I K U T DHA
ay IIT Bomb
Message From The HOD Dear Readers, We are back with the 3rd issue of the Newsletter ‘Dhatuki’ and this time in the form of hard copy, thanks to some sponsors who have advertised with us. This opens up an additional avenue for information dissemination of the industrial nature. Also let me assure you that this issue is equally interesting and enthusing in terms of the technical and the academic content. Once again compliments to the publishing team who has done a very good job. A glimpse of what is being pursued by the researchers in the Department at IIT Bombay is the new feature included in this issue of Dhatuki. This aspect will continue and we will reflect in parts the various research accomplishments in the coming issues. This should enable wider cross disciplinary interactions among workers in the country leading to useful collaborations. I am sure that the 3rd issue of Dhatuki is once again an enjoyable reading experience.
Finally I would urge all readers to give their feedback to us so that we can make future issues more interesting and informative. (R.O. Dusane) Head of the Dept.
INSIDE THIS ISSUE:
Message From the HOD
2
Internship Experiences
3
Biswas Committee Recommendations for Our Department
4
Department Placements 06-07
5
Industry and The Department
6
Materials Man
8
Materials Daily
9
Power of Powders
11
A Case of Materials
12
Clueless Crossword
14
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Internship Experiences Choosing an Internship is one of the major decisions that one takes during his/her stay in IIT. It is important, as a productive internship is not only an enriching experience, but also helps one decide his/her future career path. Here we present the internship experiences of three of our seniors, each one of them unique, and illuminating in its own way. Non Core Industrial Internship - Neha Gupta did her internship with ITC at Bangalore. She had offers from some foreign universities also, but she wanted to get a first hand understanding of how the corporate world works.
Core Industrial Internship - Chinmay did his internship with Crompton and Greeves at Mumbai. He had a very peculiar reason for his choice although he had offers from Godrej, Tata motors, Essar steels and so on. He had to appear for GRE in June, and hence an internship in Mumbai.
Her work there was to devise a way to optimize the At CG, he was asked to suggest solutions to a storage process for raw tobacco. The factory floor product related problem. He had to find a method was a different world altogether. The sudden shift for the real time detection of gases evolved in a from theory to practical was both challenging and transformer. The existing method was cumberstimulating. She had to interact with different kinds some and time consuming. The identification of of people and convince them about the feasibility of several gases required multiple sensors. Chinher plan. The work consumed much of her time and may browsed through several technical journals sometimes she had to go to the floor on Sundays and came up with about 6 or 7 commercially vialso. Her daily work hours were long; 9:00 a.m to able sensors. 7:00 p.m. Though she found the work monotonous The internship was academically informative and and demanding, but it imparted her lot of practical helped Chinmay in discovering skills, including handling people and several aspects of a transmeeting deadlines. Her managerial l former which were hitherto skills acquired while working as a ria ust d unknown to him. C & G has a In core group member for MI came in re Co dedicated materials department handy. She feels that all the hard and is fairly well equipped to work was more than worth it and Non-C ore Ind ustrial carry out serious research that she strongly recommends it to work. others. He continued with his GRE P.T. She found Bangalore a slow paced arch e preparation together with his s Re city compared to Mumbai. All and research project and managed all it was a valuable experience to do fairly well in both. It must which helped her make up her mind have been a valuable lesson for about what she intends to do after him in time management. passing out.
University Internship - Anshul opted for University of Manchester for an internship for several reasons. He wanted to know whether he would like to go for higher studies or not, before plunging into the world of software/finance. A foreign tour was also the reason for going for the PT. Once in London, he enjoyed every moment spent there. Not much is expected from an undergraduate in foreign Universities. His project included the study of residual stress in thin films. On weekdays he worked from 10:00 a.m. till 5:00 pm. The evenings were spent chatting with friends & dining out.
