In this research, infiltration behavior of W-Ag composite compacts with Nickel and Cobalt as additives has been investigated. Nickel and Cobalt were added to Tungsten powder by two distinct methods: mixing elementally and reduction of salt solution. The coated Tungsten powders were compacted under controlled pressures to make porous skeleton with 32-37 vol. % porosity. Infiltration process was ...

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 ...

Five carbonaceous nano-additives (graphite, graphene, carbon black, nanotubes, and diamond) had different impacts on the sinterability, microstructural evolution, properties of titanium carbide. In this research, sintering by spark plasma was employed to produce monolithic TiC carbon-doped ceramics under parameters 1900 ºC, 10 min, 40 MPa. The black additive best performance in densifying TiC, ...

Abstract In this project, nano-ZrO2 particles were dispersed in aluminum powder by a Y-shape mixer. The particle size of ZrO2 powder was < 40 nm and the amount of ZrO2 reinforcement varies from 3 to 15%.The mixed powders were compacted .Subsequently the compacted discs were sintered both in the microwave oven and in the conventional muffle furnace .Using microwave –assisted sintering method led...

Two compositions of ZrB2-based ceramic composites containing Si3N4, Al2O3 and Y2O3 have been hot-pressed at different temperatures between 1673 and 1773 K for 60 min in vacuum. The densification behavior of the composites was examined during the sintering process. The microstructures of the composites were characterized by scanning electron microscopy, and the crystalline phases were identified...

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...

The influence of the addition of organic compounds, such as palmitic acid and cholesteryl myristate, on the porous structure of Fe-Al intermetallics formation has been investigated in detail in this paper. It was found that additives have a significant effect on the final porosity of the obtained sinters. Formed gaseous products from combustion play the role of the foaming agent during Fe-Al in...

Microwave sintering (MWS) of commercially available 15-nm-size nanocrystalline TiN powder was studied. Densification kinetics and grain growth mechanisms of nano-TiN were evaluated using non-isothermal heating up to 1500 °C with variable heating rates. A true nanocrystalline ceramic with ~80-nm-size grains and 94.5 % theoretical density was obtained via MWS consolidation at 1400 °C. At higher t...

he role of additives has long been a theme in sintering science. Recently, it has been discovered that ceramics may contain multiple different rain boundary phases (complexions) that are chemically induced by certain additives. These complexions are useful in explaining a number of nomalous phenomena associated with sintering, such as abnormal grain growth. The current work investigates how tra...

Mortars with two different binders (Portland cement (PC) and high alumina cement (HAC)) were modified upon the bulk incorporation of nano-structured photocatalytic additives (bare TiO₂, and TiO₂ doped with either iron (Fe-TiO₂) or vanadium (V-TiO₂)). Plastic and hardened state properties of these mortars were assessed in order to study the influence of these nano-additives. Water demand was inc...