Physical properties of Al–R melts

In this work, we present experimental data of physical properties (viscosity, surface tension, magnetic susceptibility and electroresistivity) studies for Al–R (R = Ce, Pr, Sm, Gd, Dy, Ho, Yb and Y) alloys and first intermetallic compounds from aluminum side, Al11R3 (Al3R). All properties were measured during heating up to 2000 K and the following cooling down under helium atmosphere. The main results are: (1) the electronic characteristics of the objects are in good correlation with R positions in the periodic table, but rather lower than for pure elements. The conclusion is that through all investigated temperature range, the rare-earth elements have partly covalent but not only metallic states; (2) all the melts remain strongly microheterogeneous even at high overheatings above liquidus. The existence of associations with Al2R type is highly probable here. Some destruction of these associations takes place with increasing temperature above melting point at the composition of Al2R compound. However, the transformation into true solution state is somewhere above 1900 K. To check the idea, the thermodynamic modeling of the melts was performed. It was shown that associates with Al2R type are stable up to 2000 K.