Residual stresses in HVOF sprayed ceramic coatings

Giovanni Bolelli, Luca Lusvarghi (Corresponding Author), Tommi Varis, Erja Turunen, Matteo Leoni, Paolo Scardi, Cristy Leanor Azanza-Ricardo, Massimilano Barletta

Research output: Contribution to journalArticleScientificpeer-review

38 Citations (Scopus)

Abstract

In this paper, the residual stress state of thermally sprayed ceramic coatings was examined by combining different experimental and analytical techniques, in order to provide a thorough characterisation of through-thickness stress profiles and a cross-verification of results. HVOF-sprayed ceramics, manufactured using commercial and nanostructured Al2O3 powders and commercial Cr2O3 powders, and atmospheric plasma-sprayed (APS) ceramics, manufactured using commercial Al2O3 and Cr2O3 powders, were investigated.
The near-surface stress was measured by X-ray diffraction. The through-thickness profile and the intrinsic quenching stress were analytically computed by the Tsui–Clyne iterative model, using the X-ray measurement result as input, and results were validated by the substrate chemical removal method. Further verification was achieved by applying the in-situ curvature technique to the deposition of HVOF-sprayed Al2O3 coating.
HVOF-sprayed Al2O3 coatings deposited using both conventional and nanostructured powders feature a similar, almost equibiaxial tensile stress on the top surface (116.5 MPa and 136.5 MPa, respectively) and a moderate through-thickness gradient (about 12 MPa and 20 MPa, respectively). Their intrinsic quenching stresses were analytically estimated to be 184 MPa and 205 MPa, respectively. APS Al2O3 possesses higher top surface stress (220 MPa) and quenching stress (311 MPa). However, it shows a less pronounced stress gradient (≈ 3 MPa) than HVOF-sprayed Al2O3-based coatings, because cracks, pores and weak lamella boundaries in the APS coating can accommodate the deformations induced by the bending moments arising both during coating deposition and during cooling.
The model-derived quenching stress of the conventional HVOF Al2O3 coating was validated by the in-situ curvature measurement technique.
Cr2O3-based coatings are significantly different. They display a lower residual stress in the near-surface region: 20 MPa in the APS coating, 27.5 MPa in the HVOF one. The HVOF coating also exhibits a very large stress gradient of ≈ 77 MPa. Machining and sliding processes (like polishing and dry sliding tribological testing) change their surface residual stresses to compressive ones.
Original languageEnglish
Pages (from-to)4810-4819
JournalSurface and Coatings Technology
Volume202
Issue number19
DOIs
Publication statusPublished - 2008
MoE publication typeA1 Journal article-refereed

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ceramic coatings
sprayed coatings
Ceramic coatings
Sprayed coatings
residual stress
Residual stresses
Powders
Quenching
Coatings
quenching
Plasmas
coatings
gradients
sliding
curvature
ceramics
bending moments
Bending moments
lamella
profiles

Keywords

  • high velocity oxygen-fuel spraying
  • HVOF
  • ceramics
  • ceramic coatings
  • residual stress
  • residual stress measurement

