title: Mechanical and biological behavior of ultrafine-grained Ti alloy aneurysm clip processed using high-pressure torsion.
abstract: Severe plastic deformation (SPD) has recently been advanced as the main process for fabricating bulk ultrafine grained or nanocrystalline metallic materials, which present much higher strength and better bio-compatibility than coarse-grained counterparts. Medical devices, such as aneurysm clips and dental implants, require high mechanical and biological performance (e.g., stiffness, yield strength, fatigue resistance, and bio-compatibility). These requirements match well the characteristics of SPD-processed materials. Typical aneurysm clips are made of a commercial Ti-6Al-4V alloy, which has higher yield strength than Ti. In this work, Ti and Ti-6Al-4V workpieces were processed by high-pressure torsion (HPT) to enhance their mechanical properties. Tensile tests and hardness tests were performed to evaluate their mechanical properties, and their microstructure was investigated. The hardness and yield stress of the HPT-processed Ti are comparable to those of the initial Ti-6Al-4V due to significantly refined microstructure. Finite element analyses for evaluating the opening performance of a specific geometry of the YASARGIL aneurysm clip were carried out using mechanical properties of the initial and HPT-processed Ti and Ti-6Al-4V. These results indicate that SPD-processed Ti could be a good candidate to substitute for Ti-6Al-4V in aneurysm clips.
authors.affiliation: Department of Materials Science and Engineering, Pohang University of Science and Technology, Pohang 37673, Korea.
authors.forename: Ho Yong
authors.initials: HY
authors.lastname: Um
authors.affiliation: Department of Materials Science and Engineering, Pohang University of Science and Technology, Pohang 37673, Korea.
authors.forename: Byung Ho
authors.initials: BH
authors.lastname: Park
authors.affiliation: Nuclear Materials Safety Research Division, Korea Atomic Energy Research Institute (KAERI), Daejeon 34057, Republic of Korea.
authors.forename: Dong-Hyun
authors.initials: DH
authors.lastname: Ahn
authors.affiliation: Mechanical Design and Production Engineering Department, Faculty of Engineering, Zagazig University, Egypt.
authors.forename: Mohamed Ibrahim
authors.initials: MI
authors.lastname: Abd El Aal
authors.affiliation: Department of Neurosurgery, Kyungpook National University Hospital, Daegu 41944, Korea.
authors.forename: Jaechan
authors.initials: J
authors.lastname: Park
authors.affiliation: Department of Materials Science and Engineering, Pohang University of Science and Technology, Pohang 37673, Korea; Center for High Entropy Alloy, Pohang University of Science and Technology, Pohang 37673, Korea. Electronic address: hskim@postech.ac.kr.
authors.forename: Hyoung Seop
authors.initials: HS
authors.lastname: Kim
mesh_terms: D000497:Alloys; D000783:Aneurysm / Q000601:surgery*; D006801:Humans; D008422:Materials Testing; D013499:Surface Properties; D013525:Surgical Instruments; D014025:Titanium / Q000032:analysis*
chemical_list: D000497:Alloys; C031462:titanium alloy (TiAl6V4); D014025:Titanium
keywords: Aneurysm clip; Finite element method; Mechanical properties; Severe plastic deformation; Ti alloys