Mayank Garg | Cleveland State University (original) (raw)

Papers by Mayank Garg

Corrosion Reviews, 2024

Engineering materials are known to show degradation in terms of tribo-corrosion characteristics i... more Engineering materials are known to show degradation in terms of tribo-corrosion characteristics in marine environment. The concurrent increase in erosion and corrosion resistance can make them more appealing for structural applications. The thermal spray coatings are typically used to mitigate the degradation of structural components. Although, the microstructure of as-sprayed coating indicates inconsistency in the form of distinct splats and elemental segregation. Furnace annealing, microwave processing and stationary friction processing (SFP) are performed to improve the non-homogeneous microstructure of the thermal spray coating. SFP has several attractive properties to refine the grain structure and reducing the defects density on the surface. Therefore, SFP has been explored as a surface modification technique for thermal spray coating with an aim to enhance the performance of the processed coating. Slurry erosion and erosion corrosion tests are conducted on as-sprayed and processed coatings at normal and oblique impingement angle. Erosion rate of SFPed specimen is comparatively lower than that of the as-sprayed, furnace annealed and microwave processed specimens in both slurry erosion and erosion corrosion. Furthermore, the SFPed coating indicated least corrosion rate as compare to furnace annealed, microwave coating and as-sprayed coating.

Material degradation processes like cavitation erosion/ erosion-corrosion, slurry erosion/erosion... more Material degradation processes like cavitation erosion/ erosion-corrosion, slurry erosion/erosion-corrosion, and pure corrosion is a major issue of concern affecting but not limited to the marine industry, mining, power, etc. The present work focuses on the development of a complex concentrated alloy (CCA) (MoNbTiZr) subjected to these damage phenomena. For comparison studies, conventionally used standard material SS316L stainless steel was also evaluated. The microstructural characterization shows the occurrence of characteristic dendrites formation within a matrix. The typical grain size of the composition was around 300 μm. The CCA exhibited significantly higher microhardness (900HV) as compared to the SS316L (220HV) stainless steel sample. The microstructural analysis of CCA showed the presence of BCC crystal structure. Under the slurry erosion/erosion-corrosion conditions, the CCA revealed the highest erosion resistance at different impact angles in comparison to different classes of
materials. The CCA also showed 5 times higher cavitation resistance as compared to SS316L. The superior performance of CCA in the erosion /erosion-corrosion test can be explained due to its high resistance to corrosion, better work hardenability, and high hardness. The degraded
surface examination showed signs of pits, micro-cutting, and ploughing as the major material removal mechanisms.

Journal of Materials Engineering and Performance, 2024

Journal of Polymers and the Environment

Terminalia catappa Linn. (Indian almond) leaf epicuticular wax was extracted for the first time a... more Terminalia catappa Linn. (Indian almond) leaf epicuticular wax was extracted for the first time and the presence of aliphatic alkane and ester chains was confirmed using Fourier Transform Infrared (FTIR) Spectroscopy. The wax crystals had tubular microstructure and displayed excellent thermal stability. Four pectin films were developed from ~ 5% w/v film forming solution by adding wax (5 & 10% w/w) and xylitol (15 & 30% w/w). The resulting films showed a twofold reduction in water vapor permeability and a five to eight orders of magnitude reduction in oxygen permeability than control pectin films. The films showed an enhanced melting point of 160 °C against 95 °C for control pectin. Water contact angle (WCA) of 67° at 40 s after sessile drop indicated significant improvement in hydrophobic properties (WCA of control pectin was 20° at 40 s). The films showed a fivefold increase in elongation at break and toughness compared to control pectin films. Therefore, the present study introduces and demonstrates that the T. catappa leaf wax can act as an efficient hydrophobic agent with some plasticizer properties. The addition of appropriate quantities of T. catappa leaf wax and xylitol (as plasticizer) could produce pectin films with enhanced barrier and tensile properties.

