In this study, corrosion resistance was developed to ensure that AZ91 Mg alloy remains stable in the body for longer periods. For this purpose, tantalum oxide and tantalum oxide with diethanolamine coatings were made by sol–gel method on AZ91 magnesium alloy surfaces. The structural analyses of tantalum oxide and tantalum oxide with diethanolamine obtained by sol–gel method were carried out. By using the dip coating method, coatings with different concentrations of solutions and different dipping numbers were applied on AZ91 Mg alloy surfaces. Thus, the effects of dipping numbers and chemical content of the solution on the coating thicknesses, surface roughnesses, morphologies and corrosion resistances of coating layers were examined. As a result, it was determined that the coating thicknesses increased with the dipping number. The low number of dipping could not provide sufficient protective layer formation on the surface. Better results were obtained in samples with a high dipping numbers. It was observed that needle-like structures were formed in the solution using diethanolamine. As the amount of diethanolamine increased, a more homogeneous and dense coating layer was observed. Accordingly, an increase in corrosion resistance has been observed. It was determined that the corrosion rate of AZ91 Mg alloy has decreased by 86% with increasing dipping number and diethanolamine amount.

Los implantes habituales en aplicaciones biomédicas como el Ti y sus aleaciones y el acero inoxidable 316L pueden dañar los tejidos circundantes, ocasionando infecciones. Para evitar este riesgo, es necesario producir materiales de implantes de nueva generación que sean más ligeros que los biomateriales existentes, en los que las propiedades mecánicas y estructura sean similares al hueso. En este estudio, el material de implante de aleación de Mg AZ91 se obtiene mediante un procedimiento pulvimetalúrgico. Adicionalmente, para mejorar la biocompatibilidad y bioactividad, el material de implante obtenido se recubrió con hidroxiapatita (HA), conocido como biomaterial de base cerámica. Se aplicó un revestimiento de HA a la superficie de la aleación utilizan el método de deposición electroforética. Se examinaron las propiedades superficiales y la resistencia a la corrosión. Los valores de voltaje aplicados en el proceso de recubrimiento fueron 100, 150, 200 y 250 V, durante un tiempo de 2 min. Se utilizaron productos químicos de HA, etanol, alcohol polivinílico (PVA), N, N-dimetilformamida para preparar la solución de revestimiento. Se analizaron las microestructuras de los recubrimientos mediante microscopía electrónica de barrido (SEM) y se realizaron análisis elementales (EDS) de las superficies del recubrimiento. Se utilizó el método de difracción de rayos X (XRD) para determinar las fases de los recubrimientos y su concentración. Finalmente, se determinaron los valores de espesor del revestimiento y la rugosidad superficial. El comportamiento frente a la corrosión se determinó mediante la medida de potencial de corrosión, utilizando como electrolito un fluido corporal artificial.

Aluminum metal matrix composites were used in various fields such as aircraft, underwater, automobile, aerospace. Several fabrication techniques were used for the production of these composites. Among the various methods, the powder metallurgy route provides dimensional accuracy and high production rates. In this paper, metal matrix composites that include 7075 aluminum alloy chips and Al2O3 particles were produced by using a hot pressing. The effect of reinforcement amount and T6 heat treatment on the mechanical and wear properties of the composites were investigated. Al2O3 particles were added by weight of 5, 10 and 15 % and the composites were produced by hot pressing. T6 heat treatment consisted of a solution treatment at 480 degrees C for 2 h and artificially aging process at 120 degrees C for 24 h. Wear resistance of the composites was determined by a ball-ondisc dry sliding wear test. Brinell Hardness of the composites tended to increase with the increasing Al2O3 reinforcement up to 10 wt.% and with T6 treating. Particle reinforcement improved the wear resistance up to 10 wt.% Al2O3. In addition, volumetric material loss tended to decrease after the aging process.

The corrosion and bacterial behavior of AZ91 magnesium alloy coated with sol–gel-deposited amorphous tantalum oxide and hydroxyapatite have been investigated. The objective was to assess the potential suitability of AZ91 for permanent prosthesis applications. The coatings were applied in layered and hybrid configurations and characterized using various techniques including X-ray diffractometry, Fourier transform infrared spectroscopy, scanning electron microscopy/energy dispersive spectrometry, and drop analyses. The antibacterial properties were evaluated through interactions with Staphylococcus aureus and Escherichia coli strains. Mechanical properties and adhesion were determined via linear scratch tests, and electrochemical corrosion tests were conducted in different media. The release of aluminum ions from the samples in Dulbecco’s Modified Eagle’s Medium was monitored over 28 days. The findings revealed that the amorphous tantalum oxide coating, particularly in combination with hydroxyapatite, improved antibacterial properties and positively influenced corrosion and scratch resistance. The layered and hybrid coatings demonstrated the highest corrosion resistance. The release of aluminum ions remained within acceptable levels in the tested medium. Overall, the study provides valuable insights into the potential of sol–gel coatings on AZ91 for prosthetic applications, considering antibacterial behavior, corrosion resistance, and aluminum release.