Journal articles: 'Self-propagating exothermic reaction'

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Namazu, Takahiro, and Shozo Inoue. "Al/Ni Self-Propagating Exothermic Film for MEMS Application." Materials Science Forum 638-642 (January 2010): 2142–47. http://dx.doi.org/10.4028/www.scientific.net/msf.638-642.2142.

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This paper describes evaluation of the strength in Ag-Sn-jointed Si specimens heated by Al/Ni film’s exothermic reaction. The reaction generates heat enough to melt Ag-Sn film for soldering. To measure the strength, four-point micro-bending test technique has been developed. The rectangular-solid Si specimens having a Ag-Sn/AlNi/Ag-Sn section were prepared by dicing the bonded Si-wafer under various pressure loads. A higher pressure yielded a better contact condition between Al/Ni and Ag-Sn so that heat-conduction improved; consequently Ag-Sn was melted sufficiently. Al/Ni reactive film has a potential as a micro-heater in soldering for MEMS.

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Miyake, Shugo, Taisei Izumi, and Rino Yamamoto. "Effect of the Particle Size of Al/Ni Multilayer Powder on the Exothermic Characterization." Materials 13, no. 19 (October 1, 2020): 4394. http://dx.doi.org/10.3390/ma13194394.

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In this study, the exothermic temperature performance of various Al/Ni multilayer powders with particle sizes ranging from under 75 to over 850 µm, which generate enormous heat during self-propagating exothermic reactions, was determined using a high-speed sampling pyrometer. The Al/Ni multilayer powders were prepared by a cold-rolling and pulverizing method. The multilayer constitution of the Al/Ni multilayer powders was examined by observing the cross-section of the powders using scanning electron microscopy; the results indicate that the powders had similar lamellar structures regardless of the particle size. Exothermic reactions were carried out to measure the temperature changes during the experiment using a pyrometer. We found that the maximum temperature and the duration of the exothermic reaction increased with an increase in the particle size caused by the heat dissipation of the surface area of the Al/Ni multilayer powder. This indicates that the thermal characteristics of the exothermic reaction of the Al/Ni multilayer powder can be controlled by adjusting the particle size of the Al/Ni multilayer powder. Finally, we concluded that this controllability of the exothermic phenomenon can be applied as a local heating source in a wide range of fields.

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Li, Jing, Zheng Yi Fu, Jin Yong Zhang, Hao Wang, Wei Min Wang, Yu Cheng Wang, and Yi Bing Cheng. "Preparation of ZrC Powder by Self-Propagating High-Temperature Synthesis." Advanced Materials Research 66 (April 2009): 258–61. http://dx.doi.org/10.4028/www.scientific.net/amr.66.258.

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ZrC fine powder has been prepared by self-propagating high-temperature synthesis (SHS) using exothermic reaction of ZrO2-C-Mg system. By theoretical calculating, the adiabatic temperature (Tad) for the system is about 2235K enough to react as SHS process. The Tad observed during experiment is 1850K. The results show that high pure ZrC powder is obtained with appropriate Mg contents. The scanning electron micrograph shows that the average size of ZrC particles is about 2μm.

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Yamada, Osamu, Yoshinari Miyamoto, and Mitsue Koizumi. "Self-propagating high-temperature synthesis of the SiC." Journal of Materials Research 1, no. 2 (April 1986): 275–79. http://dx.doi.org/10.1557/jmr.1986.0275.

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Self-propagating high-temperature synthesis (SHS), also called combustion synthesis, is useful for fabricating numerous ceramics. In the case of SiC, heat released from the exothermic reaction is not sufficient to completely convert the mixed reactants of constituent elements into SiC in the usual nonadiabatic experimental system. This disadvantage could be overcome by a new ignition process called, the “direct passing method of electric current.” By using this method, stoichiometric fine SiC powder could be obtained rapidly and efficiently with low electric power. This paper also involves the effect of particle size of Si and C initial reactant powders on conversion efficiency into SiC and also on particle size of SiC powder fabricated by this method.

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Qiu, X., J. Graeter, L. Kecskes, and J. Wang. "Exothermic reactions in cold-rolled Ni/Al reactive multilayer foils." Journal of Materials Research 23, no. 2 (February 2008): 367–75. http://dx.doi.org/10.1557/jmr.2008.0043.

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Exothermic reactions in cold-rolled Ni/Al reactive multilayer foils were investigated in this study. A two-stage reaction process was observed in the self-propagating reactions in the cold-rolled foils that were ignited by a point-source flame. Foils taken out of the flame after completing the first stage of the reaction process were compared to those allowed to complete both stages. Differences in the phase-evolution sequence from the two types of foils were studied by differential scanning calorimetry (DSC), using slow and controlled heating of the samples. Several exothermic peaks could be identified from the DSC thermograms for both types of foils. Using the DSC, both the as-cold-rolled and partially reacted foils were heated to each peak temperature to identify the reaction product associated with each peak. X-ray diffraction and scanning electron microscopy analyses showed that the first two peaks corresponded to the formation of Al3Ni, while the third peak corresponded to the formation of AlNi.

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Wang, Xiaoting, Mingyu Li, and Wenbo Zhu. "Formation and homogenization of Si interconnects by non-equilibrium self-propagating exothermic reaction." Journal of Alloys and Compounds 817 (March 2020): 153210. http://dx.doi.org/10.1016/j.jallcom.2019.153210.

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Zhou, Zheng, Liping Mo, Hui Liu, Y. C. Chan, and Fengshun Wu. "Study of Fusion Thickness of Tin Solder Heating by Self-Propagating Exothermic Reaction." Journal of Electronic Materials 47, no. 12 (September 28, 2018): 7435–48. http://dx.doi.org/10.1007/s11664-018-6684-9.

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McDonald, Joel P., Mark A. Rodriguez, Eric D. Jones, and David P. Adams. "Rare-earth transition-metal intermetallic compounds produced via self-propagating, high-temperature synthesis." Journal of Materials Research 25, no. 4 (April 2010): 718–27. http://dx.doi.org/10.1557/jmr.2010.0091.

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Several binary intermetallic compounds—each containing a rare-earth (RE) element paired with a transition metal (TM)—were prepared by self-propagating, high-temperature synthesis (SHS). Thin multilayers, composed of alternating Sc or Y (RE element) and Ag, Cu, or Au (TM), were first deposited by direct current magnetron sputtering. Once the initially distinct layers were stimulated and caused to mix, exothermic reactions propagated to completion. X-ray diffraction revealed that Sc/Au, Sc/Cu, Y/Au, and Y/Cu multilayers react in vacuum to form single-phase, cubic B2 structures. Multilayers containing Ag and a RE metal formed cubic B2 (RE)Ag and a minority (RE)Ag2 phase. The influence of an oxygen-containing environment on the reaction dynamics and the formation of phase were investigated, providing evidence for the participation of secondary combustion reactions during metal-metal SHS. High-speed photography demonstrated reaction propagation speeds that ranged from 0.1–40.0 m/s (dependent on material system and foil design). Both steady and spin-like reaction modes were observed.

