*Computational Optimization Techniques and Applications*

**Figure 17.** *Incremental forming with die.*

the operation, negative node is set on tool whereas positive end is set on workpiece. The diamond particles, which are abrasive particles of the tool are inserted before the nickel layer which is the conductive surface**.** This arrangement allows a gap between the conductive surface layer and wall inside the hole. In ECMG material removing action occurs in two stage, as it can be seen in **Figure 19**. Initially Electrolytic action start as soon as electrolyte filled the gap while during the process electrical charge supply to the tool**.** Step 1 of the process is entirely driven by electrochemical material removal action. Passive electrolyte NaNO3 is used in step 1 which allows passivation of the metal surface inside the hole. Step 2 of material removal process is a hybrid process which is combine action of electrochemical and mechanical material removal. As the tool advances inside the hole a gap between tool and material surface is decreases. The abrasive grains on the tool is responsible for removal of the soft and non-reactive passivation layer. In result of this step a fresh metal layer is become expose for another electrolytic reaction. During the process the electrolyte is stored between tools' diamond particles while the metal forms small cells of electrolytic, and that is how the dissolution of materials occurs. At the end of step 2 diameter of hole is enlarged and at its maximum limit. To manufacture highly accurate hole and sharp edges, insulated tool is used during the process. During step 3 only electrochemical dissolution occur which result in taper

*A Review on Advanced Manufacturing Techniques and Their Applications*

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

hole and no material removal is take place during the last stage [36].

In electrochemical grinding, demonstrate in **Figure 20**, allows material to remove by combination of abrasive action and electrochemical reaction; there are many variants of this process and abrasive wire ECM is one of them. Another variant of the process is allowing abrasive-laden air jet to directed towards the melt

pool, and introduction laser milling/grooving processes has shown potential enhancement in the material removal rate (MRR) while almost eliminating the roughness and minimizing the heat affected zone of the generated surface. It is

*4.7.2 Mechanical machining and EDM*

**Figure 19.**

**109**

*ECM removing and grinding.*

**Figure 18.** *Laser assisted V bending.*

comparatively less drawing force, also it is responsible for lower number of forming steps and shows high productivity than the conventional deep drawing [32–35].
