Hasmik Kirakosyan

Mrs. Hasmik Kirakosyan


Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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20 July 2022 in Materials
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Journal Article
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MZMarieta Zakaryan
Marieta Zakaryan
AZAlina R. Zurnachyan
Alina R. Zurnachyan
NANarine H. Amirkhanyan
Narine H. Amirkhanyan
HKHasmik Kirakosyan
Hasmik Kirakosyan
Maksim AntonovMaksim Antonov
Maksim Antonov
Sofiya AydinyanSofiya Aydinyan
Sofiya Aydinyan
A novel pathway for the magnesiothermic reduction of boron oxide and magnesium dodecaboride (MgB12) in the presence of carbon by a self-propagating high-temperature synthesis method was proposed that was aimed at the direct preparation of boron carbide nanopowder. The combined utilization of two boron sources, boron oxide and MgB12, allowed tailoring the overall caloric effect of the process, increasing the yield of the target product and lessening the laborious leaching process. In addition, it is an alternative way to utilize magnesium borides, which are inevitable side products at boron production. Multivariate thermodynamic calculations performed in the B2O3-MgB12-Mg-C system allowed estimating equilibrium compositions of the products and deducing the optimum composition of the initial mixture for obtaining B4C. For the latter, the adiabatic temperature (Tad) is 2100 °C, which is theoretically enough for the implementation of the self-propagating reaction. The combustion reaction was shown to be extremely sensitive to the initial mixture composition, external pressure, as well as sample diameter (heat losses). It proceeds in self-oscillatory mode and leads to the product of a layered macrostructure. The combustion product was then consolidated by the spark plasma sintering technique at different conditions. Vickers microhardness was measured, and the wear erosion behavior was examined. The variation in lattice parameters of boron carbide reflected the influence of synthesis, sintering and erosion conditions on the ordering/disordering of the boron carbide structure.

3 December 2021 in Journal of Composites Science
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Journal Article
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HKHasmik Kirakosyan
Hasmik Kirakosyan
KNKhachik Nazaretyan
Khachik Nazaretyan
Sofiya AydinyanSofiya Aydinyan
Sofiya Aydinyan
SKSuren Kharatyan
Suren Kharatyan
Understanding of the decisive role of non-isothermal treatment on the interaction mechanism and kinetics of the MoO3-CuO-Mg-C system is highly relevant for the elaboration of optimal conditions at obtaining Mo-Cu composite powder in the combustion processes. The reduction pathway of copper and molybdenum oxides with combined Mg + C reducing agents at high heating rates from 100 to 5200 K min−1 was delivered. In particular the sequence of the reactions in all the studied binary, ternary and quaternary systems contemporaneously demonstrating the effect of the heating rate on products’ phase composition and microstructure was elucidated. The combination of two highly exothermic and speedy reactions (MoO3 + 3Mg and CuO + Mg vs. MoO3 + CuO + 4Mg) led to a slow interaction with weak self-heating (dysynergistic effect) due to a change in the reaction mechanism. Furthermore, it has been shown that upon the simultaneous utilization of the Mg and C reducing agents, the process initiates exclusively with carbothermic reduction, and at relatively high temperatures it continues with magnesiothermic reaction. The effective activation energy values of the magnesiothermic stages of the studied reactions were determined by Kissinger isoconversional method.

