Faculty Publications
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Item Microstructure Evolution and Mechanical and Corrosion Behavior of Accumulative Roll Bonded Mg-2%Zn/Al-7075 Multilayered Composite(Springer New York LLC barbara.b.bertram@gsk.com, 2017) Anne, G.; Ramesh, M.R.; Shivananda Nayaka, H.; Arya, S.B.; Sahu, S.Multilayered composite of Mg-2%Zn/Al-7075 was developed by accumulative roll bonding (ARB) of wrought Mg-2%Zn and aluminum 7075 alloy. The Mg-2%Zn/Al-7075 multilayered composite exhibited density of 2295 kg/m3 and an average grain size of 1 and 1.3 ?m in Mg-2%Zn and Al-7075 layers, respectively. A thorough microstructural characterization was performed on the composites by scanning electron microscope, electron backscatter diffraction (EBSD), transmission electron microscope and phase analysis by x-ray diffraction. In addition, mechanical properties were evaluated by microhardness and tensile tests. Corrosion behavior of the multilayered composite was examined using electrochemical polarization test. EBSD analysis showed the presence of ultrafine grains with high-angle grain boundaries. The composite exhibited a significant improvement in ultimate tensile strength (~1.82 times) and elongation (~1.5 times) as compared with Mg-2%Zn alloy, after four-pass ARB process. © 2017, ASM International.Item Tribo-corrosion study of nickel-free, high nitrogen and high manganese austenitic stainless steel(Elsevier Ltd, 2018) Vats, V.; Baskaran, T.; Arya, S.B.The electrochemical corrosion and tribo-corrosion behaviors of nickel-free high nitrogen (HN SS) and high manganese containing austenitic stainless steel were studied in simulated body fluids such as Ringer's and artificial saliva solutions (ASS) using tribo-meter attached with the potentiostat. Type 316L SS used as reference alloy for comparison. Open circuit potential (OCP) and potentiodynamic polarization techniques were used to examine the passivation and corrosion behavior of both the stainless steels under the applied loads of 5 and 10 N at room temperature and also compared with the static condition of corrosion. Pitting resistance of HN SS was found to be significantly higher over type 316L SS. © 2017 Elsevier LtdItem Electrochemical corrosion behavior of Ti-10V-2Fe-3Al in different corrosive media(Wiley-VCH Verlag info@wiley-vch.de, 2018) Arya, S.B.; Bhattacharjee, A.; Roy, M.The electrochemical corrosion behavior of Ti-10V-2Fe-3Al in different corrosive media namely, artificial sea water solution, Hank's solution, 0.5 M sulfuric acid, and 0.5 M hydrochloric acid solution has been investigated. Corrosion rates are evaluated using open circuit potential, current time transient, Tafel extrapolation potentiodynamic polarization curves, and electrochemical impedance spectroscopy. The results show that this alloy has lower corrosion rate in alkaline solution due to formation of thick, compact, and stable passive film. In acid solution corrosion rate is higher as the passive film is less compact, porous, and unstable. In general, the material is more active in C1? ion containing solution. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, WeinheimItem Hot corrosion behavior of Al2O3 + Sm2SrAl2O7 composite thermal barrier coatings(John Wiley and Sons Inc, 2022) Joseph, F.J.; Arya, S.B.; Tailor, S.Rare earth-based samarium strontium aluminate (Sm2SrAl2O7) powder has been synthesized in the laboratory through molten salt synthesis and Al2O3 + Sm2SrAl2O7 (SSA) thermal barrier coatings have been developed on an Inconel 718 superalloy substrate by atmospheric plasma spraying technique. The microstructures and surface morphologies of the samples before and after the hot corrosion tests in 50 wt% Na2SO4 + 50 wt% V2O5 (aviation atmosphere) and 90 wt% Na2SO4 + 5 wt% V2O5 + 5 wt% NaCl (marine atmosphere) at 700°C and 900°C were examined. It is observed that samples exposed to marine conditions exhibited 14.5% and 11.6% lower lifetime than the samples exposed to aviation conditions at 700°C and 900°C, respectively, due to significant chlorides attack. © 2022 Wiley-VCH GmbH.Item Hot corrosion behaviour of mullite thermal barrier coatings for marine diesel engines(Elsevier Ltd, 2024) K, S.; Babu, N.; Cadambi, S.; Arya, S.B.Mullite's inherent qualities have made it a potential material for the application of thermal barrier coatings (TBCs) for diesel engine components. Hot corrosion at 600–800 °C can cause TBC degradation, thus significantly affecting the performance of engine components and reducing their service life. This work examines the hot corrosion behaviour of atmospheric plasma-sprayed (APS) mullite coating over NiCrAlY bond coat on mild steel substrates. The coated specimen surface was covered with a mixture of Na2SO4 (sodium sulphate) and V2O5 (vanadium pentoxide) in the form of paste and heated in a muffle furnace at 700 °C for up to 300 h. SEM, EDS, and XRD characterisations were used to investigate the mechanism of hot corrosion. Coatings remained intact after corrosion tests; however, it had reacted with corrosive salts, particularly sodium sulphate. This was evidenced by the removal of amorphous silica, followed by the formation of nosean as a major phase. During the reaction between sodium sulphate