Mechanical behavior of diffusion-bonded bicrystals of boron-doped Ni3Al

We report the results of mechanical tests on a Σ5 (210) [001] symmetric tilt boundary in a diffusion-bonded artificial bicrystal of boron-doped Ni0.76Al0.24. We find that heat treatments designed to induce boron segregation appear to strengthen the boundary, whereas heat treatments designed to discourage segregation weaken it. However, the bonding of the bicrystal is non-uniform, and this introduces significant uncertainty into our data because of our very small sample size (six). Nevertheless, we conclude that such artificial bicrystals offer considerable flexibility in the study of the effects of orientation on boundary strength and solute segregation in nickel aluminides, as well as in other metals and intermetallics.