The structures, dissociation and Burgers vectors of dislocations in Al3Nb which had been laser-clad onto a Nb substrate were investigated by means of transmission electron microscopy. This involved contrast analysis using the g•b = 0 criterion, and the contrast width that was associated with edge and screw dislocations. High densities of dislocations were observed in Al3Nb grains. Contrast analysis, using the g•b = 0 criterion and contrast width, revealed the presence of [010] and [001] dislocations. High-resolution electron microscopy revealed the presence of many ½[010] (partial) edge dislocations and ½[001] (partial) edge dislocations. This suggested that the dislocation modes:

[010]  ½[010] + ½[010]

and

[001]  ½[001] + ½[001]

were operative. It was suggested that such dislocations were introduced by rapid cooling at the high temperatures which were involved in the laser-cladding process.

[010] and [001] Dislocations in Laser Clad NbAl3 on Nb. Y.Liu, J.Mazumder, B.W.Robertson, S.Tewari: Philosophical Magazine A, 1996, 73[3], 557-66