Development and Characterization of Metal/Carbon Nanomaterial Composite Coating Prepared by Electrodeposition Technique

Abstract

The carbon nanomaterials (CNMs) such as CNTs and graphene have shown remarkable utility and immense potential for high performance engineering materials due to its exceptional physical properties at nanoscale. CNTs and graphene have incredible scope in preparing nanocomposites and promising substitutes for many applications. In this study, Metal/Carbon nanomaterial composites (Cu/CNT and Zn/GO) were successfully prepared by reinforcing carbon nanomaterials (CNT/GO) using electrodeposition technique. Samples were characterized by using the scratch test, X-ray diffractometry (XRD), Transmission electron microscope (TEM), Field emission scanning electron microscopy (FESEM), Energy-dispersive X-ray spectroscopy (EDS), and Raman spectroscopy to confirm the presence and homogeneity of carbon nanomaterials (CNT/GO) in the metal matrix (Cu/Zn). The Cu/CNT nanocomposites are prepared by varying the diameter and concentrations of the CNT and are characterized by tensile test, hardness and corrosion and heat transfer rate. Maximum 24.63% and 47% higher tensile strength and hardness were observed for 450 mgL-1 compared to copper coating. Higher tensile strength in the composite coated on the Cu substrate signifies that good bounding between the Cu and CNT at atomic level is achieved by using electrodeposition technique. The Cu/MWCNT composite coatings have lower corrosion rate than pure Cu coating because the CNTs provide physical barrier to the corrosion medium. The overall heat transfer phenomena of Cu/CNT nanocomposite due to the preferential deposition of CNTs in the Cu matrix. The heat transfer rate is optimized and increased by 41.08% and 46.91% in natural and forced convection respectively compared to pure Cu coating. The reason is attributed to the better alignment, the optimum concentration of CNT in the composite, and the homogenously placed CNTs network in the composite. The aim of Zn/GO nanocomposites is to report cohesion strength and impact strength with respect to temperature using electrodeposition technique. The Zn/GO composite focused on the evaluation of cohesion strength using a scratch test from RT to 350 ºC, and residual stresses of the hybrid films deposited on the stainless steel substrate using different concentrations of GO and varying GO/surfactant ratios. Scratch tests revealed that Zn/GO hybrid films produced using 40 mgL-1 GO had 70.54% increase in cohesion strength (LC1) when compared to pure Zn films iiideposited with 30 minutes of coating time at a ratio of 1:2 GO:CTAB. In this study investigates the impact performance of Zn/GO nanocomposites under various gun pressure (2 bar, 2.5 bar, 3 bar, 3.5 bar and 4 bar) and temperature (100ºC, 200ºC and 300ºC) conditions using Split Hopkinson Pressure Bar experiments (SHPB). These findings motivated exploratory research for determining the behavior of structures in defence, aerospace, and nuclear power plant sectors subjected to the combined fire and impact. The Zn/GO nanocomposites were prepared using 40 mgL-1 concentration of GO through electrodeposition technique and characterized to maximum stress and toughness measurements. Test results show that the true stress–true strain responses are sensitive to the gun pressure and temperature. Zn/GO composite shows that 10.7% increase in compressive strength and 22.9% higher toughness at 4 bar in comparison with uncoated sample. The presences of few layered GO flakes in the coating which makes composite stronger and tougher. Because of this reason, considerable improvement in high maximum stress and higher toughness observed under high impact loading in Zn/GO composite. The maximum stress and toughness of Zn/GO nanocomposites declines with temperature from RT to 300C. The residual stresses were measured by using the X-Ray diffraction (XRD) - sin2ψ method using Co- Kα radiation. The magnitude of the residual stress diminishes as the GO concentration increases in films due to the effect of the kinetic movement of particles while deposition. Overall, experimentally measured cohesion strength values of Zn/GO hybrid films have correlated with residual stress values.