Balkrishna C Rao

Balkrishna C Rao
Indian Institute of Technology Madras | IIT Madras · Department of Engineering Design

PhD

About

83
Publications
13,394
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1,294
Citations
Introduction
I am working on "frugalizing" design, engineering and manufacturing. In this regard, I work in the realms of sustainable manufacturing, additive manufacturing and frugal engineering. Please do check out some of my publications in these areas, especially in frugal engineering, which is an upcoming area of significant potential for sustainable development.

Publications

Publications (83)
Article
In this effort, variation of mechanical properties with the geometry of Al6061 specimens was studied, while the grain size was unchanged. Young's modulus, yield strength, ultimate tensile strength, and fracture strain of dog–bone specimens with cross sections varying from 0.4 mm × 0.4 mm to 12.7 mm × 7 mm were measured from uniaxial tension tests....
Article
Full-text available
Manufacturing is a crucial activity of product development that feeds into and is also influenced by the design process. Any material conservation gained during manufacturing directly affects the green credentials of a product. Manufacturing waste can be contrived to approach zero through a recently developed frugal design approach that quantifies...
Article
The results of the investigation on the influence of texture on chip formation during machining of Ti–6Al–4V alloy are reported in this work. Different textures are produced in this alloy by cold-rolling as-received and annealed material to 30–47% reductions. As-received and annealed samples exhibited basal and transverse textures while in cold-wor...
Article
A modified Zerilli–Armstrong model has been proposed and validated in previous works for simulating distinct deformation mechanisms of continuous-shear and shear-localization during severe plastic deformation of a face centered cubic alloy. In this paper, the validity of the modified Zerilli–Armstrong model has been further tested by using it for m...
Chapter
Frugal innovations or frugal products are catching up technologically to serve the needs of humankind. Their features including minimal material consumption, affordability and good functionality make them green from the point of view of sustainable development. However, their no-frills structure typically also necessitates application of rigorous p...
Article
The objective of this work is to study the performance of modified Zerilli-Armstrong constitutive relation proposed in our previous study for the finite element modelling of a severe plastic deformation technique called large strain extrusion machining. The modified Zerilli-Armstrong constitutive relation is implemented in a finite element model of...
Article
Aluminum-water combustion method has been advocated to produce hydrogen and synthesize ceramic materials with high purity. In the present study, aluminum-water combustion was employed to synthesize alumina, along with possible co-generation of power. The exhaust gases from aluminum-water combustion comprises of 70% (by mole basis) of hydrogen. This...
Article
The morphology of fine microstructure arising from reversible martensitic transformations is known to depend on the sample size and orientation to applied thermal or mechanical loading. In this paper we study these effects using a novel discrete particle approach. Our new approach uses a multibody interparticle interaction for the discrete particle...
Article
Full-text available
Frugal products possess a proper mix of features including minimal consumption of resources, good functionality under nominal conditions and low cost. Therefore, increasing use of frugal products, that are designed and also fabricated systematically, is crucial to all-round sustainable development. However, their low factor-of-safety rigorous-desig...
Article
Discrete particle models have been widely used as an alternative to classical continuum mechanics to describe the mechanical behavior of solids, fluids and granular matter. Lattice particle models (LPM) are a subset of discrete particle models which treat the body as a set of interacting point masses with fixed sets of neighbors. Heretofore, the ty...
Chapter
Large plastic deformation through Cold-rolling refines Microstructure through the accumulation of plastic strains over multiple stages. Machining achieves similar large plastic strains (1–10) in a single stage to produce ultra-fine-grained chips. Effect of Cold-rolling and Machining on Microstructure and Mechanical properties of Al6061 was investig...
Article
A new constitutive relation has been established by modifying Zerilli-Armstrong formulation whose performance is investigated in simulating continuous-shear and shear-localisation during orthogonal machining of a super alloy. Two different procedures in consonance with strains, strain rates, temperatures and thermo-mechanical-coupling encountered d...
Article
A new constitutive relation has been established by modifying Zerilli-Armstrong formulation whose performance is investigated in simulating continuous-shear and shearlocalisation during orthogonal machining of a super alloy. Two different procedures in consonance with strains, strain rates, temperatures and thermo-mechanical-coupling encountered du...
Article
Full-text available
In recent years, frugal products of the grassroots and advanced types are being widely used due to their sustainable nature and also affordability. However, despite the origins of frugality at grassroots level, grassroots innovations continue to be fabricated in an ad hoc manner that precludes application of science and are thus susceptible to prem...
Preprint
Full-text available
