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Papers by GOPICHAND DIRISENAPU

Composites Theory And Practice, Dec 31, 2023

In this present research work, the electrical discharge machining (EDM) characteristics of an Al7... more In this present research work, the electrical discharge machining (EDM) characteristics of an Al7010/2%B4C/2%BN (the reinforcement particles are taken as wt.%) hybrid metal matrix nanocomposite (HMMNC) are discussed. The effect of the EDM process variables like the discharge current (I), pulse on time (Pon), pulse off time (Poff) and gap voltage (Vg) on the response characteristics like the material removal rate (MRR), tool wear rate (TWR), and surface roughness (SR) are presented. The results revealed that the MRR, TWR, and SR grew with an increase in Ip and Pon. MRR, TWR, and SR increased with a rise in Poff up to 25 µs then declined. MRR, TWR, and SR decreased with an increment in gap voltage. The highest MRR was observed for a discharge current of 8 A, Pon of 60 µs, Poff of 25 µs and Vg of 30 V. SR and TWR were the smallest at Ip of 2 A, Pon of 15 µs, Poff of 55 µs and Vg of 60 V. The scanning electron microscope (SEM) micrographs of the machined surfaces revealed voids, craters and micro cracks.

E3S web of conferences, 2023

In this paper, determination of optimum EDM input variables like discharge current (DC), pulse on... more In this paper, determination of optimum EDM input variables like discharge current (DC), pulse on time (Pon), pulse off time (Poff), and gap voltage (GV) on responses like material removal rate (MRR) and surface roughness (SR) using Taguchi technique on the novel Al7010/2%B4C/2%BN hybrid metal matrix nanocomposite (HMMNC) manufactured through ultrasonic assisted stir casting (UASC) route. The various experiments were planned and carried out L16 orthogonal array and regression equations were established by using Analysis of variance (ANOVA) to examine the impact of pulse factors. The outcomes exposed that discharge current greatest effect factor on MRR and SR was found with % contribution of 82.07% and 86.86%. It is also identified that the optimum level conditions of pulse factors for MRR and SR is A4B4C1D1 and A1B1C4D4. The outcomes were further determined by utilizing confirmatory experiment. The machined surface morphology was observed through Scanning electron microscope (SEM).

Transactions of the Indian Institute of Metals, Nov 27, 2020

In the present investigation, Al7010/B 4 C/BN hybrid metal matrix nanocomposites with varying wei... more In the present investigation, Al7010/B 4 C/BN hybrid metal matrix nanocomposites with varying weight percents (wt%) of 0, 0.5, 1.0, 1.5, 2.0 and 2.5 of B 4 C and BN nanoparticles were prepared by ultrasonic-assisted stir casting technique. For the prepared composites, the microhardness and the tribological characteristics were reported. The wear behavior was determined under normal loads of 10, 20, 30 and 40 N and at sliding speeds of 0.5, 1.0 and 1.5 m/s, respectively. The results showed an increase in wear resistance and decrease in friction coefficient with the addition of the nanoparticles. The wear rate and friction coefficient increased with increase in normal load and sliding speed. The scanning electron microscope (SEM) images revealed uniform dispersion of the reinforcement particles in the composite. The wear specimens showed adhesion and plowing behavior at lower loads and delamination at higher load.

Materials research express, Sep 4, 2019

In the present study, Aluminum 7010 hybrid metal matrix nanocomposites with Boron Carbide (B4C) a... more In the present study, Aluminum 7010 hybrid metal matrix nanocomposites with Boron Carbide (B4C) and Boron Nitride (BN) nanoparticles as reinforcement materials, combined in equal proportions with 0 to 2.5 weight percent (Wt%) of nanoparticles in steps of 0.5 are prepared using ultrasonic assisted stir casting technique. The composites thus obtained are tested for their microhardness, tensile strength and impact strength by using vickers micro hardness tester, universal testing machine and impact testing machine. The microstructural characterization of the composites is carried using scanning electron microscope and x-ray diffractometer. By analyzing the data obtained it was found that the percentage of elongation and impact strength of the composite are reduced with increase in particle reinforcement up to 2 Wt% and thereafter increased. While the tensile strength and microhardness increased with increase in Wt% of B4C and BN particles up to 2 and thereafter decreased.

Australian journal of mechanical engineering, Jun 16, 2021

In this present experimental investigation, Al7010/B4C/BN hybrid metal matrix nanocomposites with... more In this present experimental investigation, Al7010/B4C/BN hybrid metal matrix nanocomposites with equal weight percent of B4C and BN in steps of 0.5 from 0 to 2.5 are prepared using ultrasonic-assi...

