Differential positron annihilation spectroscopy in nondestructive testing of thin chromium coatings on copper

• Published in: Protection of metals and physical chemistry of surfaces Vol. 46; no. 5; pp. 620 - 624
• Main Authors: Bardyshev, I. I., Kotenev, V. A., Aleshin, N. P., Tsivadze, A. Yu
• Format: Journal Article
• Language: English
• Published: Dordrecht SP MAIK Nauka/Interperiodica 01.09.2010; Springer Nature B.V
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Chromium; Clusters; COATINGS; Copper; Corrosion and Coatings; Industrial Chemistry/Chemical Engineering; Inorganic Chemistry; Investigation Methods for Physicochemical Systems; Materials Science; Metallic Materials; MICROSTRUCTURES; Nanostructure; NONDESTRUCTIVE TESTS; Positron annihilation; Positron annihilation spectroscopy; POSITRONS; Tribology; VOIDS; Copper Substrate; Positron Beam; Carbide Powder; Narrow Component; Chromium Coating
• ISSN: 2070-2051; 2070-206X
• DOI: 10.1134/S2070205110050217

The differential positron annihilation spectroscopy (DPAS) is used for the nondestructive investigation of thin metallic coatings on metallic substrates when the defectiveness of the coating applied is judged from the difference between the spectra of the individual substrate and the substrate covered with the coating. Using the DPAS angular correlation curves of positron annihilation radiation (ACAR), the presence of nanoscale void clusters in the X-ray amorphous galvanic chromium coatings with a weight thickness of 9.15 mg/cm 2 (1.3 μm) is determined on the copper substrate. The ACAR curves of the coatings have a complex structure compared to those of the specimens of Cr 3 C 2 and Cr 23 C 6 carbide powders and involve a narrow peak with a half width FWHF = 3 mrad and an intensity about 2% assigned to void clusters with a size of 0.86 nm, which act as positron traps, in the coating.