| 1. |
- Feng, Peizhong, et al.
(författare)
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Combustion synthesis of (Mo1-xCrx)Si-2 (x=0.00-0.30) alloys in SHS mode
- 2012
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Ingår i: Advanced Powder Technology. - : Elsevier BV. - 0921-8831 .- 1568-5527. ; 23:2, s. 133-138
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Tidskriftsartikel (refereegranskat)abstract
- Combustion synthesis was adopted to successfully synthesize molybdenum-silicon-chromium (Mo-Si-Cr) alloys by the mode of self-propagating high-temperature synthesis (SHS). The experimental study of combustion synthesis of Mo-Si-Cr alloys was conducted on elemental powder compacts. Powder compacts with nominal compositions including MoSi2, (Mo0.95Cr0.05)Si-2, (Mo0.90Cr0.10)Si-2, (Mo0.85Cr0.15)Si-2, (Mo0.80Cr0.20)Si-2, (Mo0.75Cr0.25)Si-2 and (Mo0.20Cr0.30)Si-2 were employed in combustion synthesis experiments. The combustion mode, combustion temperature, flame-front propagation velocity and product structure were investigated. The results showed that Mo-Si-Cr alloys were synthesized by an unsteady state combustion mode with a spiral-trajectory reaction front. The peak combustion temperature reduced with the addition of Cr to Mo-Si system. The flame-front propagation velocity decreased with an increase in Cr content of the powder compact. The X-ray diffraction (XRD) results showed that the crystal structure of the combustion product changed from CIIb-type structure (Mo0.90Cr0.10)Si-2 to C40-type structure (Mo0.80Cr0.15)Si-2 with increase in Cr content of Mo-Cr-Si alloys. The intensities of diffraction peaks of the C40-type phase gradually increased with increase in Cr content.
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| 2. |
- Ran, Huashen, et al.
(författare)
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Microstructure and properties of Ti5Si3-based porous intermetallic compounds fabricated via combustion synthesis
- 2014
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Ingår i: Journal of Alloys and Compounds. - : Elsevier BV. - 0925-8388 .- 1873-4669. ; 612, s. 337-342
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Tidskriftsartikel (refereegranskat)abstract
- Porous titanium silicides (Ti5Si3-based) were produced by combustion synthesis process from reaction mixtures of titanium to silicon in varying molar ratios. The effects of combustion characteristics of the reaction mixtures on the phase formation, microstructure, porosity, pore size and compressive strength of porous titanium silicide intermetallic compounds were investigated. The results showed that the flame-front propagation velocity and temperature of the combustion reaction were the maximum for the reaction mixture containing Ti and Si in the ratio of 5 to 3 (Ti5Si3), 32.7 mm/s and 2205 K, respectively. X-ray diffraction analysis confirmed that the dominant phase formed was Ti5Si3 in all combustion synthesized porous intermetallic compounds. Ti5Si3-based intermetallic compounds were highly porous. The porosity and pore size of these intermetallics were dependent on the initial composition of the reaction mixture. The total and open porosities of Ti5Si3-based intermetallics varied from 33 to 61% and 17 to 55%, respectively. The porous titanium silicide intermetallic materials displayed high mechanical strength, in the range of 6-35 MPa, duly required for their use as filters.
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| 3. |
- Wang, Jiandong, et al.
(författare)
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Synthesis, microstructure and properties of MoSi2-5vol.%Al2O3 composites
- 2014
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Ingår i: Ceramics International. - : Elsevier BV. - 0272-8842 .- 1873-3956. ; 40:10 Part B, s. 16381-16387
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Tidskriftsartikel (refereegranskat)abstract
- MoSi2-5vol.%Al2O3 composites were prepared in situ by self-propagating combustion synthesis from Mo, Si, Al and MoO3 powders. The combustion mode and temperature of the self-propagating reaction and phase composition of the product were investigated. The results showed that the combustion mode was a steady-state self-propagating process and the composite product was composed of MoSi2 and Al2O3. MoSi2-5vol.%Al2O3 composites were consolidated by vacuum hot-pressed sintering from 1300 to 1600 °C to produce composites with high density. MoSi2-5vol.%Al2O3 composites sintered at 1400 °C exhibited a fine microstructure and excellent mechanical properties: grain size ∼5 μm, Vicker’s hardness 11.14 GPa, bending strength 435 MPa, and fracture toughness 4.53 MPa.m1/2.
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| 4. |
- Zhu, Gaoming, et al.
(författare)
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Synthesis and Properties of MoSi2–MoB–SiC Ceramics
- 2016
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Ingår i: Journal of The American Ceramic Society. - : Wiley. - 0002-7820 .- 1551-2916. ; 99:4, s. 1147-1150
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Tidskriftsartikel (refereegranskat)abstract
- MoB and SiC particulate reinforced MoSi2 matrix composites were synthesized in situ from Mo, Si, and B4C powder mixtures by self-propagating high-temperature synthesis (SHS). The SHS MoSi2–MoB–SiC products were vacuum hot-pressed (HPed) at 1400°C for 90 min to fabricate high-density (> 97.5% relative density) bulk composites. Microstructure refinement and improvements in the Vickers hardness and fracture toughness of the HPed composites were observed with increasing B4C content in the reaction mixture. The HPed composite of composition MoSi2–0.4MoB–0.1SiC exhibited grain size of 1–5 μm, Vickers hardness of 12.5 GPa, bending strength of 537 MPa, and fracture toughness of 3.8 MPa.m1/2. These excellent mechanical properties indicate that MoB and SiC particulate reinforced MoSi2 composites could be promising candidates for structural applications.
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