We only believe what we see. But what we don’t see has the potential to inflict more harm upon our environment and health than what we see, just like the non-exhaust emissions from Brake Pads of vehicles.

Navnath Kalel, our next pathbreaker, PhD Scholar at IIT Delhi, works in the field of “Development and Evaluation of Eco-friendly Brake-pads” to address the problem of Copper contamination in our environment due to its use in Brake Pads.

Navnath talks to Shyam Krishnamurthy from The Interview Portal about always wanting to work on real world problems and about the direct impact of his research on the environmental, social and economic aspects of our society.

For students, and especially those who love Automobiles, this is your chance to make your dream vehicles, not just aesthetically appealing and technologically advanced but also clean and pollution free !

Navnath, tell us about your background?

I was born and brought up in a small village (Jambhulani) in Satara district of Maharashtra, India. I come from a poor, middle class family. My father is a farmer and mother is a housewife. I have two brothers. Basically, the main source of earning was small farming and working outside to manage family expenses and our education. I did my schooling in government school (Z.P.) till 7th std. Later, I joined Karmveer Bhavrao Patil (Rayat Santha) high school which really shaped me a lot during my studies. I was good in Mathematics and Science. I used to participate in science exhibitions during school days, where my interest for creative thoughts, innovation and studies got a boost. Consequently, later I chose science stream for my under-graduae (12th)  program in K.B.P. college Devapur, Satara (MH) which is remote place. Although it was a remote place, it attracted students due to top class teaching, best results and potential for a bright future. Indeed, I would like to thank my Mathematics professor from whom I got inspired for innovative thinking, problem solving and hard work. I remember his words “Do not waste time on wrong things for temporary happiness but think about the long term for a bright future and work accordingly, which will give you growth along with happiness and satisfaction. My hobbies are playing crickets, swimming, reading etc.

What did you do for graduation/post graduation?

I did my graduation (B.E.) in Mechanical Engineering from MIT Aurangabad (MH) and postgraduation (MTech.) from Autonomous institute (RIT, Sangli). I did MTech. dissertation work in Bhabha Atomic Research Centre (BARC) Mumbai. Currently, pursuing PhD in Indian institute of Technology (IIT) Delhi since July 2017.

What made you choose such an offbeat, unconventional and unique career?

My first key influencers are my parents and my hard work, perseverance etc. Although they are not that much educated, they always supported me in my studies. Later, I would like to thank my friends and teachers who motivated/guided me for further studies at different levels.  

The real turning point in my career came when I joined BARC for my MTech. project work. In BARC, I learnt research skills and problem-solving techniques which further initiated a real passion and devotion in me towards the research field. I worked in the field of tribology for underwater nuclear applications and learned about tribology and its applications in the nuclear industry. 

To provide long term nuclear energy security to the country, there is a need for optimization of the domestic uranium and thorium reserves. Pressurized Heavy Water Reactors (PHWRs) in Atomic Centres in India, use moving components (sliding, rolling and reciprocating motion, etc.) generally in water lubricated conditions and occasionally in dry conditions (in case of emergency). Good tribological, mechanical properties apart from corrosion resistance are some of the primary requirements of such components. Starting from design stage to the failure of any component, availability of tribological data is very useful for designers and engineers. The typical components like fuelling machines, control rod drive mechanisms, shut down system and fuel transfer system etc. of PHWR have to work in underwater environment. These mechanisms consist of various elements like piston and cylinder, rack and pinion, bush and rolling bearings, ball screws and slider on rail type etc. Thus, work under different conditions leads to wear of components. My research was focused on the tribology of the mechanisms. It involved sample preparations, design of experiments (DOE), conducting experiments, and analysing results using machine learning tools and preparing reports. Through this my research work published few articles in conferences and journals.

After completing my project work, I appeared for PhD exam and got selected for PhD in IIT Delhi.

