Microstructure and tensile properties of mechanically alloyed Ti-6Al-4V with boron additions

Particulate titanium metal matrix composites (MMCs) offer advantages for a wide range of structural applications with increases in stiffness and possi bly wear resistance. A powder metallurgy/mechanical alloy route was used su ccessfully to give a fine, uniform distribution of boron in titanium alloy powder. This powder was hot isostatically pressed and during the process Ti B reinforcement was formed by an in-situ reaction. Significant tensile duct ility in MA titanium ahoy (without boron), equivalent to wrought material w as achieved, along with good tensile strength. In materials with high TiB v olume fractions it is thought that the fine boride size and high strength m atrix caused embrittlement. This suggests that the use of a lower strength matrix, such as commercial purity titanium, and shorter milling times would provide a better balance of strength, stiffness and ductility for this typ e of composite. Crown copyright (C) 2000 Published by Elsevier Science S.A. All rights reserved.