famu-fsu college of engineering department of mechanical engineering 1 orientation imaging...
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1FAMU-FSU College of EngineeringDepartment of Mechanical Engineering
ORIENTATION IMAGING MICROSCOPY (OIM)
- SOME CASE STUDIES
EML 5930 (27-750)
Advanced Characterization and Microstructural Analysis
A. D. Rollett, P.N Kalu, D. Waryoba
Spring 2006
2FAMU-FSU College of EngineeringDepartment of Mechanical Engineering
OUTLINE REVIEW OF OIM
CASE STUDIES
Development of Polishing Technique For OIM Study of
Heavily Deformed OFHC Copper
Recrystallization in Heavily Deformed OFHC Copper
Heavily Deformed Cu-Ag
Deformed and Annealed OFHC Copper
Deformed and Annealed Cu-Nb
Other Examples
3FAMU-FSU College of EngineeringDepartment of Mechanical Engineering
INTRODCUTION TO OIM - Diffraction
Diffraction of inelastically scattered electrons by lattice planes (hkl) according to Bragg’s law:
Sections of a pair of Kossel cones form a pair of parallel straight Kikuchi lines on the flat phosphor screen.
For maximum intensity, the specimen surface is steeply tilted at an angle of 20°-30° from grazing incidence.
4FAMU-FSU College of EngineeringDepartment of Mechanical Engineering
INTRODCUTION TO OIM - EBSP formation
5FAMU-FSU College of EngineeringDepartment of Mechanical Engineering
INTRODCUTION TO OIM - Data acquisition
6FAMU-FSU College of EngineeringDepartment of Mechanical Engineering
TECHNIQUE DEVELOPMENT
7FAMU-FSU College of EngineeringDepartment of Mechanical Engineering
TECHNIQUE DEVELOPMENT
(a) OIM grain boundary map and (b) EBSD patterns
EBSPs from a sample prepared by standard metallographic technique: Polished
8FAMU-FSU College of EngineeringDepartment of Mechanical Engineering
TECHNIQUE DEVELOPMENT
(a) OIM grain boundary map and (b) EBSD patterns
(b)(a)
EBSPs from a sample prepared by standard metallographic technique: Polished + etched
9FAMU-FSU College of EngineeringDepartment of Mechanical Engineering
TECHNIQUE DEVELOPMENT
(a) OIM grain boundary map and (b) EBSD patterns
(b)(a)
EBSPs from a sample prepared by Novel technique - Polished + Etched + Polished
10FAMU-FSU College of EngineeringDepartment of Mechanical Engineering
Image Quality
Image Quality
Confidence Index
Confidence Index
11FAMU-FSU College of EngineeringDepartment of Mechanical Engineering
TECHNIQUE DEVELOPMENT
IPF of wire drawn OFHC copper deformed to = 3.2, obtained via (a) OIM and (b) X-ray diffraction techniques
CONCLUSIONS Polishing by the novel technique, which consists
of polishing+etching+polishing, produced high
quality EBSPs leading to excellent OIM image.
IPF from OIM were consistent with the IPF from
X-ray diffraction
12FAMU-FSU College of EngineeringDepartment of Mechanical Engineering
Rex in HEAVILY DEFORMED OFHC COPPER
13FAMU-FSU College of EngineeringDepartment of Mechanical Engineering
Rex in HEAVILY DEFORMED OFHC COPPER
Optical micrograph showing microstructure after deformation to = 3.2, = 405 MPa. Arrows show pockets of recrystallized grains.
Microstructure
Optical micrograph showing microstructure after deformation to = 1.3, = 392 MPa. No recrystallization
14FAMU-FSU College of EngineeringDepartment of Mechanical Engineering
Rex in HEAVILY DEFORMED OFHC COPPER
OIM map showing grain orientations at (a) p = 2.3, UTS = 411.5 MPa, and (b) p = 3.2, UTS = 405 MPa. The lines represent high angle boundaries, with misorientation > 15o.
U
X
V
Y
W
DD
(b)(a)
15FAMU-FSU College of EngineeringDepartment of Mechanical Engineering
Rex in HEAVILY DEFORMED OFHC COPPER
16FAMU-FSU College of EngineeringDepartment of Mechanical Engineering
1
10
1112
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<313>85°{184}<-12 17 2>
<12-6>40°{-4-19}<-46-3>
<213>75°{-3 11 6}<-65-2>
<1-1-3>48°{-8713}<25-3>
<1-21>26°{-212}<-34-5>
<112>54°{-265}<-12 22 –7>
<-4-13>45°{1 11 18}<7 29 2>
<-1-12>60°{198}<12 23 2>
<1-1-1>64°{-201}<23-8>
<144>60°{-6 13 5}<-24-2>
<-1-15>56°{-2 14 23}<13 11 –1><-211>63°
{3-4 11}<6 10 3>
<112>65°
<-210>36°
<-210>32°
<133>65° <4-2-1>42° <313>66°
<-1-12>60°
<2-1-2>52°<2-1-1>65°
<2-1-3>55°
17FAMU-FSU College of EngineeringDepartment of Mechanical Engineering
Rex in HEAVILY DEFORMED OFHC COPPER
OIM map showing grain orientations after deformation to p = 3.6, UTS = 390.5 MPa.