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Since the weekends were absolutely free, he used it to visit nearby cities and scenic places. Anshul found the setup there very different from what he was used to. The courses offered to undergraduates are much more interactive, the research work undertaken is very rigorous, there is no dearth of expensive hi - tech equipments and the list goes on. The lab assistant with whom he interacted regularly was really helpful and a smart guy. Moreover the work environment was very formal. The work he did there did appeal to him, but he also realized that a research lab is not the place he would like to spend his next five years. The life in a foreign land is lonely where everyone is engrossed in their own affairs. But the internship experience was absolutely fantastic and in a way an opportunity to see a different culture. He has finally decided to opt for a job in a consultancy firm.
—Kunal Singh
Biswas Committee recommendations for our department
The recommendations are the same as for the entire institute. Committee has yet to be set up to implement all department policies. Department decides Practical Training policy and work visit policy on its own. BTP will become optional. Department will decide all core courses and electives to be offered. The courses to be removed will basically be information based courses, such as Mineral Processing, Extractive Metallurgy, etc. Even Iron and Steel making may also go.
Lab infrastructure is a slight bother: not enough room to manage the 150 students expected the next year due to reservations.
About the new PT policy
There is no new PT policy as of now. Department policy always maintained that PT’s must not be done in research or academic institutions but rather in a manufacturing centre or an enterprise of some sort.
In the last few years, since a few students got the opportunity to go abroad they were allowed to do so.
However, it has now been noticed that this is rampant. Foreign PT’s are not banned, as long as they are in an industry or manufacturing centre. Financial and research PT’s, either in India or abroad will not be recognised.
The philosophy behind this is to give exposure to students of ‘Engineering in practise’. It is important for engineers to have an exposure to a ‘delivery based’ atmosphere as well. This will help them realise the implementation of studied theory in real life. —Rajlakshmi Purkayastha
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Special Report
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DEPARTMENT PLACEMENTS 06-07
The placement scenario of MEMS, IIT Bombay continues to follow the trend of previous years and this year again the majority went into jobs of non core nature. It was again the lure of the lucre that was responsible for the above observed phenomenon but the job scene has definitely improved with few more core jobs on the platter.
Expectations of students to link their “learning in engineering” and practice
the same after their
graduation is marred by harder ground realities that students face each year during what is ceremoniously called the “Placement Season”. We may
Although the share of the technical companies looks substantial but that does not depict the actual mood and aspirations of the students. The comparative study of distribution of premium jobs among the B.Tech and DD student is also interesting:
ponder over some of these issues, keeping the current passing out batch of our department in perspective, from which 44 B.Tech, 20 DD and 15 PG students appeared for placements. Companies of varied profiles visited the campus though none exclusively for our department. Quantitatively and broadly the following stats explains the varied mix of companies that recruited students from our department this year:
Quick facts Analytics firm ZS Associates was the one to offer the maximum no. of A1 jobs(5) to the MEMS department graduates. Average package was 3.9 lacs for B.Techs whereas it was as high as 5.9 lacs for the DDs. The highest paying firms in the department were Schlumberger (22 lacs per annum) and Optiver (33, 700 euros)
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The placement team did a real good work overall to ensure that the maximum number of students in the 100% institute get placed. Ayush Agarwal, the department 80% placement nominee this year, stressed that they had 60% approached many core metallurgy companies but the 40% number of these core companies that were finally in20% vited was significantly small for the single most deci0% sive reason-“ the offered package being unattractive”. 2003 2004 2005 2006 2007 Later, when some of these core companies came forIITB MEMS ward for recruitment, students did not opt for these companies as coupled with low packages, the work environment and job profile of such companies are more strenuous and physically demanding. Besides the growth prospects are supposedly not as good as what is there in some other sectors. This is the general notion that the students of the department have. Metal, mining and manufacturing companies do not have exciting executive or middle-level positions to offer simply because such positions, that command handsome salaries, ask for experience combined with expertise which is definitely justified
Institute Average Vs Department
A lot of companies felt that candidates were ill prepared for interviews and had not done their home work on the background of companies. Also, not a lot of resumes were extraordinary when it came to contents. The above data can also be attributed to this fact. Looking at the prospects of potential growth of metal industries in India, with Tata’s Corus takeover and the Korean giant POSCO spreading its roots in India, we hope that there would be greater opportunities for MEMS graduates to pursue a good career in a core job. —Vibhas Singh and Shailendra Singh
Industry And The Department Currently, our department is actively engaged in some sponsored projects. The research interests of our faculty have provided scope for research in some new and innovative areas of Metallurgy and Materials Science. The project areas range from steel manufacturing to new developments in polymers, composites and nanomaterials used in various applications. Also there are ongoing interdisciplinary projects with departments like Biomedical engineering and Physics. Some of the important sponsored projects currently undertaken by the department are:
Development of conductive composites based on Polypropylene
Sponsored by Reliance Industries Faculty - Prof. A.R.Bhattacharya Polypropylene based conductive composites are prepared by melt-mixing, utilizing several conducting fillers like carbon black, expanded graphite and multiwall carbon nanotubes .Dispersion of the conducting filler are investigated by SEM and the electrical characterization is carried out by AC impendence spectroscope, and the Structure property correlation ship is studied.