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Hector, Andrew L., and Ivan P. Parkin. "Transition Metal Pnictide Synthesis: Self Propagating Reactions Involving Sodium Arsenide, Antimonide and Bismuthide." Zeitschrift für Naturforschung B 49, no. 4 (April 1, 1994): 477–82. http://dx.doi.org/10.1515/znb-1994-0408.

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Initiation of the reaction between Na 3E (E = As, Sb, Bi) and anhydrous metal halides at 25 to 550 °C produces metal arsenides MxAsy (M=Y,La, Ti, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Fe, Co, Ni, Pt ,Cu and Zn) and antimonides MxSby (M=Ti, V, Nb, Ta, Cr, Fe, Co, Ni, Pt, Cu and Zn) via an exothermic selfpropagating reaction. The metal arsenides were characterized by X-ray powder diffraction, SEM/EDAX , microanalysis and FT-IR.

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Namazu, Takahiro, Kohei Ohtani, Keisuke Yoshiki, and Shozo Inoue. "Crack-Less Wafer-Level Packaging Using Flash Heating Technique for Micro Devices." Materials Science Forum 706-709 (January 2012): 1979–83. http://dx.doi.org/10.4028/www.scientific.net/msf.706-709.1979.

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In this article, a new technique for controlling crack position and its propagation direction in solder-bonding using Al/Ni exothermic reaction is described. Sputtered Al/Ni multilayer film is able to produce heat instantly by its self-propagating exothermic reaction, and the reactive film can be used as heat source for solder-bonding. During the reaction, however, volume reduction by approximately 12% occurs due to crystal structural change from fcc to bcc and lattice-spacing reduction. Consequently, cracks are produced in the reacted NiAl structure. The cracks negatively affect the strength of the bonded system. We have found a new technique for controlling crack position and its propagation direction. Multiple ignitions for reaction demonstrated that cracks in reacted NiAl film can be controlled. When applying the flash heating technique to wafer-level bonding, cracks are probably produced. If cracks can be fabricated on dicing cut lines by using the simultaneous multiple reactions technique, crack-less solder-bonded Si hermetic packages would be realized.

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Balog, Martin, Roman Florek, Martin Nosko, and František Šimančík. "Self-Propagating Synthesis of Ti-Al-C Powder Mixtures." Key Engineering Materials 520 (August 2012): 347–52. http://dx.doi.org/10.4028/www.scientific.net/kem.520.347.

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Self-propagating synthesis of Ti-Al-C powder mixture was used for fabrication of master alloys suited to industrial scale manufacturing of Al-TiC composites. The cold compacted powder pellets were heated in a protective atmosphere until the melting point of aluminium. Then the temperature of pellets increased rapidly due to intense exothermic reaction between molten Al and Ti, resulting in simultaneous formation of Al3Ti and Al4C3. When the temperature exceeded ~1090°C, TiC particles started to form as a result of the mutual reaction between Al3Ti and Al4C3. Resulting reaction products consisted of fine (~Subscript textub>2µm) TiC particles uniformly distributed in the Al matrix. The composition of powder mixture was optimized to attain master alloy pellets containing ~50 vol.% TiC. Such pellets were then diluted in molten aluminium to produce Al+TiC composites. In-situ formation of TiC in Al matrix provided favourable interfacial quality, which avoided dewetting and rejection of particles from molten aluminium. The parameters for composite casting were optimized in order to reduce the effect of reversible reaction leading to undesired formation of Al3Ti or Al4C3. The final composites showed significantly increased Young’s modulus and strengths. The potential of using the approach for the fabrication of fine, nearly spherical TiC particulate reinforced Ti composites is briefly discussed. The simple process is very promising for economical manufacturing of highly efficient lightweight structural materials.

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Zhou, Zheng, Anna Zhang, Xu Guan, Hui Liu, Changqing Liu, and Fengshun Wu. "Microstructural and Micromechanical Characteristics of Tin-Based Solders Under Self-Propagating Exothermic Reaction Heating." Journal of Electronic Materials 49, no. 10 (August 13, 2020): 6214–22. http://dx.doi.org/10.1007/s11664-020-08363-9.

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Yeh, Chun-Liang, and Kuan-Ting Chen. "Synthesis of FeSi-Al2O3 Composites by Autowave Combustion with Metallothermic Reduction." Metals 11, no. 2 (February 3, 2021): 258. http://dx.doi.org/10.3390/met11020258.

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Fabrication of FeSi-Al2O3 composites with a molar ratio of FeSi/Al2O3 ranging from 1.2 to 4.5 was conducted by the self-propagating high-temperature synthesis (SHS) method. The synthesis reaction involved metallothermic reduction of Fe2O3 and SiO2 by Al and the chemical interaction of Fe and Si. Two combustion systems were examined: one contained thermite reagents of 0.6Fe2O3 + 0.6SiO2 + 2Al, and the other had Fe2O3 + 2Al to mix with different amounts of Fe and Si powders. A thermodynamic analysis indicated that metallothermic reduction of oxide precursors was sufficiently exothermic to sustain the combustion reaction in a self-propagating mode. The SHS reaction carrying out co-reduction of Fe2O3 and SiO2 was less exothermic, and was applied to synthesize products with FeSi/Al2O3 = 1.2–2.5, while the reaction reducing only Fe2O3 was more energetic and was adopted for the composites with FeSi/Al2O3 = 2.5–4.5. Moreover, the former had a larger activation energy, i.e., Ea = 215.3 kJ/mol, than the latter, i.e., Ea = 180.4 kJ/mol. For both reaction systems, the combustion wave velocity and temperature decreased with increasing FeSi content. Formation of FeSi-Al2O3 in situ composites with different amounts of FeSi was achieved. Additionally, a trivial amount of aluminum silicate was detected in the products of high FeSi contents due to dissolution of Si into Al2O3 during the SHS process.

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Bourim, El-Mostafa, Il-Suk Kang, and Hee Yeoun Kim. "Investigation of Integrated Reactive Multilayer Systems for Bonding in Microsystem Technology." Micromachines 12, no. 10 (October 19, 2021): 1272. http://dx.doi.org/10.3390/mi12101272.

