R KARUPPASAMY | Sethu Institute of Technology (original) (raw)
Papers by R KARUPPASAMY
Journal of natural fibers, 2020
In this investigation, the dynamic mechanical properties of Indian almond – Kenaf fiber composite... more In this investigation, the dynamic mechanical properties of Indian almond –
Kenaf fiber composite were investigated and the effect of stacking
sequence was analyzed. Four types of composites viz. kenaf, Kenaf/
Indian almond/Kenaf, Indian almond/Kenaf/Indian almond, and Indian
almond were fabricated by hand layup technique. The experimental
results revealed that the kenaf fiber composite showed the superior
storage modulus and loss modulus values compared to all other composites
due to the high stiffness of kenaf fiber and better bonding between
the matrix and fiber. Among hybrid composites, Kenaf/Indian almond/
Kenaf composite displayed a greater storage modulus and loss modulus
than Indian almond/Kenaf/Indian almond composite due to the presence
of two layers of high stiffness kenaf fiber. Further, the order of thermal
stability of the composites was observed as: Kenaf > Kenaf/Indian almond/
Kenaf > Indian almond/Kenaf/Indian almond > Indian almond. In addition,
the Indian almond fiber composite and Indian almond/Kenaf/Indian
almond composite exhibited good damping properties than other composites
owing to the more mobility of polymer chain. Cole – cole plot
showed that the structure of all the fabricated composites was heterogeneous
in nature and kenaf fiber composite displayed the higher heterogeneity
among all other materials. Moreover, the modeling of storage
modulus and damping factor was performed and compared with the
experimental results. The results showed good agreement with the theoretical
and experimental values.
Hybrid composites composed of neem fiber (N), banana (B) fiber and epoxy resin were fabricated by... more Hybrid composites composed of neem fiber (N), banana (B) fiber and epoxy resin were fabricated by hand layup method.
Journal of Thermal Science and Engineering Applications, 2020
In this investigation, the performance of the shell and tube heat exchanger operated with tin nan... more In this investigation, the performance of the shell and tube heat exchanger operated with tin nanoparticles-water (SnO 2-W) and silver nanoparticles-water (Ag-W) nanofluids was experimentally analyzed. SnO 2-W and Ag-W nanofluids were prepared without any surface medication of nanoparticles. The effects of volume concentrations of nanoparticles on thermal conductivity, viscosity, heat transfer coefficient, fiction factor, Nusselt number, and pressure drop were analyzed. The results showed that thermal conductivity of nano-fluids increased by 29% and 39% while adding 0.1 wt% of SnO 2 and Ag nanoparticles, respectively, due to the unique intrinsic property of the nanoparticles. Further, the convec-tive heat transfer coefficient was enhanced because of improvement of thermal conductivity of the two phase mixture and friction factor increased due to the increases of viscosity and density of nanofluids. Moreover, Ag nanofluid showed superior pressure drop compared to SnO 2 nanofluid owing to the improvement of thermophysical properties of nanofluid.
IOP Publishing, 2019
In this investigation, an attempt has been made to develop the surface hardness of iron-nickel-ch... more In this investigation, an attempt has been made to develop the surface hardness of iron-nickel-chromium alloy (alloy20) and the analysis on the micro structure and mechanical properties were performed. The surface modification of alloy20 was performed using HVOF (High-Velocity Oxygen Fuel) coating, plasma nitriding (PN) processes and hybrid coating (HVOF combined with PN) on 2 mm thickness plate. The HVOF thermal spray coating was performed at 450 °C using Molybdenum and the PN process was done at 500 °C for 12 h to strengthen the surface material. The microstructure and mechanical properties were investigated by x-ray diffractometry (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) techniques, tensile and bending. The result showed that the hybrid surface treatment enhanced the surface hardness of base material by 18%, tensile strength reached to 826 MPa which is 21% greater than that of base material, residual stress and corrosion rate decreased by 5 and 6% respectively compared to base material. Further, a transformation/diffusion model has been used and correlated with experimental hardness value and concluded that both the experimental and theoretical values displayed similar trend. The present investigation concluded that the formation of expanded austenite reduced the development of Cr 2 N and this led to the better results of hardness, tensile and bending strength.
IOP Publishing, 2019
Composite materials are used in place of conventional material as they reduce the weight of the s... more Composite materials are used in place of conventional material as they reduce the weight of the structure and increase the strength. Hybrid composite consists of two or more reinforcing fillers of different properties. In this investigation, a Tri layer Hybrid composites of Neem and Indian almond fruit fiber were prepared using hand layup method. Neem was used in outer layer and Indian almond fruit fiber was used in inner layer and vice versa while fabricating the hybrid composites. The tensile, flexural and impact properties of prepared hybrid composites were studied. The results displayed that the tensile and flexural properties of hybrid composite made with Neem as outer layer increased by 6.8% & 5.5% respectively compared to that of hybrid composite made with Indian almond fruit fiber as outer layer. The improvement of tensile and flexural properties was due to the presence of high strength Neem fiber at outer most layers. Moreover, the impact strength of hybrid composite made with Indian almond fruit fiber as outer layer exhibited better impact strength (5.1 kJ m −2) compared to the impact strength of hybrid composite made with Neem fiber as outer layer. The impact strength enhanced due to the surface cracks of Indian almond fruit fiber as it absorbs more impact energies while loading and finally improved the impact strength of hybrid composite.
