Research Topics

Ultra-High Temperature Testing

Hemker’s research group has made key observations and discoveries that have challenged the way the community thinks about and understands materials behavior in nanocrystalline materials, materials for microelectromechanical systems (MEMS), metallic micro-lattices, thermal barrier coatings for satellites and gas turbines, armor ceramics, extreme environments, and high temperature structural materials. They are now working on projects including characterization of high-cycle fatigue of additively manufactured materials, high temperature deformation behavior of additively-made refractory metals, temperature-dependent deformation mechanisms of multi-principle element alloys (MPEAs), and developing novel testing methods for ultra-high temperature micro-scale specimen. 

Hemker is the founding director of the Johns Hopkins Center for Additive Manufacturing and Architected Materials (JAM2) and has sponsored research projects with the JHU Applied Physics Lab (APL), the United States Air Force, Army and Navy, as well as the Department of Energy and NASA. He is currently one of the leading PIs of a SURPASS project, a multi-million dollar initiative to create solutions to some of the world’s most challenging problems. Hemker is also part of two large multi-university grants, funded via the National Science Foundation and the Office of Naval Research, aiming to understand high temperature effects of additively manufactured materials.

Research Areas:

  • Characterization and modeling of bond coat layers for thermal barrier coatings
  • Characterization of materials for MEMS applications
  • Deformation behavior of intermetallic alloys
  • Deformation behavior of nanocrystalline materials
  • Experimental characterization of dislocation core structure
  • High temperature mechanical behavior
  • Macroscopic mechanical response of advanced structural materials
  • Macroscopic mechanical response of metals and alloys
  • Microsample testing
  • Characterization of additively manufactured metals
  • Characterization of additively manufactured lattices
  • Deformation behavior of multi-principle element alloys
  • Microstructural details
  • Transmission electron microscopy (TEM)