Researcher Dr. Roy E. Crooks operates a scanning electron microscope (SEM). This instrument uses a highly-focused beam of electrons to provide visual images of the surface of materials at magnifications up to 20,000X or more. These high magnification images allow the researcher to identify details about the material's microstructure, such as the types and sizes of microscopic particles present. The beam of electrons can also be used to examine volumes (as small as 1 micrometer in diameter) of the material being analyzed to provide information about the chemistry. This information can be used to determine chemical variations as a function of location within the material's microstructure, as well as the chemical composition of individual particles. In addition, the SEM is equipped with sophisticated instrumentation that can determine the crystal structure of individual grains and how each grain is oriented with respect to neighboring grains within the material. The chemistry and crystal structure information can be related to fracture behavior and used to modify the manufacturing processes used to produce the material in order to improve its properties.