IOP Publishing, 2019
A Polycarbonate (PC)/Ceria (CeO 2) composite with 0.5 wt% CeO 2 was prepared using melt blending ... more A Polycarbonate (PC)/Ceria (CeO 2) composite with 0.5 wt% CeO 2 was prepared using melt blending method. A Thermogravimetric analysis (TGA) was done on PC and PC-CeO 2. Based on the TGA results, the activation energy of PC-CeO 2 was calculated by three iso-conversional methods viz. Friedman, Kissinger and Ozawa-Flynn-Wall (OFW). The activation energy varied along the variation of extent of conversion (α) and increased as α increased. Based on the theoretical and experimental master plots y(α), an Avrami-Erofeev (f(α)=3(1−α)[−ln(1−α)] 2/3 and g(α)=[−ln(1−α)] 1/3) reaction model was selected to describe the thermal degradation mechanism of both PC and PC-CeO 2. Further, the lifetime estimation of PC-CeO 2 meets the demand in electronic applications.
Carl Hanser Verlag GmbH & Co. KG, 2019
Polycarbonate (PC)/cerium (IV) oxide (CeO 2) composites are prepared by a melt-compounding method... more Polycarbonate (PC)/cerium (IV) oxide (CeO 2) composites are prepared by a melt-compounding method using a twin-screw extruder. The effect of the CeO 2 content on the damping property of the composites was investigated using scanning electron microscopy, dynamic mechanical analysis (DMA), and thermogravimetric analysis (TGA). In addition, the compo-sites' mechanical properties were studied through tensile and impact tests. The DMA results revealed that the addition of CeO 2 (0.5 wt%) improved the damping property of the composite. TGA showed that the thermal stability was improved when the CeO 2 became 1 wt%. Mechanical tests revealed that both the tensile and impact strengths were substantially improved when 1 wt% CeO 2 was added. Finally, it can be concluded that the 0.5 wt% CeO 2-filled PC composite can be used as a structural damping material.
Journal of natural fibers, 2020
In this investigation, the dynamic mechanical properties of Indian almond – Kenaf fiber composite... more In this investigation, the dynamic mechanical properties of Indian almond –
Kenaf fiber composite were investigated and the effect of stacking
sequence was analyzed. Four types of composites viz. kenaf, Kenaf/
Indian almond/Kenaf, Indian almond/Kenaf/Indian almond, and Indian
almond were fabricated by hand layup technique. The experimental
results revealed that the kenaf fiber composite showed the superior
storage modulus and loss modulus values compared to all other composites
due to the high stiffness of kenaf fiber and better bonding between
the matrix and fiber. Among hybrid composites, Kenaf/Indian almond/
Kenaf composite displayed a greater storage modulus and loss modulus
than Indian almond/Kenaf/Indian almond composite due to the presence
of two layers of high stiffness kenaf fiber. Further, the order of thermal
stability of the composites was observed as: Kenaf > Kenaf/Indian almond/
Kenaf > Indian almond/Kenaf/Indian almond > Indian almond. In addition,
the Indian almond fiber composite and Indian almond/Kenaf/Indian
almond composite exhibited good damping properties than other composites
owing to the more mobility of polymer chain. Cole – cole plot
showed that the structure of all the fabricated composites was heterogeneous
in nature and kenaf fiber composite displayed the higher heterogeneity
among all other materials. Moreover, the modeling of storage
modulus and damping factor was performed and compared with the
experimental results. The results showed good agreement with the theoretical
and experimental values.
Hybrid composites composed of neem fiber (N), banana (B) fiber and epoxy resin were fabricated by... more Hybrid composites composed of neem fiber (N), banana (B) fiber and epoxy resin were fabricated by hand layup method.
Journal of Thermal Science and Engineering Applications, 2020
In this investigation, the performance of the shell and tube heat exchanger operated with tin nan... more In this investigation, the performance of the shell and tube heat exchanger operated with tin nanoparticles-water (SnO 2-W) and silver nanoparticles-water (Ag-W) nanofluids was experimentally analyzed. SnO 2-W and Ag-W nanofluids were prepared without any surface medication of nanoparticles. The effects of volume concentrations of nanoparticles on thermal conductivity, viscosity, heat transfer coefficient, fiction factor, Nusselt number, and pressure drop were analyzed. The results showed that thermal conductivity of nano-fluids increased by 29% and 39% while adding 0.1 wt% of SnO 2 and Ag nanoparticles, respectively, due to the unique intrinsic property of the nanoparticles. Further, the convec-tive heat transfer coefficient was enhanced because of improvement of thermal conductivity of the two phase mixture and friction factor increased due to the increases of viscosity and density of nanofluids. Moreover, Ag nanofluid showed superior pressure drop compared to SnO 2 nanofluid owing to the improvement of thermophysical properties of nanofluid.
