Oxidation Resistance of Double-Layer MoSi2–Borosilicate Glass Coating on Fiber-Reinforced C/SiO2 Aerogel Composite

An MoSi2–borosilicate glass coating with high emissivity and oxidation resistance was prepared on the surface of the fiber-reinforced C/SiO2 aerogel composite by the slurry method combined with the embedding sintering method under the micro-oxygen atmosphere. The microstructure and phase composition of the coatings with different MoSi2 contents before and after static oxidation were investigated. This composite material has both excellent radiating properties and outstanding oxidation resistance. The total emissivity values of the as-prepared coatings are all above 0.8450 in the wavelength of 300∼2,500 nm. Meanwhile, the as-prepared M40 coating also has superior thermal endurance after the isothermal oxidation of 1,200°C for 180 min with only 0.27% weight loss, which contributes to the appropriate viscosity of the binder to relieve thermal stress defects. This material has broad application prospects in thermal protection.

Reinforcing Glaze Layer of Restorative Dental Zirconia by Adding Nano Alumina Ceramics

The objective of this work is to study the effect of adding varying ratios of Nano Alumina to the glazing powder on glazing layer of restorative dental ceramic. The effect of addition is examined by applying Vickers hardness and surface roughness tests on the glazing layer. The specimens have been cut in a cubic form. The specimens were placed in the furnace for sintering up to temperature of 1450 oC. One specimen is glazed with glazing materials and the remaining three specimens are glazed with glazing materials but supported with varying ratios of Nano Alumina (10, 15 and 25 wt%) and all these specimens sintered at 850 oC. It was found that Vickers hardness is increased with increasing the ratios of Nano Alumina but the surface roughness decreased with increasing the ratios of Nano Alumina. Weibull modulus increased with Alumina additive increases for glass coating layer.

Enhance the Biological Properties of Commercial Pure Titanium with Bioactive Glass Coating by Pulsed Laser Deposition

Titanium is the most broadly employed implant material for the load bearing dental and the orthopedic uses due to its brilliant biological and mechanical characteristics. The aim of the present study is to assay the biological behavior of pure Titanium coated with a bioactive glass coating made by pulsed laser deposition. The coating characteristic and the biological behavior of coated specimens were assessed and compared with uncoated specimens. In vitro biological behavior including bioactivity, biocompatibility and antibacterial property was evaluated. The bioactivity of the specimens was assayed by immersion in a simulated body fluid for various times (7 and 14) days. Biocompatibility was assessed by MTT assay of L929 mouse fibroblast cells after 1, 3 and 5 days. Also, the antibacterial property was evaluated against S. aures by optical density method. The obtained results revealed that the pulsed laser deposited bioactive glass coating significantly improved the potential of Titanium for dental and orthopedic applications.