Nano-structured FGM of the system AlN-Ni

Conference · Fri Dec 31 04:00:00 EST 1993

OSTI ID:143707

Atarashiya, Koji ^[1]; Uda, Masahiro ^[2]

---

1. Hokkaido Univ., Sapporo (Japan)
2. Nisshin Steel Co. Ltd., Ichikawa (Japan)

A nano-structured FGM block of the system AlN-Ni was prepared by the method of powder metallurgy. The raw material i.e. an ultrafine particle, whose size was 200 nm in average diameter, was prepared by means of the arc-plasma processing that a vaporized substance was collected in a bag filter. A compositionally gradient mixture of a nickel ultrafine particle and an aluminum-aluminum nitride ultrafine particle was pressed (200 MPa) in a steel die, followed by two-step sintering (873K and 1273K) in flowing nitrogen under null pressure. In this process, the aluminum ultrafine particle reacted with nitrogen into aluminum nitride, but the nickel ultrafine particle did not react with any species. Thus, FGM block of the system AlN-Ni was completely accomplished. The techniques of an ultrafine-particle mixing and sintering without crystal-grain growth were invented. Generally speaking the preparation of FGM block especially in the metal nitride systems, needs an extremely high temperature and high pressure. However, in this work using an ultrafine particle, the nano-structured FGM block was easily prepared. The nitriding reaction of aluminum is exothermic. Thus, it considerably progresses by self-propagating high temperature synthesis (SHS) when it has once begun. The structure and the compositional distributions of the FGM block were examined by SEM and EDX. The physical properties of the FGM block such as density, thermal expansion coefficient and micro harness were measured.

• OSTI ID: 143707
• Report Number(s): CONF-930246--; ISBN 0-87339-251-5
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM NITRIDES
COMPOSITE MATERIALS
FABRICATION
MICROSTRUCTURE
NICKEL ALLOYS
PHYSICAL PROPERTIES