Shalini Mohanty
@qub.ac.uk
Researcher, Department of Mechanical and Aerospace Engineering
Queen's University Belfast
RESEARCH INTERESTS
Surface modification, coatings, metal additive manufacturing, EDM
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
Shalini Mohanty, Adrian Murphy, and Rashi Tyagi
CRC Press
Shalini Mohanty, Garima Singh, Suryank Dwivedi, Amit Rai Dixit, and Rabesh Kumar Singh
IOP Publishing
Abstract The present work assesses the effect of textures and bath composition on Ni-P-MoS2 electroless composite coating. Aluminium alloys are subjected to textures (through electrical discharge machine) for using as substrate material in the present context of study. A comparison study is conducted to evaluate the effect of coatings on textured and non-textured surfaces prepared in two different baths (oxalic acid and hydrazine). Different surface characterization has been carried out including micro-hardness, surface roughness, topography, morphology, tribology through micro-scratch test, and composition analysis (using Energy Dispersive Spectroscopy) in the study. Results indicate that the textured coated surfaces impart better wear-resistant properties than those of coatings produced in non-textured ones. Moreover, the coating prepared using oxalic acid bath imparts better micro-hardness and tribological properties than those of hydrazine bath. The elemental presence of Mo, S, Ni and P was affirmed through EDS mapping, indicates transference of MoS2 particles on to the coated surfaces. The micro-hardness of different coated specimen prepared using oxalic acid bath range from 53.55 HV0.2 to 71.31 HV0.2 for non-textured samples and 70.47 HV0.2 to 113.52 HV0.2 for textured ones. It varied from 53.68 HV0.2 to 68.85 HV0.2 for non-textured surfaces and 63.03 HV0.2 to 98.27 HV0.2 for textured surfaces in hydrazine bath. The addition of MoS2 powder in the electroless bath account for the deposition of a tribo-adaptive layer on Al-alloys.
Shalini Mohanty and Konda Gokuldoss Prashanth
MDPI AG
Metallic additive manufacturing is expeditiously gaining attention in advanced industries for manufacturing intricate structures for customized applications. However, the inadequate surface quality has inspired the inception of metallic coatings through additive manufacturing methods. This work presents a brief review of the different genres of metallic coatings adapted by industries through additive manufacturing technologies. The methodologies are classified according to the type of allied energies used in the process, such as direct energy deposition, binder jetting, powder bed fusion, hot spray coatings, sheet lamination, etc. Each method is described in detail and supported by relevant literature. The paper also includes the needs, applications, and challenges involved in each process.
Shangavi Subramanian, Shalini Mohanty, and KG Prashanth
Elsevier BV
Shalini Mohanty, Himanshu Singh Maurya, and Konda Gokuldoss Prashanth
Elsevier BV
Garima Singh, Shalini Mohanty, Rabesh Kumar Singh, Amit Rai Dixit, and Anuj Kumar Sharma
Elsevier BV
Shalini Mohanty, Naghma Jamal, Alok Kumar Das, and Konda Gokuldoss Prashanth
MDPI AG
The work aimed to produce Ni-P-MoS2-Al2O3 on Al-7075 alloys with multiple attributes through an electroless (EL) plating route. The effects of additives (MoS2 and Al2O3) in the EL bath on the surface morphology, topography, hardness, composition (phase and elemental), roughness, wettability, and coating thickness were evaluated. Results indicate a substantial enhancement in microhardness of the EL-coated surfaces by 70% (maximum hardness = ~316 HV) using powders, and 30% (244 HV) without powders. The maximum coating thickness and water contact angle obtained with powders were 6.16 μm and 100.46°, respectively. The coefficient of friction for the samples prepared using powders was 0.12, and for the base material it was 0.18. The compositional analysis through EDS and XRD suggested the incorporation of a hard and lubricious layer on the EL-coated surface owing to the presence of different phases of Al, Mo, P, Zn, O, and S. Therefore, the resulting coating surfaces impart hardness, self-lubrication, hydrophobicity, and wear resistance simultaneously.
Mithilesh Singh, Shalini Mohanty, and Alok Kumar Das
Elsevier BV
Kiran P., Shalini Mohanty, and Alok Kumar Das
Elsevier BV
Shalini Mohanty, Alok Kumar Das, and Amit Rai Dixit
Elsevier BV
Sonakshi Hazra, Shalini Mohanty, Shakti Kumar, Ranjit Basak, and Alok Kumar Das
Elsevier BV
Abhishek Yadav, Shalini Mohanty, Suryank Dwivedi, and Amit Rai Dixit
Informa UK Limited
ABSTRACT The present study acclaims the influence of hybrid powders (MoS2 +W) mixed dielectric fluid on the surface properties of SS304 by the electro-discharge coating (or EDC) process. Hard, wear-resistant, and lubricating surfaces are produced using different blending ratios of the powders infused in the dielectric liquid. The combined effect of both powders on the substrate’s surface properties is studied. The process performance is evaluated in terms of wear analysis, surface roughness, coefficient of friction, micro-hardness, and compositional study at different peak current and duty factors. The experimental results show an aggregate increment of micro-hardness from 119.3% to 255.2% compared to substrate. The average surface roughness increases (2.69–4.32 μm) with an increase in tungsten content (from 5% to 50%) in the dielectric and decreases with MoS2 content. The wear test results reveal a substantial decrease in coefficient of friction (COF = 0.104) with maximum concentration of MoS2 and 0.274 for maximum tungsten.