and mullite coating, vanadium pentoxide was found to be acting as a flux and mineraliser. © 2023 Elsevier Ltd and Techna Group S.r.l.Item Enhancement of Corrosion Resistance of Al2O3 + Sm2SrAl2O7 Composite Thermal Barrier Coatings by Laser Treatment(Springer, 2024) James J, F.; Arya, S.B.The rare earth aluminate Sm2SrAl2O7 was synthesized in the laboratory through a molten salt synthesis technique at 1100 °C. A composite thermal barrier coating system on Inconel 718 substrate was developed with Al2O3–Sm2SrAl2O7 composite as the top coat and NiCrAlY as the bond coat using atmospheric plasma spraying. The surface of the plasma-sprayed coatings was treated using an Nd: YAG fiber laser to seal off the open porosities and reduce surface roughness. Hot corrosion tests on the laser-modified samples were performed at 700 °C and 900 °C, in aviation and marine corrosive conditions using 50 wt.% Na2SO4 + 50 wt.% V2O5 and 90 wt.% Na2SO4 + 5 wt.% V2O5 + 5 wt.% NaCl, respectively. The laser-treated samples showed higher resistance to failure than the as-coated samples under similar conditions. The corrosion products are identified, and the mechanisms involved are discussed in detail. The effect of surface modifications on the hot corrosion resistance of the coatings is investigated. © The Indian Institute of Metals - IIM 2023.Item Enhancing the Flow-Accelerated Corrosion Resistance of X70 API Steel Through Laser Surface Melting in Synthetic Oilfield Water(John Wiley and Sons Inc, 2025) Ajmal, T.S.; Singh, R.K.; Arya, S.B.; Kumar D, S.Hydrodynamic flow conditions play a critical role in piping failure due to sharp variations of the Reynolds number in process and petrochemical industries. The current study aims to enhance flow-accelerated corrosion (FAC) resistance using metallurgy of the surface by utilizing the laser surface melting (LSM) technique. The FAC behavior of API X70 steel in simulated Indian synthetic oilfield water was studied by utilizing a closed-loop corrosion apparatus to simulate the pipeline flow. Electrochemical corrosion experiments (AC and DC methods) were conducted at a constant fluid velocity of 3 m/s in untreated and LSM-treated samples (at 2.5 and 3.0 kW) placed at a 90° pipe elbow. Experimental results showed that LSM-treated samples displayed enhanced resistance to FAC, attributed to changes in surface metallurgy. Additionally, it was observed that the corrosion rate varied within the pipe elbow for the different samples at different locations. © 2024 Wiley-VCH GmbH.Item Meltpool characteristics, microstructure, and corrosion performance of laser-directed energy deposition cladded 316L SS/X70 steel for oilfield applications(Elsevier Ltd, 2025) Singh, R.K.; Arya, S.B.; Nayak, J.In oilfield pipeline transmission, complex geometries such as elbows, reducers, tees, and orifices face significant corrosion risks, especially in aggressive environments where multiphase turbulent flow and chloride ions cause sharp variations in hydrodynamic parameters. This study explores a laser cladding approach to mitigate internal corrosion in these complex geometries. The Laser-Directed Energy Deposition (L-DED) technique, known for its precision and efficiency, is employed to apply corrosion-resistant 316 L stainless steel (SS) over API X70 steel. Key parameters, including laser power and scan speed, were varied across nine combinations to evaluate their effects on melt pool characteristics, microstructure, and corrosion properties of the clads. Results showed that as laser energy increased (higher power and lower scan speed), melt pool dimensions and heat-affected zone (HAZ) thickness also increased, with clad thickness and HAZ ranging from 172 to 504 µm and 159–272 µm, respectively. Cellular and columnar sub-grain structures were present across all process combinations, with sub-grain size increasing at higher laser energy. A notable variation in chromium content was detected, with the clad produced at 500 W and 720 mm/min exhibiting superior pitting and corrosion resistance. This high-energy clad featured 16.3 % chromium and larger sub-grain sizes, facilitating stable passive film formation during corrosion. The optimized clad demonstrated approximately two orders better corrosion performance than the base X70 steel. © 2025Item Enhancing X70 steel durability: Tribo-corrosion resistance through protective laser cladding(Elsevier Ltd, 2025) Singh, R.K.; Bhole, K.B.; Arya, S.B.; Nayak, J.This study investigates the effects of laser surface cladding (L-DED technique) on the tribo-corrosion behavior of API X70 steel in the simulated Indian oilfield water. Using optimized parameters, 500 W laser power, 720 mm/min scan speed, and 4.2 g/min powder feed rate, 316 L SS was successfully clad onto X70 steel without any significant defects. The results showed a significant improvement in corrosion resistance, with the SS clad exhibiting a corrosion rate of 131.3 ?m/year at 20 N, compared to 287.9 ?m/year for the X70 substrate. SEM and 3D profilometer analyses revealed a more stable tribo-layer on the SS clad, with less damage and debris accumulation. These findings highlight the potential of laser cladding to enhance the durability and lifespan of steel components. © 2025 Elsevier Ltd