Dr. K Gopalakrishna
@jyothyit.ac.in
Principal,
Jyothy Institute of Technology, Bangalore
Gopalakrishna K holds a Master’s in mechanical engineering, having specialized in production engineering from the University of Mysore, and a Ph.D. in polymer tribology from NAL-VTU. He has an experience of more than 30 years in academics and research. In addition to tribology, his research and teaching interests include pneumatics and hydraulics, thermal engineering and engineering drawing. He is certified by industry major FESTO in the domain of mechatronics and has executed projects that have resulted in five patent filings. With significant research publications in reputed Scopus / Thomson Reuter indexed journals and a monograph to his credit, he has been active in developing autonomous systems for surveillance funded by Naval Research Board-DRDO, coating systems for RP Components by ISRO-DOS, and others.
EDUCATION
Ph.D. in Polymer Tribology from NAL-VTU.
RESEARCH INTERESTS
Mechanical Engineering, Bio-composites,Polymer tribology,
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
Gireeshkumar Basavaraj Chavati, Sharath Kumar Basavaraju, Arthoba Nayaka Yanjerappa, Handanahally Basavarajaiah Muralidhara, Krishna Venkatesh, and Keshavanarayana Gopalakrishna
American Chemical Society (ACS)
Subramanian Sundar, K. Gopalakrishna, and N. Thangadurai
Inderscience Publishers
K. Gopalakrishna, Narendra Reddy, and Yi Zhao
Springer International Publishing
Nagraj Patil, K. Gopalakrishna, and B. Sangmesh
Universiti Malaysia Pahang Publishing
The cutting tool in the machining process plays an important role as it acts on the working material. There are a few methodologies have been persued to improve tool life, for example traditional cooling, single layer coating, multilayer coating, heat treatment process, nitrogen cooling and latest being the cryogenic treatment which reported a significant improvement in cutting tool life, chip morphology, reduction in heat generation. Hence, the cryogenic treatment is emerged as the sustainable machining process. This paper presents machining of AISI 304 steel using both cryogenic treated (CT) and untreated (UT) cutting tool insert. The commercially available uncoated carbide insert has been cryogenically treated at -196°C for 24 hours soaking period. The machining test has been conducted under four different cutting speeds. The material characterization of cutting insert is studied by using scanning electron microscopy (SEM), hardness test, and microscopic image analysis has been carried out before and after cryogenic treatment. The cutting tool performance is assessed in terms of of wear, cutting temperature, chip morphology, surface roughness under the influence of cryogenic machining and the results are contrast with UT one. The exploratory findings reveals that the deep cryogenic treatment (DCT) with 24 hours soaking period, performed better wear resistance and improved surface roughness of the cutting tool. Also considerable reduction in the flank wear, crater wear, cutting temperature is obtained and found improved chip morphology.
Shylesh K. Siddalingappa, Bhaskar Pal, M. R. Haseebuddin, and K. Gopalakrishna
Springer Singapore
H.R. Aniruddha. Ram, Krishna Venkatesh, K Gopalakrishna, K.T. Kashyap, and K.S. Sridhar
IOP Publishing
In the present work, Cu-Ni phase diagram is evaluated and assessed using the CALPHAD method for the accurate prediction of liquidus and solidus curves. Phase diagrams were plotted for both bulk and nanoalloys. Phase diagrams for nanoparticles are significantly different from that of the bulk because the melting point of the nanoparticle is a function of particle size. The melting point of the nanoparticle is determined using two different models, Surface Energy model and Enthalpy and Entropy model. Phase diagrams were plotted using both models for Copper-Nickel binary isomorphous system and were compared with the experimental data. It was found that the Enthalpy and Entropy model is in good agreement with the experimental data compared to the Surface Energy model. This is because the Enthalpy and Entropy model considers the thermal interactions at various temperatures whereas the surface energy model only considers the surface free energy of the particle. Also, Enthalpy and Entropy model is a dynamic model because it can predict the melting enthalpy and entropy of the nanoparticles for various particle sizes which result in accurate free energies predictions. Hence, phase diagrams that are predicted using Enthalpy and Entropy model tend to be more accurate than that of the surface energy model.
