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Physical Matching of Metals: Grain Orientation Association at Fracture Edge
Author(s) -
Lograsso Barbara K.
Publication year - 2015
Publication title -
journal of forensic sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.715
H-Index - 96
eISSN - 1556-4029
pISSN - 0022-1198
DOI - 10.1111/1556-4029.12607
Subject(s) - misorientation , electron backscatter diffraction , fracture (geology) , materials science , orientation (vector space) , crystallography , transgranular fracture , metallurgy , composite material , grain boundary , geometry , intergranular fracture , microstructure , chemistry , mathematics
The objective of this study was to examine whether surface crystal orientation can be used to associate or differentiate metal fracture fragments. The orientations of individual crystals and crystals across the fracture plane were measured on polished steel and iron alloy surfaces using Electron Backscattered Diffraction/ Orientation Imaging Microscopy ( EBSD / OIM ). This investigation examined crystallographic characteristics within a metal. This study showed that for transgranular fracture, it is feasible that pieces of grains could be associated across the fracture surface with the difference in orientation between grains (misorientation) along a length sequence of grain orientations on one side of the fracture surface to associate the other side of a fracture surface. Regarding pair comparisons of crystals on fracture surfaces, it was estimated that the probability for an ordered sequence of six distinct oriented grains along a fracture surface to occur again is about 1 in 4.82 (10) 30 or 2.07 (10) −31 .