# Additive Manufactured FeCrNi Medium Entropy Alloy Lattice Structure with Excellent Dynamic Mechanical Properties

## TL;DR

This paper introduces a new lightweight FeCrNi alloy lattice structure with excellent mechanical properties for aerospace and marine applications.

## Contribution

The study presents a novel FeCrNi medium entropy alloy lattice structure with superior dynamic mechanical performance compared to conventional materials.

## Key findings

- The FCCZ FeCrNi MEA lattice structure achieved the highest specific compressive strength of 59.1 MPa·g−1·cm−3.
- It also demonstrated a specific energy absorption of 26.3 J/g, outperforming 316L and AlSi10Mg alloys.
- Finite element simulation and the Johnson-Cook model effectively predict the mechanical behavior of the lattice structure.

## Abstract

Aerospace and marine engineering impose higher requirements on mechanical properties and lightweight design of materials. In this work, combining the high mechanical properties of FeCrNi medium entropy alloy (MEA) and the lightweight advantages of lattice structure, four types of high-performance FeCrNi MEA lattice structures (BCC, BCCZ, FCC, and FCCZ) were prepared by selective laser melting (SLM) technology, and their dynamic mechanical properties were systematically characterized via split Hopkinson pressure bar (SHPB) method. The results demonstrate that the FCCZ FeCrNi MEA lattice structure exhibits superior comprehensive performance among the four lattice structures, achieving the highest specific compressive strength of 59.1 MPa·g−1·cm−3 and specific energy absorption of 26.3 J/g, significantly outperforming conventional lattice materials including 316L and AlSi10Mg alloys. Furthermore, the finite element simulation and Johnson-Cook (J-C) constitutive model of the dynamic compression process can effectively predict the microstructural evolution and mechanical response of lattice structure, providing critical theoretical guidance for optimizing the design of high-performance lattice structure materials.