Enhance Fatigue Resistance of Nanocrystalline NiTi by Laser Shock Peening

Yan，Kai1; Wei，Pengbo1,2; Ren，Fuzeng2; He，Weifeng3; Sun，Qingping1

2019-12-01

10.1007/s40830-019-00256-z

Shape Memory and Superelasticity   影响因子和分区

2199-384X

2199-3858

A pre-strain laser shock peening method is proposed to fabricate fatigue-resistant nanocrystalline NiTi with graded nanolayers and compressive residual stress layers. Grain size gradient surface layer of about 100 μm thick is fabricated on a 1.5-mm-thick bulk nanocrystalline NiTi plate. It is found that the nanostructure shows a gradient distribution from middle region of the plate to its laser-treated surface, and the grain size at the treated surface is about 5 nm. B2, B19′ phase and NiTi, NiTi precipitates are found at the treated surface. The nanohardness at the laser-treated surface reaches 10 GPa. Residual stress profile on the laser-treated plate cross-section is measured by a focused ion beam-digital image correlation technique. The measured maximum residual compressive stress is about 1.2 GPa at the laser-treated top surface, while there is residual tensile stress of about 200 MPa in the middle region. Four-point bending displacement-controlled experiments show that the fatigue life of the NiTi sample increases about seven times after laser treatment. The work demonstrates that pre-strain laser shock peening without surface coating is an effective method to fabricate fatigue-resistant nanocrystalline NiTi with gradient grain size and compressive residual stress layers.

Fatigue FIB-DIC Laser shock peening NiTi Residual stress

ESCI ; EI

英语

其他

Hong Kong Research Grant Council (RGC) through the GRF Grant[16239316] ; Fundamental Research Program of Shenzhen[JCYJ20170412153039309]

Materials Science

Materials Science, Multidisciplinary

WOS:000500315800001

SPRINGER INTERNATIONAL PUBLISHING AG

20203809197823

Grain size and shape ; Ion beams ; Displacement control ; Titanium alloys ; Compressive stress ; Fatigue of materials ; Stress analysis ; Residual stresses ; Nanocrystals

Titanium and Alloys:542.3 ; Nanotechnology:761 ; High Energy Physics:932.1 ; Crystalline Solids:933.1 ; Mechanical Variables Measurements:943.2 ; Materials Science:951

2-s2.0-85076012789

Scopus

1.Department of Mechanical and Aerospace Engineering,The Hong Kong University of Science and Technology,Hong Kong
2.Department of Materials Science and Engineering,Southern University of Science and Technology,Shenzhen,518055,China
3.Science and Technology on Plasma Dynamics Laboratory,Air Force Engineering University,Xi’an,710038,China

Yan，Kai,Wei，Pengbo,Ren，Fuzeng,et al. Enhance Fatigue Resistance of Nanocrystalline NiTi by Laser Shock Peening[J]. Shape Memory and Superelasticity,2019,5(4):436-443.

Yan，Kai,Wei，Pengbo,Ren，Fuzeng,He，Weifeng,&Sun，Qingping.(2019).Enhance Fatigue Resistance of Nanocrystalline NiTi by Laser Shock Peening.Shape Memory and Superelasticity,5(4),436-443.

Yan，Kai,et al."Enhance Fatigue Resistance of Nanocrystalline NiTi by Laser Shock Peening".Shape Memory and Superelasticity 5.4(2019):436-443.