Effect of pulse frequency in laser shock peening on roughness and residual stresses of nickel alloy specimens

The effect of pulse frequency during laser shock peening on microhardness, roughness, crushing and residual stresses of the surface layer of flat nickel alloy samples is considered. Laser shock peening was performed by a low-power Nd:YAG laser with a pulse duration of 10 ns on one side of the sample. Acrylic paint was used as a protective layer. It was found that laser shock peening at a low frequency led to large compressive residual stresses of –0.44…–0.28 rel. units compared to other laser pulse frequencies. At a frequency of 3 Hz, laser impact treatment leads to a minimum compression depth (reduction in sample thickness) of 7.62 μm. Roughness after laser shock peening in all processing modes from 0.32 μm to 0.90 ... 1.50 μm. Microhardness increased by 1.2 ... 2.0 times. It is recommended to include an allowance for laser shock peening of 7...10 µm.
EDN: LIQYDT, https://elibrary/liqydt

References

[1] Ren X.D., Zhan Q.B., Yang H.M. et al. The effects of residual stress on fatigue behavior and crack propagation from laser shock processing-worked hole. Mater. Des., 2013, vol. 44, pp. 149–154, doi: https://doi.org/10.1016/j.matdes.2012.07.024

[2] Ebrahimi M., Amini S., Seyed M. The investigation of laser shock peening effects on corrosion and hardness properties of ANSI 316L stainless steel. Int. J. Adv. Manuf. Technol., 2017, vol. 88, no. 5–8, pp. 1557–1565, doi: https://doi.org/10.1007/s00170-016-8873-0

[3] Burlachenko O.V., Tikhvinskaya A.Yu., Zelenskiy A.A. Strengthening of high-strength cast iron by YAG:Nd-laser radiation. Fizika i ximiya obrabotki materialov, 2009, no. 3, pp. 55–57. (In Russ.).

[4] Li B., Zhang Z. Theoretical modeling and analysis for tensioning stress formation mechanism of laser shock tensioning process. Int. J. Adv. Manuf. Technol., 2018, vol. 96, no. 1–4, pp. 247–256, doi: https://doi.org/10.1007/s00170-018-1607-8

[5] Tsimbal A.L. Lazernoe udarnoe uprochnenie. IТМО, 2010. 6 p. (In Russ.).

[6] Irizalp S.G., Salklakoglu N., Yilbas B.S. Characterization of microplastic deformation produced in 6061-T6 by using laser shock processing. Int. J. Adv. Manuf. Technol., 2014, vol. 71, no. 1-4, pp. 109–115, doi: https://doi.org/10.1007/s00170-013-5481-0

[7] Smirnova N.A., Misyurov A.I. Structure formation features at laser processing. Vestn. Mosk. Gos. Tekh. Univ. im. N.E. Baumana, Mashinostr. [Herald of the Bauman Moscow State Tech. Univ., Mechan. Eng.], 2012, speс. iss. no. 5, pp. 115–130, doi: http://dx.doi.org/10.18698/2308-6033-2012-6-233 (in Russ.).

[8] Shiryaev А.А., Milenin А.S. The influence of pressure profile on residual stresses during laser shock peening of the edge of a titanium alloy blade feather. Klimovskiye chteniya — 2025. Perspektivnyye napravleniya razvitiya aviadvigatelestroyeniya: sbornik statey nauchno-tekhnicheskoy konferentsii, 22 oktyabrya 2025 g. Sankt-PeterburgKlimovskiye chteniya — 2025: Perspektivnyye napravleniya razvitiya aviadvigatelestroyeniya: sbornik statey nauchno-tekhnicheskoy konferentsii, Sankt-Peterburg, 2025, pp. 172–178. (In Russ.).

[9] Pinakhin I.A., Chernigovskiy V.A. Osnovy obemnogo impulsnogo lazernogo uprochneniya instrumentalnykh i konstruktivnykh materialov [Fundamentals of volume pulsed laser hardening of tool and structural materials]. Stavropol, Izd-vo SKFU Publ., 2014. 160 p. (In Russ.).

[10] Nagarajan B., Castagne S., Wang Z. et al. Influence of plastic deformation in flexible pad laser shock forming — experimental and numerical analysis. Int. J. Mater. Form., 2017, vol. 10, no. 1, pp. 109–123, doi: https://doi.org/10.1007/s12289-015-1264-5

[11] Pimenova G.P. Service life of aircraft engines and reliability of turbine blades. Izvestiya vuzov. Aviatsionnaya tekhnika, 1972, no. 1, pp. 109–114. (In Russ.).

[12] Prigorovskiy N.I. Metody i sredstva opredeleniya poley deformatsiy i napryazheniy [Methods and means for determining strain and stress fields]. Moscow, Mashinostroenie Publ., 1983. 248 p. (In Russ.).

[13] Korolenko T.I. Service life assurance program for Boeing 757 and 767 aircraft. Technical Information. ONTI TsAGI, 1985, no. 12, pp. 1–5. (In Russ.).

[14] Kotlyarov V.P. Surface finishing and hardening treatment with laser irradiation. Elektronnaya obrabotka materialov, 1987, no. 1, pp. 12–17. (In Russ.).

[15] Pochtennyy E.K. Prognozirovanie dolgovechnosti i diagnostika detaley mashin [Durability prediction and diagnostics of machine parts]. Minsk, Nauka i tekhnika Publ., 1983. 246 p. (In Russ.).