HRTEM observation of silicides and Laves phase precipitates in Nb-Ti-Si based alloys
Source abstract
Abstract
Abstract The morphologies, crystallographic characteristics and formation processes of silicides and Laves phase precipitates in Nb-Ti-Si based alloys have been systematically investigated by high-resolution transmission electron microscopy (HRTEM) observation. Silicide precipitate of δNb11Si4 usually exhibits homogeneous distribution with acicular and tetrapod morphologies, possessing uniform orientation relationships (ORs) with Nbss. The occurrence of these morphologies might be caused by the symmetry decrease during the phase transformation of Nbss ⟶ δNb11Si4 + Nbss1. In some cases, the δNb11Si4 precipitates also adopt heterogeneous distribution with plate morphology and identical ORs as tetrapod precipitates with Nbss. The Laves phase precipitate, Cr2Nb, possesses C15 structure and contains high densities of stacking faults (SFs). It always forms along defects or Nbss/γNb5Si3 interfaces. The coupling precipitation behaviors and precipitation reactions of δNb11Si4, Cr2Nb and γNb5Si3 in the Nb-Ti-Si based alloys have been discussed.
Source: openaire · Quality: candidate unverified · Source record ↗
Research context
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
References (25)
Show source-provided references
1. Ultrahigh-temperature materials for jet engines10.1557/mrs2003.189 ↗
2. A review of very-high-temperature Nb-silicide-based composites10.1007/s11661-003-0269-8 ↗
3. Microstructure evolution and room temperature fracture toughness of an integrally directionally solidified Nb–Ti–Si based ultrahigh temperature alloy10.1016/j.scriptamat.2010.12.008 ↗
4. Eutectic evolution of directionally solidified Nb-Si based ultrahigh temperature alloys10.1016/j.ijrmhm.2017.11.001 ↗
5. Oxidation resistance and mechanical characterization of silicide coatings on the Nb-18Ti-14Si-9Al alloy10.1016/j.ijrmhm.2017.07.016 ↗
6. Solidification process and mechanical behavior of the Nb/Nb5Si3 two phase alloys in the Nb-Ti-Si system10.2320/matertrans.45.3264 ↗
7. Formation of multiple orientation relationships of Q precipitates in Al–Mg–Si–Cu alloys10.1016/j.scriptamat.2014.05.013 ↗
8. Orientation and diffraction patterns of δ-Ni2Si precipitates in Cu–Ni–Si alloy10.1016/j.jallcom.2012.12.154 ↗
9. Effects of alloying and high-temperature heat treatment on the microstructure of Nb-Ti-Si based ultrahigh temperature alloys10.1016/j.pnsc.2012.03.008 ↗
10. The Nb-Ti-Si ternary phase diagram: Evaluation of liquid-solid phase equilibria in Nb- and Ti-rich alloys10.1007/BF02647850 ↗
11. Characterization of silicide precipitates in primary Nb phase in Nb-10%Si in-situ composites10.1016/0956-716X(91)90199-B ↗
12. Study of three-phase equilibrium in the Nb-rich corner of Nb-Si-Cr system10.1016/j.intermet.2005.12.004 ↗
13. The Nb-Si (Niobium-Silicon) system
14. Thermodynamic description of the Cr–Nb–Si isothermal section at 1473 K10.1016/j.intermet.2005.08.013 ↗
15. Characterization of silicide precipitates in Nb–Si and Nb–Ti–Si alloys10.1080/01418610108216647 ↗
16. Characterization of a new Nb–silicide (δ-Nb11Si4) in Nb–Si binary systems10.1080/14786431003630827 ↗
17. Study of the role of Ta and Cr additions in the microstructure of Nb–Ti–Si–Al in situ composites10.1016/j.intermet.2005.10.005 ↗
18. Stacking faults and f.c.c. (γ) → h.c.p. (ε) transformation in 18/8-type stainless steel10.1016/0001-6160(72)90104-6 ↗
19. On orientation relationship of the Ti5Si3 precipitates in a TiAl alloy10.1016/S0921-5093(03)00507-0 ↗
20. Phase transition domains in Ca-based complex perovskite dielectric ceramics10.1111/j.1551-2916.2012.05302.x ↗
21. The f.c.c. to h.c.p. martensitic phase transformation in CoNi studied by TEM and AFM methods10.1016/S1359-6454(96)00184-X ↗
22. Polymorphism in the Laves-phase precipitates of a quinternary Nb–Mo–Cr–Al–Si alloy10.1016/j.scriptamat.2008.08.034 ↗
23. Effects of Cr and Hf additions on the microstructure and properties of Nb silicide based ultrahigh temperature alloys10.1016/j.msea.2015.04.003 ↗
24. Precipitation of γNb5Si3 in Nb-Si based ultrahigh temperature alloys10.1016/j.intermet.2018.04.007 ↗
25. Effect of high temperature treatments on microstructure of Nb-Ti-Cr-Si based ultrahigh temperature alloy10.1016/S1003-6326(11)60919-9 ↗