5] and Ahmadi et al [6] studied the mechanical properties of cellular structures with different unit cells used for biomedical implant.

Methods

Results

Discussion

Conclusion