The aim of this study was to characterize a conventional and a pressed porcelain for zirconia core as to biaxial flexural strength (BFS), apparent fracture toughness (FT) and microstructure composition, and to investigate the effect of glaze cooling rate on the BFS of the zirconia/porcelain bilayers. Monolayers of conventional porcelain Vita VM9 and pressed porcelain Vita PM9 (n=15) (12 mm diam...

Studies of leaf traits often focus on tradeoffs between growth and resource conservation, but little is known about variation in the mechanical traits that influence resource conservation. This study investigates how leaf mechanical traits vary across matorral vegetation in central Chile, how they correlate with environmental factors, and how these trends compare at a broader geographic scale. ...

Fracture behavior via a flexural test for newly found CaO–Al2O3–SiO2 (CAS) glass-ceramic (GC) was compared with that of enstatite GC and mica GC, which are well-known GCs high-fracture toughness machinability, respectively. By focusing on the nonelastic load–displacement curves, CAS characterized as less brittle material similar to machinable showed higher fracture toughness, KIC. The microcrac...

Mechanical property and impact resistance mechanism of bionic layered composite was investigated. Due to light weight and high strength property, white clam shell was chosen as bionic model for design of bionic layered composite. The intercoupling model between hard layer and soft layer was identical to the layered microstructure and hardness tendency of the white clam shell, which connected th...

To fully utilize the siliceous whiskers and improve the mechanical properties of oil-well cement, the cement composites with different additions of siliceous whiskers were prepared, and analyzed by means of scanning electron microscopy (SEM), mechanical testing, X-ray diffraction (XRD), and infrared spectrum analysis. The results showed that the addition of 2% siliceous whiskers could slightly ...

Melanin has been associated with increased resistance to abrasion, decreased wear and lowered barb breakage in feathers. But, this association was inferred without considering barb position along the rachis as a potentially confounding variable. We examined the cross-sectional area, breaking force, breaking stress, breaking strain and toughness of melanized and unmelanized barbs along the entir...

We have developed a concrete material exhibiting self-healing properties and corrosion inhibition. This system involves a sodium silicate solution stored in polyurethane microcapsules present in the concrete matrix. The sodium silicate, released when the capsules are ruptured by propagating cracks, reacts with the calcium hydroxide in cement and produces a C-S-H gel that partially heals the cra...

Calcium silicate hydrate (C-S-H) is the binder in concrete, the most used synthetic material in the world. The main weakness of concrete is the lack of elasticity and poor flexural strength considerably limiting its potential, making reinforcing steel constructions necessary. Although the properties of C-S-H could be significantly improved in organic hybrids, the full potential of this approach...

This work aims at studying the effect of the milling conditions on the microstructure and mechanical properties of a ZrB₂-5 vol% Si₃N₄ matrix reinforced with chopped Hi-Nicalon SiC fibers. Several composites were obtained using different milling conditions in terms of time, speed and type of milling media. The composites were prepared from commercial powders, ball milled, dried and shaped, and ...

STATEMENT OF THE PROBLEM The usage of glass ionomer cements (GICs) restorative materials are very limited due to lack of flexural strength and toughness. PURPOSE The aim of this study was to investigate the effect of using a leucite glass on a range of mechanical and optical properties of commercially available conventional glass ionomer cement. MATERIALS AND METHOD Ball milled 45μm leucite...