The distribution of boron in AlRu: Effect on ductility and toughness

Boron strongly enhances toughness and ductility in the high-temperature intermetallic compound AlRu, but the source of the improvement is unknown. Nuclear mapping of the location of the boron has been done using the 10B(n, (alpha))^7Li reaction and CR-39 as a nuclear-track detector. It is found that in the alloys for which boron has a beneficial effect the solute is located at random - in contrast to the case of boron in Ni3Al, where it preferentially occupies locations in grain boundaries. Thus, the mechanisms differ in the two intermetallics.