TY - JOUR
T1 - Effect of laser shock peening without coating on fretting corrosion of copper contacts
AU - Park, Changkyoo
AU - Jung, Donghyuck
AU - Chun, Eun Joon
AU - Ahn, Sanghoon
AU - Jang, Ho
AU - Kim, Yoon Jun
N1 - Funding Information:
This research was supported by the Korea Evaluation Institute of Industrial Technology, Republic of Korea [Project number: N055700001, 2019].
Publisher Copyright:
© 2020 Elsevier B.V.
PY - 2020/6/1
Y1 - 2020/6/1
N2 - The effects of laser shock peening without coating (LSPwC) on the degradation of copper electrical contact was investigated. A Nd:YAG laser with laser energy densities of 5.3 and 10.6 GW/cm2 was used for the LSPwC process. Surface hardness was enhanced from 55 HV to 110 and 120 HV for the laser shock-peened copper at 5.3 GW/cm2 and 10.6 GW/cm2, respectively. Moreover, near the copper surface, LSPwC introduced the max. compressive residual stress of 387.5 and 385.5 MPa for laser energy densities of 5.3 and 10.6 GW/cm2, respectively. Electron backscatter diffraction and transmission electron microscopy revealed that LSPwC introduced dislocation rearrangement, deformation twins, and grain refinement. The laser shock-peened copper exhibited superior wear resistance compared with the base metal. During the fretting test, the wear loss of the base metal was 1.61 × 10-3 mm3, and this decreased to 0.99 × 10-3 and 0.94 × 10-3 mm3 for the laser shock-peened copper at 5.3 and 10.6 GW/cm2, respectively. Thus, the laser shock-peened copper maintained a low electrical contact resistance during the fretting test, resulting in electrical contact failure delay from 2790 cycles for the base metal to 5011 and 5210 cycles for laser shock-peened copper at 5.3 and 10.6 GW/cm2, respectively.
AB - The effects of laser shock peening without coating (LSPwC) on the degradation of copper electrical contact was investigated. A Nd:YAG laser with laser energy densities of 5.3 and 10.6 GW/cm2 was used for the LSPwC process. Surface hardness was enhanced from 55 HV to 110 and 120 HV for the laser shock-peened copper at 5.3 GW/cm2 and 10.6 GW/cm2, respectively. Moreover, near the copper surface, LSPwC introduced the max. compressive residual stress of 387.5 and 385.5 MPa for laser energy densities of 5.3 and 10.6 GW/cm2, respectively. Electron backscatter diffraction and transmission electron microscopy revealed that LSPwC introduced dislocation rearrangement, deformation twins, and grain refinement. The laser shock-peened copper exhibited superior wear resistance compared with the base metal. During the fretting test, the wear loss of the base metal was 1.61 × 10-3 mm3, and this decreased to 0.99 × 10-3 and 0.94 × 10-3 mm3 for the laser shock-peened copper at 5.3 and 10.6 GW/cm2, respectively. Thus, the laser shock-peened copper maintained a low electrical contact resistance during the fretting test, resulting in electrical contact failure delay from 2790 cycles for the base metal to 5011 and 5210 cycles for laser shock-peened copper at 5.3 and 10.6 GW/cm2, respectively.
KW - Compressive residual stress
KW - Copper
KW - Fretting corrosion
KW - Grain refinement
KW - Laser shock peening without coating
UR - http://www.scopus.com/inward/record.url?scp=85080971867&partnerID=8YFLogxK
U2 - 10.1016/j.apsusc.2020.145917
DO - 10.1016/j.apsusc.2020.145917
M3 - Article
AN - SCOPUS:85080971867
VL - 514
JO - Applied Surface Science
JF - Applied Surface Science
SN - 0169-4332
M1 - 145917
ER -