Continuous In-Line Chromium Coating Thickness Measurement Methodologies: An Investigation of Current and Potential Technology

Coatings or films are applied to a substrate for several applications, such as waterproofing, corrosion resistance, adhesion performance, cosmetic effects, and optical coatings. When applying a coating to a substrate, it is vital to monitor the coating thickness during the coating process to achieve a product to the desired specification via real time production control. There are several different coating thickness measurement methods that can be used, either in-line or off-line, which can determine the coating thickness relative to the material of the coating and the substrate. In-line coating thickness measurement methods are often very difficult to design and implement due to the nature of the harsh environmental conditions of typical production processes and the speed at which the process is run. This paper addresses the current and novel coating thickness methodologies for application to chromium coatings on a ferro-magnetic steel substrate with their advantages and limitations regarding in-line measurement. The most common in-line coating thickness measurement method utilized within the steel packaging industry is the X-ray Fluorescence (XRF) method, but these systems can become costly when implemented for a wide packaging product and pose health and safety concerns due to its ionizing radiation. As technology advances, nanometer-scale coatings are becoming more common, and here three methods are highlighted, which have been used extensively in other industries (with several variants in their design) which can potentially measure coatings of nanometer thickness in a production line, precisely, safely, and do so in a non-contact and non-destructive manner. These methods are optical reflectometry, ellipsometry and interferometry.

Effect of Time Voltage and Voltage of 1100 Aluminum Coating Using Chitosan Using Electrodeposition Method

Aluminum has mechanical properties such as light, easy to form, and the ability to conduct heat and electricity, but has less corrosion resistance properties. One effort to improve corrosion resistance in aluminum is by electrodeposition method. The electrodeposition process was carried out with a variation of time 10, 20, and 30 minutes and variations in voltage of 5 V, 10 V, and 15 V using AA 1100. The electrolyte used was a mixture of acetic acid and chitosan. Coating thickness measurement was carried out using NOVOTEST TP-1M coating thickness gauge, the corrosion rate was measured with 128N Autolab PGSTAT Potentiodynamic and surface roughness measurements using Mitutoyo SJ-210 Surface Roughness Tester. Based on the research data, it was found that the results of optimum layer thickness were obtained at 10 Volt variation of 20 minutes at 11 μm ± 0.04%. Specimens without treatment had the highest corrosion rate of 0.25541 mpy while the lowest corrosion rate was in the 10 variations of 20 minutes which produced 0.0078935 mpy. The surface roughness data of the specimen without treatment was 1.034 μm. The results of the smallest surface roughness were obtained at 10 V 20 minutes variation of 0.725 μm, while the largest surface roughness results in a variation of 15 V 30 minutes which was 2.529 μm. In this stud, it is known that the higher the time and stress used in the electrodeposition process results in greater corrosion rates, because it produces a higher layer thickness but results in higher surface roughness as well.

A SIMPLE METHOD FOR DETERMINING A THICKNESS OF METAL BASED ON LOCK-IN THERMOGRAPHY

The use of coatings is an important tool in the industry. It allows protecting against oxidation, corrosion and various types of fatigue. The coating thickness is an important characteristic that influences the quality and the performance of materials. In this paper, we develop a simple method of infrared lock-in thermography (LIT) to determine galvanizing coating thickness measurement, by using a sample multiple zinc layer with thickness ranging from 0.25[Formula: see text]mm to 1.5[Formula: see text]mm. The method has the particularity of taking a sinusoidal excitation heat flux which contributes with a heat exchange coefficient fixed at 10[Formula: see text]w/m2k and a surface emissivity of about 0.1. The finite element method (FEM) is used to model and analyze the thermal response of studied structure. The metal substrate used in this study is a structural steel, covered with six zinc layers. The finite elements analysis allows us to determine the temperature evolution at different points on the specimen. The Fourier transform method is used on the Matlab software to determine the phase angle of the data found. A correlation between the coating thickness and the equivalent phase angle is defined, and the results deduced show that the estimated values are close to the actual coating thicknesses with a precision ranging from 0.029[Formula: see text]mm to 0.011[Formula: see text]mm.

The Effect of Hot Dip Galvanizing Temperature to Corrosion Rate of Steel as the Material for Chopper Machine

This study aims to find material steel for animal feed chopper machine which is not easily corroded with method of hot dip galvanizing (HDG). Steel as machinery components or construction often gets broken before the predicted time because of corrosion. The HDG method was begun by pre-treatment process which were polishing, degreasing, rinsing I, pickling, rinsing II, fluxing, and drying. The main process of galvanizing was done by dipping in 98% of zinc solution with temperature variation of 430, 450, 470, and 490°C. The coating thickness measurement was run with Coating thickness NOVOTEST TP-1M. The corrosion was tested with electrochemical method of potentiodynamic polarization with AUTOLAB PGSTAT 128. The highest value of coating thickness was at galvanized temperature of 490°C which was 88.9 ± 3.24%. The value of standard deviation was indicated by how much the coating homogeneity formed. This was in line with the amount of corrosion rate at galvanized temperature of 490°C. The highest corrosion rate values in H2SO4 and NaCl environment were 1.18 and 0.21 mm/year. The highest hardness value of Zn layer is galvanizing temperature of 490°C which rises 41.71% of the base metal. The coating thickness, corrosion and surface hardness test have thee good agreement.