Microstructure and mechanical properties of rapidly solidified NiAl-Cr(Mo) eutectic alloy doped with trace Dy

The Ni-33Al-28Cr-6Mo eutectic alloy doped with trace Dy was prepared by conventionally casting and injection casting techniques. Microstructure examination revealed that with the addition of Dy, the Ni5Dy phase precipitated along the NiAl and Cr(Mo) phases interface in the intercellular region. Compared with the conventional-cast alloy, the microstructure of injection-cast alloy got well optimized, which was characterized by the thin interlamellar spacing, high proportion of eutectic cell area and fine homogeneous distributed Ni5Dy phase. Furthermore, the mechanical tests showed that the room temperature mechanical properties of the injection casting alloy improve significantly. (C) 2008 Elsevier B.V. All rights reserved.