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A. Thakur

Bio: A. Thakur is an academic researcher from National Institute of Technology, Rourkela. The author has contributed to research in topics: Machinability & Machining. The author has an hindex of 13, co-authored 19 publications receiving 732 citations. Previous affiliations of A. Thakur include G. B. Pant University of Agriculture and Technology & Dr Emilio B Espinosa Sr Memorial State College of Agriculture and Technology.

Papers
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Journal ArticleDOI
TL;DR: In this article, the state-of-the-art on various surface integrity characteristics during machining of nickel-based super alloys are presented, including surface roughness, defects (surface cavities, metal debris, plucking, smeared material, redeposited material, cracked carbide particles, feed marks, grooves and laps).
Abstract: Nickel-based super alloys are gaining more significance, now-a-days, with extensive applications in aerospace, marine, nuclear reactor and chemical industries. Several characteristics including superior mechanical and chemical properties at elevated temperature, high toughness and ductility, high melting point, excellent resistance to corrosion, thermal shocks, thermal fatigue and erosion are primarily responsible for wide domain of application. Nevertheless, machined surface integrity of nickel-based super alloys is a critical aspect which influences functional performance including fatigue life of the component. This review paper presents state-of-the-art on various surface integrity characteristics during machining of nickel-based super alloys. Influence of various cutting parameters, cutting environment, coating, wear and edge geometry of cutting tools on different features of surface integrity has been critically explained. These characteristics encompass surface roughness, defects (surface cavities, metal debris, plucking, smeared material, redeposited material, cracked carbide particles, feed marks, grooves and laps), metallurgical aspects in the form of surface and sub-surface microstructure phase transformation, dynamic recrystallisation and grain refinement and mechanical characteristics such as work hardening and residual stress. Microstructural modification of deformed layer, profile of residual stresses and their influence on fatigue durability have been given significant emphasis. Future research endeavour might focus on development of new grades, advanced processing techniques of the same to ensure their superior stability of microstructure and thermo-mechanical properties along with advanced manufacturing processes like additive manufacturing to achieve highest level of fatigue durability of safety critical components while maintaining acceptable surface integrity and productivity.

403 citations

Journal ArticleDOI
TL;DR: In this article, a nickel-based super alloy was machined under completely dry environment using a commercially available multilayer (TiN/TiAlN) coated tool obtained using physical vapour deposition (PVD).

97 citations

Journal ArticleDOI
TL;DR: In this paper, the influence of cutting speed (51, 84 and 124 m/min) and CVD multilayer tool coating (TiN/TiCN/Al2O3/ZrCN) on various aspects of surface integrity such as surface roughness, crystal structure and microstructure of the surface and sub-surface region, thickness of white layer and work hardening tendency have been investigated during dry turning of Incoloy 825.

63 citations

Journal ArticleDOI
TL;DR: In this article, the influence of tribological properties of coated tools on performance during machining of nickel-based super alloy is not well reported, and the authors comparatively evaluated the properties of tools coated with CVD and physical vapour deposition (PVD) with reference to their uncoated counterpart.

55 citations

Journal ArticleDOI
TL;DR: In this article, the influence of CVD multilayer coated (TiN/TiCN/Al2O3/ZrCN) and cutting speed on various machining characteristics such as chip morphology, tool wear, cutting temperature, and machined surface roughness during dry turning of 17-4 PH stainless steel was investigated.
Abstract: The present research work has been undertaken with a view to investigate the influence of CVD multilayer coated (TiN/TiCN/Al2O3/ZrCN) and cutting speed on various machining characteristics such as chip morphology, tool wear, cutting temperature, and machined surface roughness during dry turning of 17-4 PH stainless steel. In order to understand the effectiveness of CVD multilayer coated tool a comparison has been carried out with that of uncoated carbide insert. The surface roughness and cutting temperature obtained during machining with chemical vapor deposition (CVD) multilayer coated tool was higher than that of uncoated carbide insert at all cutting velocity. However, the results clearly indicated that CVD multilayer coated tool played a significant role in restricting various modes of tool failure and reducing chip deformation compared to its uncoated counterpart. Adhesion and abrasion were found to be dominating wear mechanism with flank wear, plastic deformation, and catastrophic failure being majo...

