Showing 4 results for Khoshhal
R. Khoshhal, M. Soltanieh, M. Mirjalili,
Volume 7, Issue 1 (winter 2010 2010)
Abstract
Abstract:
titanium sheets in pure molten aluminum at 750
and X-Ray Diffraction Analysis results, TiAl
intermetallic layer thickness increases slowly at primary stages. After that an enhanced growth rate occurs due to layer
cracking and disruption. Presumably, reaction starts with solving titanium into the molten aluminum causing in
titanium super saturation and TiAl
intermetallic layer which consequently leads to TiAl
energy of intermetallic layer formation and growth was developed by measuring titanium thickness decreases.
In this work, kinetics of intermetallic compounds formation in Al-Ti system was studied by immersingoC, 850 oC and 950 oC. According to Scanning Electron Microscopy3 is the only phase can form at the interface. Observations revealed that3 formation. At this stage, growth may be controlled by aluminum diffusion through3 formation at the interface of Ti-TiAl3. Furthermore, activation
R. Khoshhal, M. Soltanieh, M. A. Boutorabi,
Volume 13, Issue 1 (March 2016)
Abstract
Al2O3/TiC composites are used as cutting tools for machining gray cast iron and steels. The addition of iron improves the toughness of Al2O3/TiC composites. Ilmenite, aluminum and graphite can be used to produce in-situ Al2O3/TiC–Fe composites. However, the formation mechanism and reaction sequences of this system are not clear enough. Therefore, the present research is designed to determine the reactions mechanism of the first step of reactions that may be occurred between raw materials. In this research, pure ilmenite was synthesized to eliminate the effects of impurities available in the natural ilmenite in the system. The milled and pressed samples, prepared from the synthesized ilmenite, aluminum and graphite mixture with a molar ratio of 1:2:1, were heat treated at 720°C for 48h. In addition, two samples one containing ilmenite and aluminum with a molar ratio of 1:2 and ilmenite and graphite with a molar ratio of 1:1 were heat treated at 720°C for 48h. The final products were analyzed with XRD. It was found that at 720°C, aluminum reacts with FeTiO3, forming Fe, TiO2 and Al2O3. Since the aluminum content used in the mixture was more than the stoichiometry for reaction of ilmenite and aluminum, some unreacted aluminum remains. Therefore, the residual aluminum reacts with the reduced Fe to form Fe2Al5.
Razieh Khoshhal, Seyed Vahid Alavi Nezhad Khalil Abad,
Volume 20, Issue 1 (March 2023)
Abstract
- In this article, the effect of graphite on iron-silicon interactions was investigated. It was found that, as graphite enters the iron structure, it permits further development of iron-silicon reactions. It was found that in the stoichiometric ratio of 1:0.5 of iron and silicon, when graphite is added to the system, simultaneously with the reaction of iron and silicon to form Fe3Si5, some amount of carbon can be dissolved in the iron and lead to more diffusion in iron and more iron silicide production. Silicon also reacts with carbon and produces SiC. The more amount of carbon entered into the system, the more growth of SiC occurs, while the production of other iron silicide phases, namely FeSi and Fe3Si preceded. Finally diffused carbon into the iron reaches a definite amount that can form Fe3C. In the stoichiometric ratio of 1:1 of iron and silicon, the formation of FeSi and SiC phases is observable. At the same time, the diffusion of carbon occurs in the same as the previous stoichiometric ratio. In the stoichiometric ratio of 1:2 of iron and silicon, compared with the stoichiometric ratio of 1:1, a larger amount of silicon is available and, the FeSi2 phase can form in addition to FeSi
Razieh Khoshhal, Seyed Vahid Alavi Nezhad Khalil Abad,
Volume 21, Issue 0 (IN PRESS 2024)
Abstract
This study utilized aluminum, copper powder according to the stoichiometric ratio of Al₂Cu, and calcium powder in relation to the eutectic composition of Al-Ca at the ratio of 5.5 atomic percent. Two samples were prepared, one without calcium and another with calcium, and were analyzed to determine the impact of calcium on the formation of copper aluminide. Samples were subjected to thermal treatment at temperature of 400, 600, and 800ºC. The obtained results indicated that disappearance of Al₂Cu phase at 800ºC in calcium-free sample and existence of Al₂Cu phase in calcium sample indicating a possible role of calcium in stabilization of Al₂Cu phase. Furthermore, it was concluded that calcium influences phase formation. There was higher diffusion of aluminum in to copper resulting in formation of Al₄Cu₉ not only in the sample with calcium, but also in calcium-free sample. One more finding of the research is that calcium influences microstructure and its homogenization as well. In particular, it was found that calcium-containing sample has the least number of pores and was uniform in the structure.
