PROCESSES OF ATOMIC ORDERING IN MICROCRYSTALLINE TERNARY ALLOYS BASEDON NI3MN

Stable and metastable phases are formed in the production of microcrys talline alloys by quenching from the melt. The atomic ordering of thes e phases has not been completely studied until recently. In ternary sy stems with two ordered phases having different Kurnakov temperatures T -K (the temperature of;he order-to-disorder transition), for example, an intermetallic compound and an ordinary superstructure, preferential formation of a superstructure with a high T-K is expected and the all oying atoms occupy vacancies in the ordered lattice of the intermetall ic compound. The present work concerns neutron diffraction analysis of atomic ordering in the ternary systems Ni3Mn - Ni3Al, Ni3Mn - Ni3Si, and Ni3Mn - Ni3Ti.