Effect of micro-powder suspension and ultrasonic vibration of dielectric fluid in micro-EDM processes － Taguchi approach 指導老師：戴子堯 教授 學生：杜弘翔 4A 報告日期： 2015/06/01

Outline 1. Introduction 2. Experimental setup 3. Results and discussion 4. Conclusions

1. Introduction 2. Experimental setup 3. Results and discussion 4. Conclusions

One of the problems is poor flushing away of machining debris. They found the particle concentration, the electrical resistivity, and the thermal conductivity of powders are important characteristics that significantly affect the machining performance in the EDM process.

1. Introduction 2. Experimental setup 3. Results and discussion 4. Conclusions

1. Avoid micro-powder accumulating at the bottom of the tank. 2. Increase the kinetic energy of discharge debris. This causes the debris to be removed more easily; as a result fewer short-circuits occurred in discharging.

2.1. Configurations of experiment factors and their levels 1. Ultrasonic vibration of the dielectric fluid. Yes or Not 2. Micro-MoS2 powder concentration. Pure, 2g/l, 5g/l 3. Tool electrode material. Cu, Cu-W, Brass 4. Workpiece material. Cu, Cu-W, Ag-W

1. Introduction 2. Experimental setup 3. Results and discussion 4. Conclusions

3.1. Combination of optimal level for each factor and verification test

3.2. Effect of ultrasonic vibration of dielectric fluid on material removal rate

3.3. Effect of powder concentration on material removal rate

3.4. Effect of workpiece and tool electrode material on material removal rate

3.5. Effect of dielectric containing micro- powder in micro-EDM on surface microstructure Cu–W surface, brass as the tool electrode, using a pure dielectric fluid.

Cu–W surface, brass as the tool electrode, using MoS2 powder with ultrasonic vibration of dielectric fluid and a powder concentration of 2g/l.

1. Introduction 2. Experimental setup 3. Results and discussion 4. Conclusions

1. A new method in which the addition of micro-MoS2 powder to a dielectric fluid combined with ultrasonic vibration of the dielectric was found to have a significant effect in increasing the material removal rate and improving surface quality.

2. The high lubricity levels of MoS2 also help to improve surface quality. 3. The ultrasonic vibration of a dielectric fluid is significant in increasing the material removal rate.

4. Cu is easier to machine with mirco-EDM processes using micro-MoS2 powder suspended in a dielectric than with Cu–W or Ag–W. 5. Using brass as the tool electrode is not a significant factor in obtaining a high material removal rate.

References IEEE ： Effect of micro-powder suspension and ultrasonic vibration of dielectric fluid in micro- EDM processes-Taguchi approach