APPLICATION OF BINARY INTERDIFFUSION MODELS TO GAMMA'(NI3AL) GAMMA(NI) DIFFUSION-BONDED INTERFACES/

Nickel and Ni3Al platelets have been joined by diffusion solid state b onding with two different sets of bonding parameters (applied pressure , temperature, duration). The gamma/gamma' interfaces obtained are exa mined and the transverse concentration profiles are determined. The ap plication of the classical binary interdiffusion models to this partic ular case is discussed, with increasingly refined hypotheses. A step-b y-step numerical calculation procedure is finally proposed which is ab le to account correctly for the measured profiles at the highest annea ling temperature (1100-degrees-C). To apply this procedure an experime ntal determination of the interdiffusion coefficients of Al in the pha ses gamma and gamma' as functions of the local concentration was made according to Matano's method.