scispace - formally typeset
Search or ask a question
Author

Manjunath Patel Gowdru Chandrashekarappa

Bio: Manjunath Patel Gowdru Chandrashekarappa is an academic researcher from Visvesvaraya Technological University. The author has contributed to research in topics: Composite number & Surface roughness. The author has an hindex of 3, co-authored 8 publications receiving 44 citations.

Papers
More filters
Journal ArticleDOI
04 Mar 2021
TL;DR: In this article, a comparative study was carried out on EDM of HcHcr D2 steel (DIN EN ISO 4957) by applying Taguchi L18 experimental design considering different electrode materials (copper, graphite, and brass), dielectric fluids (distilled water and kerosene), peak current, and pulse-on-time.
Abstract: Industries demand stringent requirements towards economical machining without hindering the surface quality while cutting high carbon high chromium (HcHcr) steel. Electrical discharge machining (EDM) of HcHcr steel aims at reducing machining cost (i.e., maximize material removal rate (MRR) and minimize tool wear rate (TWR)) with good surface quality (i.e., minimize surface roughness (SR)). A comparative study was carried out on EDM of HcHcr D2 steel (DIN EN ISO 4957) by applying Taguchi L18 experimental design considering different electrode materials (copper, graphite, and brass), dielectric fluids (distilled water and kerosene), peak current, and pulse-on-time. The process performances were analyzed with respect to material removal rate, surface roughness, and tool wear rate. Pareto analysis of variance was employed to estimate the significance of the process variables and their optimal levels for achieving lower SR and TWR and higher MRR. Hybrid Taguchi-CRITIC-Utility and Taguchi-PCA-Utility methods were implemented to determine the optimal EDM parameters. Higher MRR of 0.0632 g/min and lower SR of 1.68 µm and TWR of 0.012 g/min was attained by graphite electrode in presence of distilled water as dielectric fluid compared to the brass and copper. Additionally, a metallographic analysis was carried out to study the surface integrity on the machined surfaces. Micrographic analysis of the optimal conditions showed lower surface roughness and fewer imperfections (lesser impression, waviness surface, and micro-cracks) compared to worst conditions.

65 citations

Journal ArticleDOI
TL;DR: In this paper, the influence of WO3 particles on Zn deposition, the surface morphology of composite, and texture co-efficient were analyzed using a variety of techniques, such as X-ray diffraction (XRD) and scanning electron microscopy (SEM) with Energy Dispersive Xray analysis (EDX).
Abstract: Pure Zn (Zinc) and its Zn–WO3 (Zinc–Tungsten trioxide) composite coatings were deposited on mild steel specimens by applying the electrodeposition technique. Zn–WO3 composites were prepared for the concentration of 0.5 and 1.0 g/L of particles. The influence of WO3 particles on Zn deposition, the surface morphology of composite, and texture co-efficient were analyzed using a variety of techniques, such as X-ray diffraction (XRD) and scanning electron microscopy (SEM) with Energy Dispersive X-ray analysis (EDX). Higher corrosion resistance and microhardness were observed on the Zn–WO3 composite (concentration of 1.0 g/L). The higher corrosion resistance and microhardness of 1.0 g/L Zn–WO3 nanocomposite coatings effectively protect the steel used for the manufacture of products, parts, or systems from chemical or electrochemical deterioration in industrial and marine ambient environments.

