Manila Mallik

Bio: Manila Mallik is an academic researcher from Veer Surendra Sai University of Technology. The author has contributed to research in topics: Alloy & Copper. The author has an hindex of 5, co-authored 12 publications receiving 65 citations. Previous affiliations of Manila Mallik include University of Chittagong & University of Jammu.

Substrate effect on electrodeposited copper morphology and crystal shapes

Abstract: Copper has been electrodeposited on copper (FCC) and mild steel (BCC) substrates from acidic sulphate bath with and without cetyl trimethyl ammonium bromide at 0.25, 2, 6 and 9 V. It is found that the surface morphology varies with the change in overpotential, but not with the change in substrate. On the contrary, the crystal shape is found to be independent of the applied overpotential, but varies with the bath chemistry or choice of substrate.

Effect of Current Density on the Nucleation and Growth of Crystal Facets during Pulse Electrodeposition of Sn–Cu Lead-Free Solder

Abstract: The present study highlights the changes in morphology in a Sn matrix during pulsed electrodeposition of a Sn–Cu near-eutectic alloy with varying current density in an acidic electrolyte. 3D image construction has been employed using SHAPE V7.3; Shape Software: Kingsport, Tennessee, USA to replicate the shape of grown crystals and analyze the results. It is observed that the growth morphology changes with the introduction of high index planes at higher current densities. Furthermore, a growth pattern occurs with high index planes formed from a stepped structure in low index planes. There has been a change in growth direction from ⟨001⟩ to ⟨110⟩ at higher current densities. At very high current densities, sympathetic or secondary nucleation is observed.

Effect of Anodic Passivation at High Applied Potential Difference on the Crystal Shape and Morphology of Copper Electrodeposits: Thermodynamics and Kinetics of Electrocrystallization

Abstract: In this paper, we discuss the effect of potential difference and current density on the crystal morphologies of copper electrodeposits. Their individual roles have been identified by creating a passivation layer in situ at the anode during deposition, which instantaneously reduces the current density in the system while maintaining a high potential difference. It is observed that the crystal shape is decided by the potential difference and current density determines the rate at which that shape is achieved. In a copper system, at high overpotentials, coherent twin boundaries are formed due to their low formation energy as compared to high angle grain boundaries, high index surface planes, etc. Without the presence of any foreign species like H2 bubbles during the crystallization process, the slowest growth direction is identified to be . The passivation layer is formed due to a pH distribution in the electrolyte caused by the high electric field. A new methodology to explain the formation of the pa...

A review on out-of-sequence deformation in the Himalaya

Abstract: Abstract Out-of-sequence deformation in the Himalaya has been caused mainly by thrusting. Out-of-sequence thrusts, usually north- to NE-dipping foreshear planes, occur inside the Sub-Himalaya (SH), Lesser Himalaya (LH) and Greater Himalayan Crystalline (GHC) sequences. Where absolute dates are available, the youngest slip within the SH occurred near the Janauri Anticline (India) at c. AD 1400–1460. The Munsiari Thrust (India) activated within the LH at c. 1–2 Ma and the Main Central Thrust zone in the Marsyandi valley (Nepal) in the GHC was formed during the Holocene (c. 0.3 ka). Except for the Riasi Thrust (Kashmir, India), the Paonta Thrust (Himachal Pradesh, India) in the Siwalik and the Tons Thrust (Garhwal region, India) within the Main Central Thrust zone, crustal shortening related to out-of-sequence thrusting in the Himalaya has been insignificant. The major litho-/stratigraphic contacts within the SH and the GHC at some places acted as out-of-sequence thrusts. Out-of-sequence thrusts in the SH have been detected mainly based on geomorphological observations. However, more quantitative geochronological studies have detected out-of-sequence thrusting from c. 22 Ma up to Holocene age in the GHC based on age jumps, especially within the Main Central Thrust zone. Crustal channel flow (specifically for the GHC) and/or the critical taper model with or without erosion can be used to explain the Himalayan out-of-sequence thrusts.

A review of developments in the electrodeposition of tin-copper alloys

Abstract: The deposition of Sn–Cu binary alloys, mainly from aqueous electrolytes, is considered. The importance of tin–copper electrodeposits is summarised and the scope for plating them is highlighted. Sn–Cu (bronze) deposits are important in corrosion protection, decorative finishes, electronics and tribology. The past 20 years have seen a series of developments in the science and technology of bronze plating, including nanostructured deposits, environmentally friendly baths, such as methanesulfonic acid ones, and more ambitious coatings including multi-layers and composites. Among non-aqueous baths, room temperature ionic liquid electrolytes have received increasing attention. Our ability to realise controlled deposit morphology, composition and structure has been improved by newer electrolytes, improved electrolyte additives and pulse plating. The diversity of Sn–Cu deposit applications has extended to lithium batteries by newer layer structures such as composites, multi-layers and nanostructures), electrical control and relative bath/electrode movement. Electrochemical aspects of modern tin and bronze alloy deposition are illustrated by data from the authors' laboratory and elsewhere, which highlights the use of methanesulfonic acid electrolytes in tin alloy deposition due to their versatility and lack of environmental impact. A wide range of deposit composition, colour and surface finish are possible using suitable addition agents and by control of electrolyte flow and operating conditions. This review focuses on electrochemical voltammetry techniques together with morphological information from SEM imaging. Subject areas deserving further research and development are identified.

Estimation of Zwitterionic Surfactant Response in Electroless Composite Coating and Properties of Ni–P–CuO (Nano)Coating

Abstract: Electroless Ni–P and Ni–P–CuO coating on mild steel was developed successfully with the addition of Zwitterionic surfactant. The usage of nano-CuO in electroless coating was intermittent though the cost is low with high catalytic activity. Zwitterionic surfactant was introduced into the composite coating for the first time to increase the suspension of nanoparticles effectively during the coating process. Surfactant helps to reduce the intermolecular attraction between the solid and liquid interfaces and hence binding of nanoparticles with the hydrogen gas bubbles was eliminated. Also agglomeration of nanoparticles was controlled by stirring the electrolyte continuously using magnetic stirrer. The characterization and tribological properties were tested for the newly developed composites. Scanning electron microscope micrograph reveals the deposits are produced without any defects and the presence of CuO nanoparticles in the deposit. Energy-dispersive spectroscopy measurement shows the changes of weight percentage of elements available in the substrate. The surface roughness of the deposit was improved with the addition of CuO, it packs the gap between two grains and offers smooth finish and as the result the surface properties are modified. Microhardness of the substrate was improved for the substrate added with nano-CuO. The corrosion resistance of the substrate was improved when compared to the substrate produced using electroless Ni–P binary coating. Zwitterionic surfactant reduces the agglomeration of nanoparticles during chemical reaction and allows the particles to coat only on the target. Similarly, this technique can be implemented in the production of other composites in electroless coatings.