Page 64 - MSAM-3-2

Materials Science in

Additive Manufacturing

ORIGINAL RESEARCH ARTICLE
Effects of aging heat treatment on the

mechanical properties of NiTi triply periodic
minimal surface

Jinwei Li 1 , Mingkang Zhang * , Jie Chen 2 , Chang Liu 1 , Wenbin Liu 1 ,
1
and Mingjian Deng 1
1 Additive Manufacturing Laboratory, School of Mechanical and Energy Engineering, Guangdong
Ocean University, Yangjiang, Guangdong, China
2 Institute of Intelligent Manufacturing, Guangdong Academy of Sciences, Guangzhou, Guangdong,
China
(This article belongs to the Special Issue: In-situ strengthening in metal additive manufacturing)

Abstract

This study investigated the impact of aging heat treatment time on the mechanical
properties of NiTi triply periodic minimal surface structures fabricated through laser
powder bed fusion. X-ray diffraction analysis results indicate that with increasing
aging time, the NiTi phase precipitates while the content of the B19’ phase decreases.
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At 10 h of aging time, the Ni Ti phase becomes evident in the sample. The differential
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scanning calorimeter results show that R phase transformation occurs, and the phase
transformation temperature increases when the aging time reaches 6 h. Microhardness
increases with aging time, peaking at 477.8 HV after 10 h. Compression experiment
results reveal a maximum elastic modulus of 1262.82 MPa for the gyroid sheet-shaped
*Corresponding author:
Mingkang Zhang structure achieved after 2 h. In addition, the superelasticity test indicates the highest
(zhangmk@gdou.edu.cn) recoverable strains at 2%, 4%, and 6% compressive strain for the gyroid rod-shaped
structure after aging for 10 h. In cyclic compression experiments, the ratio of shape
Citation: Li J, Zhang M, Chen J,
Liu C, Liu W, Deng M. Effects memory recovery increases from 40% at 0 h to 97% at 6 h. Fracture analysis results
of aging heat treatment on the show that the transition in the fracture mechanism from brittle fracture to quasi-
mechanical properties of NiTi triply cleavage fracture occurs after aging heat treatment.
periodic minimal surface. Mater Sci
Add Manuf. 2024;3(2):3137.
doi: 10.36922/msam.3137
Keywords: NiTi alloy; Laser powder bed fusion; Aging heat treatment; Triply periodic
Received: March 11, 2024 minimal surface; Shape memory effect
Accepted: April 22, 2024
Published Online: May 24, 2024
Copyright: © 2024 Author(s). 1. Introduction
This is an Open-Access article
distributed under the terms of the Shape memory alloys (SMAs) constitute a family of metallic materials capable of
Creative Commons Attribution reverting to their original shape on heating after deformation by external forces. SMAs
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License, permitting distribution,
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and reproduction in any medium, include Cu-based, NiTi-based, and Fe-based variants. Among these variants, NiTi-based
provided the original work is SMAs exhibit excellent shape memory properties, characterized by high shape recovery
properly cited. ratios, hyperelastic strain capacities, excellent corrosion resistance, biocompatibility,
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Publisher’s Note: AccScience and superior damping properties. Compared with traditional NiTi alloy components,
Publishing remains neutral with NiTi alloy porous structures, such as minimal surface structure and lattice structure,
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regard to jurisdictional claims in
published maps and institutional offer distinct advantages, including lightweight construction, low density, large specific
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affiliations. area, and high specific strength. These attributes render them applicable across diverse
Volume 3 Issue 2 (2024) 1 doi: 10.36922/msam.3137