Journal of Polymers and the Environment, 2023

Materials Chemistry and Physics, 2022

Material processing is often performed to form a fine grain structure with uniform distribution o... more Material processing is often performed to form a fine grain structure with uniform distribution of mechanical properties. In the present study, a one-step solid phase processing technique that take advantage of in-situ reactive metallurgy, called stationary friction processing (SFP), is proposed to improve high temperature oxidation performance of AlCoCrFeNi high entropy alloy (HEA). The strategy involves producing a multi-phase fine-grain microstructure through SFP. The processed specimen retarded the oxidation kinetics by ∼52%. The electrochemical impedance spectroscopy coupled with transmission electron microscopy provided new insights into the physico-chemical nature and performance of the oxide-scale. Processed specimen demonstrated an increase in the polarization resistance with the immersion time while unprocessed HEA showed the reverse trend. The excellent oxidation performance was attributed to thin, adherent and uniform oxide layer on the processed HEA.

Journal of Polymer and Environment, 2022

Castor oil (CO) and cocoa butter (CB) were studied as potential hydrophobic and plasticizer addit... more Castor oil (CO) and cocoa butter (CB) were studied as potential hydrophobic and plasticizer additives for pectin bio-polymer films. The optimum concentration of CO and CB additives and drying temperature were determined by using a 2^3 (two-level, three-factor) statistical factorial design of experiments. The CO and CB integrated pectin films displayed remarkably lower moisture and oxygen transmission rates relative to the control pectin films. Furthermore, the hydrophobicity, ductility (elongation at break) and flexibility (low elastic modulus) of the CO and CB added films are significantly higher than that of the control pectin films. The modified films retained 90% of their weight at a temperature of 200 °C, indicating their excellent thermal stability. A very low glass transition temperature of 2 ± 2 °C and a melting point of ~ 150 °C of the films designates their stability under processing and storage conditions. Scanning electron microscopy analysis confirmed the formation of homogeneous films without any micro-cracks or agglomerations. Detailed statistical analysis shows that the optimal conditions for producing improved pectin films: the concentration of CO (15% w/w of pectin) and CB (10% w/w of pectin) and film drying temperature (T = 35–52 °C). A coating of film forming solution comprising optimum amounts of pectin, CO and CB was able to delay the ripening of a banana by 4 days and of capsicum by 15 days at atmospheric conditions.

Journal of Alloys and Compound, 2022

Engineering materials are known to show trade-off between high tensile strength and ductility. Th... more Engineering materials are known to show trade-off between high tensile strength and ductility. The simultaneous enhancement of strength and ductility can make them more appealing for various structural applications. In this study, we demonstrate a facile technique to address the conflicting strength-ductility trade-off in crystalline materials. AlCoCrFeNi high entropy alloy (HEA), one of the most popular multi-principal alloy system, was considered for the investigation. The as-cast AlCoCrFeNi alloy showed a coarse grain microstructure with BCC/B2 phase. The as-cast alloy was subjected to severe plastic deformation using a facile technique known as stationary friction processing (SFP). The SFP for only 15 min resulted in an order of magnitude reduction in the grain size along with BCC to FCC phase transformation. The processed sample demonstrated more than 2 times higher ultimate tensile strength (~650 MPa) compared to as-cast HEA (~310 MPa). Further, the ductility of the processed HEA was enhanced from 11 % to 18 %. The combination of fine grain structure along with BCC to FCC transition through SFP enabled exceptional mechanical properties in the HEA. This approach can easily be extended to other alloy systems for designing high tensile strength and superior ductility.

ACS Omega, 2022

This work investigates the effect of ultrafine-grain microstructure on the oxidation behavior of ... more This work investigates the effect of ultrafine-grain microstructure on the oxidation behavior of AlCoCrFeNi high entropy alloy (HEA). The ultrafine-grain microstructure is obtained using stationary friction processing performed at two different rotational speeds, 400 and 1800 rpm, for 5 min duration. Processed samples demonstrate high depth of refinement (DOR) and ultrafine grain size (0.43–1 μm) at high rotational speeds along with significant phase transformations from BCC/B2 to FCC microstructure. Further, surface free energy of the ultrafine-grain microstructure is enhanced up to 35%. Oxidation kinetics of the ultrafine-grained sample is decelerated up to 12–48% in a temperature range of 850–1050 °C for a duration of 100 h. Chromia and alumina were the predominant oxides formed in almost all the samples oxidized at elevated temperature. In addition, spinel Co(Cr,Fe)2O4/Fe(Co,Cr)2O4 formation is also detected in the unprocessed oxidized samples. Processed samples rich in grain boundaries (GBs) promote internal oxidation to form Al-rich inner oxides. The enhanced oxidation resistance of the processed samples is attributed to the microstructural refinement and homogenization resulting in the formation of protective chromia followed by Al-rich inner oxides.

