What tools are needed to evaluate a CVD coating surface? Let's discuss material characterization and how it applies to CVD coatings.
In this blog post you will learn:
Material surface characterization capabilities of SilcoTek®
Material surface characterization capabilities serve an essential role in supporting SilcoTek® coating science and R&D efforts. The ability to thoroughly evaluate a surface is key to developing new inert barrier coating products, and plays an essential role in assisting customers with scale up and process troubleshooting.
Various surface characterization techniques enable SilcoTek scientists to study materials, analyze surface bonding mechanisms, and develop a deep understanding of surface properties. SilcoTek® production technicians use material characterization tools in their daily QA/QC process to make sure all our inert, corrosion resistant coatings meet our quality standards and satisfy customer needs. Last but not least, it is not uncommon for customers to work with R&D staff to provide characterization help with their specific substrates or coated parts as part of their product development.
In addition to the in-house characterization capabilities, SilcoTek® also enjoys convenient access to a wide variety of characterization techniques at the Pennsylvania State University (PSU), thanks to our physical proximity to the University’s main campus, and an established academic/industry relationship between PSU and SilcoTek®. SilcoTek’s R&D scientists are certified users of many characterization instruments located at the Materials Characterization Lab (MCL) at Penn State University. Here are some of the tools we use to support our customer, products and processes.
What Tools Are Needed To Characterize A Surface?
Coating surface characterization starts with a capable and knowledgeable R&D team. Tools to help analyze the surface vary with application and need but here are a few tools we use to understand CVD coatings and surfaces.
X-ray Fluorescence (XRF) Analyzer
In order to avoid process disruptions caused by incompatible substrates, SilcoTek uses a Thermo Scientific X-ray fluorescence (XRF) analyzer, a non-destructive elemental analysis tool, to identify any unfamiliar incoming metal substrates. Why is this important? Because the substrate material affects the coating quality, surface bond, and ultimate product performance. Knowing the base material enables our process technicians to use the most appropriate processing methods to get the best coating results possible.
Fourier Transform Infrared Spectroscopy (FTIR) uses broad band infrared radiation as the excitation source to probe molecular structures of various chemical species in gas, liquid or solid state. The FTIR technique is used by SilcoTek’s technicians on a regular basis to perform select QA/QC duties, as well as by SilcoTek’s scientists to assist in their R&D projects. Why is this important? Because FTIR can be used to determine surface quality on a molecular level and can be used as an additional tool in combination with visual inspection criteria to better assess coating quality.
F20 Thin-film Analyzer
SilcoTek’s F20 thin-film analyzer is a bench top tool that can be configured to measure thin film thicknesses (30Å to 350 mm), optical constants such as refractive index, extinction coefficient and transmittance. It is primarily used by SilcoTek as a quick, accurate and non-destructive way to measure surface thicknesses and to assure consistent coating quality.
Surface contact angle measurement
Contact angle is the angle that a drop of liquid makes to its (usually solid phase) contacting surface. It is measured through the droplet, with the angle formed between the solid surface and the liquid meniscus near the line of contact. The contact angle gives an indication of the wettability of a surface to a liquid (usually water).
SilcoTek scientists rely heavily on the contact angle measurement in their research of hydrophobic and superhydrophobic surface development, where properly designed surface energy can bring out the extreme water-repellent property in a surface or can prevent surface fouling or enhance mold release.
Contact angle measurement us used to benefit SilcoTek’s customers by ensuring the anticipated surface energy (hydrophobicity/hydrophilicity) as required by application is achieved.
Electrochemical Impedance Spectroscopy (EIS)
Electrochemical impedance spectroscopy (EIS) is a mostly non-destructive and very useful tool to study and evaluate the performance of protective coatings on metal substrates. The measurement gives information such as resistance, capacitance, double layer capacitance and Faradaic impedance which are related to the performance and failure process of coatings especially during corrosion resistance testing. EIS helps SilcoTek Engineers and Scientists to identify coating pinholes and to develop better, more uniform coatings.
This blog posting highlights a range of materials characterization techniques available to SilcoTek®. It aims to help our customers understand the scope and capability of SilcoTek’s R&D activities, as well as to demonstrate how different tools can be used to facilitate SilcoTek in the development of more innovative solutions, and to help our customers solve application challenges. Easy availability of these tools also allows SilcoTek’s manufacturing team to keep a tight quality control on our inert coating products, thereby providing consistent and reliable products to all our customers.