in this research, synthesis and characterization of silver/alumina composite powders was investigated. this kind of metal/ceramic composite powders is used for fabrication of cutting tools inserts. the role of silver is toughening the final product. the powders were synthesized via co-precipitation method. the composition of the synthesized powders was ag/80% wt 〖al〗_2 o_3. silver nitrate, alum...

Tungsten sulfide (WS2)-carbon composite powders with superior electrochemical properties are prepared by a two-step process. WO3-carbon composite powders were first prepared by conventional spray pyrolysis, and they were then sulfidated to form WS2-carbon powders. Bare WS2 powders are also prepared by sulfidation of bare WO3 powders obtained by spray pyrolysis. Stacked graphitic layers could no...

Smokeless powder additives are usually detected from an extraction of post-blast residues or unburned powder particles followed by chromatographic analyses. This work presents the first comprehensive study of the detection of volatile and semi-volatile additives of smokeless powders using solid phase microextraction (SPME) as a sampling and pre-concentration technique. The goal of this study is...

ZnFe2O4 yolk-shell powders were prepared by applying a simple spray-drying process. Dextrin was used as a drying additive and carbon source material, and thus played a key role in the preparation of the powders. The combustion of precursor powders consisting of zinc and iron salts and dextrin obtained by a spray-drying process produced the yolk-shell-structured ZnFe2O4 powders even at a low pos...

Nickel and aluminum powders were mechanically alloyed with 10 or 30 vol.% refractory metal powders (molybdenum or tungsten) for times up to 50 h. Intermetallic synthesis takes place after lo-20 h alloying, with concomitant dispersion of the inert refractory metal phase, resulting in an NiAl matrix containing fine refractory dispersoids. The reactive synthesis step is direct, without intermediat...

203Hg, 35S or 131I labeled mercury (II) iodide thiocyanate (HgISCN) powders were prepared, respectively. When the powders were exposed to sunlight, some parts of the crystals of the powders were decomposed and the decomposed atoms diffused toward crystal surface. This diffusion velocity was accelerated by thermal treatment of the darkened powders. The velocity is larger in order of 35S, 203Hg, ...

The thermal behavior of eight dental acrylic resin powders was studied using differential scanning calorimetry (DSC). In addition, high performance liquid chromatography was performed to supplement the DSC analysis. The HPLC analysis revealed that the contents of residual monomers and benzoyl peroxide (BPO) in the powders were 0.01-0.97 mass% and 0.25-1.28 mass%, respectively. All the resin pow...

Data regarding bulk polycrystalline nickel samples obtained by powder metallurgy using Spark Plasma Sintering (SPS) are presented, with a special emphasis on the influence of a cold isostatic pre-compaction on the resulting morphologies and subsequent mechanical properties. Three types of initial powders are used, nanometric powders, micrometric powders and a mixture of the formers. For each ty...

Lithium nickel oxide (LiNiO2) powders with an R3 m structure are successfully synthesized via a developed reverse microemulsion process. This method can effectively reduce the calcination temperature for synthesizing monophasic LiNiO2 powders to 700 C, which is much lower than that in the solid-state process. Nanosized LiNiO2 powders with narrow particle size distribution are obtained via the m...

In this work, oven-dried, freeze-dried and spray-dried agaro-oligosaccharide powders were characterized to investigate their physicochemical and antioxidant properties. Agarooligosaccharide powders were shown to exhibit high water solubility index (88.73 – 95.88%), water absorption capacity (0.96 – 2.57 g/g) and oil absorption capacity (0.40 – 0.45 g/g). Agarooligosaccharide powders were shown ...