[010] and [001] dislocations in laser clad NbAl<sub>3</sub> on Nb
Liu, Y.; Mazumder, J.; Robertson, B. W.; Tewari, S.; Liu, Y.; Center for Laser Aided Material Processing, Department of Mechanical and Industrial Engineering, University of Illinois at Urbana-Champaign; Department of Mechanical Engineering and Center for Materials Research, Analysi University of Nebraska-Lincoln; Mazumder, J.; Center for Laser Aided Material Processing, Department of Mechanical and Industrial Engineering, University of Illinois at Urbana-Champaign; Robertson, B. W.; Department of Mechanical Engineering and Center for Materials Research, Analysi University of Nebraska-Lincoln; Tewari, S.; Center for Laser Aided Material Processing, Department of Mechanical and Industrial Engineering, University of Illinois at Urbana-Champaign
Журнал:
Philosophical Magazine A
Дата:
1996
Аннотация:
AbstractThe dislocation structure, the dislocation dissociation and the Burgers vectors in laser clad NbAl<sub>3</sub> on a Nb substrate were investigated by transmission electron microscopy including weak beam contrast analysis by the g.b equals; 0 criterion, contrast width associated with edge and screw dislocations and high resolution electron microscopy (HREM). High densities of dislocations were observed in NbAl, grains. Contrast analysis by the g.b equals; 0 criterion and contrast width showed the presence of [010] and [001] dislocations. HREM revealed many ½[010] (partial) edge dislocations and ½[001] (partial) edge dislocations, suggesting the didocation dissociation modes: [010]→½[010] + ½[010] and [001]→½[001] +½[001]. It is suggested that such dislocations were introduced by the rapid cooling at high temperatures involved in the laser cladding process.
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