H. R. Aniruddha Ram, Krishna Venkatesh, K. Gopalakrishna, K. T. Kashyap, and K. S. Sridhar
Springer Science and Business Media LLC
Nagraj patil, , Gopalakrishna K, Sangmesh B, , and
Blue Eyes Intelligence Engineering and Sciences Engineering and Sciences Publication - BEIESP
The cutting tool in the manufacturing industry is a key factor. The fulfilment of machining operation mainly depends on the tool material to improve the cutting life of the tool during machining with austenite stainless steel, however the austenite stainless steel difficult to machine and less amount of heat dissipation during machining in order to overcome. The aim of the investigation is to apply; the cryogenic treatment (CT) to the tungsten carbide insert, besides no study has been claimed on the chip thickness (tc), tool wear of machining with AISI 304. The machining test was conducted by three different speed and unchanged feed rate and depth of cut. The maximum flank wear was measured by using digital microscope also measured the chip thickness for both insert. The experimental results found that to reach the maximum flank wear for CT insert in all three speed was less in comparison with untreated insert (UT), chip thickness was also less in case of CT insert, built up edge were clearly observed in the UT insert, over all CT insert performed more desirable in compared with UT. The improvement in the microstructure properties of the CT insert owing to development of Eta (η) phase carbide and homogenous distribution in the tungsten carbide material, SEM and XRD tests are confirmed these results.
H R Aniruddha Ram, K T Kashyap, K S Sridhar, Krishna Venkatesh, K Gopalakrishna, and R Keshavamurthy
IOP Publishing
Copper and Nickel alloys form binary isomorphous system with a symmetric lens shaped curve formed by solidus and liquidus. This shape and size of the solidus and liquidus curves are altered by the particle size. This effect is greatly enhanced if the particle size is less than 100 nm. In the present work, phase diagram is predicted for nanoparticles considering Copper and Nickel and is compared with the experimental results. Copper and Nickel nanoparticles were procured and were characterized for the particle morphology and size using TEM, FE-SEM and XRD. The nanoparticles were also subjected to DSC analysis to find the melting point. The nanoparticles were blended in a high energy ball-mill for various compositions. The blending was carried out for different time intervals and was characterized using XRD to find the effective alloying time. The blended nanoparticles after effective alloying were subjected to DSC analysis to experimentally determine the solidus and liquidus points for various compositions. Phase diagram was determined experimentally and was compared with the theoretical prediction. GTE model and E&E models were used to predict the phase diagram for nanoparticles and was compared with the experimental results. It was found that the E&E model acurately predicts the nano phase diagram for Cu–Ni system with an error of 2% for 89 wt% Cu-11 wt% Ni alloy.
Nagraj Patil, , Gopalakrishna K, K Sudhakar, , , and
Universiti Malaysia Pahang Publishing
This paper attempts to compare and contrast cryogenic treated and untreated carbide cutting tool in turning operation of AISI304 steel. Machining parameters, namely cutting speed, feed rate and depth of cut are optimized for cryogenic treated tools. Tool life of the insert was determined based on the tests performed such as hardness, surface roughness and maximum wear. A design of experiments (DOE) and an analysis of variance (ANOVA) have been incorporated in the study. The objective of the paper is to determine the effects of each parameter on the surface roughness and tool wear. Material characterization was carried out using scanning electron microscope (SEM) and the maximum wear was estimated using optical microscope before and after the cryogenic treatment. The experimental results showed that cryogenic treated cutting tools significantly reduction in surface roughness, improves resistance to wear than untreated one. A confirmation test
was performed between experimental and optimum values and the results are found to be in good agreement.
Sangmesh B, , Gopalakrishna K, Manjunath S.H., Kathyayini N, K. Kadirgama, M. Samykano, G.C. Vijayakumar, , ,et al.
Universiti Malaysia Pahang Publishing
LEDs, of late, have received attention as the next generation lighting system for enhanced luminous efficiency and higher lifespan. However, the thermal management of the LEDs is the crucial parameter to be countered for global acceptance as a revolutionary illumination source. This paper reports the experimental investigation of natural convective heat transfer of high power LED COBs using MWCNT and MWCNT-CuO nanofluids mixed with de-ionized water. The study uses MWCNT based nanofluids as a route to enhance the heat transfer of high power LEDs by the passive cooling technique. This study presents an innovative cooling device integrated with numerous fluid pockets, called the HSFP, to achieve the enhanced thermal performance of heat sinks for applications in high intensity LED lights. Nanofluids of various concentrations were formulated and their heat transfer performance evaluated using a series of experiments and compared with liquid cooling and a conventional heat sink. The experimental finding reveals 20– 30% lowered thermal resistance using the new HSFP (nanofluids). Thus, the HSFP found to effectively dissipates the heat in high-power LED COBs using nanofluids as the cooling medium compared to the conventional heat sink.
