FAMU-FSU College of Engineering Department of Mechanical Engineering 1 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

FAMU-FSU College of Engineering Department of Mechanical Engineering 2 OUTLINE r REVIEW OF OIM r CASE STUDIES l Development of Polishing Technique For OIM Study of Heavily Deformed OFHC Copper l Recrystallization in Heavily Deformed OFHC Copper l Heavily Deformed Cu-Ag l Deformed and Annealed OFHC Copper l Deformed and Annealed Cu-Nb l Other Examples

FAMU-FSU College of Engineering Department of Mechanical Engineering 3 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.

FAMU-FSU College of Engineering Department of Mechanical Engineering 4 INTRODCUTION TO OIM - EBSP formation

FAMU-FSU College of Engineering Department of Mechanical Engineering 5 INTRODCUTION TO OIM - Data acquisition

FAMU-FSU College of Engineering Department of Mechanical Engineering 6 TECHNIQUE DEVELOPMENT

FAMU-FSU College of Engineering Department of Mechanical Engineering 7 TECHNIQUE DEVELOPMENT (a) OIM grain boundary map and (b) EBSD patterns r EBSPs from a sample prepared by standard metallographic technique: Polished

FAMU-FSU College of Engineering Department of Mechanical Engineering 8 TECHNIQUE DEVELOPMENT (a) OIM grain boundary map and (b) EBSD patterns (b) (a) r EBSPs from a sample prepared by standard metallographic technique: Polished + etched

FAMU-FSU College of Engineering Department of Mechanical Engineering 9 TECHNIQUE DEVELOPMENT (a) OIM grain boundary map and (b) EBSD patterns (b) (a) r EBSPs from a sample prepared by Novel technique - Polished + Etched + Polished

FAMU-FSU College of Engineering Department of Mechanical Engineering 10 Image Quality Confidence Index

FAMU-FSU College of Engineering Department of Mechanical Engineering 11 TECHNIQUE DEVELOPMENT IPF of wire drawn OFHC copper deformed to  = 3.2, obtained via (a) OIM and (b) X-ray diffraction techniques r CONCLUSIONS u Polishing by the novel technique, which consists of polishing+etching+polishing, produced high quality EBSPs leading to excellent OIM image. u IPF from OIM were consistent with the IPF from X-ray diffraction

FAMU-FSU College of Engineering Department of Mechanical Engineering 12 Rex in HEAVILY DEFORMED OFHC COPPER

FAMU-FSU College of Engineering Department of Mechanical Engineering 13 Rex in HEAVILY DEFORMED OFHC COPPER Optical micrograph showing microstructure after deformation to  = 3.2,  = 405 MPa. Arrows show pockets of recrystallized grains. r Microstructure Optical micrograph showing microstructure after deformation to  = 1.3,  = 392 MPa. No recrystallization

FAMU-FSU College of Engineering Department of Mechanical Engineering 14 Rex in HEAVILY DEFORMED OFHC COPPER OIM map showing grain orientations at (a)  p = 2.3,  UTS = MPa, and (b)  p = 3.2,  UTS = 405 MPa. The lines represent high angle boundaries, with misorientation > 15 o. U X V Y W DD (b) (a)

FAMU-FSU College of Engineering Department of Mechanical Engineering 15 Rex in HEAVILY DEFORMED OFHC COPPER

FAMU-FSU College of Engineering Department of Mechanical Engineering ° {184} 40° {-4-19} 75° { } 48° {-8713} 26° {-212} 54° {-265} 45° { } 60° {198} 64° {-201} 60° { } 56° { } 63° {3-4 11} 65° 36° 32° 65° 42° 66° 60° 52° 65° 55°

FAMU-FSU College of Engineering Department of Mechanical Engineering 17 Rex in HEAVILY DEFORMED OFHC COPPER OIM map showing grain orientations after deformation to  p = 3.6,  UTS = MPa.

FAMU-FSU College of Engineering Department of Mechanical Engineering 18 Color Key

FAMU-FSU College of Engineering Department of Mechanical Engineering 19 Sh/B in HEAVILY DEFORMED OFHC COPPER 1 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.

FAMU-FSU College of Engineering Department of Mechanical Engineering 20

FAMU-FSU College of Engineering Department of Mechanical Engineering 21 Rex in HEAVILY DEFORMED OFHC COPPER r CONCLUSION u Three regions were identified: l Low processing strain  < 2.5: No recrystallization, elongated structure. l Intermediate strain 2.5 orientation, and were inclined at 54° to the drawing direction. Their misorientation was between 5°  s  10°. l High strain  > 3.2: Extended recrystallization, recrystallized grains were mainly of Cube {001} and S{123} orientations. u OIM proved to be a viable tool in the study of heavily deformed materials.

FAMU-FSU College of Engineering Department of Mechanical Engineering 22 HEAVILY DEFORMED Cu-Ag

FAMU-FSU College of Engineering Department of Mechanical Engineering 23 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

FAMU-FSU College of Engineering Department of Mechanical Engineering 24 HEAVILY DEFORMED Cu-Ag 1 2 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°.

FAMU-FSU College of Engineering Department of Mechanical Engineering 25 DEFORMED AND ANNEALED OFHC COPPER

FAMU-FSU College of Engineering Department of Mechanical Engineering 26 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

FAMU-FSU College of Engineering Department of Mechanical Engineering 27 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.

FAMU-FSU College of Engineering Department of Mechanical Engineering 28 Color Key

FAMU-FSU College of Engineering Department of Mechanical Engineering 29 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.

FAMU-FSU College of Engineering Department of Mechanical Engineering 30 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.

FAMU-FSU College of Engineering Department of Mechanical Engineering 31 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.

FAMU-FSU College of Engineering Department of Mechanical Engineering 32 ANNEALED OFHC COPPER: OIM-IPF (a) Deformed Cu,  p = 2.3 (b) Deformed Cu,  p = 3.1

FAMU-FSU College of Engineering Department of Mechanical Engineering 33 (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

FAMU-FSU College of Engineering Department of Mechanical Engineering 34 DEFORMED AND ANNEALED Cu-Nb/Ti

FAMU-FSU College of Engineering Department of Mechanical Engineering 35 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.

FAMU-FSU College of Engineering Department of Mechanical Engineering 36 DEFORMED AND ANNEALED Cu-Nb/Ti Annealed CuNb,  p = 3.1, 250°C (Nb phase extracted)

FAMU-FSU College of Engineering Department of Mechanical Engineering 37 DEFORMED AND ANNEALED Cu-Nb/Ti Annealed CuNb,  p = 3.1, 300°C

FAMU-FSU College of Engineering Department of Mechanical Engineering 38 DEFORMED AND ANNEALED Cu-Nb/Ti Annealed CuNb,  p = 3.1, 500°C

FAMU-FSU College of Engineering Department of Mechanical Engineering 39 DEFORMED AND ANNEALED Cu-Nb/Ti Annealed CuNb,  p = 3.1, 750°C

FAMU-FSU College of Engineering Department of Mechanical Engineering 40 Other Examples

FAMU-FSU College of Engineering Department of Mechanical Engineering 41

FAMU-FSU College of Engineering Department of Mechanical Engineering 42