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In Situ Synthesis of Ti 5 Si 3 Matrix Nanocomposites Reinforced with Nanoparticles by High‐Energy Mechanical Alloying
Author(s) -
Li Chuang,
Gu Dongdong,
Shen Yifu,
Meng Guangbin,
Li Yufang
Publication year - 2011
Publication title -
advanced engineering materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.938
H-Index - 114
eISSN - 1527-2648
pISSN - 1438-1656
DOI - 10.1002/adem.201000377
Subject(s) - materials science , nanocrystalline material , nanocomposite , tin , nanoparticle , chemical engineering , metallurgy , nanocrystal , grain size , composite material , nanotechnology , engineering
In the present work, in situ TiN/Ti 5 Si 3 nanocomposite powder was prepared by high‐energy mechanical alloying of a Ti and Si 3 N 4 powder mixture via the following route: 9Ti + Si 3 N 4 = Ti 5 Si 3 + 4TiN. Constitution phases and microstructural features of the milled powders at different milling times were studied by XRD, SEM, and TEM. The operative formation mechanisms behind the microstructural developments were disclosed. It showed that the original Si 3 N 4 and Ti constituents demonstrated two different reaction mechanisms during milling, i.e., a progressive mechanism of Si 3 N 4 (≤20 h) and a speedy mechanism of Ti (≤10 h). The morphologies of the milled composite powders experienced a successive change: pre‐refining – coarsening – re‐refining on increasing the applied milling time. The variation of the operative mechanisms was ascribed to the existence/exhaustion of the ductile Ti constituent in the milling system due to the nonoccurrence/initiation of the in situ reaction. The 20 h milled powder was the typical nanocomposites featured by the nanocrystalline Ti 5 Si 3 matrix reinforced with in situ TiN nanoparticles. The grain sizes of the in situ formed Ti 5 Si 3 and TiN phases were generally ≤15 nm, exhibiting coherent interfacial structure between reinforcement and matrix.