**5. Conclusions**

achieved such as enhanced surface quality, reduced cutting forces, and lower residual stresses in a workpiece compare to conventional turning. Ultrasonic assisted is also advantageous for the machining equipment as it allows considerable life extension of the cutting tools because of lower requirements of cutting force**.** Ultrasonic Assisted Turning, however, is more efficient at lower cutting speeds compared to conventional turning. Ultrasonic-assisted machining effects decrease by increasing

*Detailed view of ultra sonic turning process, 1–4 stages of the ultrasonic-assisted machining process.*

*Computational Optimization Techniques and Applications*

The combination of USM and EDM has the potential to reduce tool wear and electrode deflection in EDM of micro-holes and grooves. The mechanical signal was generated and transmitted to the tool-electrode, which was applied to remove material. The tungsten carbide workpiece was being vibrated while the EDM process was carried out. To remove the burrs formed on the exit region of a drilled hole ultrasonic vibration assisted dry electrical discharge machining process is used. The result of the study proves that in lower pulse durations the performance of novel ultrasonic vibration assisted dry EDM process is better compare to dry EDM process. The positive effects of applying ultrasonic vibrations to electrode at EDM process are because of both cavitation effect of the working fluid and also the

Electrical discharge machining (EDM) is the process which is developed to remove conductive materials in the form of small craters. Such removal of materials are ranging from several to tens of microns. Process used electric sparks between a tool, electrode, and a workpiece which is submerged in a dielectric fluid. The sparks are strictly coordinated to control material removal rate. The micro-EDM process mechanism and EDM process mechanism is fundamentally same, the only notable differences are discharge energy supplied, tool dimensions and the resolution of the axis's movement. The gap between the tool and the electrode called spark gap, the series of sparks in a controlled spark gap is responsible for material removal, a small amount of material in the form of crater were removed from the workpiece as a spark strike the material. A pulse duration [μs], series of sparks within a certain time period, which is followed by a interval [μs], define as a pause for certain time duration in the sparking process. Each discharge cycle consists of pulse interval and

speed of cutting [39–43].

**Figure 23.**

**112**

*4.8.2 Ultrasonic assisted EDM*

vibrational action of the electrode itself [44–46].

It is observed tremendous amount of innovation and hybridization in advance manufacturing technologies. There are many researcher and universities are constantly working on innovative ideas and new technology. It can be observed that by hybridization of two manufacturing technology, more beneficial result can be achieved, and individual drawback of same process can be eliminated. Many of these innovations are potentially transformative, and not simply evolutionary. The subtractive processes and its combinations are mainly associated with the material, especially superalloys and ceramic, which are difficult to machine on the material removal processes such as milling, turning, drilling and grinding. The major contributors to material removal are EDM and other mechanical machining as such processes provided the high surface quality. Advance assisted processes such as ultrasonic vibration or laser cutting and its combination with conventional machining processes result in lower tool wear, higher surface integrity and shorter production times. Laser processing is still trending and attract many researchers to work on it in hybrid subtractive and transformative processes. It is important to be noted that the laser does not participate in actual materials removing process but introduction of it prior to the machining change the microstructures of the

materials. It allows higher material removal rate as it become easy for conventional machining operations to remove the material in terms of the lower cutting forces which also beneficial as it results in longer tool life**.** However, flexibility of the processes is the limitation in a such type of combinations, therefore, to achieve freedom of flexibility and high dimensional accuracy rapid prototyping technology has been employed by various researchers to flexibly build components with arbitrary shapes. Future research advances, need to be addressed, namely, integration with other processes; need for new process-planning., modeling representations of hybrid process capabilities, additional standards, A.I. implementation (Machine learning) [44].

**References**

pp. 596–615, 2013.

2009.

