Application of wetting to fabrication of boron nitride/aluminum composites

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

OSTI ID:143655

Fujii, Hidetoshi; Nakae, Hideo; Okada, Koji ^[1]

---

1. Waseda Univ., Tokyo (Japan). Dept. of Materials Science and Engineering

The focus of this paper is the establishment of a cheap and easy method of manufacturing metal matrix composites by optimizing the wetting and structural properties of the materials used, (i.e. boron nitride/aluminum). Although aluminum is one of the most prominent metals in the fabrication of metal matrix composites, the oxidation of aluminum prevents us from precisely measuring the wetting of ceramics. Therefore, an improved sessile drop method was devised to prevent the oxidation of the aluminum. Using this method, the contact angle between h-BN (hexagonal-BN) and molten Al was measured in a purified He+3%H{sub 2} atmosphere and in a very high vacuum in a temperature range of 1173-1373K. The contact angle progressed through four phases similar to typical ceramics. However, the contact angle became 0{degree} in phase 4 at and over 1273K. This contact angle is extremely lower than the contact angles for typical ceramics and it indicates that h-BN is an ideal material for manufacturing a metal matrix composite from the viewpoint of wetting. It was also confirmed that AlN was produced at the solid/liquid interface and caused the contact angle to decrease to 0{degree}. AlN has good structural properties whereas h-BN does not. Accordingly, it is suggested that h-BN particles, which have good wetting, be inserted into the Al melt. This will cause the surface of the h-BN to be converted into AlN which has good structural properties. Using this process, a metal matrix composite, which has good structural properties, should be produced. Further, since h-BN is lubricious, a material should be produced which has high wear resistance and good lubricating properties.

• OSTI ID: 143655
• Report Number(s): CONF-930246--; ISBN 0-87339-251-5
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
ALUMINIUM NITRIDES
BORON NITRIDES
COMPOSITE MATERIALS
FABRICATION
MICROSTRUCTURE