SHORT-CIRCUIT DIFFUSION IN NI-AL ALLOYS

The tracer grain boundary diffusivity, P, of nickel in polycrystalline Ni-B, Ni-9 at% Al-B and in NiAl-B intermetallic has been measured wit h boron concentrations x(B) up to 0.3 at% B. The measurements were don e by the residual activity method in the temperature interval from 773 to 1073 K. It was observed that P decreases with growing concentratio n of boron in Ni-B and Ni-9 at% Al-B. This behaviour is similar to the dependence of P on x(B) in Ni3Al, reported in our previous paper. In boron-doped NiAl intermetallic, on the other hand, P does not depend o n x(B). (C) 1997 Elsevier Science Limited. All rights reserved.