[1] Z. Zhu, V. G. Dhokia, A. Nassehi, and S. T. Newman, "A review of hybrid manufacturing processes - State of the art and future perspectives," Int. J. Comput. Integr. Manuf., vol. 26, no. 7,

*DOI: http://dx.doi.org/10.5772/intechopen.97702*

*A Review on Advanced Manufacturing Techniques and Their Applications*

Manuf. Process., vol. 7, no. 1, pp. 57–68,

[9] F. Liou, K. Slattery, M. Kinsella, J. Newkirk, H. N. Chou, and R. Landers,

manufacturing process for fabrication of metallic structures," Rapid Prototyp. J., vol. 13, no. 4, pp. 236–244, 2007.

[10] D. S. Choi *et al.*, "Development of a direct metal freeform fabrication technique using CO2 laser welding and milling technology," J. Mater. Process. Technol., vol. 113, no. 1–3, pp. 273–279,

[11] J. M. Pinilla and F. B. Prinz, "Leadtime reduction through flexible routing:

[12] A. M. Dollar, C. R. Wagner, and R. D. Howe, "Embedded sensors for biomimetic robotics via shape

deposition manufacturing," Proc. First IEEE/RAS-EMBS Int. Conf. Biomed. Robot. Biomechatronics, 2006, BioRob 2006, vol. 2006, pp. 763–768,

Kietzman, F. B. Prinz, J. L. Lombardi, and L. E. Weiss, "Automated fabrication of complex molded parts using Mold Shape Deposition Manufacturing," Mater. Des.,

[13] A. G. Cooper, S. Kang, J. W.

vol. 20, no. 2–3, pp. 83–89, 1999.

[14] M. Lanzetta and M. R. Cutkosky, "Shape deposition manufacturing of biologically inspired hierarchical microstructures," CIRP Ann. - Manuf. Technol., vol. 57, no. 1, pp. 231–234,

[15] A. Kelkar and B. Koc, "Geometric planning and analysis for hybrid reconfigurable molding and machining process," Rapid Prototyp. J., vol. 14, no.

Application to Shape Deposition Manufacturing," Int. J. Prod. Res., vol. 41, no. 13, pp. 2957–2973, 2003.

"Applications of a hybrid

2005.

2001.

2006.

2008.

1, pp. 23–34, 2008.

[2] K. P. Karunakaran, S. Suryakumar, V. Pushpa, and S. Akula, "Retrofitment of a CNC machine for hybrid layered manufacturing," Int. J. Adv. Manuf. Technol., vol. 45, no. 7–8, pp. 690–703,

[3] K. P. Karunakaran, S. Suryakumar, V.

manufacturing," Robot. Comput. Integr. Manuf., vol. 26, no. 5, pp. 490–499, 2010.

[4] K. P. Karunakaran, A. Sreenathbabu,

manufacturing: Direct rapid metal toolmaking process," Proc. Inst. Mech. Eng. Part B J. Eng. Manuf., vol. 218, no. 12,

[5] X. Xinhong, Z. Haiou, W. Guilan, and W. Guoxian, "Hybrid plasma deposition and milling for an aeroengine double helix integral impeller made of superalloy," Robot. Comput. Integr. Manuf., vol. 26, no. 4, pp. 291–295, 2010.

[6] J. Y. Jeng and M. C. Lin, "Mold fabrication and modification using hybrid processes of selective laser cladding and milling," J. Mater. Process. Technol., vol.

[7] J. Zhang and F. Liou, "Adaptive slicing for a multi-axis laser aided manufacturing process," J. Mech. Des. Trans. ASME, vol. 126, no. 2, pp. 254–

[8] J. Ruan, K. Eiamsa-Ard, and F. W. Liou, "Automatic process planning and toolpath generation of a multiaxis hybrid manufacturing system," J.

110, no. 1, pp. 98–103, 2001.

261, 2004.

**115**

Pushpa, and S. Akula, "Low cost integration of additive and subtractive

and V. Pushpa, "Hybrid layered

pp. 1657–1665, 2004.

processes for hybrid layered