1 March 2022 in Metals
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KNKhachik Nazaretyan
Khachik Nazaretyan
HKHasmik Kirakosyan
Hasmik Kirakosyan
MZMarieta Zakaryan
Marieta Zakaryan
AAAbovyan Abovyan
Abovyan Abovyan
OVOlga Volobujeva
Olga Volobujeva
Sofiya AydinyanSofiya Aydinyan
Sofiya Aydinyan
The influence of mechano-ultrasonic activation (MUA) and nano-additives (carbon nanotubes-CNT) on the interaction pathway of nickel–aluminum powder mixture at high heating rates was investigated. The optimum conditions of the mechano-ultrasonic activation, along with the phase and structure formation peculiarities of nickel–aluminum and nickel–aluminum–carbon nanotubes mixtures by thermal analysis method, the so-called high-speed temperature scanner (HSTS), were found out. The optimum duration of mechanical and ultrasonic activation aiming to achieve homogeneous distribution in the agitated mixtures was determined. A shift in characteristic temperatures of MUA mixtures by the influence of both heating rate and ultrasound on the Ni + Al interaction pathway for the mechano-activated (1, 3, 5 min) and 1 wt% CNT containing mixtures was observed. The formation patterns of NiAl + Ni3Al mixture or pure NiAl phase was manifested according to the interaction mechanism (depending on solid–liquid or solid–solid state of intermediates). The effective activation energy values for the Ni + Al exothermic reactions of all studied systems were determined by the isoconversional method of Kissinger.

9 August 2021 in Preprints.org
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HKHasmik Kirakosyan
Hasmik Kirakosyan
KNKhachik Nazaretyan
Khachik Nazaretyan
Sofiya AydinyanSofiya Aydinyan
Sofiya Aydinyan
SKSuren Kharatyan
Suren Kharatyan
Understanding of the decisive role of the interaction mechanism and kinetics in the combustion processes is highly relevant for the elaboration of optimal conditions for obtaining Mo-Cu composite powders. From this perspective, the efficient delivery of the reduction mechanism of copper and molybdenum oxides with combined Mg + C reducing agents at high heating rates is crucial to develop a valuable approach for the combustion synthesis of Mo-Cu composite powders. Herein, we shed light on the mechanism of the reactions in all the studied binary, ternary and quaternary systems contemporaneously demonstrating the effect of the heating rate on the conversion degree. The combination of two highly exothermic and speedy reactions (MoO3+3Mg and CuO+Mg vs MoO3+CuO+4Mg) led to a slow interaction with weak self-heating (dysynergistic effect) due to a change in the reaction mechanism. On the other hand, it has been shown that during the simultaneous utilization of the Mg and C reducing agents, the process begins exclusively with carbothermic reduction, and at relatively high temperatures it continues with magnesiothermic one. The effective activation energy values of the magnesiothermic stages of the studied reactions were determined by Kissinger isoconversional method.

1 January 2024 in AIP Conference Proceedings
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Conference Paper
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HKHasmik Kirakosyan
Hasmik Kirakosyan
KNKhachik Nazaretyan
Khachik Nazaretyan
NANarine Amirkhanyan
Narine Amirkhanyan
HBHayk Beglaryan
Hayk Beglaryan
Sofiya AydinyanSofiya Aydinyan
Sofiya Aydinyan
Silicon carbide whiskers and fiber-like structures are of keen interest because of their useful mechanical properties at high temperatures, as well as their reinforcing ability in metal and ceramic matrix composites. An interestingly unique approach has been taken in the current work to grow whiskers of silicon carbide-based composite through simultaneous utilization of solution combustion synthesis (SCS) and high-speed temperature scanner (HSTS). In particular, a homogeneous mixture of silicon oxide, carbon and alumina was firstly produced by combustion synthesis of alumina impregnated solution of silicon dioxide gel and alanine in the presence of ammonium nitrate as an auxiliary oxidant. By the next step, the pellet obtained from the SCS product was heated up to 1600oC by HSTS setup leading to the formation of silicon carbide whiskers in the alumina matrix.

1 January 2024 in AIP Conference Proceedings
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HKHasmik Kirakosyan
Hasmik Kirakosyan
KNKhachik Nazaretyan
Khachik Nazaretyan
AKAnahit Kharatyan
Anahit Kharatyan
Sofiya AydinyanSofiya Aydinyan
Sofiya Aydinyan
High-entropy refractory alloys (HERA) were synthesized by self-propagating high-temperature synthesis (SHS) using aluminothermic reduction. The amount of reduce