Abstract
Al-4Cu-xTiB2 (x=0, 2.5, 5, 10 wt %) in-situ composites were prepared by a mixed salt route technique. The composites were characterized by X-ray diffraction techniques, to confirm that no Al3Ti has formed, which is the advantage of mixed salt route technique. The scanning electron microscopy (SEM) analysis was carried out to determine the size distribution of TiB2 particles in the matrix. The results showed that there was no agglomeration of TiB2 particles throughout the matrix. The differential scanning calorimerty (DSC) studies were performed on the alloys as well as on composites to identify and characterize the precipitation sequence G.P.(I)→G.P.(II)/θ″→ θ′→ stable θ. To understand the precipitation kinetics of these precipitates in the presence of TiB2, the solutionized samples were heat treated at different temperatures of precipitation as indicated by the DSC Thermogram and subsequently quenched to room temperature to retain the precipitates that form at corresponding high temperatures. The TEM analysis was carried out to characterize the crystal structure and morphology of the different precipitates. The analysis suggested that the precipitation occur primarily on the dislocations in the matrix as well as in the TiB2 particle/Al-Cu matrix interface dislocations. It is believed that these dislocations are generated to accommodate the strain due to the difference in the coefficient of thermal expansion (CTE) of the TiB2 particles and the Al-Cu matrix. TEM results displayed that the interface contained large amount of dislocations which may possibly accelerate the precipitation sequence.
Similar content being viewed by others
References
Varma S K, Ponce J, Solis M, Andrews S and Salas D, Metall. Trans. 27A (1996) 2023.
Lu L, Lai M O and Chen F L, Acta Mater. 45 (1997) 4297.
Gerold V, Scripta Metall. 22 (1988) 927.
Mandal A, Maiti R, Chakraborty M and Murty B S, Mater. Sci. Eng. A386 (2004) 296.
Bartels C, Raabe D, Gottstein G and Huber U, Mater. Sci. Eng. A237 (1997) 12.
Salazar J M G and Barrena M I, Scripta Mater. 44 (2001) 2489.
Barlat F and Liu J, Mater. Sci. Eng. A257 (1998) 47.
Takeda M, Maeda Y, Yoshida A, Yabuta K, Konuma S and Endo T, Scripta Mater. 41 (1999) 643
Douin J, Donnadieu P, Epicier T, Dirras G F, Proult A and Silvain J F, Mater. Sci. Eng. A319–321 (2001) 270
Heinrich H, Vananti A and Kostorz G, Mater. Sci. Eng. A319–321 (2001)
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Charbhai, N., Murty, B.S. & Sankaran, S. Characterization of microstructure and precipitation behavior in Al-4Cu-xTiB2 in-situ composite. Trans Indian Inst Met 64, 117 (2011). https://doi.org/10.1007/s12666-011-0023-7
Received:
Revised:
Accepted:
Published:
DOI: https://doi.org/10.1007/s12666-011-0023-7