title: Laser surface modification of AZ31B Mg alloy for bio-wettability.
abstract: Magnesium alloys are the potential degradable materials for load-bearing implant application due to their comparable mechanical properties to human bone, excellent bioactivity, and in vivo non-toxicity. However, for a successful load-bearing implant, the surface of bio-implant must allow protein absorption and layer formation under physiological environment that can assist the cell/osteoblast growth. In this regard, surface wettability of bio-implant plays a key role to dictate the quantity of protein absorption. In light of this, the main objective of the present study was to produce favorable bio-wettability condition of AZ31B Mg alloy bio-implant surface via laser surface modification technique under various laser processing conditions. In the present efforts, the influence of laser surface modification on AZ31B Mg alloy surface on resultant bio-wettability was investigated via contact-angle measurements and the co-relationships among microstructure (grain size), surface roughness, surface energy, and surface chemical composition were established. In addition, the laser surface modification technique was simulated by computational (thermal) model to facilitate the prediction of temperature and its resultant cooling/solidification rates under various laser processing conditions for correlating with their corresponding composition and phase evolution. These predicted thermal properties were later used to correlate with the corresponding microstructure, chemical composition, and phase evolution via experimental analyses (X-ray diffractometer, scanning electron microscope, energy-dispersive spectroscopy).
authors.affiliation: Laboratory for Laser Aided Additive and Subtractive Manufacturing, Department of Materials Science and Engineering, University of North Texas, Denton, TX, USA.
authors.forename: Yee-Hsien
authors.initials: YH
authors.lastname: Ho
authors.affiliation: Laboratory for Laser Aided Additive and Subtractive Manufacturing, Department of Materials Science and Engineering, University of North Texas, Denton, TX, USA.
authors.forename: Hitesh D
authors.initials: HD
authors.lastname: Vora
authors.affiliation: Laboratory for Laser Aided Additive and Subtractive Manufacturing, Department of Materials Science and Engineering, University of North Texas, Denton, TX, USA Narendra.Dahotre@unt.edu.
authors.forename: Narendra B
authors.initials: NB
authors.lastname: Dahotre
mesh_terms: D020341:Absorbable Implants; D000497:Alloys / Q000737:chemistry; D001672:Biocompatible Materials / Q000737:chemistry; D018786:Bone Substitutes / Q000737:chemistry; D001842:Bone and Bones / Q000601:surgery; D006358:Hot Temperature; D006801:Humans; D007834:Lasers; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D013499:Surface Properties; D016474:Weight-Bearing; D017155:Wettability; D014961:X-Ray Diffraction
chemical_list: D000497:Alloys; D001672:Biocompatible Materials; D018786:Bone Substitutes; C586533:Mg-Al-Zn-Mn-Si-Cu alloy
keywords: Laser surface modification; bio-implant; bio-wettability; contact-angle measurement; grain refinement; surface energy