Wetting behavior and reactivity of liquid Si-10Zr alloy in contact with Glassy Carbon and SiC

Currently, the main challenges facing the development of advanced MMCs and CMCs are related to the costly fabrication of tailored and performant interfaces microstructures for highly demanding applications, to optimize the fabrication process and to identify ad-hoc the metal matrix for each application.

In designing advanced refractory composites, reactive infiltration of liquid Si-enriched Si-Zr alloys into C- or SiC-based preforms might be a cost-less alternative.

Fundamental investigations on interfacial phenomena between liquid Si-Zr alloys in contact with C and SiC substrates, are key steps for optimizing liquid assisted processes (reactive infiltration). Targeted wettability and reactivity studies can easily provide useful indications for solving many technological problems affecting the reactive infiltration mechanisms, such as pore closure/narrowing phenomena.

Aiming to ‘‘mimic’’ the conventional operating conditions imposed, the contact heating sessile drop method was applied to better understand of the interaction phenomena occurring between the liquid Si-10%atZr alloy in contact with glassy carbon and SiC substrates. Specifically, the contact angle values as a function of time were measured over the temperature range of T = 1354-1500°C under an Ar atmosphere.

The interaction phenomena observed in terms of wettability and spreading kinetics are temperature and time-dependent.

The kinetics of SiC crystal growth at the interface was analyzed and related to the processing parameters (i.e. T and t). In both cases, the SiC crystals growth and their packaging phenomenon, is favored at higher temperatures and longer time of contact with the substrate. 

At the Si-10%atZr alloy/GC and Si-10%atZr alloy/SiC intefaces, reactive and no-reactive wetting mechanisms, respectively, were observed.

Acknowledgements

This work was supported by National Science Center of Poland in the framework of “SIC-WIN: Reactivity of SI-alloy/C-material system: Wetting vs INfiltration project (G.A. UMO-2016/23/P/ST8/01916), POLONEZ-3. It received funding under the EU Research and innovation funding programme "Horizon 2020" G.A. no 665778 for the Marie Skłodowska-Curie actions.