Opportunity at National Institute of Standards and Technology (NIST)
Forensic Metallurgy for Post-Mortem Infrastructure Failure Investigations
Material Measurement Laboratory, Applied Chemicals and Materials Division
Please note: This Agency only participates in the February and August reviews.
|Chiaramonti Debay, Ann
The partitioning of alloy elements, as well as changes in carbide morphology and solid-state transformation products can be used to understand the details of the time-temperature history of steels. We propose that such changes can be extended to forensic investigations, where those phenomena act as fingerprints for steel thermal history during failures such as bridge collapse or building fire. Solute atom partitioning and carbide morphology changes in steels as a function of temperature are well studied and fairly well understood in physical metallurgy. However, quantitative data with associated uncertainties on the rate and extent of partitioning, the effect of the combination of heat and mechanical stress, as well as a full understanding of the detection and quantification limits for the various analytical techniques used to study these phenomena are lacking. We welcome proposals related to the study of solute atom segregation and carbide morphology evolution in steels as a tool for forensic science, particularly related to understanding detection limits, quantification, and the sources of measurement error and uncertainty, We are also interested in the possibility of extension of these measurements to more commonly accessible analytical techniques, with the ultimate goal of providing a set of sample harvesting, internal calibration, and experimental protocols for the forensic analysis of steels that have been exposed to fire. Our lab at NIST Boulder has an analytical aberration-corrected STEM with EELS and EDS, a conventional TEM, a field-emission SEM with EBSD and EDS, and a laser-assisted local electrode atom probe tomograph. We also have access to state-of-the-art mechanical testing facilities.
Atom probe tomography; Metallurgy; Failure analysis; Microanalysis; Solute segregation; TEM; Alloy element partitioning; Pearlite; Steel;
Open to U.S. citizens
Open to Postdoctoral applicants