Oxidation behavior of molybdenum silicides and their composites

Natesan, K.; Deevi, S.C.

doi:10.1016/s0966-9795(00)00060-1

Cited by 94 publications

(56 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Especially, Mo-Si-B alloys have high potential as heat-resistant materials at ultra-high temperature [1][2][3][4][5]. However, the synthesis of these materials is usually difficult because of their extremely high melting temperatures.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of Mo–Si–B in situ composites by mechanical alloying

Yamauchi

Yoshimi

Kurokawa

et al. 2007

Journal of Alloys and Compounds

View full text Add to dashboard Cite

In this study, the synthesis of Mo-Si-B multi-phase alloys, so-called in-situ composites, was attempted with the combination of mechanical alloying (MA) and spark plasma sintering (SPS) processes. MA was conducted with mixed powders of Mo, Si and B using a planetary ball mill under various milling conditions. MAed powders were characterized by X-ray diffractometry (XRD) and scanning electron microscopy (SEM). The results obtained by XRD indicated that Mo-Si-B alloyed powders were successfully produced when elemental powders were milled at a higher milling energy.Vacuum heat treatments after the MA process promoted the formation of Mo-Si-B intermetallic phase in MAed powders. On the other hand, the MAed powders were successfully consolidated by a SPS technique, and as a result, sound compacts of Mo 5 SiB 2 -based composites were synthesized. keywords：molybdenum silicides; mechanical alloying; spark plasma sintering; X-ray diffraction

show abstract

Section: Introductionmentioning

confidence: 99%

Synthesis of Mo–Si–B in situ composites by mechanical alloying

Yamauchi

Yoshimi

Kurokawa

et al. 2007

Journal of Alloys and Compounds

View full text Add to dashboard Cite

show abstract

“…[12][13][14][15][16][17][18] protective silicon oxide films for enhanced oxidation resistIndeed, in contrast to MoSi 2 and Mo 5 Si 3 , which are very ance at elevated temperatures in hostile environments. In prone to pest reactions, [10,12,14] tertiary Mo-Si-B alloys have addition, specific silicides, such as Mo 5 Si 3 (T 1 ), have excellent a reduced susceptibility to such intermediate temperature creep resistance at temperatures as high as 1400 ЊC. [2] Despite oxidation due to the formation of a protective borosilicate these advantages, most refractory silicides invariably display layer.…”

Section: Introductionmentioning

confidence: 99%

On the fracture and fatigue properties of Mo-Mo3Si-Mo5SiB2 refractory intermetallic alloys at ambient to elevated temperatures (25 °C to 1300 °C)

Choe

Schneibel

Ritchie

2003

Metall Mater Trans A

View full text Add to dashboard Cite

The need for structural materials with high-temperature strength and oxidation resistance coupled with adequate lower-temperature toughness for potential use at temperatures above ϳ1000 ЊC has remained a persistent challenge in materials science. In this work, one promising class of intermetallic alloys is examined, namely, boron-containing molybdenum silicides, with compositions in the range Mo (bal), 12 to 17 at. pct Si, 8.5 at. pct B, processed using both ingot (I/M) and powder (P/M) metallurgy methods. Specifically, the oxidation ("pesting"), fracture toughness, and fatigue-crack propagation resistance of four such alloys, which consisted of ϳ21 to 38 vol. pct ␣ -Mo phase in an intermetallic matrix of Mo 3 Si and Mo 5 SiB 2 (T 2 ), were characterized at temperatures between 25 ЊC and 1300 ЊC. The boron additions were found to confer improved "pest" resistance (at 400 ЊC to 900 ЊC) as compared to unmodified molybdenum silicides, such as Mo 5 Si 3 . Moreover, although the fracture and fatigue properties of the finer-scale P/M alloys were only marginally better than those of MoSi 2 , for the I/M processed microstructures with coarse distributions of the ␣ -Mo phase, fracture toughness properties were far superior, rising from values above 7 MPaΊm at ambient temperatures to almost 12 MPaΊm at 1300 ЊC. Similarly, the fatigue-crack propagation resistance was significantly better than that of MoSi 2 , with fatigue threshold values roughly 70 pct of the toughness, i.e., rising from over 5 MPaΊm at 25 ЊC to ϳ8 MPaΊm at 1300 ЊC. These results, in particular, that the toughness and cyclic crack-growth resistance actually increased with increasing temperature, are discussed in terms of the salient mechanisms of toughening in Mo-Si-B alloys and the specific role of microstructure.

show abstract

“…Local consumption of Si (563) may result in formation of Mo 5 Si 3 at low or high temperatures [1821] but Mo 3 Si has been observed to result from the reaction of Mo 5 Si 3 with O 2 only at low temperatures [22]. At high temperatures, upon rapid formation of a stable oxide layer, Mo 5 Si 3 , which forms beneath the oxide scale, is insulated from oxygen and formation of Mo 3 Si is prevented.…”

Section: Introductionmentioning

confidence: 99%

Effects of Nb-Alloying on High-Temperature Oxidation of MoSi₂

Sharif

2014

Acta Phys. Pol. A

View full text Add to dashboard Cite

The eects of alloying with 0.5, 1.0, and 2.0 at.% Nb on oxidation resistance of MoSi2 are investigated at temperature range of 1400• C1700• C. Rapid formation of a stable protective layer of silica resulted in a parabolic oxidation rate. The oxide layer thickness and the sample weight increased with increasing oxidation time. Impurities accelerated oxidation rate of MoSi2 only slightly, however, did not aect the rate controlling mechanism for oxidation. There was no correlation between oxidation rate and the amount of impurity. The values of activation energies for oxidation of pure MoSi2 and Nb-alloyed samples were similar to activation energy for diusion of O2 through silica. Diusion of O2 through the oxide scale remained the rate controlling mechanism with or without Nb impurity.

show abstract

Oxidation behavior of molybdenum silicides and their composites

Cited by 94 publications

References 16 publications

Synthesis of Mo–Si–B in situ composites by mechanical alloying

Synthesis of Mo–Si–B in situ composites by mechanical alloying

On the fracture and fatigue properties of Mo-Mo3Si-Mo5SiB2 refractory intermetallic alloys at ambient to elevated temperatures (25 °C to 1300 °C)

Effects of Nb-Alloying on High-Temperature Oxidation of MoSi₂

Contact Info

Product

Resources

About

Oxidation behavior of molybdenum silicides and their composites

Cited by 94 publications

References 16 publications

Synthesis of Mo–Si–B in situ composites by mechanical alloying

Synthesis of Mo–Si–B in situ composites by mechanical alloying

On the fracture and fatigue properties of Mo-Mo3Si-Mo5SiB2 refractory intermetallic alloys at ambient to elevated temperatures (25 °C to 1300 °C)

Effects of Nb-Alloying on High-Temperature Oxidation of MoSi2

Contact Info

Product

Resources

About

Effects of Nb-Alloying on High-Temperature Oxidation of MoSi₂