Hits:

Indexed by:Journal Papers

Date of Publication:2020-03-01

Journal:MATERIALS LETTERS

Included Journals:EI、SCIE

Volume:262

ISSN No.:0167-577X

Key Words:Metallic composites; Solidification; Particle dispersion; Ultrasonic vibration; Cooling rate

Abstract:In situ TiB2p/Al composites were pre-fabricated by mixed halide salt route. The composites were remelted and subjected to both ultrasonic vibration treatment (UVT) and different solidification conditions to see if it is possible to manually manipulate the particle distribution. The results indicate that except for the coarse Al3Ti (I-type) particles embed in the center of a grain, most particles are distributed along the grain boundary to form a network structure. Microstructural analysis of the raw material has further distinguished the latter particles into two categories: blocky TiB2 particles (II-type) of several microns depicting the grain boundary, and smaller particles (Al3Ti and TiB2, III-type) of a few hundred nanometers in the vicinity of the II-type particles. UVT widens the area of smaller particles adjacent to the grain boundaries, while faster cooling facilitates the engulfment of III-type particles inside alpha-Al grains. (C) 2019 Elsevier B.V. All rights reserved.