Experimental study on the contact angle formation of solidified iron–chromium droplets onto yttria ceramic substrates for the yttria/ferrous alloy system with variable chromium content

High-temperature contact angle experiments of liquid iron–chromium (Fe–Cr) drops onto ceramic yttria (Y2O3) substrates were carried out in order to investigate the wetting behavior of Y2O3 nano-particles in contact with an iron melt containing elemental Cr. Therefore, the correlation between the wetting behavior of the iron drop in contact with Y2O3 was studied for drops with variable Cr-content and for different powder grades. The wetting behavior of liquid binary Fe–Cr alloys in contact with the Y2O3 ceramic substrates at high temperature, was investigated using the static sessile drop method. The contact angle formed at the interaction interface was evaluated using static drop imaging and quantified using the method proposed by Bartlett and Hall [10]. Our experiments demonstrate that the wetting behavior of binary Fe–Cr alloys drops in contact with Y2O3 ceramics compared to other oxides such as Al2O3, is quite weak. Only for the test condition of pure electrolytic iron, i.e., without Cr addition, the contact angles (θcθc) were found to approach 90° or lower in all cases. Furthermore, a 9 wt% Fe–Cr alloy with silicon addition seems to improve the wetting behavior of liquid Fe–Cr drops in contact with Y2O3. Moreover, variation in powder purity seems to be of crucial importance.