Capabilities

We provide testing services to certify product and materials compliance, support quality control, and ensure the health and safety of workers and their environment. We provide assistance for clients who are not sure what tests they need. Our accredited materials characterization laboratory is the foundation of all the services of RJ Lee Group provides, including standardized testing for compliance, industrial hygiene and environmental analyses, quality control, and materials research and development.

We provide credentialed expertise supported built by robust scientific data. We provide significant support to industrial clients for product development, industrial hygiene and overall production support.

RJ Lee Group maintains a visible and respected reputation within the legal community, having offered scientific support in civil litigation matters for nearly 30 years. 

  • Product Liability 
  • Toxic Tort
  • Construction Defect
  • Fugitive Emission
  • Personal Injury
  • Patent Infringement
  • Contract Disputes
  • Insurance Subrogation

Subject Matter Experts

From our core business of providing scientific solutions to our clients, we have developed innovative products. Some are produced internally, and some have arisen from partnerships with other research organizations. 

For example, we build lab software solutions to help manage and streamline your labs data, and environmental testing products for a variety of applications. 

  • IntelliSEM is a powerful automated particle analysis system.
  • ParticleID is  a customizable cloud hosted web application used to identify foreign particulate matter and  assist with root cause investigations. 

Other products we create count particles and help keep the air and environment safe.

RJ Lee Group is a materials analysis laboratory and consulting company which serves many different industries. We offer scientific solutions such as industrial forensics services, laboratory and testing services, litigation support, and laboratory software to many industries:

The Role of XPS in Determining the Quality of Stainless Steel Passivation

RJ Lee Group News

July 15, 2015

This blog post was written by Dr. Jerry LaSalle, an expert in XPS surface analysis and physical and powder metallurgy. Dr. LaSalle’s areas of concentration include stainless steel passivation qualification, metallurgical failure analysis, additive manufacturing, and powder metallurgy consultation.

The surface of a bulk material is its window to the outside world, and its first point of contact with the environment around it. This thin layer of surface material dictates a material’s corrosion, adhesion, and friction properties, as well as any chemical reactions. When surface atoms and molecules are illuminated with X-rays, they generate unique electron spectra (fingerprints) that are based on each element’s electron energy and intensity. Modern detectors like the X-ray photoelectron spectroscopy (XPS), also known as Electron Spectroscopy for Chemical Analysis (ESCA), use computer software to quickly and precisely interpret the resulting spectral fingerprints and determine the elemental and molecular states of the top few atomic layers of a material’s surface.

Application

One important application of the XPS is to determine the quality of stainless steel passivation. The alloy, stainless steel, typically contains a minimum of 12% chromium (Cr) in addition to iron (Fe), and owes its corrosion resistance to the formation of a thin, self-healing chromium oxide layer (on the order of 10 atomic layers) on the surface. Passivation, typically achieved by using nitric acid treatments, enhances the corrosion resistance of stainless steel by enriching the chromium oxide to iron oxide ratio at the surface.

The XPS uses a process called sputtering, in which atomic ions gently remove surface atoms. Modern XPS software, such as that used by the K-alpha XPS unit, can then interpret the resulting spectra. Using predetermined sensitivity factors for Fe and Cr, the K-alpha XPS is able to rapidly ascertain the Croxide/Feoxide ratio and provide a pass/fail measurement of the passivation quality. The quality of the software’s algorithm and elemental sensitivity factors is key to a correct assessment. The figure below shows the Cr/Fe ratio as a function of depth. It demonstrates that the Cr/Fe ratio below the surface is in agreement with the bulk chemistry for 316L grade stainless steel, i.e., a nominal ration of Cr/Fe ~0.25. Using this feature, the analyst can document the XPS instrument’s accuracy in detecting the two key elements (Cr and Fe) that define a particular grade of stainless steel.

XPS Steel Passivation Spectrum

RJ Lee Group’s K-alpha XPS unit uses precisely calibrated elemental signatures, giving it the capability to determine a material’s surface chemical constituents and chemical states. This instrument is highly effective in rapid and accurate analysis of a material’s top few atomic layers, and can be employed in diverse applications from finding unknown surface species to rapid quality control applications, such as determining the quality of stainless steel.

For more information on XPS analysis, please contact RJ Lee Group at 1.800.860.1775.

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