The paper examines how the structure and phase composition of Ti-Al-B alloys evolve at various consolidation stages in the composite powder mechanochemical synthesis and subsequent sintering under pressure. Two powder alloys with different boron content are studied. The amount of aluminum in both initial powder mixtures is the same and corresponds to TiAl. The content of boron is selected so as to form an aluminide matrix with 10 and 25 vol.% borides. It is established that phases form in the mechanochemical synthesis in the following sequence: Ti + Al → Ti (Al) → TiAl3 and Ti3Al → TiAl. Titanium borides are formed simultaneously with TiO2 and TiAl or after them, which confirms that these processes are interrelated. The mechanochemical synthesis for 12 hours in a planetary-ball mill results in the formation of micron particles that have agglomerated or conglomerated (sometimes layered) composite structures. X-ray analysis is used to study the phase evolution of Ti-Al-and Ti-Al-B alloys. It is shown that the presence of boron in mechanical alloying reduces the degree of amorphization and promotes the formation of fine crystalline structure. In addition, the presence of boron prevents the formation of metal oxides and a number of intermetallides. It is established that the sintered dispersion-hardened Ti-Al-B material consists of an aluminide matrix with micron and submicron inclusions of borides. The increase in boron content leads to a higher amount of boride inclusions. As a result, the distance between them decreases and thus microhardness increases.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
S. L. Kamre, P. Sadler, L. Christodoulou, and D. E. Larsen, “Room-temperature strength and deformation TiB2-reinforsed near-γ-titanium aluminides,” Metal. Mat. Trans. A, 25A, 2181–2196 (1994).
K. Brand, C. Suryanarayana, B. F. Kieback, and F. H. Froes, “Phase formation during mechanical alloying and hot isostatic pressing of Ti-Al-B powders,” in: Advances in Powder Metallurgy and Particulate Materials (June 6–21, 1996, Washington, USA), Vol. 1, Washington DC (1996), pp. 2.49–2.58.
H. B. Lee, S. H. Kim, S. W. Kang, and Y. H. Han, “Characterization nanocomposite consolidated by spark plasma sintering,” British Ceramic Trans., 102, No. 6, 231–236 (2003).
W. A. Schneider, T. E. Quested, A. L. Greer, and P. S. Cooper, “A comparison of the family of AlTiB refiners and their ability to achieve a fully equiaxed grain structure in DC casting,” in: The Minerals, Metals and Materials Society (2003), pp. 1–9.
A. L. Greer, A. M. Bunn, A. Tronche, et al., “Modeling of inoculation of metallic melts: application to grain refinement of aluminum by Al-Ti-B,” Acta Mat., 48, 2823–2835 (2000).
V. E. Oliker, V. S. Kresanov, V. L. Sirovatka, et al., “Mechanochemical synthesis, structure and properties of alloys based on the system Ti-Al,” Powder Metal. Met. Ceram., 42, No. 1–2, 38–50 (2000).
X-Ray Diffraction Date Cards, ASTM, Philadelphia (1975).
P. F. Plyukhin, A. F. Belyaev, Yu. V. Frolov, etc., Combustion of Powder Metals in Active Media [in Russian], Nauka, Moscow (1972), p. 294.
C. Suryanarayana, “Mechanical alloying and milling,” Prog. Mat. Sci., 46, 1–184 (2001).
L. H. Chiu, D. C. Nagle, and L. A. Bonney, “Thermal analysis of self-propagations high-Temperature reactions in titanium, boron, and aluminum powder compacts,” Metal. Mat. Trans. A, 30A, 781–789 (1999).
V. O. Lavrenko, S. O. Firstov, A. D. Panasyuk, et al., “Corrosion of titanium-aluminum intermetallides,” Powder Metall. Met. Ceram., 42, No. 3–4, 184–188 (2003).
F. J. J. Van Loo and G. D. Riek, “Diffusion in titanium-aluminum system. I. Interdiffusion between solid Al and Ti or Ti-Al alloys,” Acta Met., 21, No. 1, 61–71 (1973).
F. J. J. Van Loo and G. D. Riek, “Diffusion in titanium-aluminum system. II. Interdiffusion in the composition range between 25–100 at.% Ti,” Acta Met., 21, No. 1, 73–84.
G. P. Jones and J. Pearson, “Factors affecting the grain-refinement of aluminum using titanium and boron additives,” Metall. Trans., 7B, 223–234 (1976).
G. K. Sigworth, “The grain refining of aluminum and phase relationships in the Al-Ti-B system,” Acta Met., 15A, No. 2, 277–282 (1984).
G. V. Samsonov (ed.), Physical and Chemical Properties of Oxides: Handbook [in Russian], Metallurgiya, Moscow (1969), p. 455.
G. V. Samsonov and I. M. Vinnitskyi, Refractory Compounds [in Russian], Metallurgiya, Moscow (1976), p. 557.
Author information
Authors and Affiliations
Corresponding author
Additional information
Translated from Poroshkovaya Metallurgiya, Vol. 47, No. 9–10 (463), pp. 55–68, 2008.
Rights and permissions
About this article
Cite this article
Oliker, V.E., Sirovatka, V.L., Gridasova, T.Y. et al. Mechanochemical synthesis and structure of Ti-Al-B-based alloys. Powder Metall Met Ceram 47, 546–556 (2008). https://doi.org/10.1007/s11106-008-9057-8
Received:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11106-008-9057-8