How did you plan the steps to get into the career you wanted? Or how did you make a transition to a new career? Tell us about your career path

I joined the mechanical industry after completing graduation. The aim was to gain practical experience in the industry and study simultaneously for higher education. Indeed, I learned many core activities related to mechanical engineering. I was curious about further studies and wanted to prepare for the GATE exam (national level entrance for MTech. admission). However, it was not easy for me to manage a good score while doing a job in the industry due to workload and lack of a study atmosphere. Moreover, I couldn’t join any coaching institute for GATE preparation and sit idle without a job and manage financial expenses. So, I started searching for teaching opportunities. After getting a teaching job, I left my industry job and joined teaching in Mumbai university as a lecturer. In the beginning, it was challenging to start preparation for the exam along with my teaching career. I faced some difficulties initially. However, I managed to get over it with time. After spending two years in teaching, I decided to move to higher studies. I started preparing for the GATE exam while doing the job and secured a good score to get MTech admission.  

As earlier mentioned, I completed my Masters dissertation work (one year) in BARC, Mumbai. 

Currently, I am working in the field of “Development and Evaluation of Eco-friendly Brake-pads” in IIT Delhi. In this whole career journey, I learned a few important things, such as being focused about your goal, time management, hard work with determinations and to keep small-small targets to achieve goal.

How did you get your first break? 

I think my first break was when I got selected for my project work in BARC Mumbai. Indeed, I learned a lot about research from Scientists and got inspired to become a researcher.

What were the challenges you faced? How did you address them?

Challenge 1: When my parents had migrated for work to a sugar factory, at that time, I was alone at home in my village during 9th and 10th std. I faced challenges like cooking, farming along with studying. 

Challenge 2: In the industry, I was handling responsibilities related to manufacturing, assembly of parts, and dispatch. Managing resources and achieving targets with good quality on time was challenging.

Challenge 3: During my PhD project work, when I started to work on development of eco-friendly brake pads, I initially faced a lot of challenges related to the arrangement of raw materials, development of new equipment, samples preparations and testing on different machines (at different places). After almost two years of hard work and determination, my efforts paid off. I succeeded in the development of eco-friendly brake-pads and published multiple research articles in reputed journals on my research work.

Where do you work now? Tell us about your research

Currently, I am working as PhD Scholar in IIT Delhi. 

Motion is the most important action of today’s world. Anything that moves, needs to be stopped also. Brakes are one of the most important parts of vehicles or moving systems because of the safety challenges related to machinery and human life. Their efficiency and reliability directly depends on the quality of the friction material (FM) which is sacrificial and used in the lining which is applied on the sliding part of a brake-pad/shoe/strip/block.

FM (Friction Material) contains four classes of ingredients viz. binder, fibrous reinforcement, friction modifiers and fillers with some overlap of functions at times. The combination of several ingredients in the right amount and combination, functioning synergistically is the key to developing the desired FM for the selected type of vehicle.

The ideal FM is expected to exhibit multiple performance requirements under wide operating conditions such as; 

  • excellent thermal and mechanical properties
  • the stable coefficient of friction (µ) under diverse operating conditions (in the range 0.3 to 0.4 depending on the category of a vehicle)
  • minimal tendency to fade and high recovery of µ
  • compatibility with the rotor or counterface friendliness
  • resistance to wear, squeal and low frequency vibrations,
  • ease and reproducibility in processing along with the cost viability etc. 

Asbestos, which was the most important ingredient of FMs for almost eight decades, was declared as a health hazard, and a new, recent class of materials called non-asbestos, low metallic fiber reinforced organic (NAO) has taken over since the last three decades. 

Environmental Concerns about the Usage of Copper in Friction Materials and Motivation for Research 

Currently, concern for vehicular traffic pollution has become very important due to the awareness of increased contribution of non-exhaust emissions. This has forced the FM industry to restrict the use of harmful ingredients (Cu, Hg, Mn, Sb etc.) in the FMs. 