P Kiran, Shalini Mohanty, and Alok Kumar Das
Informa UK Limited
ABSTRACT In this research, both eco-friendly and commercially available dielectric liquid (EDM oil, EDM oil + MoS2 powders (EDP), Sunflower oil (SF), and Sunflower oil + MoS2 powders (SFP)) was adopted to carry out the small area surface modification on Ti6Al4V sheet through the micro-EDM process. Brass rod (diameter: 0.95 mm) was used as the micro-tool electrode. The quality (surface roughness (Ra, Rq, Rz), recast layer (or coating) thickness (RLT), and the micro-hardness (MH)) of the coated surfaces was tested and compared with the change of input process parameters and dielectrics. The results indicate that the maximum micro-hardness of the coated layer for differently used dielectric mediums such as EDM oil, SF oil, EDP oil, and SFP oil is 495.9 HV, 619.05 HV, 665.42 HV, and 694.02 HV, respectively. Similarly, the coated layer thickness varies within the range of 4.56 to 24.42 μm (EDM oil), 7.24 to 28.31 μm (SF oil), 5.42 to 26.84 μm (EDP oil), and 4.66 to 32.75 μm (SFP oil). EDX plots suggest transfer of tool and the dielectric material (Ti, V, Al, C, Cu, Zn, Mo, S) to the substrate surface.
Pankaj Kumar, Alok Kumar Das, and Shalini Mohanty
Elsevier BV
Shalini Mohanty, Alok Kumar Das, and Amit Rai Dixit
Elsevier
Naghma Jamal, Shalini Mohanty, Sanu Raj, and Alok Kumar Das
Springer Singapore
Shalini Mohanty, Partha Bhattacharyya, Alok Kumar Das, and Amit Rai Dixit
Springer International Publishing
Shalini Mohanty, Alok Kumar Das, and Amit Rai Dixit
Informa UK Limited
ABSTRACT The work aims to assess the influence of tool electrode material while surface modification of Ti-alloy through the micro-electrical discharge coating (μEDC) process. Brass and tungsten micro-tool (800 μm)are chosen based on their mechanical, thermal, and electrical properties to conduct the experiments at different coating criteria such as duty cycle, voltage, and powder (tungsten disulphide) concentration. Various performance indexes i.e., micro-hardness, surface roughness, and recast surface height, are evaluated. Energy-dispersive X-ray spectroscopy (EDX) recognizes the elemental presence on the recast zone formed over Ti-alloy. A comparative analysis of the surfaces generated using both thetools is carried out for their performance measurement. The modified samples’ hardness improved by twice the base material due to the formation of hard phases of tungsten and titanium, as affirmed by the EDX study. The results indicate that both the micro-tool electrodes’ mechanical, electrical, and thermal properties significantly affect the process parameters for surface alteration of Ti-alloy.
Shalini Mohanty, Alok Kumar Das, and Amit Rai Dixit
Informa UK Limited
ABSTRACT This work contributes to the surface topographical study of miniature Ti-alloy coated samples prepared by the micro-electrical discharge coating process using powder mixed dielectric medium. Two phases of experiments were conducted, first phase: using tungsten disulfide mixed in de-ionized water and second phase: using molybdenum disulfide powders mixed in deionized water. The produced micro-parts from both the phases of experiments were characterized for micro-hardness, indentation depths, wettability (in terms of the surface contact angle), residual stress, surface roughness, and surface crack density. The results indicated that MoS2 coating is superior as compared to WS2 coating obtained through the micro-EDM process for tribological applications where lubrication is necessary. The WS2 coated samples have micro-hardness ranging from 705.8 HV to 880.34 HV, surface roughness from 0.604 microns to 0.660 microns, and a comparatively higher surface crack density and residual stresses are developed on the recast surface than the samples coated with MoS2 powders. The samples coated with MoS2 powders have a micro-hardness variation from 658.21 HV to 714.21 HV, surface roughness between 0.561 μm to 0.650 μm.
Abhishek Yadav, Shalini Mohanty, Akash Nag, Amit Rai Dixit, and Alok Kumar Das
AIP Publishing
Deepak Sharma, Shalini Mohanty, and Alok Kumar Das
Elsevier BV
R. Tyagi, S. Kumar, V. Kumar, S. Mohanty, A. K. Das, and A. Mandal
Springer Singapore
Shalini Mohanty, Brij Bhushan, Alok Kumar Das, and Amit Rai Dixit
Elsevier BV
Shalini Mohanty, Brij Bhushan, Alok Kumar Das, and Amit Rai Dixit
Springer Science and Business Media LLC
Anusha Roohi Siddique, Shalini Mohanty, and Alok Kumar Das
Informa UK Limited
ABSTRACT The paper brings forward a novel technique for localized solid lubrication coating in intricate structures. Green compact powder metallurgy electrodes (P/M) (diameter: 1 mm to 1.25 mm) were prepared from mixture of WS2 and brass powder at various mixing ratios. The prepared electrodes were used for the deposition process in micro-EDM. A permanent metal mold was fabricated to prepare the micro-EDM P/M tools. The coating operation was performed at different parameter combinations and the coated samples were characterized for evaluation of metallurgical and tribological properties. Maximum metal deposition rate (MDR) of 0.312 mg/min was obtained at powder mixing ratio of 50:50, machining voltage of 80 V, and 50 % duty factor. Uniform surface was observed at powder mixing ratio of 70:30 (WS2: Brass). Maximum micro-hardness of 578.55 HV was observed for coated surface whereas the same for base material was 280 HV. XRD analysis confirmed the presence of WS2, Al2O3 in the coating. Lower wear rate of coated surface was found as compared to uncoated work piece, and a reduction in friction coefficient 0.4 (uncoated work piece) to 0.07 (coated work piece) was obtained.