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Mapping of micro structural evolution during low temperature stress relieving of heavily drawn high carbon wire.
Sponsored by Tata Steel Faculty - Prof .Samajhdar Stress relieving is an important heat treatment process that is adopted in industries for relaxation of the stresses in heavily drawn wire. The experimentation is done to correlate the changes in the properties of the wire undergoing stress relieving with the changes in the microstructure of the wire.
Effect of Iron and Steel making slags on the pozzolanic activity of cements
Sponsored by Indorama Cements Ltd. Faculty - Prof. Satish Vitta. A pozzolanic material is one which contains active silica (SiO2) and is not cementitious in itself but will, in a finely divided form and in presence of moisture, chemically react with calcium hydroxide at ordinary temperatures to form cementitious compounds. Slag is a waste product of steel making process. BOF (Basic oxygen furnace) slags have found some use in construction purposes while EAF (Electric Arc furnace) slags are mainly being used as landfills. The objective of work is to explore the possibility of using EAF slag as a value addition material in cements. The pozzolanic behaviour of the slag will also be assessed.
Quantification of strain and its impact on the torsion ductility of the drawn wire
Sponsored by Tata Steel Faculty - Prof. Narasimhan The project aims at quantification of the through-thickness non uniformity of strain in drawn wire as a function of the ovality of feed stock and its impact on torsion ductility of the drawn wire. The work concentrates on establishing the effect of wire rod ovality on the strain non uniformity factor of the wire. —Hemant Borkar
Condolence Prof. Suresh Dixit passed away on the 28th of March 2007. He was 61. Born on 1st August 1946 in Indore, he has had a long association with the department. He did his B.Tech, MTech and PhD from here only. After his PhD, he worked as Research Assistant, before he became a lecturer in 1976, and since, was with Metallurgical Engineering and Materials Science, IIT Bombay. May his soul rest in peace.
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Materials Man The next multi-million dollar superhero movie sequel is scheduled to be released this year and sure, we can’t wait. I don’t think there’s anyone among people in our generation who hasn’t followed superheroes over the years. Be it Batman, Spiderman, Superman, The Hulk or our very own indigenous Shaktimaan, all superheroes have basked in the spotlight and enjoyed all attention. It is obviously because of the great things they do, and the great powers they have. But, have you materials scientists ever wondered what a superhero would do if we weren’t there? The question seems surprising, yes, but it’s true that a superhero does depend upon the strength and properties of materials for his/her stunts. Let us take the case of Batman. Materials are extremely indispensable for a superhero like him who has no inherent superpowers, but relies only on his gadgets. Take for instance his cape. The cape incorporates Nomex, DuPont’s fire-resistant, retardant material and Kevlar, DuPont’s bulletproof fiber. The cape is also specifically designed (by materials scientists) so that the fibers in it realign when an electric current is applied to it and the cape transforms into the shape of a bat’s wings. This allows Batman to fly or glide. A number of other gadgets from his utility belt, like his grappling hook that allows him to scale vertical walls, employ materials like titanium for the hook and Kevlar for the line. Spiderman, too, as Peter Parker, designs mechanical shooters for his adhesive based webfluid which is a shear-thinning liquid, i.e. a solid until subjected to shear rendering it fluid, related to nylon. On contact with air, the long-chain polymer knits and forms an extremely tough, flexible fiber with extraordinary adhesive properties. The web line’s tensile strength is estimated to be 120 pounds per square millimeter of cross section. The 300 pounds per square inch of pressure in each cartridge of the shooter is sufficient to force a stream of the complex web pattern to an estimated distance of 60 feet. All of this is nothing short of a materials science marvel! So the next time you ever watch a superhero movie, I am sure you will wonder and think about the materials behind the superpowers. And who knows, maybe you will be the next Peter Parker, inventing your own new cutting edge material and becoming the next big superhero!!!