Corrosion Reviews, 2022

In current study, we report an excellent high temperature oxidation resistance of AlCoCrFeNi high... more In current study, we report an excellent high temperature oxidation resistance of AlCoCrFeNi high entropy alloy (HEA) following surface modification. The surface properties of HEA were tailored through a severe surface deformation technique. The as cast HEA exhibited coarse grain BCC microstructure. In contrast, processed specimen showed significant grain refinement along with B2/BCC to FCC phase-transition. The processed specimen demonstrated 11-67 % reduction in the oxidation kinetics. Cr 2 O 3 and Al 2 O 3 were the predominant oxides formed in all the oxidized specimens. In addition, Cr, Fe and Co rich spinels were also found in the as cast oxidized specimens. The superior oxidation resistance of the processed specimen is attributed to the microstructural refinement resulting in the formation of protective dense chromia layer.

Journal of Alloys and Compounds, 2022

In the current study, the high temperature oxidation behavior of AlCoCrFeNi high entropy alloy (H... more In the current study, the high temperature oxidation behavior of AlCoCrFeNi high entropy alloy (HEA) following severe shear deformation was investigated. X-ray diffraction and transmission electron microscopy analysis confirmed spinodal distribution of B2 and BCC phase in the as cast specimen. In contrast, the processed specimen showed a dual phase microstructure (B2/BCC+FCC) after shear deformation. Electron backscattered diffraction analysis revealed significant grain refinement from 90 µm for the as-cast HEA to nearly 2 µm for the processed specimen. The processed specimen showed up to 66% reduction in the oxidation kinetics compared to the as cast alloy. The remarkable improvement in the high-temperature oxidation performance following processing is attributed to complete microstructure refinement. The current study provides a sustainable solution and a new pathway for addressing the looming problem of material deterioration at high temperatures.

Neurology India

To evaluate the outcome of patients undergoing a decompressive craniectomy (DC) in traumatic brai... more To evaluate the outcome of patients undergoing a decompressive craniectomy (DC) in traumatic brain injury (TBI) and the factors predicting outcome. A total of 1,236 patients with TBI operated with a DC from January 2008 to December 2013 at a tertiary care hospital were included in the study. The data from the hospital computerized database was retrospectively analyzed and 324 (45%) patients were followed-up for a mean duration of 25.3 months (range 3-42 months) among the cohort of 720 alive patients. The institute's ethical committee clearance was obtained before the start of the study. There were 81% males with a median age [interquartile range (IQR)] of 32 (23-45) years. The mortality rate and median (IQR) Glasgow outcome score (GOS) at discharge in patients presenting with minor, moderate, and severe head injury were 18%, 5 (4-5); 28%, 4 (1-5); and 47.4%, 2 (1-4), respectively. An overall favorable outcome (GOS 4 and 5) at discharge was observed in 46.5% patients and in 39% p...

33rd Conference on …, 2003

Recent explosion in the demand for mobile telecommunica-tion, computing and multimedia applicotio... more Recent explosion in the demand for mobile telecommunica-tion, computing and multimedia applicotions has resulted in much interest in system on chip (SOCj applications. In this work, an annlysis of the analog characteristics of scaled MOS-FET is presented. An analog ...

Neuropharmacology, 2013

Substantial evidence has implicated the endogenous opioid system in alcohol reinforcement. Howeve... more Substantial evidence has implicated the endogenous opioid system in alcohol reinforcement. However, the role of each opioid peptide in alcohol reinforcement and, particularly, reward is not fully characterized. In this study, using the conditioned place preference (CPP) paradigm as an animal model of reward, we determined the role of endogenous b-endorphin and enkephalins in the rewarding action of ethanol. Female mice lacking beta-endorphin and/or the proenkephalin gene as well as their respective wild-type controls were tested for baseline place preference on day 1, conditioned with ethanol versus saline on days 2e4 and were then tested under a drug-free state for postconditioning place preference on day 5. On each test day, mice were placed in the central neutral chamber and allowed to freely explore all three CPP chambers. The amount of time that mice spent in each chamber was recorded. We also studied the effect of naloxone, a non-selective opioid receptor antagonist, on ethanol CPP, in which wild-type mice were treated with saline or naloxone 10 min prior to ethanol or saline conditioning. Our results showed that the absence of b-endorphin or enkephalins alone failed to alter the acquisition of ethanolinduced CPP. However, the absence of both b-endorphin and enkephalins significantly reduced the CPP response. Interestingly, high but not low dose naloxone blunted ethanol CPP. These findings provide the first evidence illustrating that ethanol induces its rewarding action, at least in part, via a joint action of b-endorphin and enkephalins, possibly involving both mu and delta opioid receptors.

