Diffusion Parameters and Growth Mechanism of Phases in the Cu-Sn System
William J. Boettinger, C Ghosh, A Paul
The tracer diffusion coefficients of the elements as well as the integrated interdiffusion coefficients are measured for the Cu(sub3)Sn and Cu(sub6)Sn(Sub5) intermetallic compounds using incremental diffusion couples. The activation energies are determined for the former between 225(superscript oC) and 350 (superscript oC) and for the latter between 150 (superscript oC) and 200 (superscript oC). Sn is found to be a slightluy faster diffuser in Cu(sub6) and Sn(sub5) and Cu is found to be the faster diffuser in Cu(sub3)Sn. The results from the incremental couples are used to rpedict the behavior of a Cu/Sn couple where simultaneous growth of the phases occurs. The waviness at the Cu(sub3Sn/Cu(sub6)Sn(Sub5) interface and the possible reasons for not finding bifurcation of the Kirkendall marker plane in the Cu/Sn couple are discussed.