title: GEP-based method to formulate adhesion strength and hardness of Nb PVD coated on Ti-6Al-7Nb aimed at developing mixed oxide nanotubular arrays.
abstract: PVD process as a thin film coating method is highly applicable for both metallic and ceramic materials, which is faced with the necessity of choosing the correct parameters to achieve optimal results. In the present study, a GEP-based model for the first time was proposed as a safe and accurate method to predict the adhesion strength and hardness of the Nb PVD coated aimed at growing the mixed oxide nanotubular arrays on Ti67. Here, the training and testing analysis were executed for both adhesion strength and hardness. The optimum parameter combination for the scratch adhesion strength and micro hardness was determined by the maximum mean S/N ratio, which was 350W, 20 sccm, and a DC bias of 90V. Results showed that the values calculated in the training and testing in GEP model were very close to the actual experiments designed by Taguchi. The as-sputtered Nb coating with highest adhesion strength and microhardness was electrochemically anodized at 20V for 4h. From the FESEM images and EDS results of the annealed sample, a thick layer of bone-like apatite was formed on the sample surface after soaking in SBF for 10 days, which can be connected to the development of a highly ordered nanotube arrays. This novel approach provides an outline for the future design of nanostructured coatings for a wide range of applications.
authors.affiliation: Department of Mechanical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia.
authors.forename: A R
authors.initials: AR
authors.lastname: Rafieerad
authors.affiliation: Department of Mechanical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia; Department of Mechanical Engineering, Faculty of Engineering, University of UCLA, Los Angeles, CA 90032, United States; Department of Mechanical and Aerospace Engineering, University of California, CA 90095-1597, United States. Electronic address: bushroa@um.edu.my.
authors.forename: A R
authors.initials: AR
authors.lastname: Bushroa
authors.affiliation: Advanced Materials Research Center, Materials Engineering Department, Najafabad Branch, Islamic Azad University, Najafabad, Isfahan, Iran. Electronic address: bahman_nasiri@hotmail.com.
authors.forename: B
authors.initials: B
authors.lastname: Nasiri-Tabrizi
authors.affiliation: Department of Mechanical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia.
authors.forename: A
authors.initials: A
authors.lastname: Fallahpour
authors.affiliation: Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia.
authors.forename: J
authors.initials: J
authors.lastname: Vadivelu
authors.affiliation: Department of Mechanical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia.
authors.forename: S N
authors.initials: SN
authors.lastname: Musa
authors.affiliation: UM Power Energy Dedicated Advanced Centre (UMPEDAC),University of Malaya, Kuala Lumpur, Malaysia.
authors.forename: S H A
authors.initials: SHA
authors.lastname: Kaboli
mesh_terms: D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D006244:Hardness; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D043942:Nanotubes / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry*; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*
chemical_list: D020099:Coated Materials, Biocompatible; D010087:Oxides; C070282:Ti-6Al-7Nb alloy; D014025:Titanium
keywords: Anodization; GEP-based model; In-vitro bioactivity; PVD sputtering; Ti–6Al–7Nb