Microstructure-dependent deformation mechanisms and fracture modes of gradient porous NiTi alloys

Bibliographic Details
Title: Microstructure-dependent deformation mechanisms and fracture modes of gradient porous NiTi alloys
Authors: Yintao Zhang, Liqiang Wang, Changgong Lan, Daixiu Wei, Yang Chen, Lechun Xie, Ling Zhang, Weijie Lu, Guang Chen
Source: Materials & Design, Vol 243, Iss , Pp 113049- (2024)
Publisher Information: Elsevier, 2024.
Publication Year: 2024
Collection: LCC:Materials of engineering and construction. Mechanics of materials
Subject Terms: Gradient porous structure, Triply periodic minimal surface, Mechanical properties, Deformation mechanism, Fracture mode, Materials of engineering and construction. Mechanics of materials, TA401-492
More Details: Gradient porous structures based on triply periodic minimal surfaces offer exceptional specific strength and multi-functionality. However, strain heterogeneity complicates their deformation mechanisms and fracture modes. In this study, we fabricated a series of gradient porous NiTi alloys based on gyroid (G), diamond (D), and I-WP (I) unit cells, with porosities ranging from 50% to 70%. Surprisingly, the I structure exhibited an abnormally high compressive strength of nearly 600 MPa at around 50% porosity, more than twice that of the G and D structures. This performance gap was attributed to the activation of mixed deformation mechanisms and distinct fracture modes. While the G structure showed a uniform radial strain distribution, the D and I structures displayed pronounced radial strain gradients with concentrated central strains. The D structure deformed through relative sliding of oblique struts, while the I structure maintained macrostructural stability, with thick edge struts providing continuous strain hardening until monolithic fracture. This unique deformation behavior results from the synergistic effects of its intrinsic macrostructural stability, significant radial strain gradients, and sufficiently thicker edge struts. The integration of metallurgical and architectural design principles represents a novel approach to tailoring the mechanical properties of gradient porous metals for advanced applications.
Document Type: article
File Description: electronic resource
Language: English
ISSN: 0264-1275
Relation: http://www.sciencedirect.com/science/article/pii/S0264127524004234; https://doaj.org/toc/0264-1275
DOI: 10.1016/j.matdes.2024.113049
Access URL: https://doaj.org/article/08a6dfe2d42842d58e9ee953dd126fcc
Accession Number: edsdoj.08a6dfe2d42842d58e9ee953dd126fcc
Database: Directory of Open Access Journals
More Details
ISSN:02641275
DOI:10.1016/j.matdes.2024.113049
Published in:Materials & Design
Language:English