Design of Freeform Surface Finish Using Synchronous Processes of Electrochemical Finishing and Burnishing

Abstract:

A most effective design system and an advantage of low cost equipment using synchronous processes of electrochemical finishing and burnishing for a freeform surface following turning machining is investigated. The proposed design process uses a feeding finish-tool instead of the mate electrode as in conventional ECM. Hence higher electrical current is not required when the effective design electrode is used to reduce the response area. Through simple equipment attachment, electrochemical finishing can follow the traditional turning on the same machine. The controlled factors include the chemical composition and concentration of the electrolyte, die material, and rotational speed of workpiece. The design finish-tool is primarily discussed among the factors affecting the synchronous processes of electrochemical finishing and burnishing. The experimental parameters are initial gap width, flow rate of electrolyte, current rating, feed rate of finish tool, pulsed period, and the evaluation of different process features. The use of large electrolytic flow rate is advantageous to the finish effect. High rotational speed of the finish tool produces better finish. The finish effect is better with longer off-time because discharge of finish dregs becomes easier. Higher current rating with quicker feed rate of finish tool effectively reaches the fast improvement of the surface roughness of the workpiece is recommend in current study. The effective design finish-tool with an electrode of a globe-form and a burnishing tool of a pin-form have an optimal value for higher current density and provides larger discharge space, which produces a smoother surface. The synchronous processes of electrochemical finishing and burnishing just needs only a short time to make the workpiece smooth and bright and saves the need for the precise process of traditional machining is recommended for the finish process of the freeform surface.

• Periodical: Key Engineering Materials (Volumes 375-376)
• Pages: 308-312
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.375-376.308
• Online since: March 2008
• Authors: Pai Shan Pa
• Keywords: Burnishing, Electrochemical Finishing, Finish-Tool, Freeform Surfaces, Synchronous Process, System Design

References

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[1] Finish-tool design.

[2] Burnishing assistance promotes the freeform surface smooth and bright in electrochemical finishing.

[1] Experimental set-up (EF; PEF; BEF; BPEF) (See Fig. 2).

[2] Design of finishing process.

[1] Synchronous processes of burnishing and electrochemical finishing.

[2] Using feeding finish-tool.

[3] Adequate feed rate and current density.

[4] Large flow rate of electrolyte to discharge finish dregs.

[5] High rotation speed of finish -tool.

[6] Prolonged the off-time of pulsed current Fig. 1 Design Process with a Basis of Analysis [10] (a) System Schematics (b) Confizuration of finish tool and workpiece Fig. 2 Experimental Set-Up power supply pump electrolyte tank workpiece fixture filter flow meter electrode electrolyte pipe spindle machine table feed electrolytic tank workpiece rotational _ electrode burnishing tool burnishing tool gap width electrode burnishing-tool 100 30 R2. 0 R4. 0 15.

DOI: 10.12989/csm.2015.4.4.279

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1 0 1 2 3 4 5 Gap Width (mm) Ra (µm) Fig. 3 The geometry of design finish-tool Fig. 4 Synchronous processes of electrochemical finishing and burnish at different gap width between electrode and workpiece(ASTMH13, NaNO3, 25%wt, 10min, 40A, 120mm/min, Continous DC) Fig. 5 Synchronous processes of electrochemical finishing 0.

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08 0 20 40 60 80 100 120 Feed Rate (mm/min) Ra (µm) 15A 20A 25A 30A 35A 40A Fig. 6 Synchronous processes of electrochemical finishing.

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08 0 1 2 3 4 5 6 7 8 9 10 11 12 Flow Rate(l/min) Ra (µm) Fig. 5 Synchronous processes of electrochemical finishing and burnishing at feed rate of finish tool through different current rating(ASTMH13, NaNO3, 25%wt, 10 L/min, Continous DC) Fig. 6 Synchronous processes of electrochemical finishing and burnishing at different flow rate of electrolyte(ASTMH13, NaNO3, 25%wt, 40A, 120mm/min, Continous DC).

DOI: 10.4028/www.scientific.net/kem.375-376.308

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08 Ra (µm) continuous 100/100 100/200 100/300 100/400 100/500 0.

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08 Ra (µm) EF PEF BEF BPEF Fig. 5 Synchronous processes of electrochemical finishing and burnishing through continuous and pulse diect current (ASTMH13, NaNO3, 25%wt, 12L/min, Continous DC) Fig. 1 Effects of evaluation of finishing effect of four processes(ASTMH13, NaNO3, 25%wt, 12L/min, 40A, 120mm/min, 100ms/500ms).