… , 2007. ICC'07. IEEE …, 2007

AbstractIn order to reduce the complexity of the mobile receiver, we develop a linear precoding ... more AbstractIn order to reduce the complexity of the mobile receiver, we develop a linear precoding filter based only on the statistical knowledge of the channel. Moreover, the proposed prefilter (precoder) is based on minimizing the probability of error in downlink multiuser ...

Journal of Energy Storage, 2021

Here, we report a facile approach for the development of unique nanoporous MnO 2-Cu architecture ... more Here, we report a facile approach for the development of unique nanoporous MnO 2-Cu architecture through a combination of severe surface deformation and dealloying. The severe surface deformation of Cu-Mn alloy prior to selective dealloying resulted in the precipitation of nanoporous MnO 2 in the Cu-rich substrate. The in situ grown nanoporous MnO 2-Cu architecture demonstrated an areal capacitance of 2.8 F/cm 2 at a current density of 5 mA/cm 2 and exhibits an excellent cyclic stability of 95% retention for 4000 cycles at 15 mA/cm 2 current density. The MnO 2-Cu composite structure showed small charge transport resistance of 1.9 Ω as determined using impedance spectroscopy. The asymmetric supercapacitor fabricated using nanoporous MnO 2-Cu as anode and reduced graphene oxide as cathode delivers specific energy of 5.55 Wh kg − 1 at a specific power of 249.75 W kg − 1. The superior performance of nanoporous MnO 2-Cu architecture was attributed to its unique microstructure that ensures high surface area, small internal resistance with rapid charge transport. The current approach can be applied to different material systems and is potentially transformative in the emerging field of advanced supercapacitors.

$Research paper thumbnail of Effect of microwave processing on the oxidation behavior of refractory high entropy alloy$

Materials Chemistry and Physics, 2021

• Microwave processing of AlCrTiTaMo High entropy alloy (HEA) was performed. • Long term oxidatio... more • Microwave processing of AlCrTiTaMo High entropy alloy (HEA) was performed. • Long term oxidation studies were carried out at 900 • C and 1100 • C for 100 h. • The processed HEA showed 50% reduction in oxidation rate compared to as-cast HEA. • The impedance of the oxide formed on the as-cast alloy decreased with the immersion time. • The processed alloy showed continuous increase in impedance as a function of time.

Journal of Materials Chemistry A

The 3-dimensional hierarchical nano-porous copper oxide structure developed using thermo-mechanic... more The 3-dimensional hierarchical nano-porous copper oxide structure developed using thermo-mechanical processing and selective dealloying demonstrated excellent performance as a supercapacitor electrode.

ABSTRACT High aspect ratio arrayed micro-structures and textured surfaces are required in diversi... more ABSTRACT High aspect ratio arrayed micro-structures and textured surfaces are required in diversified applications such as electrical contacts, printing heads, electrodes for micro-batteries, injection nozzles, nano-material delivery systems, biomedical implants, and hydrophobic surfaces. Reverse micro-electrical discharge machining (R-MEDM) process has a capability to fabricate such arrayed features on a variety of workpiece materials irrespective of their mechanical properties. R-MEDM is a variant of micro-electrical discharge machining (MEDM) process, key difference being, extruded arrayed features are fabricated in the R-MEDM process against the micro-cavities that are machined in MEDM. This article highlights the recent advances in process characterization and modelling of mechanics of the R-MEDM process. The focus of discussion is on comparing the process with the other micromachining processes presently available for the fabrication of arrayed micro-features. In addition, R-MEDM process characteristics in the fabrication of arrayed features on ‘easy’ and ‘difficult’ to erode materials are presented. It is understood that R-MEDM has comparable or in some cases better performance in the fabrication of arrayed features than the processes like micro-milling, micro-wire EDM, micro-wire electrical discharge grinding (EDG) and block EDG.