ELECTRICAL DISCHARGE MACHINING PROCESS DESIGN FOR POST-PROCESSING STAINLESS STEEL 316L ADDITIVELY MANUFACTURED PARTS
Open Access
- Author:
- Bicknell, Gregory
- Graduate Program:
- Mechanical Engineering
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- March 25, 2019
- Committee Members:
- Guhaprasanna Manogharan, Thesis Advisor/Co-Advisor
Edward Demeter, Committee Member - Keywords:
- Wire Electrical Discharge Machining
Additive Manufacturing
Stainless Steel 316L
Support Structures
Trapped Powder
Post-Processing
Wire EDM Proces Optimization - Abstract:
- Wire electrical discharge machining (EDM) is a non-traditional subtractive manufacturing process. This process works by bringing a charged wire in close proximity to a conductive workpiece. When the wire is close enough to the workpiece, an electrical arc forms between the wire and the workpiece. The electrical arc melts away material from the workpiece, and the wire continues moving through the workpiece, leaving behind a slit slightly wider than the width of the wire. Wire EDM is a high-precision process that can meet very tight tolerances and is employed in several industries including the aerospace and automotive industries. Recently, wire EDM has been used in the additive manufacturing (AM) industry for metal part post-processing and removal from build plates. While wire EDM is increasingly being used in the AM industry, very little research has been conducted on the wire EDM of additively manufactured parts. This thesis discusses three studies performed on the wire EDM of additively manufactured stainless-steel 316L parts. The first study is a comparison of wrought and AM stainless-steel 316L with respect to the wire EDM process. This research tested and optimized different wire EDM process parameters for the machinability of wrought and AM 316L. The second study explored the interaction between the wire EDM process and AM stainless-steel 316L lattice support structures. Selected EDM parameters were measured while machining the support structures, and optimal support structure designs were identified for AM part removal from build-plate via wire EDM. The final study explored the interaction between the wire EDM process and stainless-steel AM parts containing pockets of trapped, un-melted powder. This study optimized wire EDM process parameters for machining trapped powder pockets and outlined a potential explanation for the high incidence of wire breakage that occurs when machining through pockets of trapped powder.