E3S Web of Conferences

In this paper, determination of optimum EDM input variables like discharge current (DC), pulse on... more In this paper, determination of optimum EDM input variables like discharge current (DC), pulse on time (Pon), pulse off time (Poff), and gap voltage (GV) on responses like material removal rate (MRR) and surface roughness (SR) using Taguchi technique on the novel Al7010/2%B4C/2%BN hybrid metal matrix nanocomposite (HMMNC) manufactured through ultrasonic assisted stir casting (UASC) route. The various experiments were planned and carried out L16 orthogonal array and regression equations were established by using Analysis of variance (ANOVA) to examine the impact of pulse factors. The outcomes exposed that discharge current greatest effect factor on MRR and SR was found with % contribution of 82.07% and 86.86%. It is also identified that the optimum level conditions of pulse factors for MRR and SR is A4B4C1D1 and A1B1C4D4. The outcomes were further determined by utilizing confirmatory experiment. The machined surface morphology was observed through Scanning electron microscope (SEM).

E3S Web of Conferences

In this study, Al-Mg-Si alloy AA6061-T6 plates were joined in a seawater environment using the Su... more In this study, Al-Mg-Si alloy AA6061-T6 plates were joined in a seawater environment using the Submerged Friction Stir Welding (SFSW) technique, and process parameters were optimized using Taguchi L9 orthogonal arrays (OA). The parameters considered were tool rotational speed, tool transverse speed, and tool pin geometry. The MINITAB-17 software was used to analyze the responses using the signal-to-noise (S/N) ratio and analysis of variance (ANOVA). The optimum process parameters for tensile strength and joint Microhardness were determined. Furthermore, the ANOVA reveals that the tool rotational speed is the most important factor in determining joint mechanical properties such as UTS and Microhardness, with transverse speed and tool pin geometries coming in second and third. Experimental results confirm the effectiveness of this approach. The parent material microstructure and submerged stir welded samples were compared using metallographic scanning electron microscopy (SEM).

De Gruyter eBooks, Apr 12, 2023

Australian Journal of Mechanical Engineering, 2021

In this present experimental investigation, Al7010/B4C/BN hybrid metal matrix nanocomposites with... more In this present experimental investigation, Al7010/B4C/BN hybrid metal matrix nanocomposites with equal weight percent of B4C and BN in steps of 0.5 from 0 to 2.5 are prepared using ultrasonic-assi...

Emerging Materials Research, 2020

In the present study, boron carbide (B4C) and boron nitride (BN) nanoparticles combined in equal ... more In the present study, boron carbide (B4C) and boron nitride (BN) nanoparticles combined in equal proportions and reinforced into aluminium 7010 alloy with 0–2.5 wt.% nanoparticles in intervals of 0.5 wt.% were prepared using the ultrasonically assisted stir-casting technique. Microstructural characterisation of the composites was carried out by using a scanning electron microscope and an X-ray diffractometer. The tensile strength was determined using an Instron testing machine. The tensile strength of the nanocomposites increased with the increase in the weight percentage of nanoparticles up to 2 wt.% and thereafter decreased. It was observed that the percentage of elongation decreased with the increase in reinforcement up to 2 wt.% and thereafter increased. The density of the hybrid metal matrix nanocomposites decreased with the increase in boron carbide and boron nitride nanoparticles. The porosity increased with the increase in the weight percentage of boron carbide and boron nit...

Materials Research Express, 2019

In the present study, Aluminum 7010 hybrid metal matrix nanocomposites with Boron Carbide (B4C) a... more In the present study, Aluminum 7010 hybrid metal matrix nanocomposites with Boron Carbide (B4C) and Boron Nitride (BN) nanoparticles as reinforcement materials, combined in equal proportions with 0 to 2.5 weight percent (Wt%) of nanoparticles in steps of 0.5 are prepared using ultrasonic assisted stir casting technique. The composites thus obtained are tested for their microhardness, tensile strength and impact strength by using vickers micro hardness tester, universal testing machine and impact testing machine. The microstructural characterization of the composites is carried using scanning electron microscope and x-ray diffractometer. By analyzing the data obtained it was found that the percentage of elongation and impact strength of the composite are reduced with increase in particle reinforcement up to 2 Wt% and thereafter increased. While the tensile strength and microhardness increased with increase in Wt% of B4C and BN particles up to 2 and thereafter decreased.

