SEM Sample Images

The following is a selection of samples recently analyzed using our SEM/EDS. These examples were chosen to show the types of materials often characterized in our laboratory. Click on a thumbnail image to view a full-size version. If you have any questions regarding a specific sample you may be interested in having analyzed, please call our laboratory for more information.

Metals

Metals are commonly analyzed using SEM/EDS. Examples of metals analysis are to determine the quality of the manufactured product, analyze a failure, look for surface irregularities, identify contaminates, and verify the alloy composition. To accomplish the analysis, one can examine fracture surfaces, layers and interfaces, inclusions or holes, surface morphology, elemental distributions, etc. Image 1 shows a fatique failure of a VCR steel mounting bracket at 1500X magnification.

Intergranular failure is another failure mechanism that occurs in metals. Image 2 was also a steel bracket that was photographed at 500X. To see more detail in the fracture surface, the magnification was increased to 2000X as shown in Image 3.

Click on a thumbnail to see a larger image
Image 1	Image 2	Image 3

Corrosion products

Metals exposed to harsh environments can exhibit evidence of corrosion. EDS can be used to determine the elements present in the corroded region. Image analysis can pinpoint the extent of the corrosion that may only be barely visible to the naked eye. The crystalline appearance may also give some insight as to the corrosion formation mechanism. Image 4 is an example of iron oxide crystals on a steel plate surface taken at 3000X magnification. By contrast, Image 5 illustrates the appearance of zinc oxide on galvanized ductwork at 2000X.

Click on a thumbnail to see a larger image
Image 4	Image 5

Contamination

Products can become contaminated with foreign debris that can inhibit their performance or affect their appearance. This may happen during the manufacturing process or occur after product use. One example is failure of an electrical contact when debris comes between the contacts interrupting the flow of current. Image 6 is an example of particles found in the contact area of a copper electrical component.

Click on the thumbnail to see a larger image

Image 6

Superconductors

The shape and structure of individual strands in a superconducting cable has a major impact on it's performance. An initial examination of a cable was performed by preparing a polished cross-section of a niobium-tin (Nb-Sn) cable with all the individual strands evident as pictured in Image 7 at 100X magnification. For a closer examination, one individual strand was imaged at 900X as Image 8.

Click on a thumbnail to see a larger image
Image 7	Image 8

Semi-conductors

Many products contain a semi-conductor chip or other electrical components. To determine if the integrated circuit (IC) from a computer had failed, it was ashed to expose the internal workings. Image 9 revealed that a wire and contact pad had broken loose from it's original connection to the board. Other electrical components such as resistors, connectors, thermal cut-off devices, thermostats etc. can be analyzed in much the same manner.

Click on the thumbnail to see a larger image

Image 9

Plastics and polymers

Plastic parts and polymer components can be examined using the variable pressure capability of our SEM/EDS without coating the sample with carbon or gold. Examples of plastic/polymer applications include determination of a failure mechanism, confirm microscopic dimensions, look for oddities as a result of manufacture, determine fill materials, pigments, and the presence of fire retardants, observe surface features and the integrity of joints, etc. Image 10 illustrates a fracture surface of a broken 3/8" diameter plastic rod.

Click on the thumbnail to see a larger image

Image 10

Glass

Windows and glass components are commonly made using a combination of glass layers, metal layers, and a variety of coatings. SEM/EDS can be used to analyze glass layers, metal traces on glass, elemental content of residue on glass, and fine detail or inclusions in glass. Image 732 shows a combination of residue on a LED glass component along with a defect in the glass (chip) between the metalized traces.

Click on the thumbnail to see a larger image

Image 11

Ceramics

Images 12, 13, and 14 illustrate the detail that becomes evident as the magnification of the SEM image is increased. This ceramic piezo-electric crystal was analyzed by EDS to determine the elemental content and also to determine if any contamination was present. SEM imaging was used to observe the grain structure, orientation, grain size etc.

Click on a thumbnail to see a larger image
Image 12	Image 13	Image 14

Textiles and fibers

The following images were taken of a medicated bandaid to illustrate the use of SEM/EDS for textiles and fibers. Image 15 shows the fiber weave. From this image, one can determine the fiber identity, percent composition of the various fibers, weave pattern, fiber length, fiber thickness, porosity, and examine fiber damage. This information would be useful in identification of product, patent infringment evaluations, validate product manufacturing specifications, discover potential product shortcomings or defects etc. To illustrate what can be discovered using the various SEM imaging modes, Image 16 shows the band-aid medicated covering in composition mode and Image 17 shows the same view in 3D mode. Clearly the surface relief is revealed in 3D mode that is not easily observed in composition mode examination. Again, this is a non-conductive sample that was analyzed "as received" with no application of carbon or gold.

Click on a thumbnail to see a larger image
Image 15	Image 16	Image 17

Organic coatings

Image 18 shows an organic coating attached to fibrous glass particle. EDS analysis confirmed that the coating contained antimony added as a fire retardant. Paint layers and other organic coatings can be prepared in cross-section so that the individual layers can be analyzed for elemental content (filler, pigment, metals etc.) and to determine layer thickness.

Click on the thumbnail to see a larger image

Image 18

Inorganics

This photograph was taken of silver chloride recrystallized out of solution (Image 551). The crystal structure and EDS data are used to determine how the crystals formed. That information can be useful in ultimately finding the source of a contamination or to check for purity of product.

Click on the thumbnail to see a larger image

Image 19

Biological

Plants, food casings, insects, and other hydrated samples can be examined using a variable pressure SEM instrument. One can actually monitor the effect of sample dehydration over time. Identification of biological samples and observation of surface texture can be important information not readily obtained when the sample is coated or already dried. To illustrate, Image 20 is a whole fly while Image 21 shows a close-up view a fly eye. A ladybug arm looks rather dramatic when viewed at even 150X magnification (Image 22).

Click on a thumbnail to see a larger image
Image 20	Image 21	Image 22

Fine particulate

Soot, dust, silica powder, minerals grains, powdered metal, pigments, pharmaceuticals, and other fine particles can be analyzed to determine the elemental composition, grain size, grain size distribution, and crystalline structure.

Unified Engineering invites you to be present for the analysis or to send your samples directly to the laboratory. Dr. Lori Streit will contact you prior to working on your project to discuss your samples, analysis objective, present options to maximize your analysis objectives, and to discuss the results.