Iranian Journal of Materials Science and Engineering

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Abstract:

as magnetic materials, semiconductors, pigments, catalysts, refractories and electronic ceramics. In this paper, we

reported the preparation of NiAl

The resulting powder was chracterized by XRD, particle size analysis and SEM. The XRD patterns show that the

combustion technique was excellent to prepare single – phased cubic NiAl

found to be around 14 nm. From the particle size analysis, it was found that the 50 % of the particles lie below 30

µm. The micrographs show the formation of fluffy agglomerates composed of fine particles.

Spinels constitute an advanced group of materials with great technologial appeal, being able to be applied2O4 spinels by low temperature combustion technique using glycine and urea as fuels.2O4 particles and the crystallite sizes were

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In this paper, the effect of MgO, BaO, Na 2 O and SrO addition to a pre-melted CaO-Al2O3 -Si 2 O synthetic slag on sulfur removal from plain carbon steel was studied under the same experimental conditions. The slags were pre-melted at 1400°C in an electric resistant furnace and desulfurization experiments were carried out in a high frequency induction furnace. The results showed that the optimum reaction time for desulfurization was 15 min. It was found that while SrO addition to the ternary slag enhances the sulfur removal capability, MgO, Na 2O and BaO additions reduce desulfurization efficiency of the ternary slag. Moreover, it was observed that restricting access to oxygen from the atmosphere by using a covered crucible, could increase desulfurization efficiency of the slag by more than two fold

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A series of MAl₂O₄ (M=Ni, Zn, and Cu) aluminates were prepared by using impregnation method; the metal content of the products was ranged between 5wt% to 25wt%. The samples were characterized by x-ray diffraction (XRD), Brunauer Emmett Teller (BET) surface area, NH₃ temperature-programmed desorption (NH₃-TPD), and inductively coupled argon plasma (ICP).

The specific surface areas of zinc, nickel and copper aluminates were in the ranges of 47-77m²/g, 63-87m²/g and 1.6-3m²/g, respectively. The surface acidity decreased in the order of CuAl₂O₄<< NiAl₂O₄< ZnAl₂O₄<< Al₂O₃. By increasing the amount of metals in the samples, the number of acidic sites decreased, but their strength did not significantly change. Ni-aluminates have fewer acidic sites than Zn-aluminates, particularly in strong acid sites