IOP Publishing, 2019
In this investigation, an attempt has been made to develop the surface hardness of iron-nickel-ch... more In this investigation, an attempt has been made to develop the surface hardness of iron-nickel-chromium alloy (alloy20) and the analysis on the micro structure and mechanical properties were performed. The surface modification of alloy20 was performed using HVOF (High-Velocity Oxygen Fuel) coating, plasma nitriding (PN) processes and hybrid coating (HVOF combined with PN) on 2 mm thickness plate. The HVOF thermal spray coating was performed at 450 °C using Molybdenum and the PN process was done at 500 °C for 12 h to strengthen the surface material. The microstructure and mechanical properties were investigated by x-ray diffractometry (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) techniques, tensile and bending. The result showed that the hybrid surface treatment enhanced the surface hardness of base material by 18%, tensile strength reached to 826 MPa which is 21% greater than that of base material, residual stress and corrosion rate decreased by 5 and 6% respectively compared to base material. Further, a transformation/diffusion model has been used and correlated with experimental hardness value and concluded that both the experimental and theoretical values displayed similar trend. The present investigation concluded that the formation of expanded austenite reduced the development of Cr 2 N and this led to the better results of hardness, tensile and bending strength.
IOP Publishing, 2019
Composite materials are used in place of conventional material as they reduce the weight of the s... more Composite materials are used in place of conventional material as they reduce the weight of the structure and increase the strength. Hybrid composite consists of two or more reinforcing fillers of different properties. In this investigation, a Tri layer Hybrid composites of Neem and Indian almond fruit fiber were prepared using hand layup method. Neem was used in outer layer and Indian almond fruit fiber was used in inner layer and vice versa while fabricating the hybrid composites. The tensile, flexural and impact properties of prepared hybrid composites were studied. The results displayed that the tensile and flexural properties of hybrid composite made with Neem as outer layer increased by 6.8% & 5.5% respectively compared to that of hybrid composite made with Indian almond fruit fiber as outer layer. The improvement of tensile and flexural properties was due to the presence of high strength Neem fiber at outer most layers. Moreover, the impact strength of hybrid composite made with Indian almond fruit fiber as outer layer exhibited better impact strength (5.1 kJ m −2) compared to the impact strength of hybrid composite made with Neem fiber as outer layer. The impact strength enhanced due to the surface cracks of Indian almond fruit fiber as it absorbs more impact energies while loading and finally improved the impact strength of hybrid composite.
IOP Publishing, 2019
A Polycarbonate (PC)/Ceria (CeO 2) composite with 0.5 wt% CeO 2 was prepared using melt blending ... more A Polycarbonate (PC)/Ceria (CeO 2) composite with 0.5 wt% CeO 2 was prepared using melt blending method. A Thermogravimetric analysis (TGA) was done on PC and PC-CeO 2. Based on the TGA results, the activation energy of PC-CeO 2 was calculated by three iso-conversional methods viz. Friedman, Kissinger and Ozawa-Flynn-Wall (OFW). The activation energy varied along the variation of extent of conversion (α) and increased as α increased. Based on the theoretical and experimental master plots y(α), an Avrami-Erofeev (f(α)=3(1−α)[−ln(1−α)] 2/3 and g(α)=[−ln(1−α)] 1/3) reaction model was selected to describe the thermal degradation mechanism of both PC and PC-CeO 2. Further, the lifetime estimation of PC-CeO 2 meets the demand in electronic applications.
Carl Hanser Verlag GmbH & Co. KG, 2019
Polycarbonate (PC)/cerium (IV) oxide (CeO 2) composites are prepared by a melt-compounding method... more Polycarbonate (PC)/cerium (IV) oxide (CeO 2) composites are prepared by a melt-compounding method using a twin-screw extruder. The effect of the CeO 2 content on the damping property of the composites was investigated using scanning electron microscopy, dynamic mechanical analysis (DMA), and thermogravimetric analysis (TGA). In addition, the compo-sites' mechanical properties were studied through tensile and impact tests. The DMA results revealed that the addition of CeO 2 (0.5 wt%) improved the damping property of the composite. TGA showed that the thermal stability was improved when the CeO 2 became 1 wt%. Mechanical tests revealed that both the tensile and impact strengths were substantially improved when 1 wt% CeO 2 was added. Finally, it can be concluded that the 0.5 wt% CeO 2-filled PC composite can be used as a structural damping material.