X-ray diffraction study of the effects of boron on occurrence of deformation faults in Ni3Al alloy

Ni₃Al and Ni₃Al alloys containing varying amounts of boron in L1₂ phase were prepared. All the samples were suitably annealed and then cold-worked by hand filing. X-ray diffraction data are collected on annealed and cold-worked samples. The deformation fault probabilities have been evaluated by two methods, viz. peak shift analysis of powder pattern X-ray reflections of annealed and cold-worked samples, and lattice parameter change between annealed and corresponding cold-worked samples. The values obtained by both the methods are in reasonable agreement. It has been found that the deformation fault probability of Ni₃Al and Ni₃Al containing boron alloys are very high compared to Ag and Cu base alloys. Further the deformation fault probability of Ni₃Al is more sensitive to boron addition. It has been found that at least 1.22 at. % of boron goes into the Ni₃Al lattice.