In recent years frugal products of the grassroots and advanced types are being widely used due to their sustainable nature and also affordability. However, despite the origins of frugality at grassroots level, grassroots innovations continue to be fabricated in an ad hoc manner that precludes application of science and are thus susceptible to prema...
Preprint
Full-text available
In recent years frugal products of the grassroots and advanced types are being widely used due to their sustainable nature and also affordability. However, despite the origins of frugality at grassroots level, grassroots innovations continue to be fabricated in an ad hoc manner that precludes application of science and are thus susceptible to prema...
Article
Full-text available
Tensile properties of metals are typically measured using dog-bone shaped specimens having dimensions as per specifications imposed by international standards organizations. However, these properties may be influenced by the size of the specimen, especially when the cross-sectional dimensions are lower. At lower length scales, microstructure could...
Article
The large strain extrusion-machining process has been used to refine the microstructure in a Titanium alloy (Ti–6Al–4V). The unconstrained cutting or machining of Ti–6Al–4V entails the formation of shear localized chips at nearly all cutting speeds, thereby hindering the use of extrusion-machining to produce fine-grained materials. The present effo...
Article
Full-text available
Frugal innovations are all the rage. Their appeal stems mainly from lower costs to society at large. The grass roots nature of these innovations has in recent years been complemented by the appearance of frugality in sophisticated products real ized through science and engineering. Such advanced frugal innovations (AFI) have appeared in a wide vari...
Poster
Microstructure evolution in horizontal and vertical depositions of a solder alloy obtained from a Direct Material Deposition machine.
Article
The accuracy of prediction made by finite element modeling of machining processes significantly depends on the constitutive model used to describe the material behaviour at typical values of strain, strain rate and temperature encountered in cutting. In this paper a new constitutive relationship is established by modifying the Zerilli-Armstrong mod...
Article
Full-text available
The conservative nature of design in engineering has typically unleashed products fabricated with generous amounts of raw materials. This is epitomized by the factor of safety whose values higher than unity suggests various uncertainties of design that are tackled through material padding. This effort proposes a new factor of safety called the fact...
Article
The process of laser engineered net shaping (LENSTM) is an additive manufacturing technique that employs the coaxial flow of metallic powders with a high-power laser to form a melt pool and the subsequent deposition of the specimen on a substrate. Although research done over the past decade on the LENSTM processing of alloys of steel, titanium, nic...
Article
Full-text available
Sustainable development necessitates the management of progress in science and technology for society’s betterment while preserving Earth’s resources. In this regard, the appearance in recent years of low-cost sophisticated products consuming resources economically is a force for good. This effort terms each of these products as an advanced frugal...
Article
This work is focused on the development of a dual-layered diamond-coated tungsten carbide tool for machining titanium Ti-6Al-4V alloy. A hot-filament chemical vapor deposition technique was used to synthesize diamond films on tungsten carbide tools. A boron-doped diamond interlayer was added to a microcrystalline diamond layer in an attempt to impr...
Article
This paper discusses tensile testing of small samples of nanocrystalline Al6061-T6 alloy obtained from an unusual application of machining as a severe plastic deformation process. Ultrafine grained (UFG) shavings obtained from plane-strain cutting show higher hardness than the bulk material in agreement with existing literature. Application of rest...
Article
Sustainable development is easy to talk about but hard to accomplish. The author proposes an ambitious agenda to alleviate poverty in the world while also maintaining the sustainability of the planet's climate and economic growth. He introduces to many readers the concept of frugal inventions to move us forward in a difficult agenda that does not r...
Article
The potent mix of crises of our times, including irreversible global warming, resource scarcity, and financial woes, are urging nations to innovate at a brisk clip. The race to innovate for achieving better standards of living at lower costs while leaving the earth in good shape for posterity is impacting every sphere of human activity. Therefore,...
Article
Two new steel-reinforced, metal-matrix composites (MMCs), Kirksite + 1080 and Kirksite + M2 are developed by adding 25 wt% of AISI 1080/AISI M2 steel machining chips to a zinc-based alloy, Kirksite (4% Al and 3% Cu). The sliding wear resistance of the Zn alloy and the two MMCs, against AISI 52100 steel, is determined under increasing normal load (1...
Article
Global warming and the recent financial crises have prompted a rethink among businesses on the production of cost-effective products and services. Frugal-innovations, with their genesis mainly in India, are accordingly becoming popular in emerging and developed economies due to their lower costs and no frills structure. By studying a variety of fru...
Article
This work focuses on the synthesis of nano-structured A16061 using machining under plane strain and evaluation of its mechanical properties. It discusses an unusual application of the machining process by using it as a severe plastic deformation (SPD) process to develop nano-structured or ultra-fine grained materials. Chips obtained from this proce...
