Please use this identifier to cite or link to this item:
|Type:||Artigo de periódico|
|Title:||Precipitation and dissolution of Co granules in CuCo alloys: Reverse effects of Joule heating|
|Author:||da Silva, FCS|
|Abstract:||Measurements of resistance R versus electrical current I were performed during annealing of melt-spun pure Cu and Cu90Co10 ribbons using linearly varying current Joule heating. Typical results of Cu90Co10 samples show three characteristic stages. For low applied currents (I < 4.0 A), a metallic behavior is observed and compared with pure Cu samples. Precipitation is the dominant process for intermediate currents (5.0 A < I < 9.0 A). Re-solution of precipitated Co back to Cu matrix appears for high current values (I > 9.0 A). Competition between precipitation and dissolution of Co granules depends also on the cooling rates, and we observed that it is possible to freeze high temperature off-equilibrium configurations down to room temperature after an appropriate quenching. Experimental annealing conditions were simulated using the Monte Carlo-Metropolis method, with Kawasaki dynamics of diffusing atoms, to study the kinetics of transformations in the Cu-Co system. Simulations show that precipitation and re-solution competition occurs as functions of both temperature and time. A relationship between simulated Co atoms configuration and resistance measurements is made. (C) 1999 American Institute of Physics. [S0021-8979(99)09723-6].|
|Editor:||Amer Inst Physics|
|Appears in Collections:||Unicamp - Artigos e Outros Documentos|
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.