Thermodynamic criterion for the formation of Laves phases in binary transition-metal systems

Abstract

A thermodynamic factor k is proposed to combine the deviation of atomic size ratio from the ideal value of 1.225 and the formation enthalpy, for the formation of Laves phases in binary transition-metal systems. Based on calculations for some 132 Laves phases, the conditions favouring the formation of the Laves phases are that k be greater than a critical value of 310 and formation enthalpy be larger than −130 kJ mol⁻¹. The calculated results are statistically in agreement with experimental observations reported so far in the literature.

Acknowledgements

Financial aid to the present study from the National Natural Science Foundation of China, The Ministry of Science and Technology (Grant No. 2000067201), and Tsinghua University is gratefully acknowledged.