title: Magnetic susceptibility and hardness of Au-xPt-yNb alloys for biomedical applications.
abstract: Metal devices in the human body induce serious metal artifacts in magnetic resonance imaging (MRI). Metals artifacts are mainly caused by a volume magnetic susceptibility (χv) mismatch between a metal device and human tissue. In this research, Au-xPt-yNb alloys were developed for fabricating MRI artifact-free biomedical metal devices. The magnetic properties, hardness and phase constitutions of these alloys were investigated. The Au-xPt-8Nb alloys showed satisfactory χv values. Heat treatments did not clearly change the χv values for Au-xPt-8Nb alloys. The Vickers hardness (HV) of these two alloys was much higher than that of high-Pt alloys; moreover, aging at 700°C increased the HV values of these two alloys. A dual phase structure consisting of face-centered cubic α1 and α2 phases was observed and aging at 700°C promoted phase separation. The Au-5Pt-8Nb and Au-10Pt-8Nb alloys showed satisfactory χv values and high hardness and are thus suggested as candidates for MRI artifact-free alloys for biomedical applications.
authors.affiliation: Department of Biomaterials and Bioengineering, Institute of Health Biosciences, University of Tokushima, 3-18-15 Kuramoto, Tokushima 770-8504, Japan.
authors.forename: Emi
authors.initials: E
authors.lastname: Uyama
authors.forename: Shihoko
authors.initials: S
authors.lastname: Inui
authors.forename: Kenichi
authors.initials: K
authors.lastname: Hamada
authors.forename: Eiichi
authors.initials: E
authors.lastname: Honda
authors.forename: Kenzo
authors.initials: K
authors.lastname: Asaoka
mesh_terms: D000497:Alloys / Q000737:chemistry; D001672:Biocompatible Materials / Q000737:chemistry*; D055119:Elastic Modulus; D006046:Gold / Q000737:chemistry*; D006244:Hardness; D060526:Magnetic Fields; D008422:Materials Testing; D009556:Niobium / Q000737:chemistry*; D010984:Platinum / Q000737:chemistry*
chemical_list: D000497:Alloys; D001672:Biocompatible Materials; D009556:Niobium; D010984:Platinum; D006046:Gold
keywords: Au–Pt–Nb alloys; Magnetic susceptibility; Phase constitution; Vickers hardness