Footnote: 1. Adamantium is a fictional metal alloy in Marvel comics, which is indestructible. 2. More information about Nomex and Kevlar can be found on Wikipedia and HowStuffWorks. —Chinmay Nivargi
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Materials Daily It was one of those mundane mornings when we were sitting in class. Our growing interest in materials science (thanks to an extremely interesting department introductory course) somehow swayed our attention to all sorts of things in the classroom leading us to question what went into the making of each of them. Here’s a brief write up on the “EVERDAY THINGS IN THE CLASSROOM”. Let us begin with the most conspicuous ones around.
Blackboard A blackboard is simply a piece of board painted with matte dark paint (usually black or dark green). The highest-grade chalkboards are made of rougher versions of porcelain enameled steel (black, green, blue or sometimes other colours), which is highly wear resistant.
Chalks (nice things to throw at friends!!) Blackboard chalk is currently made from the mineral Gypsum which is a very soft mineral composed of calcium sulfate dihydrate, with the chemical formula CaSO4·2H2O.
Paper (faithful things to jot down our thoughts on)- Paper is produced by the amalgamation of fibers, typically vegetable fibers composed of cellulose, which are subsequently held together by hydrogen bonding Synthetic fibers such as polypropylene and polyethylene are used to impart different physical properties to it.
Tables and chairs They are made of wood which is a heterogeneous, hygroscopic, cellular and anisotropic material. Wood is composed of fibers of cellulose (40%–50%) and hemicelluloses (15%–25%) held together by lignin (15%–30%), carbon being the building block (did you ever know this complicated a definition of wood???)
Windows (glasses) (to stare through a boring class!!) Glass contains about 70–72% by weight of silicon dioxide (SiO2). The major raw material is sand (or "quartz sand") that contains almost 100% crystalline silica in the form of quartz. Although it is almost pure quartz, it may still contain a small amount (< 1%) of iron oxides, which gives it the coloring.
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Window Frames Frames and sashes were traditionally made of wood, but metal, vinyl, and composites are now common. Solid metal frames and sashes are inefficient because metals conduct heat quickly. Some frames are made of vinyl-clad or aluminum-clad wood. Modern metal window parts typically consist of two halves separated by insulating spacer material. Curtains Elementally this is composed of carbon containing polymers. These materials come from four main sources: animal, plant, mineral, and synthetic. In the past, all textiles were made from natural fibres, including plant, animal, and mineral sources. In the 20th century, these were supplemented by artificial fibres made from petroleum. Tube lights (studying in a dark room??)Our tube light is a gas-discharge lamp that uses electricity to excite mercury vapor in argon or neon gas, resulting in a plasma that produces short-wave ultraviolet light. This light then causes a phosphor to fluoresce, producing visible light. Ceiling fans (we will suffocate without it!!) Our ever- rotating friend has three blades usually made of wood, MDF, metal, or plastic , an electric motor, usually encased by a decorative housing and a mounting system,again made of plastic or metal . Beams (Imagine our roof and walls collapsing!!) In contemporary construction, beams are typically made of steel, reinforced concrete, or wood. One of the most common types of steel beam is the I-beam or wide-flange beam (also known as a "universal beam") The loads carried by a beam are transferred to columns, walls, or girders, which then transfer the force to adjacent structural compression members. Paints (This enlivens our room…well to a small extent we agree) There are