THE INFLUENCE OF QUENCHED-IN AND THERMAL VACANCIES UPON SHORT-RANGE-ORDER FORMATION IN A Ni 11.4 AT % Cr ALLOY

Abstract

Different authors have reported upon resistivity anormalities after thermal treatment of alloys with at least one component being a transition metal. The abnormal increase in the resis- tivity vs. temperature curve was attributed to the formation of the so-called (c K ))-state of the alloys. In the present contribution the alloy Ni 11.4 at % Cr has been re-investigated. The shapes of the measured isochronal and isothermal curves are very similar to those found on an Au 15 at % Ag alloy. For this reason the analysis based on vacancy diffusion and short-range-order formation, as developed for the Au-Ag-alloy has been applied also to the NiCr experiments. Also here self- consistent values for the enthalpies of formation and migration of vacancies as well as the activation enthalpy of selfdiffusion could be determined in good agreement to the values found in literature.