Microstructure and phase composition of the Nb-Si based in-situ composite from plasma spheroidized powder

Goncharov, Ivan; Hisamova, Liliya; Mustafaeva, Liana; Razumov, Nikolay; Makhmutov, Tagir; Kim, Artem; Wang, QingSheng; Shamshurin, A. I.; Popovich, Anatoly

doi:10.1016/j.matpr.2019.12.427

Cited by 5 publications

(4 citation statements)

References 24 publications

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“…The powder metallurgy route generally consists of two procedures, i.e., first preparing the powder blends by mechanical alloying and then sintering the powder blends using methods such as HPS [ 18 , 19 ]. A few researchers have fabricated Nb-Si based alloys by powder metallurgy methods [ 20 , 21 , 22 ]. However, only the microstructure and mechanical properties of Nb-Si binary and Nb-Si-Fe or Nb-Si-Ti ternary alloys have been studied [ 20 , 21 , 22 ].…”

Section: Introductionmentioning

confidence: 99%

“…A few researchers have fabricated Nb-Si based alloys by powder metallurgy methods [ 20 , 21 , 22 ]. However, only the microstructure and mechanical properties of Nb-Si binary and Nb-Si-Fe or Nb-Si-Ti ternary alloys have been studied [ 20 , 21 , 22 ]. Until now, there is no report in the open literature about the preparation, microstructural characteristics and properties of more practical multicomponent Nb-Si based ultrahigh-temperature alloys through a powder metallurgy route.…”

Section: Introductionmentioning

confidence: 99%

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Microstructure, Mechanical Properties and Oxidation Resistance of Nb-Si Based Ultrahigh-Temperature Alloys Prepared by Hot Press Sintering

2023

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Nb-Si based ultrahigh-temperature alloys with the composition of Nb-22Ti-15Si-5Cr-3Al (atomic percentage, at. %) were prepared by hot press sintering (HPS) at 1250, 1350, 1400, 1450 and 1500 °C. The effects of HPS temperatures on the microstructure, room temperature fracture toughness, hardness and isothermal oxidation behavior of the alloys were investigated. The results showed that the microstructures of the alloys prepared by HPS at different temperatures were composed of Nbss, βTiss and γ(Nb,X)5Si3 phases. When the HPS temperature was 1450 °C, the microstructure was fine and nearly equiaxed. When the HPS temperature was lower than 1450 °C, the supersaturated Nbss with insufficient diffusion reaction still existed. When the HPS temperature exceeded 1450 °C, the microstructure coarsened obviously. Both the room temperature fracture toughness and Vickers hardness of the alloys prepared by HPS at 1450 °C were the highest. The alloy prepared by HPS at 1450 °C exhibited the lowest mass gain upon oxidation at 1250 °C for 20 h. The oxide film was mainly composed of Nb2O5, TiNb2O7, TiO2 and a small amount of amorphous silicate. The formation mechanism of oxide film is concluded as follows: TiO2 forms by the preferential reaction of βTiss and O in the alloy; after that, a stable oxide film composed of TiO2 and Nb2O5 forms; then, TiNb2O7 is formed by the reaction of TiO2 and Nb2O5.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Microstructure, Mechanical Properties and Oxidation Resistance of Nb-Si Based Ultrahigh-Temperature Alloys Prepared by Hot Press Sintering

2023

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“…The Nb 5 Si 3 intermetallic compound has been considered as a potential material for high-performance structural application due to its high melting point (2520 • C), low density (7.1 g/cm 3 ), and excellent strength retention at elevated temperatures [1][2][3]. However, due to the relatively low fracture toughness of 1-3 MPa•m 1/2 at ambient temperatures [4], a ductile niobium-based solid solution (Nb ss ) was brought into Nb 5 Si 3 to achieve a balance of low fracture toughness and high temperature strength [5][6][7][8][9][10][11][12]. As for the as-cast Nb-Si alloy, with the increase in Si content, the volume fraction of ductile Nb ss phase decreased, thereby significantly lowering the fracture toughness [13,14].…”

Section: Introductionmentioning

confidence: 99%

Effect of C Addition on the Microstructure and Fracture Properties of In Situ Laminated Nb/Nb5Si3 Composites

Zeng

Xiao

et al. 2023

Materials

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//Nbss and α-Nb5Si3 phases were detected. Meanwhile, Nb2C was observed, and the crystal forms of Nb5Si3 changed in the C-doped composites. Furthermore, micron-sized and nano-sized Nb2C particles were found in the Nbss layer. The orientation relationship of Nb2C phase and the surrounding Nbss was [001]Nbss//[010]Nb2C, (200) Nbss//(101) Nb2C. Additionally, with the addition of C, the compressive strength of the composites, at 1400 °C, and the fracture toughness increased from 310 MPa and 11.9 MPa·m1/2 to 330 MPa and 14.2 MPa·m1/2, respectively; the addition of C mainly resulted in solid solution strengthening.

