TY - JOUR
T1 - Experimental investigation on low cycle fatigue of DZ125 with film cooling holes in different processes of laser drilling
AU - Liang, Jianwei
AU - Ai, Xing
AU - Wen, Zhixun
AU - Yue, Zhufeng
N1 - Publisher Copyright:
© 2015 Elsevier Inc.
PY - 2016/1/1
Y1 - 2016/1/1
N2 - Due to the different low cycle fatigue (LCF) properties and fatigue fracture behavior around film cooling holes on DZ125, the LCF tests are carried out using tension cycling under stress control conditions (stress ratio R = 0.1) at 900 °C. The specimens were designed as thin-wall plate with single hole and multi holes under picosecond and nanosecond laser drilling processes. Comparative analyses of the differences between fatigue life and microscopic fracture morphology are conducted. It is shown that under the same stress condition, the relationship between fatigue life is as follows: picosecond laser single-holed specimen > nanosecond laser single-holed specimens > picosecond laser multi-holed specimens > nanosecond laser multi-holed specimens. Scanning electron microscope (SEM) analyses of the fracture revealed that the crack initiates from the film cooling holes where fatigue source zone, fatigue crack propagation zone and fatigue fracture zone can be found. However, the different processes lead to slightly different fracture morphology: radial-type ridge centering on the fatigue source zone is more apparent and uniform in picosecond laser drilling specimens than in the nanosecond laser drilling ones. On the other hand, the radial-type ridge is biased toward large-aperture side with nanosecond laser drilling.
AB - Due to the different low cycle fatigue (LCF) properties and fatigue fracture behavior around film cooling holes on DZ125, the LCF tests are carried out using tension cycling under stress control conditions (stress ratio R = 0.1) at 900 °C. The specimens were designed as thin-wall plate with single hole and multi holes under picosecond and nanosecond laser drilling processes. Comparative analyses of the differences between fatigue life and microscopic fracture morphology are conducted. It is shown that under the same stress condition, the relationship between fatigue life is as follows: picosecond laser single-holed specimen > nanosecond laser single-holed specimens > picosecond laser multi-holed specimens > nanosecond laser multi-holed specimens. Scanning electron microscope (SEM) analyses of the fracture revealed that the crack initiates from the film cooling holes where fatigue source zone, fatigue crack propagation zone and fatigue fracture zone can be found. However, the different processes lead to slightly different fracture morphology: radial-type ridge centering on the fatigue source zone is more apparent and uniform in picosecond laser drilling specimens than in the nanosecond laser drilling ones. On the other hand, the radial-type ridge is biased toward large-aperture side with nanosecond laser drilling.
KW - Directionally solidified superalloy DZ125
KW - Low cycle fatigue (LCF)
KW - Nanosecond laser
KW - Picosecond laser
KW - Scanning electron microscope (SEM)
UR - http://www.scopus.com/inward/record.url?scp=84949657478&partnerID=8YFLogxK
U2 - 10.1016/j.engfailanal.2015.10.019
DO - 10.1016/j.engfailanal.2015.10.019
M3 - 文章
AN - SCOPUS:84949657478
SN - 1350-6307
VL - 59
SP - 326
EP - 333
JO - Engineering Failure Analysis
JF - Engineering Failure Analysis
ER -