Open AccessLocal structures of mechanically alloyed Fe 100− x Cu x solid solutions studied by X‐ray absorption fine structure
Author(s) -
Wei Shiqiang,
Yan Wensheng,
Fan Jiangwei,
Li Yuzhi,
Liu Wenhan,
Wang Xiaoguang
Publication year - 2001
Publication title -
journal of synchrotron radiation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.172
H-Index - 99
ISSN - 1600-5775
DOI - 10.1107/s0909049500018318
Subject(s) - solid solution , materials science , x ray absorption fine structure , crystallography , alloy , x ray , extended x ray absorption fine structure , phase (matter) , transition metal , metallurgy , chemistry , absorption spectroscopy , spectroscopy , catalysis , biochemistry , physics , organic chemistry , quantum mechanics
The local structures of the immiscible Fe 100‐x Cu x alloys (x= 0, 10, 20, 40, 60, 80 and 100) produced by mechanical alloying have been investigated by XAFS. For the Fe 100‐x Cu x (x ≥ 40) solid solutions, the local structures around Fe atoms change from bcc structure to fcc one and the Cu atoms maintain the original coordination geometry after milling for 160 hours. On the contrary, the local structures around Cu atoms in both of Fe 80 Cu 20 and Fe 90 Cu 10 alloys appear a transition from fcc to bcc structure. We found that the Debye‐waller factor σ of fcc Fe‐Cu phase is larger than that of bcc Fe‐Cu phase, and the σ (0.099 Å) around Fe atoms is larger than that (0.089 Å) of Cu in the Fe 100‐x Cu x (x ≥ 40) solid solutions. This suggests that the mechanically alloyed Fe 100‐x Cu x supersaturated solid solution is not a homogeneous alloy, and consists of Fe‐rich and Cu‐rich regions for various compositions. A possible mechanism for bcc‐to‐fcc and fcc‐to‐bcc changes in Fe 100‐x Cu x solid solutions is discussed in relation to the interdiffusion and transition induced by the ball milling.