Study of the microstructure and thermomechanical properties of Mo/graphite joint brazed with Ti–Zr–Nb–Be powder filler metal
Source abstract
Abstract
The aim of this work was to braze molybdenum and graphite with Ti–40Zr–8.5Nb–1.5Be filler metal in order to demonstrate the possibility of its application for X-ray tube target brazing, further to investigate the joint microstructure using energy-dispersive X-ray spectroscopy (EDS), electron backscattered diffraction (EBSD), X-ray diffraction (XRD), and electron microscopy as well as to conduct shear and unbrazing tests. It is shown that the brazed joint consists of matrix from β-(Ti, Mo) solid solution, mixed ZrC and TiC carbide layers at the braze/graphite interface, and beryllides TiBe2 and MoBe2 located at the grain boundaries of β-(Ti, Mo). The presented data made it possible to propose a brazed joint formation mechanism and explain the concentration of beryllides at the grain boundaries during brazing, as well as the mixed carbide layer formation from the side of the graphite. The mechanical tests showed that Mo/graphite brazed joints have a shear strength of at least 28.0 ± 0.9 MPa. However, sample failure occurred through the graphite due to the graphite surface mechanical treatment and the presence of a ductile β-Ti phase in the joint. The evaluation of joint thermal properties was performed using unbrazing tests. The unbrazing temperature was 1882 °C, which was caused by formation of refractory phases during brazing. The microstructure study shows that unbrazing occurs through the β-(Ti, Mo) phase with grain boundaries and beryllides eutectic melting.
Source: openaire · Quality: candidate unverified · Source record ↗
Research context
OpenAlex topics: Advanced materials and composites · Intermetallics and Advanced Alloy Properties · Titanium Alloys Microstructure and Properties
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
References (31)
Show source-provided references
1. Wang J, Wang J, Li Y, Zheng D (2014) Progress of research on welding for molybdenum alloys. High Temp Mater Process 33:193–200. https://doi.org/10.1515/htmp-2013-003710.1515/htmp-2013-0037 ↗
2. Marques EAS, Da Silva LFM, Banea MD, Carbas RJC (2014) Adhesive joints for low- and high-temperature use: an overview. J Adhes 91:556–585. https://doi.org/10.1080/00218464.2014.94339510.1080/00218464.2014.943395 ↗
3. Behling R (2016) Modern diagnostic X-ray sources. CRC Press Taylor and Francis Group, London
4. Shmelev AN, Kozhahmet BK (2016) Use of molybdenum as a structural material of fuel elements for improving the safety of nuclear reactors. J Phys Conf Ser 781:1–5. https://doi.org/10.1088/1742-6596/781/1/01202210.1088/1742-6596/781/1/012022 ↗
5. Mazey DJ, English CA (1984) Role of refractory metal alloys in fusion reactor applications. J Less-Common Met 100:385–427. https://doi.org/10.1016/0022-5088(84)90078-X10.1016/0022-5088(84)90078-X ↗
6. Cermak M, Bahrami M, Kenna J (2018) Natural graphit sheet heat sinks: a review of the material properties, benifits, and challenges. In: IOP 34th SEMI-THERM Symposium. https://doi.org/10.1109/SEMI-THERM.2018.835735310.1109/SEMI-THERM.2018.8357353 ↗
7. Kostanovskii AV, Zeodinov MG, Kostanovskaya ME (2011) The thermal conductivity and emissivity of DE-24 graphite at temperatures of 2300–3000 k. Meas Tech 53(12):1380–1388. https://doi.org/10.1007/s11018-011-9670-710.1007/s11018-011-9670-7 ↗
8. Neuer G (1995) Spectral and total emissivity measurements of highly emitting materials. Int J Thermophys 16:257–265. https://doi.org/10.1007/BF0143897610.1007/BF01438976 ↗
9. Mirski Z (2011) Brazing a graphite composite to molybdenum alloy TZM using active copper-based filler metals with chromium additive. Arch Metall Mater 56:829–837. https://doi.org/10.2478/v10172-011-0092-y10.2478/v10172-011-0092-y ↗
10. Wen Y, Chen W, Ding B (2011) Diffusion welding interface reaction analysis of molybdenum and graphite. Xiyou Jinshu/Chinese J Rare Met 35:227–231. https://doi.org/10.3969/j.issn.0258-7076.2011.02.01310.3969/j.issn.0258-7076.2011.02.013 ↗
11. Dong L, Chen W, Hou L et al (2017) Metallurgical and mechanical examinations of molybdenum/graphite joints by vacuum arc pressure brazing using Ti–Zr filler materials. J Mater Process Technol 249:39–45. https://doi.org/10.1016/j.jmatprotec.2017.06.00710.1016/j.jmatprotec.2017.06.007 ↗