Article
This paper is concerned with the experimental and numerical study of face milling of Ti–6Al–4 V titanium alloy. Machining is carried out by uncoated carbide cutters in the presence of an abundant supply of coolant. Experimental analysis is conducted by focusing on the measurement of specific cutting energy, surface integrity and tool performance. T...
Article
Human ingenuity will play an ever-important role in this century and into the foreseeable future. This is because of phenomena such as globalization and climate-change that stress the need for more innovative output from developed countries. Such a picture has made it necessary to develop reliable models for quantifying innovations. The huge moment...
Article
The advent of global warming, as attested by the Intergovernmental Panel on Climate Change (IPCC), has serious ramifications for various facets of the human endeavour. Manufacturing is one such activity that is poised to undergo significant changes for curbing green-house gas emissions. This paper presents schemes for reducing the energy consumed i...
Article
The advent of globalization has provided a fillip to countries around the world for recasting their strategies to uplift their economies for survival. Consequently, governments in these countries are striving to strengthen their economies to compete in a new global arena and thereby maintain a high perch in the economic pecking order. Against this...
Article
Innovation will have an increasingly important place in the future prosperity of the world. But can we develop reliable models for quantifying innovations that enahnce social capital? This piece describes the work of one economist who has developed a technically demanding but fascinating methodology to help evaluate a nation's quality and quantity...
Article
Full-text available
The recent woes of the US manufacturing sector have prompted the search for an effective solution for its resuscitation. Such a plan can aid the big three automotive companies in regaining their market share. This article takes a holistic approach in addressing this issue and attempts to, at least, provide a new perspective on the problem.
Article
We know that innovation is vital to economic prosperity, especially over the past century. Can we now treat innovation as a commodity that can be traded in the financial markets? The authors propose an innovation derivative that can improve returns for investors in new pipelines of ideas.
Article
We demonstrate a means of extending the temperature range for structural applications of nanomaterials through introduction of a dispersion of precipitates, whose thermal stability determines the temperature at which strength deteriorates. Precipitate-stabilized nanostructures created via severe plastic deformation of Inconel are shown to be stable...
Article
The twin phenomena of globalization and global-warming have put human-innovation at the forefront for member countries of the Organization for Economic Cooperation and Development (OECD). Our research effort lays the foundation for monetizing creativity by listing the necessary concepts and methods for trading innovations. It has attempted to ident...
Article
Globalization has benefited the economies of member countries of the Organization for Economic Cooperation and Development (OECD) by helping their businesses stay profitable through cost-effective outsourcing of mostly garden-variety tasks and some knowledge-based activities. With time, the latter will account for the lion's share of work outsource...
Article
Full-text available
Plane-strain machining can be used to impart large plastic strains in alloys that are difficult to deform by other severe plastic deformation (SPD) processes. By cutting at low speeds, the heating caused by friction with the tool can be reduced to insignificant levels. The utility of this approach for characterizing microstructure development in SP...
Article
Tribological behavior of nanocrystalline oxygen-free high conductivity (OFHC) copper and commercially pure titanium produced by large strain extrusion machining (LSEM) is compared with the coarse grained counterparts. Friction and wear of these materials have been determined using a pin-on-disk tribometer, sliding against AISI 52100 steel pins. Alt...
Article
Large plastic strains between 1 and 15 can be imposed in chips formed by plane-strain (2-D) machining of metals and alloys. This approach has been used to examine microstructure changes induced by large strain deformation in model systems—copper and its alloys, precipitation-hardenable aluminum alloys, high-strength materials such as titanium, Inco...
Article
This paper presents an extended oblique machining theory applicable to the analysis of 3-D machining. Existing theories are evaluated to identify suitable formulations which are used with necessary modifications for predicting various quantities pertaining to cutting conditions of three dimensional machining. Actual chip flow angles extracted from...
Article
Severe plastic deformation of titanium at near-ambient temperature has been realized using large-strain machining. The material that received the highest levels of strain, the chip, is found to have a nanocrystalline structure with ∼100 nm sized grains. This microstructure is finer than that observed in titanium following equal channel angular pres...
Article
Globalization has benefited the economies of member countries of the Organization for Economic Cooperation and Development (OECD) by helping their businesses stay profitable through cost-effective outsourcing of mostly garden-variety tasks and some knowledge-based activities. With time, the latter will account for the lion’s share of work outsource...
Conference Paper
