*4.7.1 Mechanical machining and ECM*

**Figure 19** shows schematic view of the proposed hybrid process. The material removal process is driven by the combination of electrochemical machining and mechanical machining, a coated diamond abrasives spherical rod act as cathode and it rotates in pilot hole with certain speed in order removes material. The pilot hole is machined with a small diameter than the final hole diameter. In the process abrasives must be nonconductive while the tool core is electrically conductive. During

*A Review on Advanced Manufacturing Techniques and Their Applications DOI: http://dx.doi.org/10.5772/intechopen.97702*

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

### *4.7.2 Mechanical machining and EDM*

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

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].

**Figure 19** shows schematic view of the proposed hybrid process. The material removal process is driven by the combination of electrochemical machining and mechanical machining, a coated diamond abrasives spherical rod act as cathode and it rotates in pilot hole with certain speed in order removes material. The pilot hole is machined with a small diameter than the final hole diameter. In the process abrasives must be nonconductive while the tool core is electrically conductive. During

**4.7 Subtractive manufacturing process**

*4.7.1 Mechanical machining and ECM*

**Figure 17.**

**Figure 18.**

**108**

*Laser assisted V bending.*

*Incremental forming with die.*

*Computational Optimization Techniques and Applications*

aligned with a focused laser beam and tool this-electrode is not in contact with the material. The jet electrolyte and the laser beam are focused at a same time on the same location of workpiece. In JECM-LD manufacturing process, laser drilling is more responsible for material removing process and jet electrolyte effects is responsible to overcome the defects as it provides electrochemical reaction with

materials, transporting debris and effective cooling to workpiece [38].

*A Review on Advanced Manufacturing Techniques and Their Applications*

**Figure 22** illustrate the fundamental approach in ultrasonic assisted manufacturing processes and most potentially effective processes are mention

Ultrasonic-assisted turning (UAT) is a novel approach of machining operation which generate a vibration by an ultrasonic system. **Figure 23** shows basic setup for UAT and tool behavior during cutting operation. The ultrasonic system generates high frequency and low-amplitude vibrations**.** Main purpose of this method is to avoid continuous contact with the workpiece. Most desirable benefits can be

**4.8 Ultrasonic assisted manufacturing process-(UAM)**

i. Ultrasonic assisted turning

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

ii. Ultrasonic assisted milling

iii. Ultrasonic assisted drilling

iv. Ultrasonic assisted grinding

v. Ultrasonic assisted EDM

vi. Ultrasonic assisted FSW

*4.8.1 Ultrasonic assisted turning*

below.

**Figure 22.**

**111**

*Ultrasonic assisted process.*

#### **Figure 20.** *EDM and mechanical machining.*

evident that the hybridization in manufacturing processes is generally driven by the need that emerge due to technological limitations inherent to conventional manufacturing processes. Many hybridization in manufacturing processes applied abrasion removal machining process as one of the mechanisms by which material is removed. In electrochemical grinding process the combination of the abrasive action, which continually removes the surface material layers, and electrochemical material removal also contribute in removal of the material [37].
