in this article, failure and fracture mechanisms in an aluminum alloy (which has been used in diesel internal combustion engines), with and without ceramic thermal barrier coatings, have been investigated under isothermal and non-isothermal fatigue loadings. in this research, the base material is an aluminum-silicon-magnesium alloy and the thermal barrier coating includes a metallic bond coat l...

Multilayer thermal barrier coatings (TBCs) on superalloy substrates are comprised of an intermetallic bond coat, a thermally grown oxide (TGO) layer, and a porous zirconia top coat that provides thermal protection. The TGO attains a thickness of 1±10 lm prior to failure, while the bond coat and zirconia layer are each about 50±100 lm thick. The preferred method for manufacturing TBCs comprises ...

AIM This study tested the null hypothesis that there is no difference on microleakage of dentin-bordered composite restorations using single or double coats of adhesive from one-bottle adhesive systems. METHODS AND MATERIALS The enamel surface was removed from freshly extracted bovine teeth, and standardized Class V cavities (3 x 3 x 1.5 mm) were made at the cervical areas of buccal surfaces....

Thermal barrier coatings (TBCs) are commonly used to protect gas turbine components from high temperatures and oxidation. Such consist of ceramic top coats metallic bond coats. The mismatch in thermal expansion the coat, coat component material is one main factor leading failure coating system. Columnar-structured offer an enhanced tolerance strain during cycling. On a flat coated surface, thes...

n air plasma spray process has been used to deposit tri-layer environmental barrier coatings consisting of a silicon bond coat, a mullite interiffusion barrier, and a Yb2SiO5 top coat on SiC substrates. Solidified droplets in as-deposited Yb2SiO5 and mullite layers were discovered to be epleted in silicon. This led to the formation of an Yb2SiO5 + Yb2O3 two-phase top coat and 2:1 mullite (2Al2O...

This study evaluated the effect of adhesive systems and application strategies on dentin hydraulic conductance (HC). The buccal enamel was removed from bovine incisors to simulate laminate cavity preparations. After removing the roots and the coronal pulp, the buccal dentin was treated with EDTA solution (0.5 M) for 5 minutes, rinsed, ultrasonicated for 12 minutes and connected to a permeabilit...

AIM The aim of this study was to evaluate the effects of multiple consecutive coatings of a one-step self-etch adhesive system (Clearfil Tri-S Bond) on the microtensile bond strength (MBS) to dentin. METHODS AND MATERIALS Nine caries-free human lower third molars were sectioned perpendicular to the long axis to expose the mid-coronal dentin. The teeth were separated into three experimental gr...

Thermally insulating ceramic coatings also known as thermal barrier coatings (TBCs) have been essential technologies to improve the performance and efficiency of advanced gas turbines in service at extremely high temperatures. The damage mechanisms of air-plasma sprayed YSZ thermal barrier coatings (TBC) with various microstructures were studied by microscopic techniques after thermal cycling. ...

The objective of this study was to mimic the microstructure of MCrAlY coatings sprayed using HVOF (High Velocity Oxy-Fuel) processes by using an Air Plasma Spray (APS) process in order to improve oxidation and spallation life of MCrAlY APS coatings. Figure 1 shows the typical microstructures obtained when spraying bond coats using the (a) HVOF process, and (b) the APS process. The microstructur...