Development of microstructure in mechanically alloyed NiAl

Conference · Tue Aug 01 04:00:00 EDT 1995

OSTI ID:78378

Pyo, S G; Kim, N J ^[1]

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1. Pohang Univ. of Science and Technology (Korea, Republic of)

NiAl intermetallic powder has been synthesized by mechanical alloying of elemental powders in an attritor mill using controlled atmosphere. The mechanically alloyed (MA) powders were consolidated by vacuum hot pressing (VHP), resulting in a material which was fully dense. Analytical transmission electron microscopy has been used to understand the development of microstructure with processing. The dispersoid particles present are mostly Al{sub 2}O{sub 3} with small amount of AlN. It has been shown that morphology of the dispersoid particles are not uniform and the larger dispersoid particles are located mostly along the grain boundaries with the dispersoid-free zones near them. Coarsening behavior of the dispersoid particles is different depending on their locations, i.e., within the grain or along the grain boundaries. The accelerated coarsening of dispersoids along the grain boundaries occurs concurrently with that of the grains and the formation of dispersoid-free zones (DFZs) are observed along the grain boundaries. It is suggested that this abnormal dispersoid coarsening and the formation of DFZ are due to the coupled migration of dispersoids and grain boundaries.

• OSTI ID: 78378
• Report Number(s): CONF-941144--; ISBN 1-55899-265-0
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
ALUMINIUM NITRIDES
ALUMINIUM OXIDES
HEAT RESISTING ALLOYS
INTERMETALLIC COMPOUNDS
MICROSTRUCTURE
MILLING
NICKEL ALLOYS