Kevin Jacob — Postdoctoral Research Scholar, Iowa State University
Materials for extreme environments protect people, structures, and the planet — from radiation inside a reactor core, to the heat inside a turbine blade, to the cold vacuum of orbit. Understanding how materials survive these extremes is the first step toward engineering ones that can.
Research interests
- Processing–microstructure–property relationships in extreme-environment alloys
- Advanced microscopy (TEM / APT) and in-situ mechanical testing
- Radiation-tolerant and high-temperature structural materials
- Small-scale mechanical testing and nanomechanics
- Phase transformations in thin films
Multi-scale mechanical testing
From µm to mm, I bridge the micro, meso, and macro length scales to understand how a material’s microscopic structure dictates its overall performance. High-throughput nanoindentation makes it possible to map mechanical behaviour rapidly across many orientations and phases, and to test materials available only in tiny volumes — from neutron-irradiated samples too hazardous to handle in bulk, to rare fossilised and meteoritic specimens.
Advanced microscopy
From single atoms to bulk grain structure, I use correlative microscopy to resolve a material’s structure across scales — atom probe tomography for precipitate composition and morphology, transmission electron microscopy for lattice and interface analysis, and SEM and EBSD for microstructure and phase distribution. Combining them on the same material links chemistry and structure directly to mechanical behaviour.
Research highlights
Click to enlarge ↗
Click to enlarge ↗
Click to enlarge ↗
Micropillar compression — effect of orientation on deformation behaviour
In-situ SEM micropillar compression of the same material in two crystallographic orientations. The orientation of the loading axis relative to the available slip systems changes how the pillar deforms — from the slip offsets and shear character to the overall shape change.
Micro-tensile testing
In-situ SEM micro-tensile testing. The ⟨114⟩-oriented tantalum deforms by homogeneous, distributed slip, the ⟨113⟩ orientation by multiple single slip, while the irradiated HT-9 undergoes crack nucleation and failure driven by irradiation-induced damage.