Date of Award

8-2012

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Legacy Department

Automotive Engineering

Advisor

Mears, Laine

Committee Member

Kurfess , Thomas

Committee Member

Collins , Randy

Committee Member

Grujicic , Mica

Abstract

This thesis contains all of the steps which allow the Electrically-Assisted Manufacturing (EAM) technique to be experimentally explored and analytically modeled for an electrically-assisted forging operation. Chapter 1 includes the problem statement, proposed solution, and literature reviews on EAM. Chapter 2 describes a thorough background on the EAM technique, highlights prior EAM research, and explains the research approach taken for this thesis. The coupled thermo-mechanical modeling strategy, along with the introduction of the Electroplastic Effect Coefficient (EEC) is provided in Chapter 3. Chapter 4 explains the two different approaches to determine the EEC profiles when modeling a particular metal. The simplified EAF mechanical model for electrically-assisted forging is presented in Chapter 5. Also in this chapter, the same modeling methodology (i.e. thermo-mechanical, EEC, etc.) is used to predict loads for an electrically-assisted bending (EAB) process.
The following chapters explore how different material- and process-based parameters affect the EAF technique. Chapter 6 examines how different workpiece contact areas affect EAF effectiveness, along with an exploration of how well different metal forming lubricants perform with EAF. Chapter 7 explores if there is a difference in the thermal or mechanical profiles of specimens undergoing EAF forging tests with different average grain sizes. Chapter 8 examines the same effects as the previous chapter on specimens with varying levels of prior cold work. The materials- and process-based simplifications and sensitivities of the proposed modeling strategy are outlined in Chapter 9. Chapters 10-14 include the science behind the electroplastic effect, conclusions, future work, broader impacts, and intellectual merit, respectively. The overall intention of this thesis is to show the candidate's ability to take an idea for a new manufacturing process, prove that it works, and then understand and model the process such that it may be competitive within relevant industries.

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