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J. K. Sarin Sundar

Bio: J. K. Sarin Sundar is an academic researcher from Arc International. The author has contributed to research in topics: Nd:YAG laser & Laser. The author has an hindex of 6, co-authored 8 publications receiving 618 citations.
Topics: Nd:YAG laser, Laser, Pulse duration, Welding, Alloy

Papers
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Journal ArticleDOI
TL;DR: Pulsed Nd-YAG laser welding characteristics of Inconel 718 sheet material (2.mm thick) were investigated in this article, where Weld microstructures and room temperature tensile properties were evaluated.

221 citations

Journal ArticleDOI
TL;DR: In this paper, Nd:YAG laser drilling of 4 and 8mm thick sections of IN718 and Ti-6Al-4V materials has been investigated and relevant geometrical features of the drilled holes, like hole diameter and taper angle, have been comprehensively investigated.

159 citations

Journal ArticleDOI
TL;DR: In this paper, a typical cutting regime for pulsed Nd:YAG laser cutting of 1mm thick Hastelloy-X sheet has been constructed and explained in terms of extent of spot overlap.

154 citations

Journal ArticleDOI
TL;DR: In this paper, the authors used Taguchi design of experiments technique to study the effects of the above process variables on the quality of the drilled holes and ascertain optimum processing conditions for laser-drilled holes.

70 citations

Journal ArticleDOI
TL;DR: In this paper, the selective laser sintering (SLS) of iron powder has been investigated through a number of experiments statistically planned as per Taguchi L8 design, where seven input parameters, namely, laser peak power density, laser pulse on-time, laser scan speed, stepping distance (distance traveled between pulses), interval-spot ratio (ratio of laser scan line interval and laser spot diameter), size range of powder particles, and powder layer thickness, were selected for the investigation.
Abstract: The selective laser sintering (SLS) of iron powder has been investigated through a number of experiments statistically planned as per Taguchi L8 design. Seven input parameters, namely, laser peak power density, laser pulse on-time, laser scan speed, stepping distance (distance traveled between pulses), interval–spot ratio (ratio of laser scan line interval and laser spot diameter), size range of iron powder particles, and powder layer thickness, were selected for the investigation. Density, porosity, and hardness were considered for the characterization of the sintered samples. Analysis of the results show that these properties are significantly affected by these factors. A discussion on the probable physical phenomena contributing to such dependence and an attempt towards the optimization of the process have also been included.

58 citations


Cited by
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Journal ArticleDOI
TL;DR: The experimental and theoretical studies of LBM show that process performance can be improved considerably by proper selection of laser parameters, material parameters and operating parameters, and the trend for future research is outlined.
Abstract: Laser beam machining (LBM) is one of the most widely used thermal energy based non-contact type advance machining process which can be applied for almost whole range of materials. Laser beam is focussed for melting and vaporizing the unwanted material from the parent material. It is suitable for geometrically complex profile cutting and making miniature holes in sheetmetal. Among various type of lasers used for machining in industries, CO2 and Nd:YAG lasers are most established. In recent years, researchers have explored a number of ways to improve the LBM process performance by analysing the different factors that affect the quality characteristics. The experimental and theoretical studies show that process performance can be improved considerably by proper selection of laser parameters, material parameters and operating parameters. This paper reviews the research work carried out so far in the area of LBM of different materials and shapes. It reports about the experimental and theoretical studies of LBM to improve the process performance. Several modelling and optimization techniques for the determination of optimum laser beam cutting condition have been critically examined. The last part of this paper discusses the LBM developments and outlines the trend for future research.

754 citations

Journal ArticleDOI
TL;DR: In this paper, the starting material, manufacturing processes, heat treatment and characterization procedures of mechanical properties are presented, and the microstructure is crucial for the mechanical properties of IN718.

602 citations

Journal ArticleDOI
TL;DR: In this paper, two kinds of balling phenomena during direct metal laser sintering of 316L stainless steel powder were investigated and the metallurgical mechanisms of the balling were elucidated; it was found that using a low laser power gave rise to highly coarsened balls possessing an interrupted dendritic structure in the surface layer of balls.

483 citations

Journal ArticleDOI
TL;DR: In this paper, the laser deposition process is optimized through a set of designed experiments to reduce the porosity to less than 0.03 pct, and failure modes of the tensile specimens were analyzed with fractography.
Abstract: Laser net shape manufacturing (LNSM) is a laser cladding/deposition based technology, which can fabricate and repair near-net-shape high-performance components directly from metal powders. Characterizing mechanical properties of the laser net shape manufactured components is prerequisite to the applications of LNSM in aircraft engine industrial productions. Nickel-based superalloys such as INCONEL 718 are the most commonly used metal materials in aircraft engine high-performance components. In this study, the laser deposition process is optimized through a set of designed experiments to reduce the porosity to less than 0.03 pct. It is found that the use of plasma rotating electrode processed (PREP) powder and a high energy input level greater than 80 J/mm are necessary conditions to minimize the porosity. Material microstructure and tensile properties of laser-deposited INCONEL 718 are studied and compared under heat treatment conditions of as deposited, direct aged, solution treatment and aging (STA), and full homogenization followed by STA. Tensile test results showed that the direct age heat treatment produces the highest tensile strength equivalent to the wrought material, which is followed by the STA-treated and the homogenization-treated tensile strengths, while the ductility exhibits the reverse trend. Finally, failure modes of the tensile specimens were analyzed with fractography.

393 citations

Journal ArticleDOI
TL;DR: In this article, a unified equation to compute the energy density is proposed to compare works performed with distinct equipment and experimental conditions, covering the major process parameters: power, travel speed, heat source dimension, hatch distance, deposited layer thickness and material grain size.

369 citations