High-temperature wetting and interfacial interaction between liquid Al and TiB 2 ceramic L. Xi • I. Kaban • R. Nowak • B. Korpala • G. Bruzda • N. Sobczak • N. Mattern • J. Eckert Received: 3 June 2014 / Accepted: 4 September 2014 / Published online: 24 January 2015 Ó Springer Science+Business Media New York 2015 Abstract The wetting behaviour and interfacial interac- tions between liquid Al and TiB 2 ceramic have been studied by the sessile drop technique in the temperature range from 700 to 1400 °C. At about 800 °C, liquid Al starts to wet TiB 2 and at about 1000 °C it completely spreads over the ceramic. Al 3 Ti and Al 2 O 3 are found to be the main phases precipitating at the interface. Starting from 1000 °C, liquid Al either fill pores or penetrates along the grain boundaries of the TiB 2 ceramic. Scanning electron microscopy analysis of the interfaces evidences that the TiB 2 grains remain intact after the aluminium melt/ceramic interaction even at 1400 °C. Introduction Diboride compounds of the group IV transition metals (TiB 2 , ZrB 2 , and HfB 2 ) are characterised by very high melting temperatures, superior hardness, and chemical inertness to corrosive substances [1, 2] and are, therefore, very important for applications under extreme conditions. In particular, TiB 2 with a melting temperature of about 3200 °C[3] and a theoretical density of 4.52 g/cm 3 [1] is interesting as an electrode material in the aluminium industry, as temperature or wear protective coating or as constituent of light-weight composites for aerospace, automotive and defence applications [4–6]. Besides, tita- nium diboride is used for the microstructure refinement of cast Al-based alloys [7–9]. In general, processing and properties of these materials are mainly determined by the following features: (i) stability of TiB 2 in contact with a liquid metal or alloy; (ii) wetting, spreading and infiltration behaviour of a metallic melt in contact with TiB 2 ceramic; (iii) new phases which may be formed at the melt/TiB 2 interface. High-temperature interaction in the Al–TiB 2 system has been investigated in various works so far (e.g. see Refs. [10–16] ). Although a good wetting of TiB 2 by liquid aluminium has been generally reported, the contact angle values as well as the temperatures are rather scattered. For example, Rhee [10] studied the wetting of dense TiB 2 (98.5 % of the theoretical density) by liquid aluminium under high vacuum (better than 2.7 9 10 -7 mbar) by the sessile drop technique. After keeping the system for at least 30 min at a given temperature, the equilibrium contact angle reached about 90° at 710 °C and about 60° at 840 °C [10]. Samsonov et al. [11] did not observe any wetting of TiB 2 substrates (about 95 % of the theoretical density) by liquid aluminium at 900–1000 °C in vacuum, whereas the contact angle decreased to about 75° and to about 30° after 20 min of isothermal heating at 1150 °C and at 1250 °C, respectively. Weirauch et al. studied the wetting behaviour of liquid Al on different TiB 2 substrates at a constant temperature of 1025 °C[12]. It was reported that the initial contact angle of about 120°–140° for liquid Al on a pol- ished TiB 2 substrate (99.8 % or better purity, 99.7 % of the L. Xi (&)  I. Kaban  N. Mattern  J. Eckert IFW Dresden, Institute for Complex Materials, P.O. Box 270116, 01171 Dresden, Germany e-mail: l.xi@ifw-dresden.de I. Kaban  J. Eckert TU Dresden, Institute of Materials Science, 01062 Dresden, Germany R. Nowak  B. Korpala  G. Bruzda  N. Sobczak Center for High-Temperature Studies, Foundry Research Institute, Zakopianska Str. 73, 30-418 Cracow, Poland N. Sobczak Motor Transport Institute, Jagellonska Str. 80, Warsaw, Poland 123 J Mater Sci (2015) 50:2682–2690 DOI 10.1007/s10853-015-8814-6