SUBJECT: Ph.D. Proposal Presentation
BY: Ali Khosravani
TIME: Friday, August 5, 2016, 10:00 a.m.
PLACE: Love Building, 295
TITLE: High throughput prototyping and multiscale characterization of metallic alloys
COMMITTEE: Dr. Surya R. Kalidindi, Chair (ME)
Dr. Hamid Garmestani (MSE)
Dr. Richard W. Neu (ME)
Dr. Antonia Antoniou (ME)
Dr. Raja. K Mishra (General Motors R&D Center)


Accelerating discovery and deployment of advanced material systems requires moving away from traditional sample prototyping, testing methods, and microstructure characterization techniques. In addition, the hierarchical multiscale structure of advanced materials holds the key to improving their performance characteristics. In order to understand and characterize microscale constituents, and length scale effects, novel high throughput approaches are necessary to explore mechanical responses from nano to meso, and macro scale. Several different techniques exist for testing materials at small length scale, including, microtension, micro-pillar compression, micro-bending, and nanoindentation. Among these, spherical nanoindentation is the most efficient and most reliable one. This high throughput mechanical protocol is capable of capturing local mechanical responses at different length scales in polycrystalline metals in the form of indentation stress-strain curves. These responses can then be correlated to local material structure using modern data-driven approaches.
The goal of this research is to develop high throughput protocols to characterize and understand mechanical property length scale effects in multiphase metallic alloys, and to establish reliable process-structure-property (PSP) linkages. Couple of different material systems are chosen for this research. More specifically, we will focus on: (i) process-structure-property linkages in dual-phase steels involving thermo-mechanical processing conditions, indentation measurements, and microstructure information from EBSD (electron backscatter diffraction); (ii) structure-property linkages in Fe-5%Ni steels that exhibit lath martensite with a very high density of dislocations produced during austenite-to-martensite transformation; (iii) structure-property linkages in high purity magnesium that deforms extensively by extension twining., and (iv) structure-property linkages in Ti-based bulk metallic glass (BMG).
The proposed work will have a profound impact on speeding up the process of developing new structural materials by reducing the time and energy spent in mechanical characterization at different length scales and establishing PSP linkages.