Monolithic ceramics have been fabricated from coated green fibers to create fibrous microstructures. The fibrous monoliths consist of high aspect ratio polycrystalline regions (cells) of a primary phase separated by thin secondphase regions (cell boundaries) designed to improve fracture resistance. The cells are the remnants of the green fiber which consists of ceramic powder and a polymer bind...

OBJECTIVES This study aimed to evaluate the effect of different ceramic surface treatments after machining grinding on the biaxial flexural strength (BFS) of machinable dental ceramics with different crystalline phases. MATERIALS AND METHODS Disk-shape specimens (10mm in diameter and 1.3mm in thickness) of machinable ceramic cores (two silica-based and one zirconia-based ceramics) were prepar...

This report presents the results obtained by the five U.S. participating laboratories in the Versailles Advanced Materials and Standards (VAMAS) round-robin for fracture toughness of advanced ceramics. Three test methods were used: indentation fracture, indentation strength, and single-edge pre-cracked beam. Two materials were tested: a gas-pressure sintered silicon nitride and a zirconia tough...

BACKGROUND Numerous studies have reported that microgrooves on metal and polymer materials can affect cell adhesion, proliferation, differentiation and guidance. However, our knowledge of the cell activity associated with microgrooves on ceramics, such as alumina, zirconia, hydroxyapatite and etc, is very incomplete, owing to difficulties in the engraving of microgrooves on the hard surface of ...

Although alumina has been used in orthopaedic surgery since the 1970s, the long-term clinical results of zirconia have not been well documented in vivo. We studied hips with these two different ceramics during the same period and with a minimum follow-up of ten years. Because the size of the alumina and zirconia heads was different, hips with 32 mm alumina heads and those with 28 mm zirconia he...

Article history: Received: 01.05.2016. Received in revised form: 25.07.2016. Accepted: 06.09.2016. This study presents the results of investigating the cause of contamination of aluminum oxide ceramics (Al2O3) in the form of brown colored stain. Contaminated ceramic surfaces were examined with the scanning electron microscope (SEM) equipped with the Energy Dispersive Spectrometer (EDS). The res...

This paper discusses the challenges involved in producing high-quality alumina ceramics, particularly when it comes to achieving a suitable degree of surface roughness and high accuracy. Alumina ceramics are widely used various applications due their exceptional properties, including strength, wear resistance chemical stability. The ceramic pistons with desired properties performance were produ...

A study has been made of Hertzian contact damage in compressive shear stress field beneath the contact area. The observed microcrack density increases with grain size, porous and dense liquid-phase-sintered aluminas. Indentation stress–strain curves show increasing nonlinearity as the implying a threshold microstructural scale for crack initiation. In contrast, the micromechanisms controlling f...

Ceramics bonding is becoming an important technology and has found wide applications in different engineering and electronic industries. In this paper, furnace bonding of ceramics using solder glass frit was investigated with emphasis on the effects of surface treatment and bonding conditions on bonding strength. Alumina (Al2O3) sheet and SCHOTT solder glass G017-393 were used as the base and b...

The aim of this study was to clarify the effects of micro surface defects introduced by the focused ion beam (FIB) technique on the fracture strength of ceramics. Three-point bending tests on alumina-silicon carbide (Al₂O₃/SiC) ceramic composites containing crack-like surface defects introduced by FIB were carried out. A surface defect with area in the range 19 to 35 µm was introduced at the ce...