Recently, it has been demostrated that large plastic strains imposed on a chip, during machining, results in significant microstructure refinement [1]. Titanium chip obtained by machining is found to have a nanocrystalline structure with ∼100 nm size grains. The hardness and strength of the nanostructures are seen to be substantially higher than th...
Article
Characteristics of the deformation fields associated with chip formation in plane strain machining are described. The ability to impose very large strain deformation in a controlled manner is highlighted. The creation of nano- and ultra-fine grained structures by machining is demonstrated in a variety of metals and alloys. These results indicate th...
Article
The creation of nanostructured materials with enhanced mechanical properties by controlled chip formation has been demonstrated. The present study examines the microstructure and mechanical properties of chips from various alloys -Waspaloy AMS 5704, Inconel 718, Al 6061-T6, and titanium - produced in aerospace machining operations. While the deform...
Conference Paper
Large strain deformation, a key parameter in microstructure refinement by Severe Plastic Deformation (SPD) processes, is a common feature of chip formation in machining. It is shown that the imposition of large plastic strains by chip formation can create metals and alloys with nanocrystalline or ultra-fine grained microstructures. The formation of...
Conference Paper
This paper is concerned with the experimental and numerical study of the high speed face milling of Ti-6Al-4V titanium alloy. Machining is carried out by uncoated carbide and polycrystalline diamond cutters in the presence of an abundant supply of coolant. Experimental analysis is conducted in terms of cutting forces, chip morphology, surface integ...
Article
The objective of this study is to develop scientific tools for predicting microscopic and macroscopic quantities in machining and thereby analyze the high speed face milling of aerospace alloys using popular cutting tool materials. The aerospace alloys studied in this research are 7075-T6 aluminum and Ti-6Al-4V titanium. This work presents the mech...
Article
This research is concerned with the analytical and experimental study on the high-speed face milling of 7075-T6 aluminum alloys with a single insert fly-cutter. The results are analyzed in terms of cutting forces, chip morphology, and surface integrity of the workpiece machined with carbide and diamond inserts. It is shown that a high cutting speed...
Article
This paper presents a model of the dynamic cutting force process for the three-dimensional or oblique turning operation. To obtain dynamic force predictions, the mechanistic force model is linked to a tool–workpiece vibration model. Particular attention was paid to the inclusion of the cross-coupling between radial and axial vibrations in the force...
Article
A series of miniaturized, surface-driven rotary and linear electrostatic actuators was designed and fabricated. The finite element analysis method was used to aid in the design and analysis of the electrostatic drive mechanism. The actuators, consisting mainly of a copper-coated 200 μm-thick glass epoxy stator board and a 34 μm-thick carbon-coated...
Article
A novel on-line cutting geometry inspection technique based on the integrated force-sensing method has been developed. A piezoelectric force sensor, mounted at the back of a single crystal diamond tool, was used to measure the cutting forces encountered by the tool system as it plunge-cut parallel micro flow channels on copper foils about 125 μm in...
Article
A novel on-line cutting geometry inspection technique based on the integrated force sensing method has been developed. A compact force sensor, mounted at the back of a single crystal diamond tool, was used to measure the cutting forces encountered by the tool system as it plunge-cut parallel micro flow channels on copper foils about 125 μm in thick...
Article
The advent of globalization has provided a fillip to countries around the world for recasting their strategies to uplift their economies for survival. Consequently, governments in these countries are striving to strengthen their economies to compete in a new global arena and thereby maintain a high perch in the economic pecking order. Against this...

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Projects

Projects (3)
Project
In this project I am working with my group to develop 3D printing techniques for depositing metallic parts with possibly intricate geometries that are at par in their quality with parts obtained form subtractive processes.
Project
Sustainable manufacturing using subtractive and additive manufacturing processes are transforming this world by joining the fight against climate change and creating products to improve living standards globally. Sustainable manufacturing is crucial to the success of both engineering from here onwards and design and fabrication of frugal products (or frugal innovations).
Project
I have been one of the early researchers in frugal innovations and frugal engineering. In this regard, it should be noted that both Advanced Frugal Innovations (AFI) and Factor of Frugality have been coined by me in course of my research. These have been documented in papers published to date. What started as a grass roots phenomenon, Frugal Innovations have made many appearances in sophisticated products employing serious science and technology. Such Advanced Frugal Innovations (AFI) and grass roots innovations need rigorous design procedures to create frugal products that are low-cost but not frugal in their quality! The factor-of-frugality approach can facilitate the design and fabrication of advanced and grass roots frugal innovations in a systematic manner to create robust frugal products in various sectors of industry and research.