12. Smid II, Kny E, Kneringer G, Reheis N (1990) Influence of cyclic thermal loading on brazed composites for fusion applications. J Nucl Mater 171(1):165–171. https://doi.org/10.1016/0022-3115(90)90362-Q10.1016/0022-3115(90)90362-Q ↗
13. Traxler H, Arnold W, Knabl W, Rödhammer P (2003) Non-destructive evaluation of brazed joints by means of acoustic emission. J Acoust Emiss 20:257–264
14. Smid I, Croessmann CD, Salmonson JC (1991) Brazed graphite/refractory protection elements metal composites for first-wall. J Nucl Mater 179–181:169–172. https://doi.org/10.1016/0022-3115(91)90053-A10.1016/0022-3115(91)90053-A ↗
15. Wang KS, Tan JF, Hu P et al (2015) La2O3 effects on TZM alloy recovery, recrystallization and mechanical properties. Mater Sci Eng A 636:415–420. https://doi.org/10.1016/j.msea.2015.03.11410.1016/j.msea.2015.03.114 ↗
16. Pérez RJ, Sundman B (2003) Thermodynamic assessment of the Mo–Zr binary phase diagram. Calphad Comput Coupling Phase Diagrams Thermochem 27:253–262. https://doi.org/10.1016/j.calphad.2003.09.00310.1016/j.calphad.2003.09.003 ↗
17. Fedotov VT, Suchkov AN, Kalin BA et al (2014) Stemet solders for brazing of modern technology materials. Tsvetnye Met 1:32–37
18. Kalin BA, Fedotov VT, Sevrjukov ON et al (2007) Development of brazing foils to join monocrystalline tungsten alloys with ODS-EUROFER steel. J Nucl Mater 367–370:1218–1222. https://doi.org/10.1016/j.jnucmat.2007.03.22210.1016/j.jnucmat.2007.03.222 ↗
19. Kalin BA, Suchkov AN, Fedotov VT et al (2014) Brazing of the ITER first wall by a copper-based rapidly quenched ribbon-type filler metal. Fusion Sci Technol 65(2):212–221. https://doi.org/10.13182/FST13-66710.13182/FST13-667 ↗
20. Kalin BA, Suchkov AN, Fedotov VT et al (2016) Brazing of Be with CuCrZr-bronze using copper-based filler metal STEMET. Nucl Mater Energy 9:388–393. https://doi.org/10.1016/j.nme.2016.07.00410.1016/j.nme.2016.07.004 ↗
21. Suchkov AN, Fedotov VT, Sevryukov ON et al (2014) Brazing of metals, alloys and ceramics using rapidly quenched ribbon-type filler metal STEMET. Adv Sci Technol 88:156–161. https://doi.org/10.4028/www.scientific.net/ast.88.15610.4028/www.scientific.net/ast.88.156 ↗
22. Bachurina D, Suchkov A, Gurova J et al (2020) Joining tungsten with steel for DEMO: simultaneous brazing by Cu–Ti amorphous foils and heat treatment. Fusion Eng Des 162. https://doi.org/10.1016/j.fusengdes.2020.11209910.1016/j.fusengdes.2020.112099 ↗
23. Ivannikov AA, Sevryukov ON, Penyaz MA, Popov NS (2018) Development of nickel-based filler metal for producing high-strength joints in critical products from heat-resistant materials. Non-ferr Met 45:43–49. https://doi.org/10.17580/nfm.2018.02.0810.17580/nfm.2018.02.08 ↗
24. Svetogorov RD, Dorovatovskii PV, Lazarenko VA (2020) Belok/XSA diffraction beamline for studying crystalline samples at kurchatov synchrotron radiation source. Cryst Res Technol 55:1–6. https://doi.org/10.1002/crat.20190018410.1002/crat.201900184 ↗
25. Li Y, Katsui H, Goto T (2015) Phase decomposition of TiC–ZrC solid solution prepared by spark plasma sintering. Ceram Int 41:14258–14262. https://doi.org/10.1016/j.ceramint.2015.07.05510.1016/j.ceramint.2015.07.055 ↗
26. Zhang C, Zhao C, Yin H et al (2018) Thermodynamic Calculation of Phase Equilibria in the C–Mo–Zr System. J Phase Equilibria Diffus 39:766–777. https://doi.org/10.1007/s11669-018-0664-x10.1007/s11669-018-0664-x ↗
27. Bandyopadhyay D, Haldar B, Sharma RC, Chakraborti N (1999) The Ti–Mo–C (Titanium–Molybdenum–Carbon) system. J Phase Equilibria 20:332–336. https://doi.org/10.1361/10549719977033585710.1361/105497199770335857 ↗
28. Tokunaga T, Ohtani H, Hasebe M, Nakashima K (2007) Thermodynamic analysis of the BeMo binary phase diagram. J Jpn Inst Met Mater 71(2):187–189. https://doi.org/10.2320/jinstmet.71.18710.2320/jinstmet.71.187 ↗
29. Tokunaga T, Ohtani H, Hasebe M (2006) Thermodynamic evaluation of the phase equilibria and glass-forming ability of the Ti–Be system. J Phase Equilibria Diffus 27:83–91. https://doi.org/10.1361/105497106X9284410.1361/105497106X92844 ↗
30. Chen Y, Xu L, Liu Z (2006) Microstructures and properties of titanium alloys Ti–Mo for dental use. Trans Nonferr Met Soc China 16:824–828. https://doi.org/10.1016/S1003-6326(06)60308-710.1016/S1003-6326(06)60308-7 ↗
31. Murray JL (1981) The Mo–Ti (Molybdenum–Titanium) system. Bull Alloy Phase Diagrams 2:185–192. https://doi.org/10.1007/BF0288147610.1007/BF02881476 ↗