IMR Materials Testing Technical Blog

Surface and Sub-Surface Material Contamination Testing Methods

When materials don’t perform to specifications, contaminants can sometimes be the culprit. Surface and sub-surface impurities in alloys, composites, paints and coatings are often difficult to spot with the naked eye, so having a reliable testing process can determine their source to ensure predictable product characteristics.

Contaminants can come from a wide range of sources including oils from equipment, residues from human hands, smudges and streaks from manufacturing processes and corrosion from leaks of water, coolants and more. These testing methods can uncover what part of the manufacturing process is compromising the cleanliness of the materials.

• Total Organic Carbon (TOC) Analysis is a rapid examination of extracts for residual organic materials such as oils, cleaning agents, lubricants, etc. If nothing is found in a TOC analysis, the sample can be said to be free of such contaminants. If a TOC test is positive for a contaminant, then the sample can be sent for additional analysis to determine more specifically what the contaminant is from. 
• Fourier Transform Infrared Spectroscopy (FTIR) Analysis is used to identify organic materials such as oils, cleaning agents, plastic particulates, and packaging residue extracted from sample surfaces and internal passages.
• ICP Chemical Analysis identifies elemental contaminants in extracts, such as residual iron from tooling during cutting, as well as providing a thorough breakdown of metallic particulates.
• Ion Chromatography (IC) is an analytical technique that permits the dynamic separation and detection of anions in an aqueous solution. Most anions can be reported to ppb levels. We can work with a variety of solvents, from reagent grade, to common cleaners or your proprietary blends. Residual ionics can lead to corrosion and other degradation of components.
• Scanning Electron Microscopy / Energy Dispersive X-ray Analysis (SEM/EDS) allows for high magnification examination of particulate and other debris removed during extraction procedures. Chemical analysis by EDs provides information on the elemental makeup of particles, allowing them to be traced back to their sources.

Proper precautions need to be taken when preparing samples for testing so cross-contamination doesn’t occur. Testing labs will have proper protocols specified for best practices.

For information on IMR Test Labs Cleanliness and Contaminant Testing Services, click here.