The Significant Effect of Mechanical Treatment on Ceramic Coating for Biomedical Application.

Titanium and its alloys are commonly preferred materials used for biomedical implants. However, these alloys have issues related to corrosion resistance as a result of the aggressive attack of human body fluids. Several researchers have attempted to produce a ceramic coating via physical vapour deposition (PVD). A PVD layer consists of pores, pinholes, and columnar growth that attack the substrate as an aggressive medium. The aim of this research is to evaluate the influence of ultrasonic vibration parameters on a TiN-coated biomedical Ti-13Zr-13Nb alloy. This study used TiN to formulate and coat disk-type samples in a fixed condition. Ultrasonic vibration at fixed frequencies was applied to TiN-coated samples for three sets of exposure times. The findings revealed that all TiN-coated samples exposed to ultrasonic vibration had improved corrosion resistance compared to untreated samples. Field emission scanning electron microscopy (FESEM) was employed to analyse sample's microstructures. The top parameter (16 kHz and 11 min) yielded the most compact coating. Ultrasonic vibration's hammering effect decreased the size of microchannels in the lining and reduced the rate of corrosion attack. The nanoindentation test showed that coated ultrasonic treated samples had a higher hardness/elasticity (H/E) ratio than untreated samples.

The Utilization of a Fiberglass Mesh-Reinforced Foamcrete Jacketing System to Enhance Mechanical Properties.

Foamcrete is fabricated by combining mortar slurry and constant foam. Owing to the existence of air entrained in its cementitious matrix, foamcrete is tremendously brittle compared to normal-strength concrete. The addition of synthetic and natural plant fibers demonstrates an enhancement to foamcrete's mechanical performance yet exerts a harmful effect on long-term performance. Depreciation of natural plant fibers and corrosion of synthetic fibers impact the lifespan and durability properties of foamcrete. Hence, this study aims to investigate the mechanical properties and mode of failures of foamcrete reinforced with fiberglass mesh (FM). The parameters assessed were the compression, flexural, and splitting tensile strengths of 1100 kg/m3 density foamcrete confined with various layers of 145 g/m2 of FM. The optimal foamcrete mechanical properties enhancement was attained with three-layer jacketing. Notable augmentations of 108% in the compressive strength, 254% in flexural strength, and 349% in splitting tensile strength were achieved in comparison to the control specimens at day 28. The control foamcrete samples under compressive, flexural, and tensile loads encountered brittle failure in comparison to the confined foamcrete. The mode of failure under the tensile load indicates that only a slight crack occurred at the upper side and a perpendicular mark at the lateral section of the foamcrete with one to three layers of FM jacketing. Thus, the jacketing system of foamcrete with FM enhances the behavior and load carrying capacity of foamcrete to the extent of preventing the propagation of cracks.

Mechanical Properties of Lightweight Foamed Concrete Modified with Magnetite (Fe3O4) Nanoparticles.

The advancement in sustainable construction has stimulated wide-ranging investigation of construction materials and practices globally. With exceptional thermal properties, fire resistance performance, excellent strength, and outstanding durability, concrete is the utmost extensively utilized construction material around the world. Taking into consideration the quantity of concrete necessary for numerous constructions works, improving concrete sustainability would be an extremely attractive potential. Lightweight foamed concrete (LFC) is tremendously permeable, and its mechanical properties weaken with a growth in the volume of voids. Air-void segregation from solid cement phases by means of aging, drainage, and merging of voids can trigger and reduce the stability and consistency of the emitted pores, making the LFC less reliable for main utilization in load-bearing components and structural elements. In turn, to augment LFC mechanical properties, the LFC cementitious matrix can be adjusted by adding various nanoparticles. The influence of magnetite nanoparticles (MNP) in LFC was not examined in the past; hence, there is some vagueness considering the mechanism to which level the MNP can affect the LFC mechanical properties. Thus, the aim of this study is to investigate the influences of MNP on the compressive, splitting tensile, and flexural LFC of 1000 kg/m3 density. Six MNP weight fractions of 0.10%, 0.15%, 0.20%, 0.25%, 0.30%, and 0.35% were considered. The parameters accessed were compressive, splitting tensile and flexural strengths. The correlation between strength parameters was established as well. The results indicated that a 0.25% weight fraction of MNP gave the best performance in terms of compressive, flexural, and splitting tensile strengths. The presence of MNP in the LFC matrix enhances the viscosity and yield stress of the mixture as well as an augmented utilization of LFC cementitious binder content, which can sustain the integrity of the wet networks hence preventing further amalgamation and aging of the voids.