Tracer diffusion of 65Zn, 110mAg and 88Y in QE22 metal matrix composite was measured by serial sectioning method at 646 to 728K. The volume diffusion coefficients of Zn and Ag in the non-reinforced alloy obeyed Arrhenius dependences:

Zn:     D (m2/s) = 9.5 x 10−5 exp[-125.3(kJ/mol)/RT]

Ag:     D (m2/s) = 6.0 x 10−3 exp[-153.5(kJ/mol)/RT]

In the case of the reinforced alloy, the effective diffusion coefficients Deff were obtained and interface diffusion coefficients Di in the interface boundaries were estimated. Both temperature dependences of Deff and Di were not of Arrhenius type. This feature was explained by the large difference in coefficients of the thermal expansion of the metal matrix and the reinforcement. In the case of 88Y diffusion in un-reinforced QE22 alloy, it was found that Y diffused along dislocations that acted as paths of rapid diffusion. The diffusivity of 88Y along dislocations, a2sDd, was estimated.

Tracer Diffusion of 65Zn, 110mAg and 88Y in QE22 Metal Matrix Composite. I.Stloukal, J.Čermák: Journal of Alloys and Compounds, 2009, 471[1-2], 83-9