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For the integration of a reactive multilayer system (iRMS) with a high exothermic reaction enthalpy as a heat source on silicon wafers for low-temperature bonding in the 3D integration and packaging of microsystems, two main conflicting issues should be overcome: heat accumulation arising from the layer interface pre-intermixing, which causes spontaneous self-ignition during the deposition of the system layers, and conductive heat loss through the substrate, which leads to reaction propagation quenching. In this work, using electron beam evaporation, we investigated the growth of a high exothermic metallic Pd/Al reactive multilayer system (RMS) on different Si-wafer substrates with different thermal conduction, specifically a bare Si-wafer, a RuOx or PdOx layer buffering Si-wafer, and a SiO2-coated Si-wafer. With the exception of the bare silicon wafer, the RMS grown on all other coated wafers underwent systematic spontaneous self-ignition surging during the deposition process once it reached a thickness of around 1 μm. This issue was surmounted by investigating a solution based on tuning the output energy by stacking alternating sections of metallic reactive multilayer Pd/Al and Ni/Al systems that have a high and medium enthalpy of exothermic reactions, respectively. This heterostructure with a bilayer thickness of 100 nm was successfully grown on a SiO2-coated Si-wafer to a total thickness of 3 μm without any spontaneous upsurge of self-ignition; it could be electrically ignited at room temperature, enabling a self-sustained propagating exothermic reaction along the reactive patterned track without undergoing quenching. The results of this study will promote the growth of reactive multilayer systems by electron beam evaporation processing and their potential integration as local heat sources on Si-wafer substrates for bonding applications in microelectronics and microsystems technology.

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Školáková, Andrea, Pavel Salvetr, Jindřich Leitner, Tomáš Lovaši, and Pavel Novák. "Formation of Phases in Reactively Sintered TiAl3 Alloy." Molecules 25, no. 8 (April 21, 2020): 1912. http://dx.doi.org/10.3390/molecules25081912.

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This work highlights new results on the synthesis of the TiAl3 intermetallic phase using self-propagating high-temperature synthesis. This method is considered a promising sintering route for intermetallic compounds. It was found that the reactions proceed in two stages. Below the melting point of aluminum, the Ti2Al5 phase forms at 450 °C after long annealing times by a direct solid-state reaction between the aluminum and titanium, and is converted consequently to TiAl3. This is a completely new finding; until now, many authors have believed in the preferential formation of the TiAl3 phase. The second stage, the self-propagating strongly exothermic reaction, proceeds above the melting point of aluminum. It leads to the formation of the TiAl3 phase accompanied by Ti2Al5 and Ti3Al phases. The reaction mechanism was shown in the form of chemical equations, which were supported by calculating Gibbs energy. Reaction temperatures (Tonset, Tmaximum, and Toffset) were determined after induction heating thanks to recording by an optical pyrometer. This finding provides completely new opportunities for the determination of activation energy at heating rates, in which common calorimeters are not able to detect a response or even measure. Now, the whole procedure will become accessible.

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Ko, Seog Gueon, Chang Whan Won, Byong Sun Chun, and H. Y. Sohn. "Magnesium reduction of WO3 in a self-propagating high-temperature synthesis (SHS) process." Journal of Materials Research 10, no. 4 (April 1995): 795–97. http://dx.doi.org/10.1557/jmr.1995.0795.

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High-purity tungsten was prepared by the self-propagating high-temperature synthesis (SHS) process from a mixture of WO3 and Mg. The MgO in the product was leached with an HCl solution. The complete reduction of WO3 required a 33% excess of magnesium over the stoichiometric molar ratio Mg/WO3 of 3. The product tungsten had a purity of 99.980% which was higher than that of the reactant WO3. This is because the impurities were either volatilized at the high temperatures generated during the rapid exothermic reaction or dissolved into the HCl solution during leaching.

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Yatsenko, Igor V., Vladimir V. Yatsenko, Aleksandr P. Amosov, and A. R. Samboruk. "Fe Reduction by Carbon during Self-Propagating High-Temperature Synthesis of Fe-TiC Composite." Key Engineering Materials 685 (February 2016): 768–71. http://dx.doi.org/10.4028/www.scientific.net/kem.685.768.

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The results of experimental investigations of combustion of the powder mixture of titanium, carbon, and ferrous oxide (III) are shown in this paper. Iron reduction by carbon is an endothermic reaction and proceeds in combustion wave of SHS due to the heat of high-exothermic reaction of TiC formation. It was found that it is impossible to initiate the combustion process with (Fe2O3+C) content of 50 wt. % or more of the initial charge composition. With not very high content of (Fe2O3+C), only Fe and TiC are found in the reaction products. When approaching its content to 50 wt. %, also С and FeO impurity phases are detected. The SHS product is a cake of separate granules of Fe-TiC with the granule size of 100-500 μm.

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Li, Xi En, and Xu Hua Zhu. "Preparation of Ultrafine Cobalt Ferrite Particles by Solution SHS Method." Advanced Materials Research 284-286 (July 2011): 645–48. http://dx.doi.org/10.4028/www.scientific.net/amr.284-286.645.

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Nanosized CoFe2O4powders of 12nm particle size were directly prepared by solution SHS method at room temperature. The overall process involves three steps: formation of homogeneous sol; formatiom of dried gel; and combustion of the dried gel. Experiments revealed that CoFe2O4dried gel derived from citrate and nitrate sol exhibited self-propagation combustion(SHS) at room temperature once it was ignited in air. After self-propagating combustion, the gel directly transforms into nanosized CoFe2O4particles. The self-propagating combustion was considered as a heat-induced exothermic oxidation-reduction reaction between nitrate ions and carboxyl group. Differential thermal analysis-thermogravimetry (DTA-TG) was used to study the decomposition of the precursor. The structure of the nanosized CoFe2O4powders was characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM).

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Zhu, Wenbo, Fengshun Wu, Baihui Wang, Eric Hou, Paul Wang, Changqing Liu, and Weisheng Xia. "Microstructural and mechanical integrity of Cu/Cu interconnects formed by self-propagating exothermic reaction methods." Microelectronic Engineering 128 (October 2014): 24–30. http://dx.doi.org/10.1016/j.mee.2014.05.035.

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Santos Silva, Gabriel, Lukasz Maj, Jerzy Morgiel, Maria Teresa Vieira, and Ana Sofia Ramos. "Development of Actuators for Repairing Cracks by Coating W Wires with Reactive Multilayers." Materials 15, no. 3 (January 24, 2022): 869. http://dx.doi.org/10.3390/ma15030869.