De Gruyter eBooks, Apr 12, 2023

Composites Theory And Practice, Dec 31, 2023

In this present research work, the electrical discharge machining (EDM) characteristics of an Al7... more In this present research work, the electrical discharge machining (EDM) characteristics of an Al7010/2%B4C/2%BN (the reinforcement particles are taken as wt.%) hybrid metal matrix nanocomposite (HMMNC) are discussed. The effect of the EDM process variables like the discharge current (I), pulse on time (Pon), pulse off time (Poff) and gap voltage (Vg) on the response characteristics like the material removal rate (MRR), tool wear rate (TWR), and surface roughness (SR) are presented. The results revealed that the MRR, TWR, and SR grew with an increase in Ip and Pon. MRR, TWR, and SR increased with a rise in Poff up to 25 µs then declined. MRR, TWR, and SR decreased with an increment in gap voltage. The highest MRR was observed for a discharge current of 8 A, Pon of 60 µs, Poff of 25 µs and Vg of 30 V. SR and TWR were the smallest at Ip of 2 A, Pon of 15 µs, Poff of 55 µs and Vg of 60 V. The scanning electron microscope (SEM) micrographs of the machined surfaces revealed voids, craters and micro cracks.

E3S web of conferences, 2023

In this paper, determination of optimum EDM input variables like discharge current (DC), pulse on... more In this paper, determination of optimum EDM input variables like discharge current (DC), pulse on time (Pon), pulse off time (Poff), and gap voltage (GV) on responses like material removal rate (MRR) and surface roughness (SR) using Taguchi technique on the novel Al7010/2%B4C/2%BN hybrid metal matrix nanocomposite (HMMNC) manufactured through ultrasonic assisted stir casting (UASC) route. The various experiments were planned and carried out L16 orthogonal array and regression equations were established by using Analysis of variance (ANOVA) to examine the impact of pulse factors. The outcomes exposed that discharge current greatest effect factor on MRR and SR was found with % contribution of 82.07% and 86.86%. It is also identified that the optimum level conditions of pulse factors for MRR and SR is A4B4C1D1 and A1B1C4D4. The outcomes were further determined by utilizing confirmatory experiment. The machined surface morphology was observed through Scanning electron microscope (SEM).

Transactions of the Indian Institute of Metals, Nov 27, 2020

In the present investigation, Al7010/B 4 C/BN hybrid metal matrix nanocomposites with varying wei... more In the present investigation, Al7010/B 4 C/BN hybrid metal matrix nanocomposites with varying weight percents (wt%) of 0, 0.5, 1.0, 1.5, 2.0 and 2.5 of B 4 C and BN nanoparticles were prepared by ultrasonic-assisted stir casting technique. For the prepared composites, the microhardness and the tribological characteristics were reported. The wear behavior was determined under normal loads of 10, 20, 30 and 40 N and at sliding speeds of 0.5, 1.0 and 1.5 m/s, respectively. The results showed an increase in wear resistance and decrease in friction coefficient with the addition of the nanoparticles. The wear rate and friction coefficient increased with increase in normal load and sliding speed. The scanning electron microscope (SEM) images revealed uniform dispersion of the reinforcement particles in the composite. The wear specimens showed adhesion and plowing behavior at lower loads and delamination at higher load.

Materials research express, Sep 4, 2019

In the present study, Aluminum 7010 hybrid metal matrix nanocomposites with Boron Carbide (B4C) a... more In the present study, Aluminum 7010 hybrid metal matrix nanocomposites with Boron Carbide (B4C) and Boron Nitride (BN) nanoparticles as reinforcement materials, combined in equal proportions with 0 to 2.5 weight percent (Wt%) of nanoparticles in steps of 0.5 are prepared using ultrasonic assisted stir casting technique. The composites thus obtained are tested for their microhardness, tensile strength and impact strength by using vickers micro hardness tester, universal testing machine and impact testing machine. The microstructural characterization of the composites is carried using scanning electron microscope and x-ray diffractometer. By analyzing the data obtained it was found that the percentage of elongation and impact strength of the composite are reduced with increase in particle reinforcement up to 2 Wt% and thereafter increased. While the tensile strength and microhardness increased with increase in Wt% of B4C and BN particles up to 2 and thereafter decreased.

Australian journal of mechanical engineering, Jun 16, 2021

In this present experimental investigation, Al7010/B4C/BN hybrid metal matrix nanocomposites with... more In this present experimental investigation, Al7010/B4C/BN hybrid metal matrix nanocomposites with equal weight percent of B4C and BN in steps of 0.5 from 0 to 2.5 are prepared using ultrasonic-assi...

