In order to study the influence on the mechanical properties caused by microstructure evolution of metal powder in extreme environment, 3D real-time observation of the microstructure evolution of Al-Ti mixed powder in high temperature and microwave compound fields was realized by using synchrotron radiation computerized topography (SR-CT) technique; the spatial resolution was enhanced to 0.37  ...

TiAl with between 0 and 20 volume percent (v%)Ti5Si3 was produced by reactive sintering of cofd pressed compacts of elemental Ti, Al and Si powder mixtures at 7OO0C for 15 minutes in vacuum. The results show that adding Si to Ti and A1 reduces the swelling associated with reactive sintering of TiAI, as composites containing more than 5 vYoTigSi3 densified during reactive sintering. However, com...

This article explores the effects of SiO2/Al2O3 ratios (S/A) on sintering characteristics and provides guidance for alleviating ash depositions in a large-scale circulation fluidized bed. Five synthetic coal ash (SCA) samples with different S/As were treated in a muffle furnace for 12 h at different temperatures (from 773 K to 1373 K, in 100 K intervals). The morphological and chemical results ...

An iron based powder blend has been developed for rapid tooling using a direct laser sintering process. The powder consists of a mixture of different elements including Fe, C, Cu, Mo and Ni. High sintering activities were obtained by tailoring the powder characteristics and optimizing the chemical constituents. The manufacturing of complex-shaped parts is possible at rates of 6.75 cm3/h accordi...

A two-dimensional method based on basic and mixed models for simulation of liquid phase sintering of a porous structure will be developed. These models will be tested in order to conduct a study of diffusion phenomena and gravitational effects on microstructural evolution during liquid phase sintering of a W-Ni system.

Composites of yttria-stabilized zirconia (YSZ) with Sr-doped LaCrO3 (LSC) and Sr-doped LaMnO3 (LSM) were prepared by impregnation of a porous YSZ matrix with aqueous solutions of the appropriate metal salts, followed by sintering to various temperatures. XRD measurements showed that perovskite phases formed after sintering at 1073 K, a temperature well below that at which solid-state reactions ...

In this thesis, we report on a process to obtain yttrium oxide nanosized particles doped with ytterbium and a sintering method that leads to transparent polycrystalline ceramics. First, nano-powder of yttria was fabricated from a precursor with transient morphology, i.d. yttrium hydroxynitrate platelets that decompose into spherical yttria nano-particles during calcination. The influence of dif...

Materials that can capture and store CO2 are important. Though CaO is a cheap sorbent, it is inefficient for practical purposes due to sintering and poor diffusion of CO2 through the surface-CaCO3 layer. We have developed a high performance, sintering-resistant CaO-based sorbent by uniformly nanofabricating the CaO nanocrystals on SiO2 microtubes made by organogel templated polymerization.

Two materials were prepared with composition PbMg0.3Nb0.6Zr0.1O3 (PMNZ/10) and PbMg0.32Nb0.65Zr0.03O3 (PMNZ/3). Slight modifications in lead oxide content of these materials were made to study its influence on the sintering properties. The stoichiometric PMNZ/3 gave the best results. It has a sintering temperature as low as 900°C and a relative dielectric constant of 10 000 at room temperature.

DC flash sintering of both pure and 0.5 mol.% Bi2O3-doped ZnO at a relatively high activating field of 300 V/cm has been investigated. It is demonstrated that even high-purity ZnO single crystals can “flash” at 870 C. In comparison, flash sintering occurs at a substantially lower onset temperature of 550 C in ZnO powder specimens, indicating the important roles of surfaces and/or grain boundari...