Cite this

Bolelli, G., Lusvarghi, L., Varis, T., Turunen, E., Leoni, M., Scardi, P., ... Barletta, M. (2008). Residual stresses in HVOF sprayed ceramic coatings. Surface and Coatings Technology, 202(19), 4810-4819. https://doi.org/10.1016/j.surfcoat.2008.04.066
Bolelli, Giovanni ; Lusvarghi, Luca ; Varis, Tommi ; Turunen, Erja ; Leoni, Matteo ; Scardi, Paolo ; Azanza-Ricardo, Cristy Leanor ; Barletta, Massimilano. / Residual stresses in HVOF sprayed ceramic coatings. In: Surface and Coatings Technology. 2008 ; Vol. 202, No. 19. pp. 4810-4819.
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abstract = "In this paper, the residual stress state of thermally sprayed ceramic coatings was examined by combining different experimental and analytical techniques, in order to provide a thorough characterisation of through-thickness stress profiles and a cross-verification of results. HVOF-sprayed ceramics, manufactured using commercial and nanostructured Al2O3 powders and commercial Cr2O3 powders, and atmospheric plasma-sprayed (APS) ceramics, manufactured using commercial Al2O3 and Cr2O3 powders, were investigated.The near-surface stress was measured by X-ray diffraction. The through-thickness profile and the intrinsic quenching stress were analytically computed by the Tsui–Clyne iterative model, using the X-ray measurement result as input, and results were validated by the substrate chemical removal method. Further verification was achieved by applying the in-situ curvature technique to the deposition of HVOF-sprayed Al2O3 coating.HVOF-sprayed Al2O3 coatings deposited using both conventional and nanostructured powders feature a similar, almost equibiaxial tensile stress on the top surface (116.5 MPa and 136.5 MPa, respectively) and a moderate through-thickness gradient (about 12 MPa and 20 MPa, respectively). Their intrinsic quenching stresses were analytically estimated to be 184 MPa and 205 MPa, respectively. APS Al2O3 possesses higher top surface stress (220 MPa) and quenching stress (311 MPa). However, it shows a less pronounced stress gradient (≈ 3 MPa) than HVOF-sprayed Al2O3-based coatings, because cracks, pores and weak lamella boundaries in the APS coating can accommodate the deformations induced by the bending moments arising both during coating deposition and during cooling.The model-derived quenching stress of the conventional HVOF Al2O3 coating was validated by the in-situ curvature measurement technique.Cr2O3-based coatings are significantly different. They display a lower residual stress in the near-surface region: 20 MPa in the APS coating, 27.5 MPa in the HVOF one. The HVOF coating also exhibits a very large stress gradient of ≈ 77 MPa. Machining and sliding processes (like polishing and dry sliding tribological testing) change their surface residual stresses to compressive ones.",
keywords = "high velocity oxygen-fuel spraying, HVOF, ceramics, ceramic coatings, residual stress, residual stress measurement",
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Bolelli, G, Lusvarghi, L, Varis, T, Turunen, E, Leoni, M, Scardi, P, Azanza-Ricardo, CL & Barletta, M 2008, 'Residual stresses in HVOF sprayed ceramic coatings', Surface and Coatings Technology, vol. 202, no. 19, pp. 4810-4819. https://doi.org/10.1016/j.surfcoat.2008.04.066

Residual stresses in HVOF sprayed ceramic coatings. / Bolelli, Giovanni; Lusvarghi, Luca (Corresponding Author); Varis, Tommi; Turunen, Erja; Leoni, Matteo; Scardi, Paolo; Azanza-Ricardo, Cristy Leanor; Barletta, Massimilano.

In: Surface and Coatings Technology, Vol. 202, No. 19, 2008, p. 4810-4819.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - Residual stresses in HVOF sprayed ceramic coatings

