Grain-level Flow Property Quantification with Micro/Nano Indentation

National Laboratory: 
Pacific Northwest National Laboratory
Characterization Class: 
Mechanical Behavior of Materials
Computational Tools Class: 
Structure-Properties
Description: 

Instrumented nano- and micro-indentation have been used to obtain elastic modulus and hardness of various materials. Pacific Northwest National Laboratory recently developed a unique capability by combining nano- and/or micro-indentation with an inverse computational approach to obtain the individual grain-level yield strength and hardening parameters based on indentation load versus depth curves. The method can be used to examine the effects of alloying and thermomechanical processes on various strengthening methods, as well as to calibrate crystal plasticity parameters.

Capability Bounds: 

Grains can be as small as 1 mm, with no upper bounds.

Unique Aspects: 

Among the literature, there are some non-unique solutions presented earlier by a group from Massachusetts Institute of Technology (currently not aware of similar capabilities within other national laboratories).

Availability: 

The equipment is available at PNNL, and analysis routines are developed and published by PNNL.

Single Point of Contact: 

Name: Erin Barker
Email: erin.barker@pnnl.gov
Phone: 509-372-4727

References: 
  1. G Cheng, KS Choi, X Hu, X Sun. Determining Individual Phase Properties of a Multi-phase Q&P Steel Using Nanoindentation. Accepted Materials Science and Engineering A. 2015.
  2. MD Taylor, KS Choi, X Sun, DK Matlock, CE Packard, L Xu, F Barlat. Correlations Between Nanoindentation Hardness and Macroscopic Mechanical Properties in DP980 Steels. Materials Science and Engineering A. 597(2014) 431-439.
  3. G Cheng, E Barker, KS Choi, E Stephens, X Sun. Quantify Grain Level Stress vs. Strain Behaviors for AM40 via Instrumented Micro-indentation. Invited paper, MRS Advances, 2015.
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