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Ultrasonic linear and nonlinear properties of fatigued aluminium 6061-T6 with voids

기공을 포함한 피로손상 알루미늄 6061-T6의 초음파 특성평가

  • Received : 2015.08.10
  • Accepted : 2015.10.10
  • Published : 2015.10.30

Abstract

It is known that in aluminum 6061-T6, which is composed of $Mg_2Si$ and ${\beta}-Al_5FeSi$, void nucleation grows around ${\beta}-Al_5FeSi$ of Al606-T6. In this work, growth of voids was checked by scanning a 6061-T6 specimen with SEM observation. The effects of dislocation damping, coherency strain and voids on ultrasonic attenuation and nonlinearity parameters were experimentally measured. It was observed that a nonlinearity parameter increases until 75 percent of fatigue life and decreases after that. From the results, the authors inferred that dislocation damping and coherency damping increase nonlinearity parameters and void nucleation decreases them as ultrasonic scattering increases with void. The application of nonlinearity parameters in estimating degradation of materials with complex microstructures through fatigue process, therefore, should be carefully considered.

Keywords

Al6061-T6;voids;attenuation;nonlinearity parameter

References

  1. Wang, Q. G., "Microstructural effects on the tensile and fracture behavior of aluminum casting alloys A356/357", Metall Mater Trans A, 34(12), 2887-2899, (2003) https://doi.org/10.1007/s11661-003-0189-7
  2. Ran, G., Zhou, J. E., Wang, Q. G., "Precipitates and tensile fracture mechanism in a sand cast A356 aluminum alloy", Jounral of Material Process Technology, 207(1-3), 46-52, (2008) https://doi.org/10.1016/j.jmatprotec.2007.12.050
  3. Agarwal, H., Gokhale, A. M., Graham, S., Horstemeyer M. F., "Void growth in 6061-aluminum alloy under triaxial stress state", Materials Science Engineering A, 341(1-2), 35-42, (2003) https://doi.org/10.1016/S0921-5093(02)00073-4
  4. Raj, R., Ashby, M. F., "Intergranular fracture at elevated temperature", Acta Metall, 23, 363-371, (1975)
  5. Joshi, N.R., Green Jr. R.E., "Ultrasonic detection of fatigue damage", Engineering Fracture Mechanics, 4(3), 577-583, (1972) https://doi.org/10.1016/0013-7944(72)90067-7
  6. Hirao, M., Ogi, H., Suzuki, N., Ohtani, T., "Ultrasonic attenuation peak during fatigue of polycrystalline copper", Acta Materilia, 48(2), 517-524, (2000) https://doi.org/10.1016/S1359-6454(99)00346-8
  7. Cantrell, J.H., Yost, W.T., "Nonlniear ultrasconic characterization of fatigue micro structures", International Journal of Fatigue, 23(1), 487-490, (2001) https://doi.org/10.1016/S0142-1123(01)00162-1
  8. Kang, T., Kim, H. H., Song, S. J., Kim, H. J., "Characterization of fatigue damage of Al6061-T6 with ultrasound", NDT & E International., 52, pp. 51-56, (2012) https://doi.org/10.1016/j.ndteint.2012.08.001
  9. Truell, R., Elbaum, C., Chick, B.B., Ultrasonic methods in solid state physics, Academic Press, New York and London, (1969)
  10. Na, J. K., Yost, W. T., Cantrell, J. H., Kessel, G. L., "Effect of surface roughness and nonparallelism on the measruement of the acoustic nonliearity parameter in steam turbine blades", Review of Progress in Quantitative Nondestructive Evaluation, 19, 1417-1424
  11. Gauster, W.B., Breazeale M.A., "Detector for measurement of ultrasonic strain amplitudes in solid", 37(11), Review of Scientific Instruments, 1544-1548, (1966) https://doi.org/10.1063/1.1720040
  12. Kang, T., Na, J.K., Song, S.-J., Park, J.H., "Nonlinear acoustics for practical applications", Proc. of SPIE, 9473, 94370U1-94370U 2, (2015)
  13. Wang, Q. G., "Fatigue voids in structural Al-alloys under high-frequency cyclic loading", Journal of Materials Science, 39(1), 365-367, (2004) https://doi.org/10.1023/B:JMSC.0000008091.55395.ee
  14. Martin B.G., "Ultrasonic attenuation due to voids in fiber-reinforced plastics", NDT&E International, 9(5), 242-246, (1976) https://doi.org/10.1016/0308-9126(76)90004-3

Acknowledgement

Grant : 원자력계통 건전성 선진화 체계 구축