Manikandan Ilangovan, Vijaykumar Guna, Gopalakrishna Keshavanarayana, and Narendra Reddy
Springer Science and Business Media LLC
Prashanth Swaminathan and Gopalakrishna Keshavanarayana
ASTM International
Constant-velocity (CV) joints are transmission joints used in steering sub-assemblies. This component resembles a segment of a hollow sphere with six equally spaced windows of the same size cut around its periphery. The six-window gauge is used to check oversized windows in the CV joint. It contains six probes, each of which examines simultaneously the oversized windows in the component. The probe used in checking is constantly subjected to wear because of spring-loaded stress exerted on it while checking. An automated test rig has been developed to simulate the application to identify the best material for the probe used in the checking zone. Several probe materials were tested in the test rig, and the best material was chosen. This finding can pave the way for an optimized gauging system that fits a production line well. The test rig was designed specifically to select the best probe material to be used on the gauging system.
B.K. Anil Kumar, M.G. Ananthaprasad, and K. GopalaKrishna
Elsevier BV
Sharon Olivera, Handanahally Basavarajaiah Muralidhara, Krishna Venkatesh, Vijay Kumar Guna, Keshavanarayana Gopalakrishna, and Yogesh Kumar K.
Elsevier BV
Anil Kumar Basavarajaiah Kenchanahalli, Ananthaprasad Maravanji Gangadharaiah, and Gopalakrishna Keshavanarayana
FapUNIFESP (SciELO)
An investigation in the present research was made to fabricate and evaluate the microstructure and mechanical properties of metal matrix composites developed using cryogenically cooled copper chills, consisting of ASTM A 494 M grade nickel alloy matrix and garnet particles as the reinforcement. The particle's amount added ranges from 3 wt. % to 12 wt. % in steps of 3%. A stir casting process was used to fabricate the composite. The matrix alloy was melted in a casting furnace at around 1350˚C, the garnet particulates preheated to 600˚C, were introduced into the molten metal alloy. When pouring melt into mould, an arrangement was made at one end of the mould by placing copper chill blocks of varying thickness brazed with MS hallow block in which liquid nitrogen was circulated simultaneously for cryogenic effect. After solidification produced composite materials thus synthesized were examined for microstructural and mechanical properties as per ASTM standards.
B K Anil Kumar, M G Ananthaprasad, and K GopalaKrishna
IOP Publishing
In the area of material science engineering, metallurgists may be at the forefront of new technologies, developing metals for new applications, or involved in the traditional manufacture. By doing so it is possible for metallurgist to apply their knowledge of metals to solve complex problems and looking for ways to improve the mechanical properties of the materials. Therefore, an investigation in the present research was made to fabricate and evaluate the microstructure and mechanical properties of composites developed using cryogenically cooled copper chills, consisting of nickel alloy matrix and garnet particles as the reinforcement. The reinforcement being added ranges from 3 to 12 wt.% in steps of 3%. A stir casting process was used to fabricate the nickel base matrix alloy fused with garnet reinforcement particle. The matrix alloy was melted in a casting furnace at around 1350°C, the garnet particulates which was preheated to 600°C, was introduced evenly into the molten metal alloy. An arrangement was made at one end of the mould by placing copper chill blocks of varying thickness brazed with MS hallow block in which liquid nitrogen was circulated for cryogenic effect. After solidification, the composite materials thus synthesized were examined for microstructural and mechanical properties as per ASTM standards.
Sharon Olivera, Handanahally Basavarajaiah Muralidhara, Krishna Venkatesh, Keshavanarayana Gopalakrishna, and Chinnaganahalli Suryaprakash Vivek
Springer Science and Business Media LLC
B. K. Anil Kumar, M. G. Ananthaprasad, and K. GopalaKrishna
Indian Society for Education and Environment
This paper presents a review on the behaviour of mechanical and tribological properties of Nickel matrix composites developed by using different process. Nickel and Nickel containing base alloys are identified as an invaluable and indispensable material over a wide range of industrial application due to its outstanding properties like good mechanical property, resistance to chemicals and to handle complex process. So there has been steadily increasing demand for such material to exhibit high performance in their mechanical and tribological properties in different applications. Development of such newer materials with better performance for mechanical and tribological applications has made researchers to come out with innovative and novel materials to be fabricated from conceptual methods. Metal matrix composites provide advantage over the development as they are particularly suited for applications requiring good strength at high temperature, good structural rigidity, dimensional stability, and light weight. This composites material also offer a combination of resistant to corrosion, thermal fatigue, thermal shock, strength, toughness, metallurgical stability, fabricability, weldability and also their ability to withstand a wide variety of severe operating conditions involving high temperatures, high stresses as well as creep. Many researchers have shown that reinforcements like oxides of silicon, graphene, alumina particulate; silicon carbide particles, tungsten, graphite etc. can easily be incorporated into Nickel matrix for the development of composites. High performance nickel and nickel alloy are very widely used in steel making, marine, aerospace, defense, automotive, construction, computers etc.