Characterization
Many of the characterization tools that the Burns Research Group leverages are housed within the Nanoscale Materials Characterization Facility (NMCF), which is a state-of-the-art user facility located within the Materials Science Department. Not only is the facility available for use by all qualified students, but technicians, other students, and even faculty are available to assist researchers in using the instruments. A survey of the equipment available for use by students can be found below:
Characterization Techniques
Sample Preparation
Equipment available for use in sample preparation include: cut-off saws, plasma cleaner, vibratory polisher, automatic polisher, 8" and 12" polishing wheels, electropolishing equipment, hardness testers (Knoop, Vickers, and Rockwell), jet polisher, and a variety of compound and stereo optical microscopes.
Digital Microscope
A Hirox KH 7700 digital microscope is often used by the Burns Research Group for more accurate measurements of machined notches in samples, but is also used for imaging at magnifications ranging from 0-7000x. The microscope offers a number of other interesting features, such as the ability to map a sample surface using tiling and the ability to dynamically focus on samples with surface height variations.
White Light Interferometry
The Zygo white light interferometer (WLI) is heavily utilized by the Burns Research Group, especially those students who are investigating pitting and want to gather information on the depth of the pits. WLI has also been used in the Burns Group to characterize the 3D fracture surface plane to investigate out-of-plane cracking.
Scanning Electron Microscope (SEM) and Associated Techniques
The NMCF offers three SEMs for students to use: a FEI Quanta 200, a FEI Quanta 650 FEG, and the newer Helios Dual Beam FIB / SEM / STEM. These tools are the bread and butter for the group, with students using them to image samples, conduct electron backscatter diffraction, or energy dispersive X-ray spectroscopy (EDS). The Dual Beam FIB is used a lot by the group for TEM foil preparation. The Burns Group has also fine-tuned FIB sample preparation techniques to significantly reduce the damage layer (efficentively eliminating it) from the sample during TEM foil preparation with a Ga+ ion beam FIB. Read about it HERE!
Transmission Electron Microscope (TEM)
The NMCF also offers two TEMs for students to use: Themis 60-300 kV Transmission Electron Microscope and the FEI Titan Transmission Electron Microscope. These tools are currently being leveraged to image dislocations at the fracture surface at specific stress intensities. These instruments also allow the student to collect diffraction patterns of their materials and can be set up for electron energy loss spectroscopy (EELS) and EDS.