23 citations

Journal ArticleDOI
TL;DR: In this paper, the corrosion performance of Zn-Ni coating and Zn−Ni-WC composite nanocoatings fabricated on mild steel substrate in an environmentally friendly bath solution was investigated.
Abstract: Zinc (Zn) is one of the five most widely consumed metals in the world. Indeed, more than 50% of all the zinc produced is used in zinc-galvanizing processes to protect steel from corrosion. Zn-based coatings have the potential for use as a corrosion-resistant barrier, but their wider use is restricted due to the poor mechanical properties of Zn that are needed to protect steel and other metals from rusting. The addition of other alloying elements such as Ni (Nickle) and WC (Tungsten Carbide) to Zn coating can improve its performance. This study investigates, the corrosion performance of Zn–Ni coating and Zn–Ni–WC composite nanocoatings fabricated on mild steel substrate in an environmentally friendly bath solution. The influence of WC nanoparticles on Zn–Ni deposition was also investigated. The surface morphologies, texture coefficients via XRD (X-ray diffraction), SEM (Scanning Electron Microscopy), and EDS (Energy-dispersive X-ray spectroscopy) were analyzed. The electrochemical test such as polarization curves (PC) and electrochemical impedance spectroscopy (EIS) resulted in a corrosion rate of 0.6948 A/min for Zn–Ni–WC composite nanocoating, and 1.192 A/min for Zn–Ni coating. The results showed that the Zn–Ni–WC composite nanocoating reduced the corrosion rate by 41.71% and showed an 8.56% increase in microhardness compared to the hardness of the Zn–Ni coating. These results are augmented to better wettable characteristics of zinc, which developed good interfacial metallurgical adhesion amongst the Ni and WC elements. The results of the novel Zn–Ni–WC nanocomposite coatings achieved a great improvement of mechanical property and corrosion protection to the steel substrate surface.

21 citations

Journal ArticleDOI
TL;DR: In this paper, the effect of adding different amounts of MWCNTs fillers (0.3, 0.6, and 0.9% wt) to hybrid composites on the mechanical properties was investigated.
Abstract: The mechanical properties of hybrid composites are largely influenced by the reinforcing fibres, nanofillers, matrix materials and fabrication methods. Multi-wall carbon nanotubes (MWCNTs) fillers reinforced to E-glass/Kevlar/epoxy composites (GKEC) are best suited for structural applications. The present study investigates the effect of adding different amounts of MWCNTs fillers (0.3%, 0.6%, and 0.9% wt) to hybrid neat (E-glass, Kevlar, epoxy) composites on the mechanical properties. Strength (tensile and bending) and hardness properties of the developed composites fabricated using compression moulding technique were evaluated. The effect of compression pressure, mould temperature and the time duration of applied pressure on hybrid (0.6MWCNT-GKEC) were also investigated. The compression pressure had the maximum effect on the tensile and bending strength of the composite, followed by mould temperature and pressure duration. The optimized compression moulding conditions resulted in 181.2 MPa of tensile strength, 143.3 MPa of bending strength and 22.8 HV. The wear rate of hybrid composites is less than that found in neat GKEC composites and showed fewer wear debris, which indicate their exists a smooth surface on worn surface morphologies.

19 citations

Journal ArticleDOI
TL;DR: In this paper, the effect of the extrusion process and the addition of reinforcements (FA and S-glass-fibres) on the gravimetric, electrochemical, and electrochemical impedance corrosion behaviour of Al 7005 composites in 1M HCl (Hydrochloric acid) solution were investigated.
Abstract: The stringent demand to develop lightweight materials with enhanced properties suitable for various engineering applications is the focus of this research work. Industrial wastes such as fly ash (FA) and S-glass-fibres (GF) were used as reinforcement materials for high-strength alloy, i.e., Al 7005. Stir casting routes were employed for fabricating the four samples, Al 7005, Al 7005 + 5% GF, Al 7005 + 6% FA and Al 7005 + 5% GF + 6% FA. The extrusion process with different extrusion ratios (ER: 5.32:1, and 2.66:1) was used to examine the properties of all four samples. Extruded samples with ER: 5.32: 1 resulted in equiaxed grains with refined structure compared to stir casting parts. The effect of the extrusion process and the addition of reinforcements (GF and FA) on the gravimetric, electrochemical, and electrochemical impedance corrosion behaviour of Al 7005 composites in 1M HCl (Hydrochloric acid) solution were investigated. The results of all three corrosion methods showed that Al 7005 + 6% FA exhibited higher corrosion resistance. Corrosion rate of Al 7005, Al 7005 + 5% GF, Al 7005 + 6% FA and Al 7005 + 5% GF + 6% FA is found equal to 3.25, 2.41, 0.34, and 0.76 mpy, respectively. The FA particles remain inert and act as a physical barrier with corrosive media during the corrosion test. GF undergoes fibre degradation or disrupts the continuity of the glass network as a result of fibre leaching, which increases the corrosion rate in the sample. The gravimetric study showed that the corrosion rates decreased with an increase in extrusion ratio, which might be due to corrosion passivation increases and improved properties. The scanning electron microscopy reveals that corrosion fits, flakes and micro-cracks were observed more in the as-cast composites than that of extrusion composites, promoting the corrosion rate.

