Željko Alar

Uncertainty Estimation of Coating Thickness Measurement Results

Abstract This contribution presents an estimation of the measurement uncertainty of coating thickness measurement results. The measurements were performed on a steel sheet sample with an outside shell plating. The sample is protected against corrosion with two layers of 100 ¼m thick dry film. In the present case, the criteria of “80-20” have been applied. The measurement uncertainty evaluation has been carried out using Monte Carlo simulations (MCS method) in accordance with the document OIML G 1-101 Edition 2008 (E) Evaluation of Measurement Data – Supplement 1 to the Guide to the Expression of Uncertainty in Measurement – Propagation of Distributions Using a Monte Carlo Method. The criteria “80-20” was evaluated based on the mean coating thickness measurement results, as well as, on the basis of the complete measuring information. Aside from the expected value, complete measuring information comprises the value of measurement uncertainty. In the case where measurement result is described only as the mean of the measurement values a wrong conclusion regarding the fulfillment “80-20” is reached.

Coating Distribution Depending on Surface Microgeometry

Abstract This paper investigates the effects of surface microgeometry on coating thickness, both theoretically and experimentally. In the theoretical part of the paper, surface roughness parameters are analyzed and basic definitions and general requirements on coating quality defined. The experimental part of the paper gives a calculation for the coating quantity required in order to fill “dead volume” depending on surface roughness. Coating distribution is analyzed using scanning electronic microscopy (SEM). The paper also evaluates quality of a measuring system using magnetic method for measuring coating thickness.

Waste Water Treatment after Removal of Thermic Oxides from Stainless Steel Welding Joints

This work describes chemical methods of removal of thermic oxides from stainless steel welding joints, as well as waste water treatment. Thermal oxides were removed from the stainless steel surface using chemical and electrochemical procedures. A pickling paste that contains HNO3 and HF in different ratios was used for chemical cleansing of thermal oxides (A, B, and C). Electrochemical removal was done using an apparatus Magic Cleaner, and as electrolyte a solution H2SO4

Measurement and control of copper and tin coatings

Abstract Comparison of thickness measurement for selectively applied copper and tin coatings on printed circuit boards was performed by use of destructive and non-destructive methods. The analysis of measurement results was performed by applying criterion of critical difference of repeatability and reproducibility according to international standard ISO 5725-(1-6):1994. Comparison of results for measuring ranges on the basis of critical difference of reproducibility, shows that results of measurement for copper and tin coatings obtained by using different methods are mutually comparable. In measuring tin coating, repeatability of measurement results was achieved and that means that results obtained in very strict conditions are comparable.

Characterization of Thermal Oxides on Austenitic Stainless Steel

Abstract In this paper, phases, chemical compositions and size of thermal oxides on an austenitic stainless steel AISI 316L were investigated. The steel specimens were subjected to isothermal heating at 200 °C up to 1000 °C in order to simulate production conditions and then compared with unheated specimens. X-ray diffraction analysis, Auger electron spectroscopy, Scanning electron microscopy and optical micrography have been used for characterization of the thermal oxides on the steel specimens.