three primary components to paint: binder, diluents, and additives. However, only the binder is absolutely required. The binder is the part, which eventually solidifies to form the dried paint film. The volatile diluent serves to adjust the viscosity of the paint. There are various additives that are added to improve properties, such as color opacity and matness, pigment dispersion, or stability. Pigments or dyes are among the most common additives. They give color to the paint. Typical binders include synthetic or natural resins such as acrylics, polyurethanes, polyesters, melamine, epoxy, or oils. Typical diluents include organic solvents such as petroleum distillate, alcohols, ketones, esters, glycol ethers, and the like. Water is a common diluent. Sometimes volatile low-molecular weight synthetic resins also serve as diluents. And last but not the least…the spider webs…yuck!!! (They are always there in a classroom J !! ) A spider web, spider's web or cobweb (from the obsolete word "coppe", meaning "spider") is a proteinaceous spider silk extruded from a spider’s spinnerets. Not all spiders build webs to catch prey, and some do not build webs at all. And so by the end of our class we had enlightened ourselves with the material aspect of a few things that existed there. Feeling satisfied, we rushed for our next class. —Ayesha Ghanekar and Aishwarya Ramakrishnan
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Power of Powders What do you think the machine parts in these pictures have in common, nothing visible for sure, but they are similar, similar in their forming technique. They have been manufactured using powder metallurgy. Powder metallurgy, or PM, is a process for forming material parts by heating compacted material powders to just below their melting points.
liquid slurries of the powders (a thick suspension of solids in a liquid) and casting them using methods like slip casting, gel casting, tape casting, and so on.
. Powder metallurgy mainly comprises of following processes: 1.
Powder synthesis.
2.
Molding.
3.
Sintering.
Powder synthesis is very important as rest of the processing depends on how the powders have been prepared. Common route for synthesis of powders include atomization (forcing a molten metal stream through an orifice at moderate pressures which creates micron size metal droplets, which cool down as powders), direct grinding metal scrap by applying immense rotational torque, and so on. Powders are molded in desired shape to form what is called as a green body: a body generally con-
taining organic binders which cohesively bind powder particles together. Converting powders to
desired shapes (green bodies) can be achieved by many techniques. It can be done directly by pressing the powders in molds and dyes or by preparing
Sintering is an inevitable process in any type of technique used in powder metallurgy. Sintering is formally defined as: â&#x20AC;&#x153;The thermal treatment of a
powder or compact at a temperature below the melting point of the main constituent, for the purpose of increasing its strength by bonding together of the particles.â&#x20AC;? The principle aim of sintering is to reduce porosity and increase strength of compact. However, sintering results in changes in various properties of the compact, such as hardness, fracture toughness, electrical and thermal conductivity and so on. We can manipulate temperature and sintering time to alter properties during the process. We can also do co-sintering in which two or more green compacts are stuck and sintered together. This technique is widely used in preparing SOFC electrodes. Powder processing is preferred over traditional casting processes. This is primarily because of two reasons. Firstly in conventional casting process one needs a very high temperature (due to very high melting points of ceramics and reasonably high melting points of metals) which is expensive as it requires more energy.
