Mechanical Properties Regulation of Invar36 Alloy Metastructures Manufactured by Laser Powder Bed Fusion

Invar36 alloy, renowned for its exceptionally low coefficient of thermal expansion and excellent mechanical properties, is widely used in precision instruments, high-accuracy molds, and related fields. Metastructures fabricated via laser powder bed fusion (LPBF) have significantly broadened the appl...

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Main Authors: Jianyu Feng, Jialei Yan, Xiaoqiang Peng, Gening He, Ke Huang
Format: Article
Language:English
Published: MDPI AG 2025-07-01
Series:Metals
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Online Access:https://www.mdpi.com/2075-4701/15/7/773
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author Jianyu Feng
Jialei Yan
Xiaoqiang Peng
Gening He
Ke Huang
author_facet Jianyu Feng
Jialei Yan
Xiaoqiang Peng
Gening He
Ke Huang
author_sort Jianyu Feng
collection DOAJ
description Invar36 alloy, renowned for its exceptionally low coefficient of thermal expansion and excellent mechanical properties, is widely used in precision instruments, high-accuracy molds, and related fields. Metastructures fabricated via laser powder bed fusion (LPBF) have significantly broadened the application scope of Invar36 alloy, owing to their unique advantages such as lightweight design, high specific strength, and high specific stiffness. However, the structure–property coupling relationship in Invar-based metallic lattice structures remains insufficiently understood, which poses a major obstacle to their further engineering utilization. In this study, 36 lattice structures with varying design parameters were fabricated and experimentally evaluated. The design variables included lattice architecture (body-centered cubic (BCC), diamond (DIA), face-centered cubic (FCC), and octet (OCT)), strut diameter (0.6 mm, 0.8 mm, and 1.0 mm), and inclination angle (35°, 45°, and 55°). The influence of these structural parameters on the mechanical performance was systematically investigated. The results indicate that lattice architecture has a significant impact on mechanical properties, with the OCT structure, characterized by stretch-dominated behavior, exhibiting the best overall performance. Under the conditions of a 35° inclination angle and a strut diameter of 1.0 mm, the elastic modulus, compressive strength, plateau stress, and energy absorption of the OCT structure reaches 2525.92 MPa, 110.65 MPa, 162.26 MPa, and 78.22 mJ/mm<sup>3</sup>, respectively. Furthermore, increasing the strut diameter substantially improves mechanical performance, while variations in inclination angle primarily influence the dominant deformation mode. These findings demonstrate that the mechanical properties of Invar36 alloy lattice structures fabricated via LPBF can be effectively tuned over a broad range, offering both theoretical insights and practical guidance for customized performance optimization.
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spelling doaj-art-9a7f36bc070e43069000567835b32cac2025-08-20T03:08:01ZengMDPI AGMetals2075-47012025-07-0115777310.3390/met15070773Mechanical Properties Regulation of Invar36 Alloy Metastructures Manufactured by Laser Powder Bed FusionJianyu Feng0Jialei Yan1Xiaoqiang Peng2Gening He3Ke Huang4College of Pittsburgh, Sichuan University, Chengdu 610200, ChinaCollege of Materials Science & Engineering, Sichuan University, Chengdu 610065, ChinaCollege of Materials Science & Engineering, Sichuan University, Chengdu 610065, ChinaNuclear Power Additive Manufacturing Key Laboratory of Sichuan Province, Nuclear Power Institute of China, Chengdu 610213, ChinaCollege of Materials Science & Engineering, Sichuan University, Chengdu 610065, ChinaInvar36 alloy, renowned for its exceptionally low coefficient of thermal expansion and excellent mechanical properties, is widely used in precision instruments, high-accuracy molds, and related fields. Metastructures fabricated via laser powder bed fusion (LPBF) have significantly broadened the application scope of Invar36 alloy, owing to their unique advantages such as lightweight design, high specific strength, and high specific stiffness. However, the structure–property coupling relationship in Invar-based metallic lattice structures remains insufficiently understood, which poses a major obstacle to their further engineering utilization. In this study, 36 lattice structures with varying design parameters were fabricated and experimentally evaluated. The design variables included lattice architecture (body-centered cubic (BCC), diamond (DIA), face-centered cubic (FCC), and octet (OCT)), strut diameter (0.6 mm, 0.8 mm, and 1.0 mm), and inclination angle (35°, 45°, and 55°). The influence of these structural parameters on the mechanical performance was systematically investigated. The results indicate that lattice architecture has a significant impact on mechanical properties, with the OCT structure, characterized by stretch-dominated behavior, exhibiting the best overall performance. Under the conditions of a 35° inclination angle and a strut diameter of 1.0 mm, the elastic modulus, compressive strength, plateau stress, and energy absorption of the OCT structure reaches 2525.92 MPa, 110.65 MPa, 162.26 MPa, and 78.22 mJ/mm<sup>3</sup>, respectively. Furthermore, increasing the strut diameter substantially improves mechanical performance, while variations in inclination angle primarily influence the dominant deformation mode. These findings demonstrate that the mechanical properties of Invar36 alloy lattice structures fabricated via LPBF can be effectively tuned over a broad range, offering both theoretical insights and practical guidance for customized performance optimization.https://www.mdpi.com/2075-4701/15/7/773Invar36 alloylattice structurelaser powder bed fusion (LPBF)mechanical propertiesenergy absorption
spellingShingle Jianyu Feng
Jialei Yan
Xiaoqiang Peng
Gening He
Ke Huang
Mechanical Properties Regulation of Invar36 Alloy Metastructures Manufactured by Laser Powder Bed Fusion
Metals
Invar36 alloy
lattice structure
laser powder bed fusion (LPBF)
mechanical properties
energy absorption
title Mechanical Properties Regulation of Invar36 Alloy Metastructures Manufactured by Laser Powder Bed Fusion
title_full Mechanical Properties Regulation of Invar36 Alloy Metastructures Manufactured by Laser Powder Bed Fusion
title_fullStr Mechanical Properties Regulation of Invar36 Alloy Metastructures Manufactured by Laser Powder Bed Fusion
title_full_unstemmed Mechanical Properties Regulation of Invar36 Alloy Metastructures Manufactured by Laser Powder Bed Fusion
title_short Mechanical Properties Regulation of Invar36 Alloy Metastructures Manufactured by Laser Powder Bed Fusion
title_sort mechanical properties regulation of invar36 alloy metastructures manufactured by laser powder bed fusion
topic Invar36 alloy
lattice structure
laser powder bed fusion (LPBF)
mechanical properties
energy absorption
url https://www.mdpi.com/2075-4701/15/7/773
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