Title: Comparative study of three methods for measuring thickness of PVD hard coatings

Authors: Miguel A. Quinones-Salinas; Rafael David Mercado-Solis

Addresses: Facultad de Ingeniería Mecánica y Eléctrica, Universidad Autónoma de Nuevo León, Av. Universidad S/N, Cd. Universitaria, San Nicolás de los Garza, Nuevo León, CP. 66451, México ' Facultad de Ingeniería Mecánica y Eléctrica, Universidad Autónoma de Nuevo León, Av. Universidad S/N, Cd. Universitaria, San Nicolás de los Garza, Nuevo León, CP. 66451, México

Abstract: This study presents a comparison between three methods that are widely employed for measuring thickness of PVD hard coatings, namely: the calotte grinding method (CGM), glow discharge optical emission spectroscopy (GDOES) and metallographic micro polishing (MMP). Thickness measurements were performed in several coating structures deposited on steel substrates. Based on the results, a discussion of their main advantages and disadvantages is presented, focusing on the complementarities between the three methods. Each method provided results at various levels of cost, accuracy and time. The high precision of MMP is the main advantage of this method; however sample preparation is time consuming. GDOES provides quick results but the equipment and testing costs are high. The CGM is the quickest and less expensive, but not the most accurate. It was concluded from this study that no method is better than the others; instead, each method should be regarded as complementary to one another.

Keywords: PVD coatings; calotte grinding method; CGM; glow discharge OES; optical emission spectroscopy; GDOES; metallographic micro polishing; MMP; scanning electron microscopy; SEM; coating thickness; hard coatings; steel substrates.

DOI: 10.1504/IJSURFSE.2015.072831

International Journal of Surface Science and Engineering, 2015 Vol.9 No.6, pp.493 - 509

Available online: 04 Nov 2015 *

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