E3S Web of Conferences

In this paper, determination of optimum EDM input variables like discharge current (DC), pulse on... more In this paper, determination of optimum EDM input variables like discharge current (DC), pulse on time (Pon), pulse off time (Poff), and gap voltage (GV) on responses like material removal rate (MRR) and surface roughness (SR) using Taguchi technique on the novel Al7010/2%B4C/2%BN hybrid metal matrix nanocomposite (HMMNC) manufactured through ultrasonic assisted stir casting (UASC) route. The various experiments were planned and carried out L16 orthogonal array and regression equations were established by using Analysis of variance (ANOVA) to examine the impact of pulse factors. The outcomes exposed that discharge current greatest effect factor on MRR and SR was found with % contribution of 82.07% and 86.86%. It is also identified that the optimum level conditions of pulse factors for MRR and SR is A4B4C1D1 and A1B1C4D4. The outcomes were further determined by utilizing confirmatory experiment. The machined surface morphology was observed through Scanning electron microscope (SEM).

E3S Web of Conferences

In this study, Al-Mg-Si alloy AA6061-T6 plates were joined in a seawater environment using the Su... more In this study, Al-Mg-Si alloy AA6061-T6 plates were joined in a seawater environment using the Submerged Friction Stir Welding (SFSW) technique, and process parameters were optimized using Taguchi L9 orthogonal arrays (OA). The parameters considered were tool rotational speed, tool transverse speed, and tool pin geometry. The MINITAB-17 software was used to analyze the responses using the signal-to-noise (S/N) ratio and analysis of variance (ANOVA). The optimum process parameters for tensile strength and joint Microhardness were determined. Furthermore, the ANOVA reveals that the tool rotational speed is the most important factor in determining joint mechanical properties such as UTS and Microhardness, with transverse speed and tool pin geometries coming in second and third. Experimental results confirm the effectiveness of this approach. The parent material microstructure and submerged stir welded samples were compared using metallographic scanning electron microscopy (SEM).

De Gruyter eBooks, Apr 12, 2023

Australian Journal of Mechanical Engineering, 2021

In this present experimental investigation, Al7010/B4C/BN hybrid metal matrix nanocomposites with... more In this present experimental investigation, Al7010/B4C/BN hybrid metal matrix nanocomposites with equal weight percent of B4C and BN in steps of 0.5 from 0 to 2.5 are prepared using ultrasonic-assi...

Emerging Materials Research, 2020

In the present study, boron carbide (B4C) and boron nitride (BN) nanoparticles combined in equal ... more In the present study, boron carbide (B4C) and boron nitride (BN) nanoparticles combined in equal proportions and reinforced into aluminium 7010 alloy with 0–2.5 wt.% nanoparticles in intervals of 0.5 wt.% were prepared using the ultrasonically assisted stir-casting technique. Microstructural characterisation of the composites was carried out by using a scanning electron microscope and an X-ray diffractometer. The tensile strength was determined using an Instron testing machine. The tensile strength of the nanocomposites increased with the increase in the weight percentage of nanoparticles up to 2 wt.% and thereafter decreased. It was observed that the percentage of elongation decreased with the increase in reinforcement up to 2 wt.% and thereafter increased. The density of the hybrid metal matrix nanocomposites decreased with the increase in boron carbide and boron nitride nanoparticles. The porosity increased with the increase in the weight percentage of boron carbide and boron nit...

Materials Research Express, 2019

In the present study, Aluminum 7010 hybrid metal matrix nanocomposites with Boron Carbide (B4C) a... more In the present study, Aluminum 7010 hybrid metal matrix nanocomposites with Boron Carbide (B4C) and Boron Nitride (BN) nanoparticles as reinforcement materials, combined in equal proportions with 0 to 2.5 weight percent (Wt%) of nanoparticles in steps of 0.5 are prepared using ultrasonic assisted stir casting technique. The composites thus obtained are tested for their microhardness, tensile strength and impact strength by using vickers micro hardness tester, universal testing machine and impact testing machine. The microstructural characterization of the composites is carried using scanning electron microscope and x-ray diffractometer. By analyzing the data obtained it was found that the percentage of elongation and impact strength of the composite are reduced with increase in particle reinforcement up to 2 Wt% and thereafter increased. While the tensile strength and microhardness increased with increase in Wt% of B4C and BN particles up to 2 and thereafter decreased.

De Gruyter eBooks, Apr 12, 2023