Scanning Electron Microscopy and Energy Dispersive Spectroscopy (SEM/EDS)

Scanning electron microscopy (SEM) is often a first screening inspection for many material issues. Energy dispersive spectroscopy (EDS) is an accompanying elemental analysis technique that detects atomic numbers 6 through 92 with a detectability limit of approximately 0.1 weight percent. The analysis diameter and depth for EDS is typically a few micrometers. Images obtained in backscatter electron mode offer quick identification of areas with different atomic number.

SEM/EDS is an ideal technique for inspections of a wide range of materials. Typical applications include metallic and ceramic failures, electrical contact issues, coatings, polymers and paper products. EDS is a very rapid technique for measuring coating thickness in the range of 1000Å – 20,000Å if standards are available. EDS mapping illustrates the distribution of species in the near-surface region.

For studies that require the best in resolution, field emission scanning electron microscopy is also available. Insulating and fragile samples can be imaged without coating in a variable pressure system.

Scanning Electron Microscopy/Energy Dispersive Spectroscopy Features

  • Elemental concentration from atomic numbers 6-92
  • 1 -3 µm analysis depth
  • Backscattered electron imaging
  • Color maps and line scans

Metal Component Failure Analysis

SEM/EDS is one of the primary methods used to inspect failed components in a wide variety of applications. The micrographs below show materials that failed by ductile overload or by grain boundary embrittlement. The cross section illustrates a 330 stainless steel sample exhibiting carbon pick-up in a heat treating furnace.

Metal component failure 1

Metal component failure 2

Paper Coating

A coated cardboard product was cross-sectioned to investigate the thickness of coating layers (organic top coat, alumino-silicate kaolin, and calcium carbonate subcoatings).

 

scanning electron microscopy

SEM image

SEM investigation of carbon map

Carbon map

Silicon map of paper coating

Silicon map

Calcium map of coated cardboard product

Calcium map

aluminum map of ccoated cardboard product, aluminum-silicate kaolin

Aluminum map