Abstract
This paper aims an investigation of the microstructure and crystallographic structure as well as the thermal stability of Al–Ti–Nb formed by selective electron beam surface alloying. The fabrication of the samples has been carried out using circular sweep mode, as two velocities of the sample movement have been chosen: V1 = 1 cm/s and V2 = 0.5 cm/s. The studied microstructure and crystallographic structure have been investigated by X-ray diffraction (XRD) and Scanning electron microscopy (SEM) respectively. The thermal behavior of the obtained surface alloys are evaluated by the coefficient of thermal expansion (CTE) which has been evaluated by neutron diffraction measurements at high temperature. The results show that in the earlier stages of formation, the microstructure of the intermetallic phase is mainly in the form of coarse fractions, but at the following moments they dissolve, forming separated alloyed zone and base Al substrate as the alloyed zone consists of fine (Ti,Nb)Al3 particles dispersed in the Al matrix with small amount of undissolved intermetallic fractions. Formation of preferred crystallographic orientation as a function of the speed of specimen motion has not been observed. The performed neutron diffraction measurements show that the lattice parameters of the obtained intermetallic (Ti,Nb)Al3 are less upshifted in comparison to pure Al. It has been found that the aluminium lattice is much more unstable at high temperatures than that of the intermetallic phase. The CTE for the intermetallic phase is 8.70 ppm/K for a axis and 7.75 ppm/K for c axis respectively while considering Al it is 12.95 ppm/K.
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References
H. Clements and S. Mayer, Adv. Eng. Mater. 15 (4), 191 (2013).
F. Appel, J. Paul and M. Oehring, Gamma Titanium Aluminides: Science and Technology (Wiley VCH, 2011).
D. Dimiduk, Mater. Sci. Eng., A 263 (2), 281 (1999).
A. Almeida and R. Vilar, Rev. Metal. (Madrid, Spain) 34 (2), 114 (1998).
W. Jiru, M. Sankar and U. Dixit, J. Mater. Eng. Perform. 25, 1172 (2016).
U. Wendt, S. Settegast and I.-U. Grodrian, J. Matter. Sci. Lett. 22, 1319 (2003).
A. Almeida, P. Petrov, I. Nogueira and R. Vilar, Mater. Sci. Eng., A 303, 273 (2001).
L. Jacobson and J. McKittrick, Mater. Sci. Eng., R 11, 355 (1994).
P. Petrov, Vacuum 48 (1), 49 (1997).
C. Draper and J. Poate, Int. Met. Rev. 30 (2), 85 (1985).
C. Reip and G. Sauthoff, Intermetallics 1, 159 (1993).
P. Petrov, S. Valkov, R. Lazarova, S. Parshorov, R. Bezdushnyi, D. Dechev and N. Ivanov, J. Mater. Sci. Technol. (Sofia, Bulg.) 24 (2), 92 (2016).
S. Valkov, P. Petrov, R. Lazarova, R. Bezdushnyi and D. Dechev, Appl. Surf. Sci. 389, 768 (2016).
R. Vilar, O. Conte and S. Franko, Intermetallics 7, 1227 (1999).
S. Valkov, P. Petrov and R. Lazarova, Proc. SPIE 10226, 102260I (2017). doi 10.1117/12.2262352
R. E. Reed-Hill and R. Abbachian, Physical Metallurgy Principles (PWS Publ., Boston, MA, 1994).
D. R. Ackerland, The Science and Engineering of Materials (PWS Engineering, Boston, MA, 1985).
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Valkov, S., Neov, D., Bezdushnyi, R. et al. Study of the Microstructure, Crystallographic Structure and Thermal Stability of Al–Ti–Nb Alloys Produced by Selective Electron Beam Alloying. J. Surf. Investig. 12, 436–441 (2018). https://doi.org/10.1134/S1027451018030187
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DOI: https://doi.org/10.1134/S1027451018030187