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Secondly, those metals, which can not form alloys by conventional casting route, can be mixed as their powders. Also handling powders is far easier than handling melts. This is a brief overview of how components are made through powder processing. It is a powerful tool for manufacturing components having intricate and complex shapes (e.g. in automobile industries, etc.) Although the process has existed for more than 100 years, the double digit annual growth of the Powder Metallurgy industry, particularly over the past quarter century has been remarkable. Currently, there are over 400 powder manufacturers ($2 billion annual sales), 100 tooling and equipment makers ($300 million annual sales), and 700 manufacturers of PM parts ($5 billion annual sales). We unknowingly use many products which are directly or indirectly produced from powders , right from gears in our car, tiles that we stand on up to very high-tech applications such as bio-implants or refractory coating outside a space-craft. With its undeniable advantages over competing metalforming technologies, PM has established itself as a technology to be reckoned with. --Prateek Jivrajka & Milind Gadre
A Case of Materials Proper use of proper materials can solve a lot of problems faced by us. We all have sure heard this a lot of times, but here we are going to present two real life cases, where, by using the appropriate material in an appropriate way, the problems were done away with. TAR PLASTIC ROADS
Of the major problem faced by towns and cities is the poor condition of tar roads. It is observed that if it rains heavily, even the newly laid surfaces disappear within hours.. Looking at today’s traffic scenario, plain asphalt – tar roads prove to be inefficient. The solution that has been found out is use of polymers mainly plastics along with tar in lying of roads. The bitumen and gravel mix used for laying roads is combined with flakes or granules made from domestic plastic wastes like carry bags tea cups and variety of domestic plastics. This technique was first tried out in Salem. With this technology, we can partly overcome the problems faced by cities in disposal of plastic waste. People can sell their domestic plastic wastes instead of discarding them. Roads made this way display better hardness and resistance to water
penetration and hence lasts longer. Also, costs of production are largely reduced as plastic waste is cheaper than bitumen, (Rs.6 per kg vs Rs.14 per kg)
A SUCCESSFUL EXPERIMENT Considering the advantages of tar plastic roads over the conventional ones, Municipal Corporation of Greater Mumbai (MCGM), decided to test this technology. Accordingly a trial was organized for mixing of plastic waste with stones and bitumen in MCGM’s high speed Central mixing plant and this aggregate was used for construction / repair work of tar road .It was observed that plastic and bitumen could be successfully mixed and the stone- plastic adhesion was good. The roads were periodically tested and they were found to have no problems. With the success of this experiment the authorities have ordered to lay out larger stretches of tar-plastic roads
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DAM PROBLEMS IN INDIA With the increasing demand for water supply, dam construction in India has seen a rise over the years, but they face major problems of inefficient techniques and poor material quality, and they are highly prone to failure. Embankment dams are most vulnerable to being washed away when water flows over their crest leading to overtopping. It occurs mainly due to inadequate capacity of its spillways to discharge floodwaters, because of a spillway blockage with flood-borne debris, or due to mechanical or electrical problems which prevent the spillway gates being opened in time. Internal erosion caused by leaks through the core of a dam can also cause it to slump and be overtopped. 40 % of dam failures are due to this cause. SOLUTION: RUBBER DAM What is a rubber dam? Rubber dams are flexible hydraulic structures consisting of four parts: (1) a rubberized fabric dam body; (2) a concrete foundation; (3) a control room housing mechanical and electrical equipment (e.g. air blower/water pump, inflation and deflation mechanisms); and (4) an inlet/outlet piping system. A typical foundation of the rubber dam has upstream and downstream cutoff walls to lengthen the groundwater seepage path and thus reduce the uplift force of ground water. How does it work? When inflated by a medium (air, water or their combination) it rises to retain water; when deflated by releasing the medium, it flattens onto the
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foundation, completely opening the channel for free passage of water. The rubber dam can also be adjusted to operate at intermediate heights to meet the needs for different upstream/downstream water levels at different times.
A schematic for an inflatable rubber dam Advantages of a rubber dam Not only are these dams not prone to overtopping, but they also offer a lot of other advantages like short construction period, easy maintenance and repair, low project life cycle cost, environment friendly, earthquake resistant due to a light upper structure, uniform load on the rubber body, and light concrete foundation. RUBBER DAMS IN INDIA: India's first rubber dam, which is also the first to be erected in Asia, would be installed across the Janjhavathi in Andhra Pradesh. The dam would benefit about 9000 acres of land. The dam is the first step of ambitious Jalayagnam launched by the Government to complete 30 major and 16 medium irrigation projects at a cost of Rs.65K cores. â&#x20AC;&#x201D;Prathamesh Donvalkar, Mayank Bagri, Shipra Agarwal
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Clueless Crossword !!! Each square contains two letters, strike out the incorrect ones to obtain a grid consisting of words pertaining to the field of metallurgy or materials science. The words are made up of three or more letters. For solutions please visit http://www.met.iitb.ac.in
â&#x20AC;&#x201D;Kadam Aggarwal