Science & Technology Thrust (STT) 1: Multiscale Metal Forming and Pattern Replication

Research Objectives of STT1

  • Understand plasticity and microstructural length scale effects.
  • Understand and engineer solid/solid interfacial mechanical integrity.
  • Combining experimentation with multiscale modeling/simulation.
  • Demonstrate high-throughput fabrication technologies & structure/devices relevant to engineering applications.

STT1 Challenges

An incomplete understanding of:

  • Mechanical size effects as the characteristic dimension of plastic deformation approches the regime where materials’ mechanical mechanical responses exhibit a strong length scale dependence.
  • Additional size effects as the characteristic dimension of deformation approaches the microstructural length scale of the material.
  • Engineered interfaces between coatings and substrates in coated forming tools.

Research Examples: Progress and Accomplishments

Understanding Micron Scale Plasticity Size Effects

Flow Stress of Confined Thin Plastic Layers as a Function of Geometry and Microstructure

MRS Communications, 6, 289-294 (2016).

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Engineering the Mechanical Integrity of Solid/Solid Interfaces

Quantitative Testing of Mechanical Integrity of Coating/Substrate Interfaces

J. Materials Research, doi:10.1557/jmr.2016.516 (2017).

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Demonstrating High-Throughput Micromanufacturing Technologies

Instrumented Microscale Roll Molding Allows Metal-Based Microscale Structures to be Fabricated in a Continuous Roll-to-Roll Printing Fashion

Roll Molded One- and Two-Dimensional (1D/2D) Aluminum Micro Fin Array Structures

J. Micromechanics & Microengineering 27, 025012/1-9 (2017).

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Metal/Ceramics Interfacial Shear Failure at Critical Strain

The shear response of the metal/ceramic interface is modeled using a Ti-TiN bi-crystal using MEAM potential.

The structure of the interface is studied, and the shear response is also considered by subjecting the bicrystal in to a pure shear loading.

Modeled in MD using Ti-TiN bilayer system, using MEAM potential.

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Structure of the Misfit Dislocation Network (MDN) Depends on the Orientation of Ti

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Interfacial Shear Failure is Associated with Motion of MDN with Low Shear Strength

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DFT Calculations on Coherent Interfaces Provide Confidence to MD Predictions

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