18 citations


Cited by
More filters
Journal ArticleDOI
TL;DR: In this paper, multi-walled carbon nanotubes (MWCNTs) were mixed with dielectric fluid in the wire electrical discharge machining (WEDM) process to enhance the machining performance of Nitinol shape memory alloy (SMA).
Abstract: Excellent characteristics of multi-walled carbon nanotubes (MWCNTs), such as higher toughness and stiffness, enlarged strength, and high thermal conductivity, make them an attractive choice to improve surface characteristics and machining performance. In the current study, MWCNTs mixed with dielectric fluid in the wire electrical discharge machining (WEDM) process was used to enhance the machining performance of Nitinol shape memory alloy (SMA). Significance of WEDM machining variables such as current, pulse-on time (Ton), pulse-off time (Toff), and variation in powder concentration of MWCNTs are studied on material removal rate (MRR) and surface roughness (SR). The addition of MWCNTs substantially improves the machining performance by increasing MRR and simultaneously reducing the SR. Improvement in the MRR of 75.42% and SR of 19.15% is achieved with the use of MWCNTs at 1 g/L in comparison to the conventional WEDM process. An advanced parameterless TLBO algorithm is used for simultaneous optimization of multiple responses. An advanced parameterless TLBO algorithm is used to find the optimal solution of multiple responses. Single objective optimization result has yielded maximum MRR of 0.5262 g/min at a current of 5 A, Ton 110 μs, Toff 1 μs and MWCNTs amount of 1 g/L while minimum SR of 1.27 μm at a current of 1 A, Ton 1 μs, Toff 24 μs and MWCNTs amount of 1 g/L. MOTLBO algorithm is used for simultaneous optimization of MRR and SR. Lastly, the surface integrity of machined surfaces using a field emission scanning electron microscope (FESEM) is also studied to evaluate the effect of MWCNTs on recast layer thickness (RLT) and other surface defects. The incorporation of MWCNTs has shown a substantial reduction in RLT and other surface defects such as reduction in globules of debris, melted material deposition, micro-crack-free, and micro-pores-free surfaces.

36 citations

Journal ArticleDOI
TL;DR: In this article, the effect of laser cladding on the microstructure evolution and mechanical properties of laser-cladings of high temperature resistance alloys (SS316) has been investigated.
Abstract: The multi-layer laser cladding of high temperature resistance alloys i.e., Stellite 6 and Inconel 718 on SS316 was developed with an objective to investigate the effect of cladding materials on clad geometry, microstructure evolution and mechanical properties. The analysis was performed using Optical Microscope, SEM with EDS and Microhardness tester respectively. The results have shown a comparable difference in all the aspects of study. A 50% and 30% increment in clad height is measured while cladding at 12 mm/s and 16 mm/s scan speed as compared to 20 mm/s for both the alloys. The Inconel 718 deposits has shown 15–25% larger clad height, than Stellite 6. Also, under varying process parameters, 15–45% penetration depth and 10–15% higher dilution in Inconel 718 is obtained. SEM results have revealed that the microstructure evolution from top to bottom of the clad is nearly the same except at low laser powers. The decrement in microhardness is observed near the interface due to dilution and is higher in the first layer than the second layer. Whereas, the low dilution obtained in the second layer is because of the newly deposited layer over the substrate. The present work has given the optimum parameters (laser power and scan speed) as 2900 W and 20 mm/s for Stellite 6 and 3400 W, 12 mm/s for Inconel 718 respectively.