54 citations


Cited by
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Journal ArticleDOI
TL;DR: In this article, the state-of-the-art on various surface integrity characteristics during machining of nickel-based super alloys are presented, including surface roughness, defects (surface cavities, metal debris, plucking, smeared material, redeposited material, cracked carbide particles, feed marks, grooves and laps).
Abstract: Nickel-based super alloys are gaining more significance, now-a-days, with extensive applications in aerospace, marine, nuclear reactor and chemical industries. Several characteristics including superior mechanical and chemical properties at elevated temperature, high toughness and ductility, high melting point, excellent resistance to corrosion, thermal shocks, thermal fatigue and erosion are primarily responsible for wide domain of application. Nevertheless, machined surface integrity of nickel-based super alloys is a critical aspect which influences functional performance including fatigue life of the component. This review paper presents state-of-the-art on various surface integrity characteristics during machining of nickel-based super alloys. Influence of various cutting parameters, cutting environment, coating, wear and edge geometry of cutting tools on different features of surface integrity has been critically explained. These characteristics encompass surface roughness, defects (surface cavities, metal debris, plucking, smeared material, redeposited material, cracked carbide particles, feed marks, grooves and laps), metallurgical aspects in the form of surface and sub-surface microstructure phase transformation, dynamic recrystallisation and grain refinement and mechanical characteristics such as work hardening and residual stress. Microstructural modification of deformed layer, profile of residual stresses and their influence on fatigue durability have been given significant emphasis. Future research endeavour might focus on development of new grades, advanced processing techniques of the same to ensure their superior stability of microstructure and thermo-mechanical properties along with advanced manufacturing processes like additive manufacturing to achieve highest level of fatigue durability of safety critical components while maintaining acceptable surface integrity and productivity.

403 citations

Journal ArticleDOI
TL;DR: In this paper, a comprehensive analysis of literature pertaining to ecological trends in machining processes of difficult-to-cut materials (e.g. hard steels, Ti-based alloys, Ni based alloys) has been performed.

260 citations

Journal ArticleDOI
TL;DR: In this article, the authors present a systematic, critical, and comprehensive review of all aspects of dry machining including the sustainability aspects of machining, especially focusing on three research objectives.

195 citations

Journal ArticleDOI
TL;DR: In this paper, the application of nanofluids (NFs) in small quantity lubrication (SQL) mode by suspending eco-friendly Silver and Zinc oxide nanoparticles in deionized water was explored.

155 citations

Journal ArticleDOI
TL;DR: In this paper, the authors provide an informative literature survey of the research done in the field of conventional and non-conventional machining of CMCs with a main focus on critically evaluate how different machining techniques affect the machined surfaces.
Abstract: Ceramic Matrix Composites (CMCs) are currently an increasing material choice for several high value and safety-critical components, fact that has recently originated the need of understanding the effect of several machining processes. Due to the complex nature of CMCs - i.e. heterogeneous structure, anisotropic thermal and mechanical behaviour and generally the hard nature of at least one of the constituents (e.g. fibre or matrix) - machining become extremely challenging as the process can yield high mechanical and thermal loads. Furthermore, the orthotropic, brittle and heterogeneous nature of CMCs result in different material removal mechanisms which lead to unique surface defects. Hence, this review paper attempts to provide an informative literature survey of the research done in the field of conventional and non-conventional machining of CMCs with a main focus on critically evaluate how different machining techniques affect the machined surfaces. This is achieved by exploring and recollecting the different material characterisation techniques currently used to observe and quantify the mechanical and thermal surface and subsurface damages and highlight their governing removal mechanisms.

146 citations