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The aim of this research work was to optimize the coating of tungsten wires with reactive multilayer thin films and promote an exothermic self-propagating reaction. The ultimate goal is to use this heat to liquify low melting temperature materials, and thus block crack propagation in metallic materials. Ni/Me (Me = Al, Ti) multilayers were deposited by a DC (direct current) magnetron sputtering onto tungsten wires with diameters of 0.05 and 0.20 mm. The depositions were carried out to obtain films with near equiatomic average chemical composition and a modulation period (bilayer thickness) between 20 and 50 nm. The cross-section of the films was analyzed using electron microscopy before and after electrical ignition. A new substrate holder was developed to improve the quality of the Al/Ni films, allowing a reduction in the defects previously observed. The Ni/Ti thin films showed no discernible defects, regardless of the substrate holder. However, after ignition, the Ni + Ti reaction occurred in a non-self-propagating mode. Passing an electric current through a wire (ϕ = 0.05 mm) coated with an Al/Ni thin film, promoted a flash of light that was associated with the start of a self-propagating reaction. The reaction product was a B2-AlNi intermetallic phase. W wires coated with reactive multilayers may contribute to crack filling, and have potential to be self-healing actuators.

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Lee, Jae Ryeong, Ikkyu Lee, Hee Young Shin, Jong Gwan Ahn, Dong Jin Kim, and Hun Saeng Chung. "Nitride-Related Compounds Preparation from Waste Aluminum Dross by Self-Propagating High-Temperature Process." Materials Science Forum 486-487 (June 2005): 297–300. http://dx.doi.org/10.4028/www.scientific.net/msf.486-487.297.

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Nitride-related compounds containing AlN and AlON were synthesized from aluminum dross using a combustion reaction, irrespective of the content of Al in Al-dross. The formation of AlON is induced by the exothermic reaction between Al and nitrogen. On the occasion of using high-grade dross, unreacted Al was detected in the combustion products. This may be originated from Al in the dross because Al in dross exists in the dispersed oxide layer. Therefore, its reactivity with nitrogen is relatively lower, compared to Al powder mixed with the dross in the beginning. It is noted that, on the occasion of using low-grade dross, unreacted Al in the product can be controlled by means of adjusting particle size of dross, resulting in improvement of the permeation of nitrogen gas into the compact through the well established open pore channels.

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FUJITA, Hiroshi, Takahiro NAMAZU, and Shozo INOUE. "Development of Novel MEMS Soldering Technique Using Self-Propagating Exothermic Reaction in Al/Ni Multilayer Films." Journal of the Society of Materials Science, Japan 56, no. 10 (2007): 932–37. http://dx.doi.org/10.2472/jsms.56.932.

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Namazu, Takahiro, Shun Ito, Shunsuke Kanetsuki, and Shugo Miyake. "Size effect in self-propagating exothermic reaction of Al/Ni multilayer block on a Si wafer." Japanese Journal of Applied Physics 56, no. 6S1 (May 17, 2017): 06GN11. http://dx.doi.org/10.7567/jjap.56.06gn11.

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GOTO, Daiki, Yasuhiro KUNTANI, Kana MAEKAWA, Shunsuke KANETSUKI, Shugo MIYAKE, and Takahiro NAMAZU. "Time of resolved X-ray analysis in Self-propagating exothermic reaction of Al/Ni multilayer films." Proceedings of Conference of Tokai Branch 2019.68 (2019): 113. http://dx.doi.org/10.1299/jsmetokai.2019.68.113.

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Chen, Chang, Jian Feng Yang, Ji Qiang Gao, and Cong Yang Chu. "Fabrication of Nano-MgO Reinforced Fe-Cr-Ni Composites by Reactive Hot Pressing." Materials Science Forum 620-622 (April 2009): 551–54. http://dx.doi.org/10.4028/www.scientific.net/msf.620-622.551.

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The self-propagating combustion reaction 0.741Mg + 0.247Fe2O3 + 0.188Ni + 0.318Cr → 0.741MgO + Fe0.494Ni0.188Cr0.318 was applied to prepare a nano-MgO reinforced Fe-Cr-Ni composite, by reactive hot pressing (RHP) under a condition of 700°C/30MPa/2h. The densification was enabled by the low temperatures produced by the exothermic reaction. According to TG-DTA and X-ray diffractometry (XRD), the highly-exothermic thermite reaction began at about 600°C and the in-situ formation of composites comprised predominantly of (FCC) Cr0.19Fe0.7Ni0.11, (FCC) Fe-Cr, (BCC) MgO and a small quantity of (BCC) MgFe2O4. The Vickers hardness was 3.67GPa, the three-point bending strength was 112.5±10MPa, and the fracture toughness was 3.28 MPa•m1/2. The microstructure of the composite was observed via scanning electron microscopy. This indicated that the distributions of in-situ-formed (BCC) MgO phases (~800 nanometers) were homogeneous into in a matrix of a fine-grained metallic alloy phases that gather together to form agglomerates in the composite.

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Liu, W., P. Feng, X. Ren, and L. Zhu. "Preparation of silicon boride SiBx (x = 3, 4, 5, 6) powders by chemical oven self-propagating combustion synthesis." International Journal of Materials Research 111, no. 10 (October 1, 2020): 792–98. http://dx.doi.org/10.1515/ijmr-2020-1111002.

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Abstract A new method was developed for quickly preparing a highemissivity silicon boride compound of SiBx (x = 3, 4, 5, 6) by highly exothermic Ti-TiO2-Si-Al chemical oven preheating. The SiBx combustion synthesis process and adiabatic combustion temperature were investigated. A large exothermic reaction occurred at the combustion temperature of 1 700 K. X-ray diffraction results indicate that an SiBx phase and a substantial amount of unreacted Si were identified in the products. By increasing the boron content until the Si-B ratio reached to 1 : 6, the diffraction peaks primarily indicated SiB6, SiB4, and Si11B33 in the final product. According to the spectra and quantitative results, the atomic chemical composition ratio of Si and B was close to the nominal composition. Thus, this method offers an efficient way to produce Si-B compounds with less time and energy consumption than current methods.

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Wiktor, Tomasz, Sebastian Sobula, Andryi Burbelko, and Michał Ptasznik. "An Evaluation of Combustion Kinetics for the Synthesis Reaction of the Reinforcing Phase During Casting Phase During Casting." Journal of Casting & Materials Engineering 4, no. 2 (June 30, 2020): 23–28. http://dx.doi.org/10.7494/jcme.2020.4.2.23.