32 citations

Journal ArticleDOI
01 Jul 2022-Fuel
TL;DR: In this article , the influence of multi-walled carbon nanotubes (MWCNTs) and TiO2 nanoparticles (NPs) on lubricant and fluid flow within natural gas turbine meters was evaluated.

26 citations

Journal ArticleDOI
TL;DR: In this paper , the performance of powder-mixed EDM of nitinol SMA with the considerations of design variables of current, pulse-on-time, nano-graphene powder concentration (PC), and pulse-off-time (T off ) on surface roughness, dimensional deviation (DD), and material removal rate (MRR).
Abstract: Excellent characteristics of Nitinol shape memory alloys (SMAs) makes them favourable for use in industrial applications. Precision machining of such advanced alloys becomes a key requirement for industrial applications. Conventional machining processes imposes many difficulties for nitinol SMAs. Electrical discharge machining (EDM) process is appropriate for fabricating intricate and complex profile geometries and also provides a better alternative for difficult-to-cut materials. Addition of nano-particles in an appropriate amount in the dielectric fluid improves the machining by producing good dimensional accuracy, higher productivity, and good surface finish for machining of newly developed advanced alloys. The current study investigated the performance of powder-mixed EDM of nitinol SMA with the considerations of design variables of current, pulse-on-time (T on ), nano-graphene powder concentration (PC), and pulse-off-time (T off ) on surface roughness, dimensional deviation (DD), and material removal rate (MRR). Taguchi's L9 (3 ˆ 4) design was employed to perform the experiments and Minitab 17 software was used for statistical analysis of design variables using ANOVA, residual plots, and main effect plots. ANOVA results depicted that PC, T on , and T off were identified to be the highest contributing parameters with 75.18%, 29.37%, and 45.72% to affect MRR, SR, and DD, respectively. Obtained results has depicted a preferred combined positive trend of increase in MRR with a simultaneous drop in SR and DD after the addition of nano-graphene PC. HST algorithm was used to optimize single and multiple responses. Validation trials were also conducted to reveal the ability and suitability of the HTS technique. Field emission scanning electron microscopy revealed the minor occurrence of resolidified debris particles, globules, micro-pores, and micro-cracks after the addition of nano-graphene PC at 2 g/L.

26 citations

Journal ArticleDOI
TL;DR: In this paper, the corrosion performance of Zn-Ni coating and Zn−Ni-WC composite nanocoatings fabricated on mild steel substrate in an environmentally friendly bath solution was investigated.
Abstract: Zinc (Zn) is one of the five most widely consumed metals in the world. Indeed, more than 50% of all the zinc produced is used in zinc-galvanizing processes to protect steel from corrosion. Zn-based coatings have the potential for use as a corrosion-resistant barrier, but their wider use is restricted due to the poor mechanical properties of Zn that are needed to protect steel and other metals from rusting. The addition of other alloying elements such as Ni (Nickle) and WC (Tungsten Carbide) to Zn coating can improve its performance. This study investigates, the corrosion performance of Zn–Ni coating and Zn–Ni–WC composite nanocoatings fabricated on mild steel substrate in an environmentally friendly bath solution. The influence of WC nanoparticles on Zn–Ni deposition was also investigated. The surface morphologies, texture coefficients via XRD (X-ray diffraction), SEM (Scanning Electron Microscopy), and EDS (Energy-dispersive X-ray spectroscopy) were analyzed. The electrochemical test such as polarization curves (PC) and electrochemical impedance spectroscopy (EIS) resulted in a corrosion rate of 0.6948 A/min for Zn–Ni–WC composite nanocoating, and 1.192 A/min for Zn–Ni coating. The results showed that the Zn–Ni–WC composite nanocoating reduced the corrosion rate by 41.71% and showed an 8.56% increase in microhardness compared to the hardness of the Zn–Ni coating. These results are augmented to better wettable characteristics of zinc, which developed good interfacial metallurgical adhesion amongst the Ni and WC elements. The results of the novel Zn–Ni–WC nanocomposite coatings achieved a great improvement of mechanical property and corrosion protection to the steel substrate surface.

21 citations