ALLOYING BEHAVIOUR OF Mg, Ca,Y, La AND Ce IN Ni_3Al
Mg,Ca,Y,La和Ce在Ni3Al中的合金化行为

The alloying behavioUrs of Mg, Ca, Y, La and Ce in Ni3Al have been determined by X-ray diffraction measurement. It is found that Mg, Ca, Y, La and Ce atoms occupy the Al site in the L12structure. Besides, the additive atoms can further increase the long-range order degree for Ni3Al and this increment becomes more pronounced in the sequence of Mg, Ca, Y(La-Ce). Finally, the lattice parameters of the Ni3Al alloys with the alloy additions have also been determined. It is found that the lattice parameters of Ni3Al increase linearly with increasing elemental content. and this increment becomes more pronounced in the sequence of Ma, Ca. Y, La-Ce.