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The computer modeling of the solidification process in castings with local composite reinforcement (LCR) obtained as a result of in situ reactions of self-propagating high temperature synthesis (SHS) is difficult due to limited data on the thermo-physical parameters of exothermic effects and the kinetics of the synthesis reaction. In the present study, Hadfield cast steel casting was manufactured with LCR containing titanium carbide particles obtained in situ by the SHS method. Reaction kinetics of titanium carbide synthesis in the composite casting were determined on the basis of temperature measurements in the area of LCR during the process. For the estimation of the reaction, the Fourier Thermal Analysis method was used. The paper presents the results of temperature measurement and the results of the calculation of SHS reaction kinetics. It was found that the reaction time under the conditions of the analyzed casting is below 3 s.

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Doğan, C. P., and D. E. Alman. "Microstructure of intermetallic-matrix composites produced in situ by self-propagating high-temperature synthesis." Proceedings, annual meeting, Electron Microscopy Society of America 52 (1994): 708–9. http://dx.doi.org/10.1017/s0424820100171274.

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Self-propagating, high-temperature synthesis (SHS) is one method of material production in which elemental constituents are ignited, initiating a self-sustaining, exothermic reaction that results in their transformation into intermetallic and ceramic compounds. In addition, several reactions can be initiated within a single body to form intermetallic-intermetallic, intermetallic-ceramic, or ceramic-ceramic composites in situ. The driving force for the reactions is the negative heats of mixing of the forming compounds, which results in the liberation of heat. The obvious advantages of SHS processing are that it presents an opportunity to produce near net-shape advanced materials and composites with a high level of purity in a relatively low-cost and energy efficient manner.At the U.S. Bureau of Mines, we are actively involved in the SHS processing of a wide range of singlephase intermetallic and intermetallic-matrix composites: TiAl, TiAl+TiB2, TiAl+TiC, TiAl+Ti5Si3, MoSi2+SiC. One key element of our study is a thorough understanding of the effect of processing variables, such as composition, temperature, pressure, time, powder morphology, etc., on the microstructure, and hence the properties, of these materials.

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Sereda, Borys, and Vitaliy Volokh. "FORMATION OF LOW-CARBON WIRE ROD STRUCTURE UNDER SHS CONDITIONS USING MAGNETIC COERCIMETRIC CONTROL." Scientific Journal "Metallurgy", no. 1 (February 17, 2021): 50–54. http://dx.doi.org/10.26661/2071-3789-2020-1-07.

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The article discusses the use of a self-propagating high-temperature synthesis of SHS ofsolid chemical compounds – it is a new technological process that possible to obtain a materialwith a given structure based on carrying out an exothermic reaction of interaction of reagents inthe combustion regime. The influence of cold deformation and intermediate annealing underSHS conditions on the structure, magnetic and mechanical properties of low-carbon steel is determined.The use of magnetic coercimetric control possible to control changes in the structureand mechanical properties of during technological cycle for low-carbon welded wire in productionconditions.

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Miyake, Shugo, Shunsuke Kanetsuki, Katsuya Morino, Junki Kuroishi, and Takahiro Namazu. "Thermal property measurement of solder joints fabricated by self-propagating exothermic reaction in Al/Ni multilayer film." Japanese Journal of Applied Physics 54, no. 6S1 (May 27, 2015): 06FP15. http://dx.doi.org/10.7567/jjap.54.06fp15.

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Kuntani, Yasuhiro, Daiki Goto, Kana Maekawa, Kenta Kodama, Shunsuke Kanetsuki, Shugo Miyake, and Takahiro Namazu. "Mechanical shock-induced self-propagating exothermic reaction in Ti/Si multilayer nanofilms for low-power reactive bonding." Japanese Journal of Applied Physics 59, SI (April 28, 2020): SIIL09. http://dx.doi.org/10.35848/1347-4065/ab827f.

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32

Sen, Seema, Markus Lake, Norman Kroppen, Peter Farber, Johannes Wilden, and Peter Schaaf. "Self-propagating exothermic reaction analysis in Ti/Al reactive films using experiments and computational fluid dynamics simulation." Applied Surface Science 396 (February 2017): 1490–98. http://dx.doi.org/10.1016/j.apsusc.2016.11.197.

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33

Aghajani, Hossein, Arvin Taghizadeh Tabrizi, Salva Arabpour Javadi, Mohammad Ehsan Taghizadeh Tabrizi, Aytak Homayouni, and Sahand Behrangi. "Thermodynamically study of phase formation of Ni-Ti-Si nanocomposites produced by self-propagating high-temperature synthesis method." Synthesis and Sintering 1, no. 4 (November 8, 2021): 189–96. http://dx.doi.org/10.53063/synsint.2021.1443.

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Understanding the phase formation mechanisms in self-propagating high-temperature synthesis from the thermodynamical aspect of view is important. In this study, the phase formation of the ternary system of nickel-titanium-silicon was studied by using the HSC software V6.0, and phase formation is predicted by calculating the adiabatic temperature of exothermic reaction between reagents. Then, by using X-ray diffractometer analysis, the results of the simulation were evaluated by experimental achievements. Results showed a good correlation between thermodynamical calculation and prediction with experimental. It could be concluded that the equilibrium mechanism is the dominant mechanism in phase formation in the SHS synthesis method. NiTiSi solid solution phase is obtained from the reaction between Ti5Si3 and Ni2Si and Ni.

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34

Xanthopoulou, Galina. "Catalytic Properties of the SHS Products - Review." Advances in Science and Technology 63 (October 2010): 287–96. http://dx.doi.org/10.4028/www.scientific.net/ast.63.287.

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The Self-Propagating High-Temperature Synthesis (SHS) method has been used to produce a new class of active catalyst materials based on metals, metal oxides and spinels for various applications. The method is characterized by very fast processing times (of the order of minutes), relatively low preheating temperatures and very high reaction temperatures produced as a result of carefully designed exothermic reactions. A large range of materials have been produced and characterized by a variety of physico-chemical and mechanical tests. This review devoted to Catalytic properties of SHS products. A number of catalytically active materials all over the world have been identified which offer promise for applications ranging from oxidation of CO and hydrocarbons to reduction of NOx, methane dehydrogenation and other.

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Yeh, Chun-Liang, and Min-Chia Chen. "Metallothermic Reduction of MoO3 on Combustion Synthesis of Molybdenum Silicides/MgAl2O4 Composites." Materials 14, no. 17 (August 24, 2021): 4800. http://dx.doi.org/10.3390/ma14174800.

