Journal of Thermal Spray Technology

, Volume 22, Issue 1, pp 48–56

Colour Matching in Decorative Thermally Sprayed Glass Coatings

  • Thierry Poirier
  • Pierre Bertrand
  • Christian Coddet
Peer Reviewed

DOI: 10.1007/s11666-012-9848-9

Cite this article as:
Poirier, T., Bertrand, P. & Coddet, C. J Therm Spray Tech (2013) 22: 48. doi:10.1007/s11666-012-9848-9

Abstract

Coloured coatings were obtained on steel by plasma spraying without severe in-flight alteration of pigments, taking profit of the low thermal conductivity of the glassy matrix of glaze particles. Colour matching was studied by mixing 3 different glazes, comparing Grassmann and Kubelka-Munk based algorithms. Results suggest that the latter method should be preferred upon Grassmann method, particularly when the light absorption/dispersion ratios of coloured feedstocks are very different.

Keywords

atmospheric plasma spray (APS)colourglassoptical spectroscopy

List of Symbols

a, b

Light absorption/scattering parameters, dimensionless

a*, b*

Orthogonal colour parameters, dimensionless

c

Volume concentration of pigment, %

C*

Chroma, dimensionless

CTE

Coefficient of thermal expansion (10−6 K−1)

E

Colour global parameter

h

Coating thickness, μm

h*

Hue, dimensionless

h

“Infinite” coating thickness, μm

i

Variable (dimensionless)

K

Light absorption, m−1

KM

Kubelka-Munk method

L*

Lightness of colour, dimensionless

n

Constant (dimensionless)

P

Colorimetric characteristic, dimensionless

RGB

Grassmann method

S

Light scattering, m−1

Greek Symbols

Δ

Difference between reference and experimental value

λ

Wavelength, nm

μ

Viscosity (Pa s)

ρ*

Corrected light reflectance (excluding specular effect) of the coating, dimensionless

ρ

Experimental light reflectance (including specular effect) of the coating, dimensionless

ρ0

Experimental light reflectance of the substrate, dimensionless

ρ0*

Experimental light reflectance of the substrate, dimensionless

ρ*

Corrected light reflectance of coating with “infinite thickness”

Ψ

Average difference between calculated and experimental reflectance spectra, dimensionless

Copyright information

© ASM International 2012

Authors and Affiliations

  • Thierry Poirier
    • 1
  • Pierre Bertrand
    • 2
  • Christian Coddet
    • 2
  1. 1.Grupo de Ingeniería de SuperficiesUniversidad Simón BolívarCaracasVenezuela
  2. 2.LERMPS, UTBMBelfort cedexFrance