Self-growth of micro- and nano-structured Mg(OH)₂on electrochemically anodised Mg–Li alloy surface

Abstract

Formation of Mg(OH) 2 nanowires and their assemblies with sphere-shaped, echinus-shaped and nest-like micro-structures on a Mg-Li alloy surface was successfully demonstrated. Mg(OH) 2 nanowires were formed on the alloy surface via a self-growth process, after the alloy was electrooxidised in NaCl solution and the oxidation products were removed. The nanowires were characterised by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and Infrared spectroscopy. The nanowires have hexagonal rod-like or brush-like morphology and are poorly crystallised. Pre-anodisation and the presence of Li in the alloy are key factors for the nanowire growth, which likely proceeds via a dissolution-precipitation mechanism. The roles of Li can be attributed to the prohibition of the formation of passivation film on the alloy surface and the acceleration of the formation of OH À anions through hydrogen-evolution reaction.

Enhanced corrosion resistance of plasma electrolytic oxidation coatings prepared on Mg alloy ZX using nano-Al2O3 and NaF incorporated electrolyte

“…Usually, through normal anodization, the Mg yielded MgOH phase [27,28] Equations ( 1) and ( 2). Here, Plasma electrolytic oxidation process yielded MgO phase Equations ( 1) and ( 3) accompanied by a vigorous evolution of H 2 .…”

Surface Morphologies and Mechanical Properties of Mg-Zn-Ca Amorphous Alloys under Chemistry-Mechanics Interactive Environments

“…Figure 3d,e, and b. When the pressure was set at 30 MPa (Figure 3d), a small number of micro-cracks accompanied by a certain number of Mg(OH) 2 microwires [28,29] formed on the sample surface. When the pressure was increased to 90 MPa (Figure 3e), the crack grew and spread.…”