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Combustion synthesis involving metallothermic reduction of MoO3 by dual reductants, Mg and Al, to enhance the reaction exothermicity was applied for the in situ production of Mo3Si–, Mo5Si3− and MoSi2–MgAl2O4 composites with a broad compositional range. Reduction of MoO3 by Mg and Al is highly exothermic and produces MgO and Al2O3 as precursors of MgAl2O4. Molybdenum silicides are synthesized from the reactions of Si with both reduced and elemental Mo. Experimental evidence indicated that the reaction proceeded as self-propagating high-temperature synthesis (SHS) and the increase in silicide content weakened the exothermicity of the overall reaction, and therefore, lowered combustion front temperature and velocity. The XRD analysis indicated that Mo3Si–, Mo5Si3– and MoSi2–MgAl2O4 composites were well produced with only trivial amounts of secondary silicides. Based on SEM and EDS examinations, the morphology of synthesized composites exhibited dense and connecting MgAl2O4 crystals and micro-sized silicide particles, which were distributed over or embedded in the large MgAl2O4 crystals.

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36

Jung, J. C., S. G. Ko, C. W. Won, S. S. Cho, and B. S. Chun. "The self-propagation high-temperature synthesis of ultrafine high purity tungsten powder from scheelite." Journal of Materials Research 11, no. 7 (July 1996): 1825–30. http://dx.doi.org/10.1557/jmr.1996.0230.

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High-purity tungsten was prepared by the self-propagating high-temperature synthesis (SHS) process from a mixture of CaO · WO3 and Mg. The complete reduction of CaO · WO3 required a 33% excess of magnesium over the stoichiometric molar ratio Mg/CaO · WO3 of 3: 1. The MgO and CaO in the product were leached with an HCl solution. The product tungsten had a purity of 99.980% which was higher than that of the reactants. The high purity results because the nontungsten reactants and products are volatilized by the high temperatures generated during the rapid exothermic SHS reaction and are dissolved during HCl leaching of the product.

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37

Miyake, Shugo, Shunsuke Kanetsuki, Katsuya Morino, Junki Kuroishi, and Takahiro Namazu. "Erratum: “Thermal property measurement of solder joints fabricated by self-propagating exothermic reaction in Al/Ni multilayer film”." Japanese Journal of Applied Physics 54, no. 9 (August 26, 2015): 099201. http://dx.doi.org/10.7567/jjap.54.099201.

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38

Mullins, Michael E., and Erica Riley. "The effect of carbon morphology on the combustion synthesis of titanium carbide." Journal of Materials Research 4, no. 2 (April 1989): 408–11. http://dx.doi.org/10.1557/jmr.1989.0408.

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Titanium carbide may be readily produced in high purity via direct reaction between the solid phases of titanium and carbon in the process of combustion synthesis, also known as self-propagating high-temperature synthesis (SHS). The high temperatures generated by this exothermic reaction (<3000 °C) melt the titanium phase which subsequently flows to and reacts with the solid carbon. As a result, with lightly or uncompressed green bodies a product is obtained which retains most of the carbon precursor powder morphology down to the μm scale. The effect of three distinctly different carbon precursor powders on the final titanium carbide morphology has been examined. Subsequent effects of particle size and microstructure on the quality of the titanium carbide product are also noted.

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Li, Junchen, Yu Wang, Xutao Huang, Chao Zhang, Junqiang Ren, Xuefeng Lu, Fuling Tang, and Hongtao Xue. "Tensile mechanical performance of Al/Ni dissimilar metals bonded by self-propagating exothermic reaction based on molecular dynamics simulation." Materials Today Communications 26 (March 2021): 102079. http://dx.doi.org/10.1016/j.mtcomm.2021.102079.

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Lu, Xi Rui, Si Jin Su, and Meng Jun Chen. "Self-Propagating High-Temperature Synthesis of Simulated ⁹⁰SrO-Contained Radioactive Graphite in N₂ Atmosphere." Applied Mechanics and Materials 525 (February 2014): 45–52. http://dx.doi.org/10.4028/www.scientific.net/amm.525.45.

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In order to evaluate the performance of the self-propagating high-temperature synthesis (SHS) to treat 90SrO-contained radioactive graphite in N2 atmosphere, waste forms were prepared with the self-developed SHS reactor according to the waste forms formulation designed with a solid-soluted content of 010 wt% (calibrated in mass, hereinafter the same). The waste forms were made with the exothermic reaction (3C + 4Al + 3TiO2 = 2Al2O3 + 3TiC + Q), where, 88SrO (a stable Sr isotope)-containing 88SrO was used to simulate 90SrO. And the raw materials for the waste forms were the powdery materials of graphite (C), aluminum (Al) and titanium dioxide (TiO2). Then, X-ray diffractometer (XRD) and scanning electron microscope (SEM) were used to test and analyze the phase composition and morphology of the prepared waste forms. According to the results in dealing with the treatment with the given exothermic reaction of the 90SrOcontaining radioactive graphite in N2 atmosphere, the SrO solid solubility could be up to 8 wt%. Besides, with a SrO content of 0~2 wt%, the major composition of the waste forms was including: alumina (Al2O3) in diamond scheme, titanium carbide (TiC) in cubic phase, graphite (C), anatase titanium dioxide (TiO2) and aluminum nitride (AlN) in cubic phase. Comparatively, with a SrO content of 3~8 wt%%, the major composition of the waste forms was including: alumina (Al2O3) in diamond scheme, titanium carbide (TiC) in cubic phase, graphite (C), anatase titanium dioxide (TiO2), aluminum nitride (AlN) in cubic phase and rhomboid aluminum titanate (Al2TiO5). Furthermore, diffractive peaks of unidentified phase occurred at 2θ = 7.7°, 15.6°, 19.8° and 24.1° position, whose intensities were increased with the increasing additional SrO content. The grain sizes of the prepared waste forms are mainly within 515μm, majorly exist in pieces.

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Ma, Tao, Qing Xuan Zeng, Ming Yu Li, and Tao Wang. "Fabrication and Characterization of Al/Ni Multilayer Films." Advanced Materials Research 1088 (February 2015): 76–80. http://dx.doi.org/10.4028/www.scientific.net/amr.1088.76.

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Self-propagating exothermic formation reactions have been intensively studied in a variety of reactive multilayer films, which typically include alternating layers of two or more reactants. Here, we introduce a reactive multilayer film which contains a thermite reaction between Ni and Al.Al/Ni multilayer films which were composed of alternate Al and Ni layers were prepared by DC magnetron sputtering.The total thickness of each films was approximately 1.2 μm having bilayer thicknesses of 60, 100, 150 nm. Each bilayer consisted of an aluminum layer and a nickel layer in a 3:2 thickness ratio to maintain an overall 1:1 atomic composition.Meanwhile, Al/Ni multilayer films with the bilayer thickness of 60 nmwas prepared. In each bilayer, the thickness ratio of Al to Ni was maintained at 1:2 to obtain an overall 1:3 atomic composition.The total thickness of Al/Ni multilayer films was around 1.2 μm.DSC curves show that the values of heat release in Al/Ni multilayer films with bilayer thicknesses of 60 (Al:Ni), 100 (Al:Ni), 150 (Al:Ni) and 60 (Al:3Ni) nm are 324.63 Jg-1, 348.51 Jg-1, 400.45 Jg-1 and 69.85 Jg-1, respectively. XRD measurements show that the final products of exothermic reactions with Al:Ni atomic ratio of 1:1 and 1:3 are the compound of AlNi and AlNi3, respectively.