18FAMU-FSU College of EngineeringDepartment of Mechanical Engineering
Color Key
19FAMU-FSU College of EngineeringDepartment of Mechanical Engineering
Sh/B in HEAVILY DEFORMED OFHC COPPER
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2
OIM maps of a heavily drawn Cu ( = 3.2) showing regions of shear bands.
Shaded IQ map of a heavily drawn Cu ( = 3.2) showing regions of shear bands.
20FAMU-FSU College of EngineeringDepartment of Mechanical Engineering
21FAMU-FSU College of EngineeringDepartment of Mechanical Engineering
Rex in HEAVILY DEFORMED OFHC COPPER CONCLUSION
Three regions were identified: Low processing strain < 2.5: No recrystallization,
elongated structure.
Intermediate strain 2.5 < < 3.2: Nucleation of recrystallization, shear bands formation. Shear bands occurred in grains with S{123}<634> orientation, and were inclined at 54° to the drawing direction. Their misorientation was between 5°s10°.
High strain > 3.2: Extended recrystallization, recrystallized grains were mainly of Cube {001}<100> and S{123}<624> orientations.
OIM proved to be a viable tool in the study of heavily deformed materials.
22FAMU-FSU College of EngineeringDepartment of Mechanical Engineering
HEAVILY DEFORMED Cu-Ag
23FAMU-FSU College of EngineeringDepartment of Mechanical Engineering
Optical micrograph of a heavily drawn CuAg ( = 3.2) showing regions of shear bands.
Shaded IQ map of a heavily drawn CuAg ( = 3.2) showing regions of shear bands.
HEAVILY DEFORMED CuAg
24FAMU-FSU College of EngineeringDepartment of Mechanical Engineering
HEAVILY DEFORMED Cu-Ag
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OIM maps of a heavily drawn CuAg ( = 3.18) showing regions of shear bands. The Grain boundaries were constructed with a misorientation criteria of 15°.
25FAMU-FSU College of EngineeringDepartment of Mechanical Engineering
DEFORMED AND ANNEALED OFHC COPPER
26FAMU-FSU College of EngineeringDepartment of Mechanical Engineering
ANNEALED OFHC COPPER - Microstructure
(a) Optical micrograph of annealed Cu, p = 3.1, 350°C
(a) Optical micrograph of annealed Cu, p = 3.1, 750°C
27FAMU-FSU College of EngineeringDepartment of Mechanical Engineering
ANNEALED OFHC COPPER
OIM tiled IPF map showing grain orientations for Cu wire drawn to a strain of 3.1 and annealed at 250°C for 1 hr.
28FAMU-FSU College of EngineeringDepartment of Mechanical Engineering
Color Key
29FAMU-FSU College of EngineeringDepartment of Mechanical Engineering
ANNEALED OFHC COPPER
OIM tiled IPF map showing grain orientations for Cu wire drawn to a strain of 3.1 and annealed at 300°C for 1 hr.
30FAMU-FSU College of EngineeringDepartment of Mechanical Engineering
ANNEALED OFHC COPPER
OIM tiled IPF map showing grain orientations for Cu wire drawn to a strain of 3.1 and annealed at 500°C for 1 hr.
31FAMU-FSU College of EngineeringDepartment of Mechanical Engineering
ANNEALED OFHC COPPER
OIM tiled IPF map showing grain orientations for Cu wire drawn to a strain of 3.1 and annealed at 750°C for 1 hr.
32FAMU-FSU College of EngineeringDepartment of Mechanical Engineering
ANNEALED OFHC COPPER: OIM-IPF
(a) Deformed Cu, p = 2.3 (b) Deformed Cu, p = 3.1
33FAMU-FSU College of EngineeringDepartment of Mechanical Engineering
(a) Annealed Cu, p = 3.1, 250°C (b) Annealed Cu, p = 3.1, 300°C
(c) Annealed Cu, p = 3.1, 500°C (d) Annealed Cu, p = 3.1, 750°C
34FAMU-FSU College of EngineeringDepartment of Mechanical Engineering
DEFORMED AND ANNEALED Cu-Nb/Ti
35FAMU-FSU College of EngineeringDepartment of Mechanical Engineering
DEFORMED AND ANNEALED Cu-Nb/Ti
SEM micrograph of a heavily drawn Cu-Nb ( = 3.2) annealed at 500°C.
SEM micrograph of a heavily drawn Cu-Nb ( = 3.2) showing elongated Cu and Nb phases.
36FAMU-FSU College of EngineeringDepartment of Mechanical Engineering
DEFORMED AND ANNEALED Cu-Nb/Ti
Annealed CuNb, p = 3.1, 250°C
(Nb phase extracted)
37FAMU-FSU College of EngineeringDepartment of Mechanical Engineering
DEFORMED AND ANNEALED Cu-Nb/Ti
Annealed CuNb, p = 3.1, 300°C
38FAMU-FSU College of EngineeringDepartment of Mechanical Engineering
DEFORMED AND ANNEALED Cu-Nb/Ti
Annealed CuNb, p = 3.1, 500°C
39FAMU-FSU College of EngineeringDepartment of Mechanical Engineering
DEFORMED AND ANNEALED Cu-Nb/Ti
Annealed CuNb, p = 3.1, 750°C
40FAMU-FSU College of EngineeringDepartment of Mechanical Engineering
Other Examples
41FAMU-FSU College of EngineeringDepartment of Mechanical Engineering
42FAMU-FSU College of EngineeringDepartment of Mechanical Engineering