Effect of titanium on the wettability between Fe-P-Ti alloy and Al2O3 substrate

It is of significance that the wettability between the molten alloy and the Al₂O₃ affects the inclusion removal, nozzle clogging and refractory erosion. In the present work, the wettability between the Al₂O₃ substrate and Fe–P–Ti alloys with different Ti content was investigated by using the sessile droplets method. The interfacial characteristics were investigated by scanning electron microscope (SEM). The contact angles between the sintered Al₂O₃ substrate and Fe–P–Ti alloys with 0, 0.05, 0.10 and 0.15 ​wt% Ti are 100.1°, 97.3°, 94.5° and 90.5°, respectively. The oxidation of [Al] and [Ti] in the molten alloys leads to the formation of the oxides on the droplets. With the increase of Ti content in the Fe–P–Ti alloys, the formed oxides change from Al₂O₃ to Ti-containing oxides. The reaction between [Ti] and Al₂O₃ substrate in the interface results in the formation of Ti-containing oxides. The quantity of the interfacial oxides increases with the increase of Ti content in the alloys. As a result, the synergetic effect of the formation of the interfacial products and the oxides on the surface of droplets leads to the decrease of the contact angles between the Al₂O₃ substrate and Fe–P–Ti alloys due to the increase of Ti content.