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Yeh, Chun-Liang, and Chih-Yao Ke. "Intermetallic/Ceramic Composites Synthesized from Al–Ni–Ti Combustion with B4C Addition." Metals 10, no. 7 (July 1, 2020): 873. http://dx.doi.org/10.3390/met10070873.

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The fabrication of intermetallic/ceramic composites by combustion synthesis in the mode of self-propagating high-temperature synthesis (SHS) was investigated in the Al–Ni–Ti system with the addition of B4C. Two reaction systems were employed: one was used to produce the composites of xNiAl–2TiB2–TiC with x = 2–7, and the other was used to synthesize yNi3Al–2TiB2–TiC with y = 2–7. The reaction mechanism of the Al–Ni–Ti system was strongly influenced by the presence of B4C. The reaction of B4C with Ti was highly exothermic, so the reaction temperature and combustion velocity decreased due to increasing levels of Ni and Al in the reactant mixture. The activation energies of Ea = 110.6 and 172.1 kJ/mol were obtained for the fabrication of NiAl- and Ni3Al-based composites, respectively, by the SHS reaction. The XRD (X-ray diffraction) analysis showed an in situ formation of intermetallic (NiAl and Ni3Al) and ceramic phases (TiB2 and TiC) and confirmed no reactions taking place between Ti and Al or Ni. The microstructure of the product revealed large NiAl and Ni3Al grains and small TiB2 and TiC particles. With the addition of TiB2 and TiC, the hardness of NiAl and Ni3Al was considerably increased and the toughness was also improved.

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Zhou, Qiang, Peng Wan Chen, Xiang Gao, and Wei Ping Shen. "Experiment Study on the Hot-Shock Consolidation of Tungsten Powder." Materials Science Forum 673 (January 2011): 107–12. http://dx.doi.org/10.4028/www.scientific.net/msf.673.107.

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Experiments have been conducted to consolidate tungsten powder using hot-shock consolidation technique combining with underwater shock wave. An exothermic mixture (TiO2-C-Al-Fe2O3) was ignited by an electric wire coil to release a large mount of heat via a self-propagating high-temperature synthesis reaction which was used to pre-heat the sample powder. As getting the needed isothermal temperature, the powder was subsequently consolidated by shock wave generated by explosion of nitro methane, with a detonation velocity of 6.3 km/s and a detonation pressure of 11.9 GPa. The density and Vickers micro-hardness of the consolidated sample were determined and its microstructure was analyzed by scanning electron microscope (SEM). High-density tungsten samples were obtained by optimizing the experimental conditions. In this paper, the relative density and hardness of the recovered sample are 96.5% and 670 HV, respectively.

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44

Yeh, Chun-Liang, Kuan-Ting Chen, and Tzong-Hann Shieh. "Effects of Fe/Si Stoichiometry on Formation of Fe3Si/FeSi-Al2O3 Composites by Aluminothermic Combustion Synthesis." Metals 11, no. 11 (October 26, 2021): 1709. http://dx.doi.org/10.3390/met11111709.

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Aluminothermic combustion synthesis was conducted with Fe2O3–Al–Fe–Si reaction systems under Fe/Si stoichiometry from Fe-20 to Fe-50 at. % Si to investigate the formation Fe3Si/FeSi–Al2O3 composites. The solid-state combustion was sufficiently exothermic to sustain the overall reaction in the mode of self-propagating high-temperature synthesis (SHS). Dependence of iron silicide phases formed from SHS on Fe/Si stoichiometry was examined. Experimental evidence indicated that combustion exothermicity and flame-front velocity were affected by the Si percentage. According to the X-ray diffraction (XRD) analysis, Fe3Si–Al2O3 composites were synthesized from the reaction systems with Fe-20 and Fe-25 at.% Si. The increase of Si content led to the formation of both Fe3Si and FeSi in the final products of Fe-33.3 and Fe-40 at.% Si reaction systems, and the content of FeSi increased with Si percentage. Further increase of Si to Fe-50 at.% Si produced the FeSi–Al2O3 composite. Scanning electron microscopy (SEM) images revealed that the fracture surface morphology of the products featured micron-sized and nearly spherical Fe3Si and FeSi particles distributing over the dense and connecting substrate formed by Al2O3.

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45

Burkes, Douglas E., and John J. Moore. "Combustion Synthesis of a Functionally Graded NiTi-TiCx Composite." Journal of Engineering Materials and Technology 128, no. 3 (February 27, 2006): 445–50. http://dx.doi.org/10.1115/1.2204950.

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Combustion synthesis (CS) is an alternative technique for producing advanced materials and is dependent upon a highly exothermic chemical reaction to become self-sustaining after only a short energy pulse is applied to initiate the reaction. A NiTi-TiCx functionally graded material (FGM) was investigated that combines superelastic and shape memory capabilities of NiTi with the high hardness, wear, and corrosion resistance of TiCx. CS was employed to produce a FGM from 100% TiCx ceramic to 100% NiTi intermetallic. Temperature and burning velocity data of the CS reaction were recorded. XRD of the final product layers was conducted to determine phase composition. The combustion temperature, burning velocity, and cooling rate in each layer decreased with increasing NiTi content. Large blowholes were present in the high NiTi content layers as a result of outgassing of volatile species from the reactant powders. XRD analysis revealed the presence of Ni-Ti intermetallics along with a substoichiometric TiC (TiC0.7). Production of a NiTi-TiCx FGM is possible through use of a CS reaction employing the propagating mode (SHS). The material layers were observed as functionally graded in both composition and porosity.

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Kobashi, Makoto, and Naoyuki Kanetake. "Novel Processing of Porous Titanium Composite for Producing Open Cell Structure." Materials Science Forum 539-543 (March 2007): 1004–9. http://dx.doi.org/10.4028/www.scientific.net/msf.539-543.1004.

