Dislocations in the ductile B2 YAg intermetallic compound

The Burgers vectors of dislocations in plastically deformed, polycrystalline B2 YAg intermetallic compound were determined by transmission electron microscopy using the g.b = 0 analysis. Both < 0 0 1 > and < 1 1 1 >-type dislocations were observed in specimens that had been deformed in tension; the < 0 0 1 > dislocations were more abundant. An active < 1 1 1 > slip direction satisfies the von Mises requirement of five independent slip systems that are necessary for a polycrystal to undergo a general homogeneous strain. Thus, < 1 1 1 > slip in YAg appears to be a key contributor to the high ductility and high fracture toughness previously reported for polycrystalline YAg. (C) 2009 Elsevier B.V. All rights reserved.