Record Details
An investigation into the electrochemical removal of unwanted residual material protrusions from parts
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | An investigation into the electrochemical removal of unwanted residual material protrusions from parts |
| Names |
Bingham, Bruce C.
(creator) Parmigiani, John (advisor) |
| Date Issued | 2014-06-11 (iso8601) |
| Note | Graduation date: 2014 |
| Abstract | Manuscript I: The removal of residual casting material from gating has traditionally been performed by abrasive grinding techniques. However, high amounts of belt wear can occur when working with high strength alloys, especially those typically seen in the aerospace industry. An alternative machining process called electrochemical machining (ECM) uses electrolysis to precisely remove material at high rates. ECM has many advantages over conventional grinding: no tool wear, no induced mechanical or thermal stresses, and high removal rates independent of material hardness or strength. The industrial application of ECM to residual casting material removal can potentially realize large cost savings and decreased component processing time by eliminating belt wear and increasing material removal rates. The approach taken in this work is the design and fabrication of a laboratory apparatus for the purpose of testing the ECM of casting material. Commercial ECM machines, while more powerful, can be excessively large and cost prohibitive when performing an initial feasibility study. Many times these commercial machines are calibrated to mass produce a specific part, and do not have the level of variability desired for laboratory experimentation. The test apparatus presented provides a robust and relatively low cost method of investigating the applicability of ECM to this purpose. The device is comprised of an electrolyte filtration and delivery system, a stable machining enclosure, and a single axis computer controlled tool. The ECM variables that can be adjusted include electrolyte temperature, mass flow rate, applied voltage, tool feed rate, and electrode gap. Process data from these variables is collected via multiple sensors in the machine and provides real-time feedback to users. A universal tool connection and workpiece fixture allows for different experimental setups to be easily tested. From experimentation with this test apparatus, it will be possible to identify optimum methods for the ECM of these residual casting artifacts. Manuscript II: Rapid tool wear can occur during the removal of residual protrusions from high strength alloy parts. In this work, a new method of using electrochemical machining (ECM) capsules to remove protrusions without any tool wear is presented. An ECM capsule is an electrochemical cell that is placed on a part over a protrusion, and removes material through electrolysis. These capsules are advantageous due to their low cost and simplicity compared to conventional ECM equipment. The use of these capsules is demonstrated in two ways. First, a parameter optimization was performed on the material removal rates of Inconel 718 and Titanium 6-4 bar stock using a 2⁸⁻⁴ fractional factorial design of experiments. Then, using the optimized values, torch-cut protrusions were machined off of manufactured Titanium 6-4 parts. Inherent variability in the geometry of the protrusions rendered it difficult to completely remove the protrusions without cutting into the part. Surface scans of the parts showed that the capsules were able to successfully remove between 63% and 80% of each protrusion. Properly integrated into a protrusion removal operation, these ECM capsules could offer significant cost savings due to their ability to machine protrusions with no incurred tool wear. |
| Genre | Thesis/Dissertation |
| Topic | ECM |
| Identifier | http://hdl.handle.net/1957/50025 |
