Influence of Laser Treatment Medium on the Surface Topography Characteristics of Laser Surface-Modified Resorbable Mg3Zn Alloy and Mg3Zn1HA Nanocomposite

Abstract

In this study, a Mg3Zn alloy and a Mg3Zn1HA nanocomposite were fabricated through disintegrated melt deposition, followed by the hot extrusion process. The specimens were subjected to fiber laser surface modification in air and demineralized water (DM) medium to determine the influence of the laser treatment medium on the microstructure, microhardness, grain size, and surface topography. During the laser treatment, the samples under the water medium produced a lower surface roughness when compared with the air medium. The atomic force microscope (AFM) surface topography scan showed the presence of surface modifications caused by the presence of nanohydroxyapatite (nHA) in the matrix, resulting in a 367.4% and 632.4% increase in the surface roughness (Ra) in the Mg3Zn1HA nanocomposite when compared with the Mg3Zn alloy in water and air media, respectively.

Keywords

• magnesium alloy
• hydroxyapatite
• metal matrix composite
• resorbable implant
• surface modification
• topography