China 
Africa 
Explore chapters and articles related to this topic
Laser Machining of Metals
Published in V. K. Jain, Advanced Machining Science, 2023
Laser drilling is usually performed using pulsed lasers with a pulse duration from several milliseconds to a few nanoseconds. Pulsed lasers with high intensities are focused on the workpiece material to cause sufficient heating to vaporize the material to generate holes. An assist gas jet that is coaxial with the laser beam is also used to assist material removal and to protect the focusing lens from ejected vapor or debris. Laser drilling has the unique capability of producing very high-aspect-ratio holes (~100:1) with hole diameters as small as a few micrometers, which is extremely difficult to produce using conventional drilling techniques. Besides, laser drilling can be used to produce holes with different shapes (non-circular) and sizes. Due to these advantages, it has wide application in many industries.
LASER-Based Manufacturing as a Green Manufacturing Process
Published in R. Ganesh Narayanan, Jay S. Gunasekera, Sustainable Material Forming and Joining, 2019
Ashish K. Nath, Sagar Sarkar, Gopinath Muvvala, Debapriya Patra Karmakar, Shitanshu S. Chakraborty, Suvradip Mullick, Yuvraj K. Madhukar
Historically, laser drilling was the first industrial application introduced by Western Electric in 1985 for drilling of diamond wire-drawing dies using ruby laser (Anon 1966). Since then laser drilling is finding ever-increasing applications in drilling precision holes in a wide variety of engineering and exotic materials in many industries such as aerospace, automobile, electronic, and medical industries (Dahotre and Harimkar 2008; Steen and Mazumder 2010; Yeo et al. 1994). In this process, a focused laser beam of high intensity is incident on the job along with a coaxial gas jet to drill a hole. The main attributes of laser drilling which make it attractive include (Dahotre and Harimkar 2008; Steen and Mazumder 2010), Any material, irrespective of its hardness can be drilled without tool wearHigh quality of holes with high precision and minimum burr and spatterHoles of any size and shape at any angleVery high drilling speedCost-effective process with all the above qualities
Fabrication Technologies
Published in Cinzia Da Vià, Gian-Franco Dalla Betta, Sherwood Parker, Radiation Sensors with Three-Dimensional Electrodes, 2019
Cinzia Da Vià, Gian-Franco Dalla Betta, Sherwood Parker
Although deep reactive ion etching using the Bosch process is by far the most standard and reliable technique for 3D sensor fabrication, two alternative techniques for deep anisotropic etching are worth mentioning: laser drilling and photo-electro-chemical (PEC) etching. Although these techniques have not yet reached the same level of maturity as DRIE, they are interesting approaches for special applications. Comparison among them and DRIE is reported in [34] and, in more detail, in [35]. Laser drilling has the advantage of being material-independent and of providing a high aspect ratio. An example is reported in [36] where an aspect ratio of 100:1 was obtained for cylindrical opening arrays in silicon [36]. This technique can, however, induce non-negligible damage to the sidewalls and is not an easy scalable process since holes are etched one by one. Currently, laser drilling was successfully used in processing 3D diamond detectors, making it the center of several studies, which will be addressed in more detail in Chapter 9. PEC, another promising anisotropic etching option, allows for very high aspect ratios while inducing minor damage to the sidewalls. The etching rate, however, is slower than DRIE, and most of all, it depends on the silicon lattice orientation, with etched holes having square rather than circular shapes, which is not ideal for sensor behavior since sharp corners could always be the cause of spikes, electric field peaks, and consequent sensor breakdown.
A review on strengthening, delamination formation and suppression techniques during drilling of CFRP composites
Published in Cogent Engineering, 2021
Dhruv Rathod, Mihir Rathod, Ronak Patel, S.M. Shahabaz, S. Divakara Shetty, Nagaraja Shetty
Laser beam drilling provides tool wear free and excellent flexibility in drilling of composites (El-Hofy & El-Hofy, 2019; Tamrin et al., 2019). In laser drilling, the material removal is performed by high-intensity stationary laser beam focused on surface to be drilled. Material removal takes place due to phase change leading to higher magnitude of heat-affected zone (HAZ). Thermal and mechanical properties of composites are mainly affected due to HAZ (Herzog et al., 2008). To cut CFRP plates, continuous CO2 laser was used and the minimum HAZ value obtained was 540 nm (Riveiro et al., 2012). Similarly, IR and UV laser were used in cutting CFRP of 2 mm thickness by Takahashi et al. (Takahashi et al., 2016). They found that UV laser was more effective in cutting compared to IR laser.
Magnetic field and ultrasonic aided laser drilling effect on Ti6Al4V microstructural characteristics
Published in Materials and Manufacturing Processes, 2020
Soheil Amiri, Mohsen Khajehzadeh, Mohammad Reza Razfar
Nowadays, millisecond pulse laser drilling is widely utilized in a variety of applications, including aerospace, medical and automotive industries. The creation of high aspect ratio microholes,[1] formation of angular holes[2] as well as creation of cooling holes in turbine blades and aero engines [3,4] are among the desired application.
Effect of cooling passage imperfection on the flow characteristics of film-cooled gas turbine blade
Published in International Journal of Ambient Energy, 2019
H. Bharathkumar, J. Jensin Joshua, P. Booma Devi, D. Raja Joseph
The laser drilling process is widely used in drilling film cooling holes in turbine blades present in the gas turbine engines. It is inevitable that slight imperfections of the order of nanometres to micrometres are formed on the walls of film cooling holes due to the re-solidification of the leftover from the drilling process.