2008 Volume 94 Issue 3 Pages 86-90
It is well known that Cu particles precipitate during aging from super-saturated ferrite Fe initially as bcc structure, then transform to stable fcc structure as aging progresses to over-aging. It is also well known that the structure transformation goes through intermediate structures such as 3R and 9R. Several previous investigations have suggested that plastic deformation enhances structure transformation of meta-stable precipitates. However, no direct experimental evidence to show this hypothesis has been observed. SR-X-ray absorption fine structure (XAFS) is a useful method to analyze crystal structure of Cu precipitates in Fe. XAFS profiles were compared before and after plastic deformation. A possibility of transformation in crystal structure was observed when Cu precipitates were most likely meta-stable condition.