Mechanical-Thermal Coupling and Deformation Mechanisms of Cellular High-Entropy Alloy Lattice Structures Under Elevated Temperatures | Chapter 9 | Chemical and Materials Sciences: Developments and Innovations Vol. 8

 The lattice structures were a novel applied structure based on lightweight design, which had potential applications in industrial fields such as turbomachinery, aerospace, and automotive. To investigate the effect of elevated temperature service conditions on the compressive strength of CoCrFeMnNi high entropy alloy with lattice structures prepared by powder bed fusion, the mechanical properties of the lattice structures at a temperature in a range from 20^oC to 900^oC were obtained through a self-developed in-situ mechanical-thermal coupling compressive system. The real-time deformation behaviors of the lattice structures were observed by an optical-infrared dual-spectrum imaging system. The experimental results indicated that the compressive strength, structural stiffness, and energy absorption of the specimens increased with the increasing temperature ranging from 20^oC to 600^oC during the load-bearing stage, accompanied by a fracture mode from cleavage step to dimple. At an elevated temperature of 900^oC, the specimens exhibited the lowest compressive strength and structural stiffness but the highest densification strain. Significantly, the temperature-dependent deformation behaviors were revealed, as the gradually increased temperature promoted the deformation failure behavior transforming from “layer by layer” to a “45^o shear band”. The improved plasticity at elevated temperatures enhanced the deformation capacity of lattice structures, released the local concentrated load and effectively weakened the stress concentration. The above research indicated that the designed lattice structures were suitable for extreme working conditions such as aerospace or automotive, due to their excellent elevated temperature service performance.

 

Author (s) Details

 

Shuai Tong
School of Mechanical and Aerospace Engineering, Jilin University, Changchun, 130025, China and Key Laboratory of CNC Equipment Reliability Ministry of Education, Jilin University, Changchun, 130025, China.

 

Guoxiang Shen
School of Mechanical and Aerospace Engineering, Jilin University, Changchun, 130025, China and Key Laboratory of CNC Equipment Reliability Ministry of Education, Jilin University, Changchun, 130025, China.

 

Zhengchen Han
School of Mechanical and Aerospace Engineering, Jilin University, Changchun, 130025, China and Key Laboratory of CNC Equipment Reliability Ministry of Education, Jilin University, Changchun, 130025, China.

 

Zhichao Ma
School of Mechanical and Aerospace Engineering, Jilin University, Changchun, 130025, China and Key Laboratory of CNC Equipment Reliability Ministry of Education, Jilin University, Changchun, 130025, China.

 

Hongwei Zhao
School of Mechanical and Aerospace Engineering, Jilin University, Changchun, 130025, China and Key Laboratory of CNC Equipment Reliability Ministry of Education, Jilin University, Changchun, 130025, China.

 

Luquan Ren
Weihai Institute for Bionics, Jilin University, Weihai, 264400, China.

 

Chuliang Yan
Beijing Aircraft Strength Institution, Beijing, 100083, China.

 

Please see the book here:- https://doi.org/10.9734/bpi/cmsdi/v8/3614