The silver toughened alumina ceramics, which were fabricated via a conventional ceramic processing route using commercially available alumina and silver oxide powders as the starting materials, exhibit a higher fracture toughness (6 to 9 MPamo.5) than the monolithic alumina ceramic ( 2.5 to 3.0 MPamo.5). The weak interfacial bonding between the silver inclusions and the alumina matrix is charac...

Alumina toughened zirconia (ATZ) and zirconia toughened alumina (ZTA) are currently the materials of choice to meet the need for tough, strong, and bioinert ceramics for medical devices. However, the mechanical properties of ZrO2/Al2O3 dispersion ceramics could be considerably increased by reducing the corresponding grain sizes and by improving the homogeneity of the phase dispersion. Here, we ...

a water–soluble gelatin combined with polyethylene microspheres were developed to prepare alumina composite foam. gelatin was used as the gelling agent and polyethylene was used as pore making template. on the other hand, kaolin was used to provide green strength and cuo was applied to decrease the required temperature as a sinter aid. alumina bodies need elevate temperature for sintering, incr...

It has recently been reported that in the Y203-stabilized tetragonal zirconia phase (TZP) system the addition of a small amount of transition-metal oxides (e.g. CuO, MnO and ZnO) which form a liquid or amorphous grain boundary phase significantly enhances superplasticity [1, 2]. In CuO-added 2Y-TZP abrupt changes have been found in the stress exponent and activation energy across the melting te...

OBJECTIVES The aim of this study was to evaluate the effect of mechanical cycling on the biaxial flexural strength of two densely sintered ceramic materials. METHODS Disc shaped zirconia (In-Ceram Zirconia) and high alumina (Procera AllCeram) ceramic specimens (diameter: 15 mm and thickness: 1.2 mm) were fabricated according to the manufacturers' instructions. The specimens from each ceramic ...

The need to move large volumes of highly abrasive materials, such as coal, grain, sand, and various waste products, places great demands on the piping systems through which they are conveyed. Excessive wear is a common problem, especially evident in the sections of pipe, which change the direction of flow of the abrasive material. . Due to their excellent wear characteristics, ceramic materials...

The sintering behaviour of several green compacts made with olivine or olivine/alumina powder blends has been examined. To this goal, powders were attrition milled, uniaxially pressed into specimens and air sintered at temperatures ranging from 1100 to 1300 °C. The resulting samples were characterized by water absorption, shrinkage, phase composition and density. Compositions containing 5%, 10%...

his study used quantitative image analysis to examine the effect of powder forming method on a population of dense heterogeneities that could e imaged in partially sintered alumina using optical microscopy. Powder pressing resulted in a higher area fraction of dense heterogeneities than lip casting. Extreme value analysis was used to predict the size of the largest heterogeneity in the populati...

OBJECTIVE To evaluate the bond stability of resin cements when luted to glass-reinforced alumina and zirconia CAD/CAM dental ceramics. STUDY DESIGN Eighteen glass-infiltrated alumina and eighteen densely sintered zirconia blocks were randomly conditioned as follows: Group 1: No treatment; Group 2: Sandblasting (125 µm Al₂O₃-particles); and Group 3: Silica-coating (50 µm silica-modified Al₂O₃-...

The refractory solid electrolyte, sodium beta alumina, is cold sintered at 375 °C which over 1000 lower than conventional sintering. A relative density above 90% and an ionic conductivity of 10 ?3 S cm ?1 (300 °C) obtained.