Copper (Cu) is the second most important ingredient of FMs because of its multi-functionality such as;

  • Imparts high thermal conductivity, which is necessary to conduct away frictional heat from the tribo-surface, thus protecting FM from fade related problems
  • Contribution towards beneficial film formation
  • Structural integrity and reducing wear
  • Solid lubrication at elevated temperature

Among all metals used in FMs, such as Iron, Brass, Al etc., Copper is most favored in spite of its high cost. However, it has a serious environmental impact. Brake wear debris in pads/ shoes etc. ending up in the waterways, which has proved to be toxic to aquatic organisms. 

According to the State of Washington’s Department of Ecology, up to half of the copper entering into their waterways was due to the brake-pads. Therefore, Legislation recently signed into the law in the states of California and Washington, which prohibits brake FMs containing asbestos fibers, Cd and its compounds, Pb and Hg and compounds from being sold in both the states by 2014. By 2021, no brake FM will be sold or offered for sale in both states, which contain more than 5% copper and its compounds by weight. By 2025, the State of California and by 2023, the State of Washington will ban the brake-FM which has more than 0.5% Cu. Thus, currently, Copper is identified as the chief fresh water pollutant in urban areas, which endangers marine life and has become a focus of concern for the FM Industry. Worldwide efforts are being made to find its substituent, which will be environment friendly, cost effective, easily available and will impart all the functions of Cu in FMs.

What skills are needed for your job? How did you acquire the skills?

It requires a lot of reading, acquiring knowledge in that domain, hard work and determination to become a researcher. The most important thing is patience. 

I already had some background in the field of tribology, noise, and vibration. Here, my research work started from gathering raw materials to final testing. It involves manufacturing of brake-pads, characterizations and performance evaluation of brake-pads on a brake dynamometer which simulates actual road vehicle conditions.

Initially, I came across some problems during my research activity, but overcame it with the help of supervisors, seniors, and technicians. Reading research papers, attending conferences, and visiting different brake-industries also helped a lot. 

What is a typical day like?

Well, I wake in the morning around 6-6.30 o’clock. After getting freshened up, I do exercise and yoga in the morning. Before starting work, I usually make plans for a day and try to follow that. I start my research work in the lab around 10 am and continue till around 7 pm. I watch news, listen to music, and do meditation in the evening time. After dinner (9.30 pm), i again start reading/writing related to my research related work and go to bed around 11 pm. 

What is it you love about this job? 

I love to work on real-life problems, which I am getting a chance to execute here. 

How does your work benefit society? 

My research work has led to a final product (brake-pads for passenger cars) which was free from Copper, a recent threat to the environment – aquatic life. The research project has explored the potential of different kinds of stainless-steel particles for use in brake-pads are was based on various un-addressed issues.

Following are the deliverables, which will have direct impact on the environmental, social and economic aspects.

  • Cu-free brake-pads containing stainless steel particles with best tribological (good friction and low wear-long life) and NV (low noise-vibration) performance which are environment friendly (since Copper is being banned world-wide in brake-pads). – (Scientific aspect) 
  • Improvement in NV performance is controlling noise pollution and comfort during braking. – (Social aspect)
  • From an economical point of view in general the cost of copper material is higher (~25 %) than stainless steel material and SS is lighter than copper. – (Economical aspect)

Tell us an example of a specific memorable work you did that is very close to you!

As a researcher, I love my research work and keep a positive attitude for better output from my work. Coming to a specific memorable work, during my research work, I developed Cu-Free brake-pads which performed better than Cu based pads. This innovative effort helped me in getting selected for the Euro-Brake student opportunity Program 2019 (Dresden, Germany) and I learned more about recent challenges/opportunities in brake industries.

Your advice to students based on your experience?

Keep on learning, choose a field which you love and be positive. I believe, there is no secret of success. It’s the result of preparation, hard work, consistency and learning from failures. We need to keep a positive attitude and keep moving forward.

Future Plans?

I want to continue my research work in the engineering field and give my best to solve real-life problems.