Materials Science Project Profiles

Material Identification – Odorizing Plug-ins

The purpose of the analysis was to determine the cause of darkening in an odorizing plug-in component. The plug-in liquid component contained unknown black deposits and was subjected to identification analysis. The particles were filtered and analyzed by stereomicroscopy, polarized light microscopy (PLM), and scanning electron microscopy with energy dispersive x-ray (SEM/EDX). In conclusion, the dark deposits were composed of a mixture of metal oxides (iron (Fe), chromium (Cr), and nickel (Ni)) and fine metal dust. The mixture is typically related to corrosion products of stainless steel. The ability to use various microscopy instruments proved invaluable regarding unknown particulate identification.

Material Identification – Coal/Fly Ash in Water

The purpose of the analysis was to determine the presence of coal/fly ash in a water sample. The water was filtered and the residue on the filter was analyzed by stereomicroscopy, polarized light microscopy (PLM), and scanning electron microscopy with energy dispersive x-ray (SEM/EDX). The particles showed morphology and elemental composition associated with coal/fly ash. The ability to use various microscopy instruments proved invaluable regarding unknown particulate identification.

Material Identification – Residue of Needle

The purpose of the analysis was to determine the identification of deposits on the tip of surgical needles. The sample in the as-received condition showed dark deposits on selected needle tips. The needle tips were removed from the metal base and analyzed by stereomicroscopy and scanning electron microscopy with energy dispersive x-ray (SEM/EDX). In conclusion, SEM/EDX analysis showed the presence of carbon (C) and silicon (Si), most likely as silicone.

Material Identification – Mislabeled Chemical

The purpose of the analysis was to determine the identification of the individual components from a potentially mislabeled product. The sample was labeled as ammonium nitrate. The sample was analyzed by stereomicroscopy, polarized light microscopy (PLM), scanning electron microscopy with energy dispersive x-ray (SEM/EDX), and Fourier Transform Infrared Spectroscopy (FTIR). PLM image showed the material was crystalline in nature. SEM/EDX spectrum showed the material contained zinc (Zn), oxygen (O), and nitrogen (N). FTIR spectrum of the sample showed a match to zinc nitrate (library search and match). In conclusion, the sample was mislabeled as ammonium nitrate and found to be zinc nitrate after laboratory analysis. The ability to use various microscopy instruments proved invaluable regarding the identification of an unknown chemical.

Material Identification – Foreign Material Analysis

The purpose of the analysis was to determine the identification of unknown particulate in two different samples. Sample 1 contained a translucent, rubbery like material. Sample 2 contained a metallic-like particle. Sample 1 was analyzed by stereomicroscopy and Fourier Transform Infrared Spectroscopy (FTIR). Stereomicroscopy showed the presence of translucent, rubbery material. FTIR spectrum showed chemical similarities with ethylene/ethyl acetate using library search and match. Sample 2 was analyzed by stereomicroscopy and scanning electron microscopy with energy dispersive x-ray (SEM/EDX). Stereomicroscopy showed the presence of a metallic fragment. SEM image and corresponding EDX spectrum showed elemental composition consistent with stainless steel fragment. In conclusion, Sample 1 showed chemical similarities to ethylene/ethyl acetate; Sample 2 showed material was consistent with stainless steel. The ability to use various microscopy instruments proved invaluable regarding unknown particulate identification.

Material Identification – Corrosion

The purpose of the analysis was to identify the deposits in selected alcohol bottles and characterize scratches on the inside of aluminum cans. The can samples were cut to expose affected areas. Stereomicroscopy was used to show the affected can area vs. the unaffected can area. The affected area showed scratch marks and pit perforation in the can wall. Scanning electron microscopy/SEM was used to show pit perforation. Energy dispersive x-ray/EDX showed that the deposits near the perforation were carbon-based/organic. SEM/EDX imaging also showed numerous scratch marks from a tool or object with tip dimension of ~ 0.2mm in width (likely related to dragging motion). No visible defects were found in the unaffected can for comparison. The deposits in the alcohol sample were filtered through a filter and analyzed by SEM/EDX. SEM analysis showed the particulate were carbon-based/organic and also contained aluminum (Al) and phosphorus (P). Small aluminum (Al) fragments were also found. In conclusion, (1) the scratch marks found on the interior can walls were consistent with damage of the organic coating (down to aluminum base), most likely from a drag motion of a tool or object, (2) scratched cans showed pit perforations, and (3) the deposits filtered from alcohol bottles were a mixture of organic matter (with lower amounts of aluminum and occasionally phosphorus) and small aluminum fragments. The ability to use various microscopy instruments proved invaluable regarding corrosion analysis.

Material Identification – Aluminum Corrosion

The purpose of the analysis was to determine the identification of individual components related to corrosion. Possible corrosion was noticed on aluminum fins in cooling/heating coil-heat pump. The material was analyzed by stereomicroscopy, polarized light microscopy (PLM), and scanning electron microscopy with energy dispersive x-ray (SEM/EDX). PLM image of particles showed presence of nearly amorphous material. SEM image and corresponding EDX elemental spectrum of sample showed presence of aluminum (Al) and oxygen (O), most likely as a mixture of oxide/hydroxide/ oxy-hydroxide. In conclusion, analysis showed the material is composed of a mixture of aluminum oxide/hydroxide/oxy-hydroxide. The material is most likely produced due to corrosion of aluminum in humid and hot environment. Elements known to accelerate the corrosion such as chlorine and sulfur were not found. The ability to use various microscopy instruments proved invaluable regarding unknown material identification in relation to corrosion.

Materials Science Project Profiles