Y2O3:Eu were prepared through precursors synthesized by leaching tests, removing impurities, enrichment of Y and Eu from residual purified liquors, annealing treatment, and high temperature solid-state reaction method, which is the most suitable for large-scale production. The analysis of product shows that the purity is 99.42%. The resultant powders were characterized by X-ray diffraction (XRD...

This work deals with sintering additives for the low temperature pressureless sintering of Si3N4, via a transient liquid technique. Much attention has been given to the development of a sintering process using low-cost Si3N4 powder (Silzot HQ, Germany) as the starting material and employing sintering additives which are also both economically attractive and enable sintering at low temperatures....

Sintering behavior with and without external stress was investigated using undoped and doped (1500 ppm yttria) sub-micron a-alumina powders. The yttria doped alumina showed anomalous behavior with grain size around 0.9 pm, a second peak in densification rate during free sintering and a stagnation followed by a steep increase in flow stress during sinter forging. These were thought to correspond...

Quantitative microstructural analysis was performed on Si3N4 materials doped with 5 wt% Y203 and 5 wt% Sc203 as sintering aids. Two different processing routes were utilized to achieve complete densification: (i) gas-pressure sintering of Si3N4-starting powders (SSN) and (ii) post-sintering of reaction-bonded Si3N4 (SRBSN). Apart from quantitative evaluation of grain diameter and aspect ratio o...

In this paper, we present a mathematical model that describes the calcination and sintering of calcium-based sorbents in furnace sorbent injection (FSI) conditions. We assumed that the sorbent decomposition follows a shrinking core model with a changing pore size distribution in every layer and we used a comprehensive mathematical model for sintering. Cylindrical and plate-like or slit pore geo...

Carbon nanofiber growth on palladium particles from ethylene–oxygen mixtures was investigated with respect to thermal history. Electron microscopy, combined with focused ion beam cross-sectioning show particles sinter quickly, but can be stabilized by the addition of a short carbon deposition step at a temperature below the general reaction temperature. This step generates a thin layer of carbo...

Protonic conductors of BaZr0.5Ce0.3Ln0.2O3-δ (BZCLn532, Ln=Y, Sm, Gd, Dy) were successfully synthesized by using a cost-effective solid state reactive sintering (SSRS) method with 1 wt.% NiO as a sintering aid. The pellets of the BZCLn532 were obtained at sintering temperatures between 1300 1600 °C. The results show that the morphologies and the final relative densities of the obtained BZCLn532...

Mechanical alloying and vacuum sintering have been used to produce bulk nanostructured Ti5Si3 and Ti5Si3-15Wt.% Al2O3 nanocomposite. X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) were used to study the microstructural characteristics of the samples. Indentation method was used to calculate hardness, elastic modulus and fracture toughness ...