Non-layer-wise fracture and deformation mechanism in beta titanium cubic lattice structure manufactured by selective laser melting
Document Type
Journal Article
Publication Title
Materials Science and Engineering: A
Volume
822
Publisher
Elsevier
School
School of Engineering
RAS ID
36183
Funders
National Natural Science Foundation of China US Department of Energy Office of Science Office of Basic Energy Science
Abstract
The layer-wise fracture is a common fracture in porous metal structures, where the whole layer with stress concentration fractures firstly, and then the adjacent layers fracture sequentially. The brittle layer-wise fracture has always been a major obstacle that restricts the development of metallic porous structures, which may induce catastrophic failure under occasional overloading. This work reports that the non-layer-wise fracture was achieved in a beta-type Ti–25Nb–3Zr–3Mo–2Sn (TLM) titanium alloy with 50% porosity cubic lattice structure manufactured by selective laser melting (SLM), mainly due to the stress-induced progressive martensitic transformation (β→α″) supplemented by deformation twinning, resulting in uniform deformation without cracks in the struts even under a large compression strain of ~50%. The in situ synchrotron high-energy X-ray diffraction (HE-XRD) was utilized to study the dynamic deformation behavior of a strut, revealing that the martensitic transformation initiates at the early stage of the compression with a strain of 1.47%, followed by progressive martensitic transformation upon further straining, which probably contributes to the “double-yielding” platform. TEM microstructural observations of the {112} < 111 > β twins in the strut implies that deformation twinning was activated as a supplementary deformation mechanism for the accommodation of large strain. The findings in this work provide an alternative strategy of introducing non-layer-wise fracture in porous metallic materials through the coupled effect of phase transformation and twinning.
DOI
10.1016/j.msea.2021.141696
Access Rights
subscription content
Comments
Liu, Y. J., Zhang, J. S., Liu, X. C., Wu, X., Wang, J. C., Zhang, Y. S., ... Zhang, L. C. (2021). Non-layer-wise fracture and deformation mechanism in beta titanium cubic lattice structure manufactured by selective laser melting. Materials Science and Engineering: A, 822, article 141696. https://doi.org/10.1016/j.msea.2021.141696