Journal ArticleDOI
The Nb-Ti-Si ternary phase diagram: Evaluation of liquid- solid phase equilibria in Nb-and Ti-rich alloys
TLDR
In this paper, phase equilibria in ternary Nb-Ti-Si alloys have been investigated using scanning electron micros-copy, XRD, and electron beam microprobe analysis.Abstract:
Phase equilibria in ternary Nb-Ti-Si alloys have been investigated using scanning electron micros-copy, XRD, and electron beam microprobe analysis. Alloys containing up to four phases, Nb(Ti)
5
Si
3
, Ti(Nb)
5
Si
3
, (Nb,Ti)
3
Si, and (Nb,Ti,Si) were directionally solidified using cold crucible Czochralski crystal growth. A broad range of Nb and Ti compositions were investigated for Si concentrations up to 35.0%. Microstructural and microchemical evidence provided a clear definition of the Nb-Ti-Si liquidus surface and indicate that the metal-rich end of the ternary phase diagram possesses two transition reactions: L + Nb(Ti)
5
Si
3
→ (Nb,Ti)
3
Si + Ti(Nb)
5
Si
3
L + (Nb,Ti)
3
Si → (Nb,Ti,Si) + Ti(Nb)
5
Si
3
The first of these transition reactions occurs at a composition of approximately Nb-66Ti-19Si, and probably at a temperature between 1600 and 1650 ‡C. The second of these transition reactions oc-curs at a composition of approximately Nb-76Ti-13.5Si and a temperature of approximately 1350 ‡C. No ternary eutectic was observed in the compositions that were investigated.read more
Citations
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Journal ArticleDOI
A study of the microstructures and oxidation of Nb–Si–Cr–Al–Mo in situ composites alloyed with Ti, Hf and Sn
TL;DR: In this article, the effects of alloying on the microstructures, solidification path, phase stability and oxidation kinetics of Nb ss /Nb 5 Si 3 base in situ composites of the Nb-Ti-Si-Al-Cr-Mo-Hf-Sn system have been investigated.
Journal Article
A study of the microstructures and oxidation of Nb-Si-Cr-AI-Mo in situ composites alloyed with Ti, Hf and Sn
Jie Geng,P Tsakiropoulos +1 more
Journal ArticleDOI
Mapping of the Nb-Ti-Si phase diagram using diffusion multiples
TL;DR: In this paper, a high-efficiency diffusion-multiple approach was employed to map the phase diagram of the Nb-Ti-Si ternary system, which is critical for the design of niobium silicide-based composites.
Journal ArticleDOI
On the oxidation mechanism of niobium-base in situ composites
TL;DR: In this paper, the metal and silicide composite (MASC) was studied in static oxidising condition in air at 815, 1100 and 1200 ǫ c. Pesting did not occur at 8 15 c before 100h of exposure while internal oxidation took place at each temperature and affected the Nb solid solution.
Journal ArticleDOI
Microstructural and mechanical characterization of Nb-based in situ composites from Nb-Si-Ti ternary system
TL;DR: In this paper, the effects of Si content, Ti addition and strain rates on the sample microstructural characterization, flexural strength, fracture toughness, quasi-static compressive deformation and failure processes were investigated.
References
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Book
Binary alloy phase diagrams
TL;DR: Binary Alloy Phase Diagrams, Second Edition, Plus Updates, on CD-ROM offers you the same high-quality, reliable data you'll find in the 3-volume print set published by ASM in 1990.
Journal ArticleDOI
High-temperature refractory metal-intermetallic composites
Melvin Robert Jackson,Bernard Patrick Bewlay,Raymond Grant Rowe,David William Skelly,H. A. Lipsitt +4 more
TL;DR: In this paper, toughness, oxidation, and rupture behaviors of present-generation refractory metal-intermetallic composites are compared to the performance requisites necessary to make these materials a competitive choice for the jet engine turbine environment of the future.
Journal ArticleDOI
The Nb-Si (Niobium-Silicon) system
Alloy phase diagrams
TL;DR: In this article, a Symposium on Alloy Phase Diagrams was held, focusing on crystal phase transformations, order-disorder transformations, crystal lattices, metallic glasses, metastable states, solubility, and binary alloy systems.