In many traditional manufacturing processes (e.g., metal forming in auto body manufacturing), some hard-to-deform metals need to be heated to high temperature to be processed. This can lead to poor surface quality, and requires high energy consumption. An approach to improve the process capability has been researched, by which electrical pulses are directed at specific locations to allow formability of metal sheet at low temperatures. This Faculty Early Career Development Program (CAREER) award supports fundamental research to provide needed knowledge to understand this process and how it affects the material properties. This innovative process has the potential to enable the manufacture of hard-to-deform metals without significant bulk temperature increase, which can improve significantly the processing capability of many traditional manufacturing processes, including forming, peening, rolling, and forging. This advanced manufacturing capability will contribute to the competitiveness of the US by reducing the cost, lowering energy consumption and environmental impact of many metal manufacturing processes that play a vital role in the defense and manufacturing industry. The education and outreach program is designed to motivate students from underrepresented groups to pursue manufacturing careers, strengthening the workforce critically needed to revitalize US manufacturing industry.
The research objective of this project is to understand the electroplasticity effect by studying electric-defect interaction, dislocation mobility, and their effects on plasticity and microstructure evolution in metals subjected to electropulsing-assisted plastic deformation. Multiscale simulation will be used to study how microstructure defects (grain boundaries, precipitates, and dislocations) affect the distribution of electric current and how the heterogeneously distributed electric current affects dislocation mobility and metal plasticity. Tensile tests will be used to study how pulsed current affects flow stress. Comparison with heating by continuous current and furnace will be made to reveal the advantages of pulsed current. A constitutive model of the flow stress in Ti64 subjected to pulsed current will be built, and the model will be validated using the experimental data. The microstructure evolution in electropulsing-assisted laser shock peening and its effects on the plastic-affected depth, residual stresses and mechanical properties of Ti64 will be studied. By integrating multiscale simulation with experimental study, this research will reveal the physics-based fundamental mechanisms of electroplasticity, new knowledge critical to broaden the process capability of deformation-based manufacturing.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