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Processing technique to produce open-cell porous titanium composite was developed. One of the outstanding benefits of porous titanium composite is both physical and mechanical properties can be controlled widely by changing the metal/ceramic fraction and cell structures. In this work, porous titanium composite was fabricated by a chemical reaction between titanium powder and boron carbide (B4C) powder. The reactions between titanium and B4C generates a large amount of latent heat and, therefore, it was a combustion and self-propagating mode. Precursors were made by compacting the starting powder blend (Ti and B4C), and heated in an induction furnace to induce the reaction. The reaction was strongly exothermic and, therefore, the precursor was sintered by its latent heat when the Ti/B4C blending ratio was appropriate. The reaction products were titanium boride (TiB and/or TiB2) and titanium carbide (TiC). By controlling the Ti/B4C blending ratio, it was possible to control the volume fraction of reaction products in titanium matrix. The combustion synthesized titanium composite was porous and its cell structure was strongly affected by the processing condition of the precursor (porosity and Ti/B4C blending ratio). High porosity with open pores was obtained with small Ti/B4C ratios and high porosity of the precursor, while the cell structure was closed and spherical with high Ti/B4C ratio. The cell-wall size was varied from several tens of microns to about 500 microns by changing the combustion temperature.

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FUJITA, Hiroshi, Takahiro NAMAZU, and Shozo INOUE. "1108 Evaluation of bond strength in MEMS soldering silicon-package heated by using self-propagating exothermic reaction in Al/Ni multilayer films." Proceedings of the Conference on Information, Intelligence and Precision Equipment : IIP 2007 (2007): 25–28. http://dx.doi.org/10.1299/jsmeiip.2007.25.

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48

Van Heerden, D., T. R. Rude, J. Newson, J. He, E. Besnoin, O. M. Knio, and T. P. Weihs. "A Tenfold Reduction in Interface Thermal Resistance for Heat Sink Mounting." Journal of Microelectronics and Electronic Packaging 1, no. 3 (July 1, 2004): 187–93. http://dx.doi.org/10.4071/1551-4897-1.3.187.

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Reactive NanoTechnologies (RNT) has developed a new platform joining technology that can form a metallic bond between a chip package and a heat sink and thereby offer a thermal interface resistance that is up to ten times lower than current thermal interface materials (TIM). The joining process is based on the use of reactive multilayer foils as local heat sources. The foils are a new class of nano-engineered materials, in which self-propagating exothermic reactions can be initiated at room temperature with a hot filament or laser. By inserting a multilayer foil between two solder layers and a chip package and heat sink, energy generated by a chemical reaction in the foil heats the solder to melting and consequently bonds the components. The joining process can be completed in air, argon or vacuum in approximately one second. The resulting metallic joints exhibit thermal resistances up to an order of magnitude lower, than current commercial TIMs. We also demonstrate, using numerical modeling, that the thermal exposure of microelectronic packages during joining is very limited. Finally we show numerically that reactive joining can be used to solder Si dies directly to heat sinks without thermally damaging the chip.

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Balaba, Willy M., Douglas A. Weirauch, Anthony J. Perrotta, George H. Armstrong, Princewill N. Anyalebechi, Suzanne Kauffman, Andrew N. MacInnes, Angela M. Winner, and Andrew R. Barron. "The effect of siloxane spin-on-glass and reaction bonded silicon oxycarbide coatings with a self-propagating interfacial reaction treatment (ASPIRE) in the synthesis of carbon/graphite fiber-reinforced aluminum metal matrix composites." Journal of Materials Research 8, no. 12 (December 1993): 3192–201. http://dx.doi.org/10.1557/jmr.1993.3192.

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Carbon fibers were treated with siloxane spin-on-glass and reaction bonded silicon oxycarbide coatings. The spin-on-glass (SOG) coatings were prepared by pyrolyzing solutions of polymethylsilsesquioxane (PMSO), polydimethoxysilane (PDSO), and poly(ethoxysilane)ethyltitanate copolymer (ESET). Since the flexibility of the coatings was found to be dependent on the concentration of the siloxane solution, only those of PMSO and PDSO below 1.25% were determined to be suitable for fiber coatings, and an alternative approach to the formation of a pliable silicon-based ceramic coating on the fibers was developed. Carbon fiber tows were impregnated by ethanolic solutions of organosilicon chlorides and fired at temperatures up to 900 °C to form a flexible reaction bonded silicon oxycarbide (RB–SiOC) coatings. Uncoated, SOG coated, and RB–SiOC coated carbon fibers were embedded in aluminum metal at 1000 °C. While both silica-based coatings protected the carbon surface, no wetting was observed, leading to fiber pull-out. When the coated fibers were treated with a mixture of Ti and B prior to immersion into the molten aluminum, complete wetting of the fibers occurred. In the presence of molten aluminum, the Ti/B coating enabled the exothermic formation of TiB2 and titanium aluminides, which facilitate wetting. This reaction is termed ASPIRE (Aluminum Self-Propagating Interfacial Reaction) and in combination with silicon-based ceramic coatings provides a scientific approach to the formation of stable carbon fiber/aluminum metal-matrix composites. The coated fibers and composites were characterized by scanning electron microscopy (SEM) with energy dispersive x-ray (EDX) analysis, and x-ray photoelectron spectroscopy (XPS).

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Aydinyan, Sofiya, Suren Kharatyan, and Irina Hussainova. "SHS-Derived Powders by Reactions’ Coupling as Primary Products for Subsequent Consolidation." Materials 14, no. 17 (September 6, 2021): 5117. http://dx.doi.org/10.3390/ma14175117.

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The capability of self-propagating high-temperature synthesis (SHS) to produce powders that are characterized by a high sintering ability, owing to high heating and cooling rates inherent to the exothermic reaction, is of a special interest for the industry. In particular, SHS-derived powders comprise a significant defect concentration in order to effectively enhance the mass transfer processes during the sintering, which allows for the successful consolidation of difficult-to-sinter materials at relatively low sintering temperatures. From this perspective, the design of precursors suitable for sintering, synthesis in a controlled temperature regime and the optimization of geometrical and structural parameters of SHS powders as a potential feedstock for the consolidation is of key importance. Here, we report on the comparative studies concerning the SHS processing of composites for advanced powder metallurgy techniques. The synthesis and sintering peculiarities of the SHS through coupled reactions in the Me’O3(WO3,MoO3)-Me’’O(CuO,NiO)-Mg-C, Ti-B-Al12Mg17 systems are comparatively reviewed. The SHS coupling approach was used for the preparation of powders with a tuned degree of fineness (a high specific surface area of particles), a high-homogeneity and a controllable distribution of elements via both the regulation of the thermal regime of combustion in a wide range and the matching of the thermal and kinetic requirements of two interconnected reactions. Microstructural features of the powder feedstock greatly contributed to the subsequent consolidation process.

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Journal articles on the topic 'Self-propagating exothermic reaction'

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