AU - Bolelli, Giovanni

AU - Lusvarghi, Luca

AU - Varis, Tommi

AU - Turunen, Erja

AU - Leoni, Matteo

AU - Scardi, Paolo

AU - Azanza-Ricardo, Cristy Leanor

AU - Barletta, Massimilano

PY - 2008

Y1 - 2008

N2 - In this paper, the residual stress state of thermally sprayed ceramic coatings was examined by combining different experimental and analytical techniques, in order to provide a thorough characterisation of through-thickness stress profiles and a cross-verification of results. HVOF-sprayed ceramics, manufactured using commercial and nanostructured Al2O3 powders and commercial Cr2O3 powders, and atmospheric plasma-sprayed (APS) ceramics, manufactured using commercial Al2O3 and Cr2O3 powders, were investigated.The near-surface stress was measured by X-ray diffraction. The through-thickness profile and the intrinsic quenching stress were analytically computed by the Tsui–Clyne iterative model, using the X-ray measurement result as input, and results were validated by the substrate chemical removal method. Further verification was achieved by applying the in-situ curvature technique to the deposition of HVOF-sprayed Al2O3 coating.HVOF-sprayed Al2O3 coatings deposited using both conventional and nanostructured powders feature a similar, almost equibiaxial tensile stress on the top surface (116.5 MPa and 136.5 MPa, respectively) and a moderate through-thickness gradient (about 12 MPa and 20 MPa, respectively). Their intrinsic quenching stresses were analytically estimated to be 184 MPa and 205 MPa, respectively. APS Al2O3 possesses higher top surface stress (220 MPa) and quenching stress (311 MPa). However, it shows a less pronounced stress gradient (≈ 3 MPa) than HVOF-sprayed Al2O3-based coatings, because cracks, pores and weak lamella boundaries in the APS coating can accommodate the deformations induced by the bending moments arising both during coating deposition and during cooling.The model-derived quenching stress of the conventional HVOF Al2O3 coating was validated by the in-situ curvature measurement technique.Cr2O3-based coatings are significantly different. They display a lower residual stress in the near-surface region: 20 MPa in the APS coating, 27.5 MPa in the HVOF one. The HVOF coating also exhibits a very large stress gradient of ≈ 77 MPa. Machining and sliding processes (like polishing and dry sliding tribological testing) change their surface residual stresses to compressive ones.

AB - In this paper, the residual stress state of thermally sprayed ceramic coatings was examined by combining different experimental and analytical techniques, in order to provide a thorough characterisation of through-thickness stress profiles and a cross-verification of results. HVOF-sprayed ceramics, manufactured using commercial and nanostructured Al2O3 powders and commercial Cr2O3 powders, and atmospheric plasma-sprayed (APS) ceramics, manufactured using commercial Al2O3 and Cr2O3 powders, were investigated.The near-surface stress was measured by X-ray diffraction. The through-thickness profile and the intrinsic quenching stress were analytically computed by the Tsui–Clyne iterative model, using the X-ray measurement result as input, and results were validated by the substrate chemical removal method. Further verification was achieved by applying the in-situ curvature technique to the deposition of HVOF-sprayed Al2O3 coating.HVOF-sprayed Al2O3 coatings deposited using both conventional and nanostructured powders feature a similar, almost equibiaxial tensile stress on the top surface (116.5 MPa and 136.5 MPa, respectively) and a moderate through-thickness gradient (about 12 MPa and 20 MPa, respectively). Their intrinsic quenching stresses were analytically estimated to be 184 MPa and 205 MPa, respectively. APS Al2O3 possesses higher top surface stress (220 MPa) and quenching stress (311 MPa). However, it shows a less pronounced stress gradient (≈ 3 MPa) than HVOF-sprayed Al2O3-based coatings, because cracks, pores and weak lamella boundaries in the APS coating can accommodate the deformations induced by the bending moments arising both during coating deposition and during cooling.The model-derived quenching stress of the conventional HVOF Al2O3 coating was validated by the in-situ curvature measurement technique.Cr2O3-based coatings are significantly different. They display a lower residual stress in the near-surface region: 20 MPa in the APS coating, 27.5 MPa in the HVOF one. The HVOF coating also exhibits a very large stress gradient of ≈ 77 MPa. Machining and sliding processes (like polishing and dry sliding tribological testing) change their surface residual stresses to compressive ones.

KW - high velocity oxygen-fuel spraying

KW - HVOF

KW - ceramics

KW - ceramic coatings

KW - residual stress

KW - residual stress measurement

U2 - 10.1016/j.surfcoat.2008.04.066

DO - 10.1016/j.surfcoat.2008.04.066

M3 - Article

VL - 202

SP - 4810

EP - 4819

JO - Surface and Coatings Technology

JF - Surface and Coatings Technology

SN - 0257-8972

IS - 19

ER -