Electrochemical Corrosion Behavior of Pure Mg Processed by Powder Metallurgy

Abstract

Pure Mg samples were prepared by powder metallurgy using the cold and hot compacting methods. Cold compacted pure Mg (500 MPa/RT) was characterized by 5% porosity and the mechanical bonding of powder particles. Hot compacted samples (100 MPa/400 °C and 500 MPa/400 °C) exhibited porosity below 0.5%, and diffusion bonding combined with mechanical bonding played a role in material compaction. The prepared pure Mg samples and wrought pure Mg were subjected to corrosion tests using electrochemical impedance spectroscopy. Similar material corrosion behavior was observed for the samples compacted at 500 MPa/RT and 100 MPa/400 °C; however, hot compacted samples processed at 500 MPa/400 °C exhibited longer corrosion resistance in 0.9% NaCl solution. The difference in corrosion behavior was mainly related to the different binding mechanisms of the powder particles. Cold compacted samples were characterized by a more pronounced corrosion attack and the creation of a porous layer of corrosion products. Hot compacted samples prepared at 500 MPa/400 °C were characterized by uniform corrosion and the absence of a layer of corrosion products on the specimen surface. Powder-based cold compacted samples exhibited lower corrosion resistance compared to the wrought pure Mg, while the corrosion behavior of the hot compacted samples prepared at 500 MPa/400 °C was similar to that of wrought material.

Microstructure and electrochemical corrosion behavior of CaP/PEO duplex coating on AZ31 magnesium alloy

“…In the last few decades, magnesium-based materials have gained much attention as bioabsorbable metal implants due to their good mechanical properties, biocompatibility and biodegradability in physiological environments [1][2][3][4]. The use of Mg materials in-vivo is limited mainly by their high reactivity and associated low corrosion resistance.…”

“…the development of large amounts of hydrogen gas and surface alkalization are of concern. The hydrogen accumulated around the implant can cause cracks in the bone tissue and the alkalization of the body fluid can lead to tissue necrosis [1][2][3][4][5].…”

Microstructural and Mechanical Behaviourial Properties of Cold Compacted Ultra-Fined Grained (UFG) Magnesium AZ31B Alloy Prepared by Ball Milling Process

“…The microstructural and mechanical Properties of Magnesium alloys were modified by Severe plastic deformation (SPD) methods, such as Accumulated Roll Bonding (ARB), High pressure Torsion (HPT), Equal channel axial pressing (ECAP), Spark Plasma Sintering (SPS) etc. [2][3][4][5][6][7][8][9]. Magnesium alloy Properties are wellbeing improved by reducing the grain size and improving the strength by replacement of dense particles which have been indeed researched by present Researchers.…”

“…The researchers have found to be successful in preparing high strengthened Magnesium alloys through several SPD processes i.e. ARB, HPT, SPS, ECAP etc [2][3][4][5][6][7][8][9]. Heny Faisal et al (2016) detected the microstructure of Al/Mg composites through cold compaction process followed by sintering the bonding of grains are formed with increased density.…”

“…these sub grains further deformed to fall to nanometer scale. From the previous researchers [1][2][3][4][5][6][7][8][9][10]. The grain size refinement about to nanocrystalline size of less than 100nm under severe plastic deformation (SPD) of Magnesium alloys has shown improved strength, to that of that of an inverse Hall-Petch relation under nanometric scale [2][3][4][5][6][7][8][9][10].…”