Laser Trepan Drilling of Monel k-500 Superalloy in Low Power Laser Beam Machining

Laser Trepan Drilling of Monel k-500 Superalloy in Low Power Laser Beam Machining

D. Pramanik, N. Roy, A. S. Kuar, S. Sarkar, S. Mitra, Dipankar Bose
Copyright: © 2021 |Pages: 23
DOI: 10.4018/978-1-7998-3624-7.ch009
OnDemand:
(Individual Chapters)
Available
$37.50
Current Special Offers
No Current Special Offers
TOTAL SAVINGS: $37.50

Abstract

In the field of micro processing of materials, laser has great importance as a source of heat and for its ability to deliver a coherent beam. The use of 50-watt average power for through-hole is impossible to achieve good quality drilling of the metal sheet upto 2 mm thickness. But the use of unique parameter sawing angle and constant focal point distance plays a significant role on hole diameter and circularity in laser trepan drilling. In the present research study, laser trepan drilling is investigated through multi diode pulsed fiber laser beam machining. Experimental analysis based on central composite design (CCD) of response surface methodology (RSM) has been fulfilled to find out the mathematical model. A study of the effect of sawing angle with other process parameters such as cutting speed, power, duty cycle, and pulse frequency on overcut bottom diameter and circularity at bottom for a monel k-500 has been conducted. Experimental validation of the proposed model shows that desired hole quality can be obtained by optimization of controllable of suitable process parameters.
Chapter Preview
Top

Laser Ablation With Nano Second Laser

Material ejection and generation of nano particles are caused by photo thermal process in ns laser ablation. Rate of energy deposition being slow it combines with electronic and vibrational mode of the work-piece to hit the target material. Thermal penetration depth gives the estimated depth of effective laser energy absorption at low laser value (Roy et al. 2015). Thermal evaporation dominates the ablation process in the regime of thermal penetration. Direct heating of laser radiation causes ionization of vapor plume when the laser value comes near the threshold value. As the laser intensity goes to be higher than the gas ionization threshold optical break down process helps the ionization phenomenon to occur. The laser irradiant being greater than 109 w/cm2 and surface temperature being equal to thermo dynamic critical point phase explosion phenomenon happens to change the matter from an overheated liquid droplet. Creation of plasma with high temperature and pressure occurs at the end of the laser pulse, leading to ejection of molten droplets at supersonic velocity. Re-solidification of the expelled liquid into thin films helps to alter topography at the rim and surroundings area of the ablated region (Pramanik et al. 2018; 2019; Sharma et al. 2018; Chien et al. 2007; Ghoreishi et al. 2002). Figure 1 shows the schematic representation of laser material interaction.

Figure 1.

Schematic picture of laser material interaction

978-1-7998-3624-7.ch009.f01
Top

Advantages Of Fiber Laser Over Other Solid-State Lasers

The significance of fiber laser system for the micro machining domain is inevitable. Evolving of fiber lasers in the most versatile and rapid developing laser system for the recent years is a significant achievement in various fields of manufacturing, medical, metrological and military applications which were perform by conventional solid-state laser including gas lasers. Fiber laser has the qualities like high efficiency, high beam quality, less maintenance and ability to process highly reflective material, for which it is acquiring the fields of CO2 and Nd: YAG laser in different manufacturing fields (Lopez et al. 2017; Ezugwu et al. 1999). Due to following reasons fiber laser become more acceptable from other type of laser.

Complete Chapter List

Search this Book:
Reset