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“…In the Nb–10Si–2Fe alloy, (a) the as-sintered microstructure consisted of the Nb ss , Nb 3 Si, Nb 5 Si 3 and Nb 4 Fe 3 Si 5 phases, and after annealing, Nb 3 Si transformed into Nb ss and αNb 5 Si 3 ; (b) the fracture toughness increased from K Q = 11.2 MPa√m for the as-sintered condition to K Q = 20.1 MPa√m for the extruded and heat-treated condition and (c) Nb ss and Nb 4 Fe 3 Si 5 were suggested to play an important role in the fracture process—in particular, the latter [ 18 ]. The microstructure of mechanically alloyed and plasma spheroidized powder particles of Nb–25Ti–16Si–2Al–2Cr–2Fe RM(Nb)IC consisted of the Nb ss , Nb 3 Si and Nb 5 Si 3 phases [ 19 ].…”

Section: Introductionmentioning

confidence: 99%

The Effect of Fe Addition in the RM(Nb)IC Alloy Nb–30Ti–10Si–2Al–5Cr–3Fe–5Sn–2Hf (at.%) on Its Microstructure, Complex Concentrated and High Entropy Phases, Pest Oxidation, Strength and Contamination with Oxygen, and a Comparison with Other RM(Nb)ICs, Refractory Complex Concentrated Alloys (RCCAs) and Refractory High Entropy Alloys (RHEAs)

Vellios

Tsakiropoulos

2022

Materials

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In this work, the RM(Nb)IC alloy Nb–30Ti–10Si–5Cr–5Sn–3Fe–2Al–2Hf (NV2) was studied in the as-cast and heat-treated conditions; its isothermal oxidation at 700, 800 and 900 °C and its room temperature hardness and specific strength were compared with other Sn-containing RM(Nb)ICs—in particular, the alloy Nb–24Ti–18Si–5Cr–5Fe–5Sn (NV5)—and with RCCAs and RHEAs. The addition of Fe (a) stabilised Nbss; A15–Nb3X (X = Al, Si and Sn) and Nb3Si; metastable Nb3Si-m’ and Nb5Si3 silicides; (b) supported the formation of eutectic Nbss + Nb5Si3; (c) suppressed pest oxidation at all three temperatures and (d) stabilised a Cr- and Fe-rich phase instead of a C14–Nb(Cr,Fe)2 Laves phase. Complex concentrated (or compositionally complex) and/or high entropy phases co-existed with “conventional” phases in all conditions and after oxidation at 800 °C. In NV2, the macrosegregation of Si decreased but liquation occurred at T >1200 °C. A solid solution free of Si and rich in Cr and Ti was stable after the heat treatments. The relationships between solutes in the various phases, between solutes and alloy parameters and between alloy hardness or specific strength and the alloy parameters were established (parameters δ, Δχ and VEC). The oxidation of NV2 at 700 °C was better than the other Sn-containing RM(Nb)ICs with/without Fe addition, even better than RM(Nb)IC alloys with lower vol.% Nbss. At 800 °C, the mass change of NV2 was slightly higher than that of NV5, and at 900 °C, both alloys showed scale spallation. At 800 °C, both alloys formed a more or less continuous layer of A15–Nb3X below the oxide scale, but in NV5, this compound was Sn-rich and severely oxidised. At 800 °C, in the diffusion zone (DZ) and the bulk of NV2, Nbss was more severely contaminated with oxygen than Nb5Si3, and the contamination of A15–Nb3X was in-between these phases. The contamination of all three phases was more severe in the DZ. The contamination of all three phases in the bulk of NV5 was more severe compared with NV2. The specific strength of NV2 was comparable with that of RCCAs and RHEAs, and its oxidation at all three temperatures was significantly better than RHEAs and RCCAs.

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Microstructure and phase composition of the Nb-Si based in-situ composite from plasma spheroidized powder

Cited by 5 publications

References 24 publications

Microstructure, Mechanical Properties and Oxidation Resistance of Nb-Si Based Ultrahigh-Temperature Alloys Prepared by Hot Press Sintering

Microstructure, Mechanical Properties and Oxidation Resistance of Nb-Si Based Ultrahigh-Temperature Alloys Prepared by Hot Press Sintering

Effect of C Addition on the Microstructure and Fracture Properties of In Situ Laminated Nb/Nb5Si3 Composites

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