Abstract
Based on equilibrium in Al-REE and C-REE systems data, possibility of improvement carbon surface wetting with aluminum melt by their alloying with REE assumption is made. Aluminum melts MPG-6 graphite substrate flat surface wetting contact angle over time change data is presented. The experiments were carried out in a vacuum of 10 -2 Pa at temperatures up to 1100 °C. Melts of Al-10 wt% Ce, La, Nd, Sm; Al -3 wt% Y; Al-2.5 wt% Cu-3 wt% Ti and pure aluminum are used. It is shown that up to 1000 ° C wetting of the graphite surface by aluminum melts of these compositions does not occur, while the wetting angle is established in the first seconds and practically does not change with time. Above 1000 °C, wetting is improved, with the wetting contact angle of Al / 10 wt% Ce and Al / 10 wt% Sm being set in the first seconds and does not change thereafter, and in case of other melts decreases with time. It is most convenient at 1100 °C that the graphite surface is wetted with Al-10 wt% La, Al-3 wt% Y and Al-2.5 wt% Cu-3 wt% Ti melts. Aluminum melt and graphite substrate interface structure change data is presented. It is shown that in the interval from 1000 to 1100 °C interaction between melt and graphite intensifies, there is no significant dissolution of the graphite surface and aluminum carbide is formed. Melts Al / 10 wt% Sm and Al-2.5 wt% Cu-3 wt% Ti interact most active. It is concluded that the activity of the diffusion interaction, in particular the formation of aluminum carbide, is not directly related to the value of the contact angle of wetting. By calculating the Gibbs energy of alumina with REE and Y interaction, it is shown that the reaction can take place in direction of alumina to the metallic state by all elements reduction. The alloying elements used in experiments actually exert various impacts on a superficial tension and properties of an oxide film on the melt surfaces. The most actively superficial tension is changed by elements Y, Ti, Sm. Ti and Sm promote active formation of carbide of Al 4 C 3 aluminum. Lanthanum, obviously, influences a superficial tension a little, but promotes destruction of an oxide film that improves contact with a substrate.