TY - GEN
T1 - Brazilian tests in lamellar TiAl
AU - Chiang, Fu Pen
AU - Uzer, Gunes
AU - Ding, Yi
AU - Ho, Andrew
AU - Rosenberger, Andrew H.
PY - 2006
Y1 - 2006
N2 - Brazilian tests are performed for the purpose of investigating the mixed mode crack propagation characteristics in lamellar TiAl with the grain size of ∼450pm. Circular disks of about 1mm in thickness and 3.5mm to 9mm in diameter are manufactured. Slits of 0.15mm in width are cut into the central part of the disks with length being 1/3 of the diameter. A multi-scale speckle method is employed to measure the full field strain distributions at both macro and micro scales. Specimens with three different slot orientations are tested in order to control the crack initiation. Micro scale tests are performed inside the chamber of Hitachi S2460-N scanning electron microscope. Results indicate that the highest strain occurs at the point where the surface of the straight line edge of the slot meets the curved edge, regardless of the slot orientation. The crack propagation speed slows down when the crack approaches a grain boundary. It then either stops or jumps to the next grain depending on the grain orientation. A technique is proposed to evaluate the mode mixity from two representative displacement vectors on either side of the crack.
AB - Brazilian tests are performed for the purpose of investigating the mixed mode crack propagation characteristics in lamellar TiAl with the grain size of ∼450pm. Circular disks of about 1mm in thickness and 3.5mm to 9mm in diameter are manufactured. Slits of 0.15mm in width are cut into the central part of the disks with length being 1/3 of the diameter. A multi-scale speckle method is employed to measure the full field strain distributions at both macro and micro scales. Specimens with three different slot orientations are tested in order to control the crack initiation. Micro scale tests are performed inside the chamber of Hitachi S2460-N scanning electron microscope. Results indicate that the highest strain occurs at the point where the surface of the straight line edge of the slot meets the curved edge, regardless of the slot orientation. The crack propagation speed slows down when the crack approaches a grain boundary. It then either stops or jumps to the next grain depending on the grain orientation. A technique is proposed to evaluate the mode mixity from two representative displacement vectors on either side of the crack.
UR - http://www.scopus.com/inward/record.url?scp=33750353832&partnerID=8YFLogxK
M3 - Conference contribution
AN - SCOPUS:33750353832
SN - 091205395X
SN - 9780912053950
T3 - Proceedings of the 2006 SEM Annual Conference and Exposition on Experimental and Applied Mechanics 2006
SP - 2014
EP - 2020
BT - Proceedings of the 2006 SEM Annual Conference and Exposition on Experimental and Applied Mechanics 2006
T2 - SEM Annual Conference and Exposition on Experimental and Applied Mechanics 2006
Y2 - 4 June 2006 through 7 June 2006
ER -