Guess the Materials Characterization Technique Part II

materials characterizationWhen unknown contaminants appear on your products due to failures in manufacturing processes, there are techniques that can help you identify the cause of the issue. Materials analysis laboratories use materials characterization to analyze and reverse engineer unknown materials to discover their composition.

In our last post, we brought up four issues and asked you to name the materials analysis technique required to troubleshoot the problem. If you have your answers, let’s go over them together.

  1. Plastic parts supplied by a new vendor have a strong odor that parts from a previous supplier did not have. How can you determine if the off gassing material is hazardous to workers health or detrimental to your product?

ANSWER: Gas Chromatography Mass Spectroscopy – Also known as GC/MS

The plastic parts were sealed in a glass vial and heated to drive off any potentially volatile materials.  The evolved gasses were then analyzed using GC/MS.  The parts were outgassing a mixture of hydrocarbons and residual solvents; none of the products found in the outgassing study would be detrimental to the integrity of the parts.  The findings were forwarded to an industrial hygienist for determination if the levels were hazardous to employee health.

  1. The prototype of a medical device made with the specialized alloy Nitinol is showing unforeseen signs of wear. Medical devices made with metals like Nitinol need to be passivated to maintain biocompatibility. Which materials characterization technique do you need to measure the passivation layer?

ANSWER: Auger Electron Spectroscopy – Also known as Auger

Along with sputter depth profiling, Auger quantifies surface impurities in the passivation oxide layer and determines its thickness.  In the prototype, analysts find the thickness of the passivation layer  inconsistent, with portions of the layer being much thinner than other areas.

The measurement allows the product engineers to submit their next prototype to have a thicker, more consistent passivation layer and prevent any future biocompatibility issues.

  1. A plastic toy manufacturer needs to ensure that if a child put one of the company’s toys in their mouth, it won’t make them sick. After noticing abnormal particulates upon their final product, the manufacturer needs to determine the composition of the particulate and see if their manufacturing process needs an update. Which materials characterization technique should you use to analyze it?

ANSWER: Fourier Transform Infrared Spectroscopy – Also known as FTIR Analysis

With the particulate isolated, a microscope attachment on the FTIR uses infrared light upon the particulate. The spectrum of the material is characterized as a surfactant, normally used to clean the surface of the toy. Upon this discovery, a surfactant sample used in manufacturing the toy is analyzed and proves to be the same material.

This result helps the toy engineers reevaluate how they remove cleaning agents before distribution.

  1. You’re seeing spots on your Low-E glass and suspect corrosion is occurring somewhere in the stack of metal oxide layers. How can you determine if this is the case and where in the stack the corrosion is occurring.

Electron Spectroscopy for Chemical Analysis – Also known as ESCA

Using Electron Spectroscopy for Chemical Analysis (ESCA), the corrosion spot was analyzed.  The result showed the presence silver and sulfur among other things.  The detection of silver indicated that some of the film stack layers were missing and the presence of sulfur indicated the silver film had been corroded.”

So how did you do? If you did not get a perfect score, don’t worry. If you don’t know how to analyze an unknown contaminant, the materials characterization professionals at Innovatech Labs will. Whatever the unknown material, we have a technique that can help identify its composition and help you figure out how to make sure it doesn’t appear again.

For more information, see the list of all of the materials analysis techniques performed by Innovatech Labs or contact us with questions.

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