**7. Advantages**

*Practical Applications of Laser Ablation*

using a gas jet during the cutting process.

*Three-dimensional LBM for (a) lathe operation and (b) milling operation.*

**6.3 Three-dimensional LBM**

**Figure 14.**

to get intricate shapes of machining.

the higher amount of silicon element material.

materials where mechanism of material removal is similar to drilling operation. In contrast to the drilling process, the erosion front is located at the front of line of laser beam as shown in **Figure 13**. However, the temperature field and erosion front is fixed based on the coordinate moves along with produced laser source that ensures steady state process. The erosion front molten material is flushed away

Three-dimensional LBM uses two or more number of laser beams simultaneously focused to obtain an intersected volume for material removal. To precisely create such volumes with relative motions, highly accurate optical manipulating systems are therefore necessary. Recent systems equipped with optical scanning systems have high level of control over the motion of laser beams which enables efficient and effective machining operations. The material removal using these tools is referred as 3-dimensional (3D) laser material processing. In general, the 3D laser material processing is grouped into various categories such as laser beams along with 3D LBM, 5-axis heads along with 3D processing workstation and 3D remote laser processing. **Figure 14** illustrate the graphical picture of two-beam laser machining processes for lathe and milling operations. Each beam creates a groove like volume of material removal when they intersect with some incidence angle. The incidence angle may be changed and dynamically varied along with relative motion

LBM is successfully adapted in micromachining field due to its high flexibility to automation and high degree of radiance. Laser beam micromachining is capable of producing parts with sizes ranging from micro to sub-micro scales. It usually employs the pulsed lasers with an average power of less than 1 kW. The pulses of femtosecond duration are widely used for micromachining. Micromachining can be performed on wide range of materials such as metals, glasses, diamond and other difficult to machining materials. Laser-assisted manufacturing (LAM) is another technique helps to enhance the maximum productivity, quality with minimized machine tool vibrations, machining forces and tool wear. LAM is also an effective technique to machine brittle materials without cracks and failure. This hybrid machining process, laser beam is focused on the work piece just before the cutting tool engages. Scanning of laser initially heats up the work therefore helps in plastic deformation rather than brittle deformation during machining. The LAM processes are suitable for brittle and hard type of material such as ceramics, nickel alloys and

**98**

LBM is an excellent manufacturing technique to process wide ranges of difficult to machine materials especially ceramics and advanced composite materials. LBM technique is capable of machining intricate shapes that cannot be reached or processed by conventional machining processes. LBM is an alternate to conventional machining processes due to many advantages as follow:

