Role of Si in the wetting of TiC by Al

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Role of Si in the wetting of TiC by Al Rui-Fen Guo1,2, Ya Wang1, Yun-Hai Ma2, and Ping Shen1,* 1

Key Laboratory of Automobile Materials (Ministry of Education), School of Materials Science and Engineering, Jilin University, No. 5988 Renmin Street, Changchun 130022, People’s Republic of China 2 College of Biological and Agricultural Engineering, Jilin University, Changchun, People’s Republic of China

Received: 15 June 2020

ABSTRACT

Accepted: 22 October 2020

The wettability of TiC by Al alloys plays a key role in the preparation of TiCreinforced Al matrix composites. Despite some prior work has been reported on this issue, few studies concern the influence of Si. In this work, the effects of Si concentration (0, 7Si, 12Si in wt%) and temperature on the wettability in the Al/ TiC system were investigated by a dispensed sessile drop method at 1073–1173 K in a high vacuum. The initial contact angles were 103°–105°, almost independent of temperature, while the final contact angles decreased with increasing temperature. Formation of an Al4C3 phase and adsorption of the displaced [Ti] at the solid–liquid interface were two primary driving forces for the wetting improvement. On the other hand, an increase in the Si concentration greatly weakened the stability of TiC in Al melt, promoted the formation of Al4C3, and thus led to the faster spreading of the liquid in the early wetting stage. However, as the interfacial reaction progressed, the displaced [Ti] was bound by the Si in the Al melt due to their strong chemical affinity, thus weakening the adsorption effect of [Ti] for the wetting. As a consequence, the final apparent wettability of the Al–Si/TiC system was even worse than that of the Al/TiC system, and this situation was more prominent with increasing Si content.

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Springer Science+Business

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Introduction TiC is an important reinforcement for the preparation of the Al matrix composites due to its good mechanical and physicochemical properties [1, 2]. As known, when a liquid casting or infiltration route is employed, the wettability of ceramic by molten metal

Handling Editor: Philip Nash.

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https://doi.org/10.1007/s10853-020-05496-4

and their reactivity play a crucial role in determining the ease of processability and the quality of the final product. Therefore, a comprehensive understanding of the wettability and reactivity between Al or Al alloy and TiC is of vital importance. Wetting of TiC by molten Al has been widely investigated and strong temperature dependence was reported [3–6]. At temperatures below 1200 K, the

J Mater Sci

oxide film covering the Al surface inhibited an intimate Al–TiC contact, leading to large contact angles. As temperature increased, a transition from nonwetting to wetting occurred due to the disruption of the oxide film as a result of a self-cleaning reaction [4Al(l) ? Al2O3(s) = 3Al2O(g)] [7–9] in a high vacuum. Moreover, Froumin et al. found that the wettability of TiCx by Al was s