title: Enhancement of the mechanical properties of AZ31 magnesium alloy via nanostructured hydroxyapatite thin films fabricated via radio-frequency magnetron sputtering.
abstract: The structure, composition and morphology of a radio-frequency (RF) magnetron sputter-deposited dense nano-hydroxyapatite (HA) coating that was deposited on the surface of an AZ31 magnesium alloy were characterized using AFM, SEM, EDX and XRD. The results obtained from SEM and XRD experiments revealed that the bias applied during the deposition of the HA coating resulted in a decrease in the grain and crystallite size of the film having a crucial role in enhancing the mechanical properties of the fabricated biocomposites. A maximum hardness of 9.04 GPa was found for the HA coating, which was prepared using a bias of -50 V. The hardness of the HA film deposited on the grounded substrate (GS) was found to be 4.9 GPa. The elastic strain to failure (H/E) and the plastic deformation resistance (H(3)/E(2)) for an indentation depth of 50 nm for the HA coating fabricated at a bias of -50 V was found to increase by ~30% and ~74%, respectively, compared with the coating deposited at the GS holder. The nanoindentation tests demonstrated that all of the HA coatings increased the surface hardness on both the microscale and the nanoscale. Therefore, the results revealed that the films deposited on the surface of the AZ31 magnesium alloy at a negative substrate bias can significantly enhance the wear resistance of this resorbable alloy.
authors: Department of Theoretical and Experimental Physics, National Research Tomsk Polytechnic University, 634050 Tomsk, Russia. Electronic address: surmenevamaria@tpu.ru.
authors: M A
authors: MA
authors: Surmeneva
authors: NanoCenter "Nanotechnology and Nanomaterials", G.R. Derzhavin Tambov State University, 392000 Tambov, Russia.
authors: A I
authors: AI
authors: Tyurin
authors: Department of Theoretical and Experimental Physics, National Research Tomsk Polytechnic University, 634050 Tomsk, Russia.
authors: T M
authors: TM
authors: Mukhametkaliyev
authors: NanoCenter "Nanotechnology and Nanomaterials", G.R. Derzhavin Tambov State University, 392000 Tambov, Russia.
authors: T S
authors: TS
authors: Pirozhkova
authors: NanoCenter "Nanotechnology and Nanomaterials", G.R. Derzhavin Tambov State University, 392000 Tambov, Russia.
authors: I A
authors: IA
authors: Shuvarin
authors: Department of General Physics, National Research Tomsk Polytechnic University, 634050 Tomsk, Russia.
authors: M S
authors: MS
authors: Syrtanov
authors: Department of Theoretical and Experimental Physics, National Research Tomsk Polytechnic University, 634050 Tomsk, Russia; Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB, 70569 Stuttgart, Germany.
authors: R A
authors: RA
authors: Surmenev
mesh_terms: D000497:Alloys / Q000737:chemistry*; D020099:Coated Materials, Biocompatible / Q000737:chemistry; D017886:Durapatite / Q000737:chemistry*; D004583:Electrons; D006244:Hardness; D008274:Magnesium / Q000737:chemistry*; D060526:Magnetic Fields; D008422:Materials Testing; D055595:Mechanical Phenomena; D049329:Nanostructures / Q000737:chemistry*; D011846:Radio Waves; D013499:Surface Properties
chemical_list: D000497:Alloys; D020099:Coated Materials, Biocompatible; D017886:Durapatite; D008274:Magnesium
keywords: Hardness; Hydroxyapatite coating; Magnesium alloy; RF magnetron sputtering; Substrate bias; Wear resistance; Young׳s modulus