An Approach to Eddy-Current Evaluation of the Structural State in a Cast Aluminum–Silicon Alloy Subjected to Surface Laser Heat Treatment
The effect of surface laser heat treatment on the eddy-current parameters of the cast Al–6.34Si–0.32Mg alloy has been studied at excitation frequencies of f = 6–136 kHz. It has been established that the laser heat treatment affects both the amplitude A and the phase angle φ of the eddy-current probe signal. The observed changes in the eddy-current parameters of the laser-treated alloy are caused by the changes in the structural state of the alloy, particularly, by the high dispersity of the structure, increased content of alloying elements in the solid solution, and residual stresses resulting from accelerated cooling under laser melting. The depth of the molten zone and the homogeneity of the structure at different depths can be estimated by measuring the amplitude A, whereas the presence and level of residual stresses can be estimated by measuring the phase angle φ at different probe excitation frequencies. The results clearly show the advantage of separate measurements of the amplitude A and the phase angle φ from the perspective of eddy-current evaluation of the structural state of the laser-treated alloy.
KeywordsEddy-current method Cast aluminum alloy Laser heat treatment Structure Residual stresses
This work was done within the Complex Program of UB RAS, project No. 18-10-1-40, with regard to the studied material and methods of its processing, and within the state order for IES UB RAS, reg. no. AAAA-A18-118020790147-4, with regard to the eddy-current measurements. Optical microscopy was performed in Collective Use Center “Plastometriya” of the Institute of Engineering Science UB RAS.
- 1.Shabel, B.S., Granger, D.A., Truckner, W.G.: Friction and wear of aluminum-silicon alloys. In: Blau, P.J. (ed.) ASM Handbook. V. 18. Friction, Lubrication, and Wear Technology, pp. 785–794. ASM International, Materials Park (1992)Google Scholar
- 9.Pakieła, W., Tański, T., Brytan, Z., Labisz, K.: The influence of laser alloying on the structure and mechanical properties of AlMg5Si2Mn surface layers. Appl. Phys. A Mater. Sci. Process. 122(352), 1–9 (2016)Google Scholar
- 11.Savrai, R.A., Malygina, I.Y., Makarov, A.V., Osintseva, A.L., Rogovaya, S.A., Davydova, N.A.: Effect of the composition of absorbing coatings on the structure and properties of a cast aluminum alloy subjected to surface laser heat treatment. Diagn. Resour. Mech. Mater. Struct. 5, 86–105 (2018). https://doi.org/10.17804/2410-9908.2018.5.086-105 CrossRefGoogle Scholar
- 16.Savrai, R.A., Makarov, A.V., Gorkunov, E.S., Kogan, L.K., Soboleva, N.N., Malygina, I.Y., Osintseva, A.L.: Eddy-current testing of fatigue degradation under contact loading of NiCrBSi coatings obtained through gas–powder laser cladding. Russ. J. Nondestr. Test. 51(11), 692–704 (2015)CrossRefGoogle Scholar
- 17.Savrai, R.A., Makarov, A.V., Gorkunov, E.S., Soboleva, N.N., Kogan, L.K., Malygina, I.Y., Osintseva, A.L., Davydova, N.A.: Eddy-current testing of the fatigue degradation of a gas powder laser clad NiCrBSi–Cr3C2 composite coating under contact fatigue loading. AIP Conf. Proc. 1915(040049), 1–4 (2017). https://doi.org/10.1063/1.5017397 CrossRefGoogle Scholar
- 18.Savrai, R.A., Makarov, A.V., Gorkunov, E.S., Soboleva, N.N., Kogan, L.K., Malygina, I.Y., Osintseva, A.L.: Eddy-current testing of fatigue degradation in additionally heat-treated gas powder laser clad NiCrBSi coating under contact fatigue loading. AIP Conf. Proc. 2053(040088), 1–4 (2018). https://doi.org/10.1063/1.5084526 CrossRefGoogle Scholar
- 25.Ruud, C.O., Green Jr., R.E. (eds.): Nondestructive Methods for Material Property Determination. Plenum Press, New York (1984)Google Scholar
- 26.Hagemaier, D.J.: Fundamentals of Eddy Current Testing. American Society for Nondestructive Testing, Columbus (1990)Google Scholar
- 27.Serway, R.A., Jewett, J.W.: Physics for Scientists and Engineers, 6th edn. Thomson Brooks/Cole, Belmont (2004)Google Scholar