The journey of the friction industry – Part 4: No one knows?
“Welcome to the age of radical change in the automotive industry”. This is the “dramatic” opening sentence of a recent report from PwC describing the five trends that are going to transform the automotive industry in the next decade. As introduction they state “Since the introduction of the smartphone, it has become clear that customers are quick to adopt even highly complex and expensive technology if it makes their lives easier. In other words, users value convenience and ease. These core values turned the automobile into the defining technical cultural item of the 20th century. Now it is time to translate these properties into the context of today’s – and tomorrow’s – technology and society.” So, automotive industry is now under a technological revolution that can change not only the products, but also the business model itself. This can potentially have the biggest impact in the friction industry in recent years [1].
If you like rock, maybe you will be familiar with the song “No one knows” from Queens of the Stone Age, and it’s first verse, “We get some rules to follow, that and this, these and those, no one knows”. And many friction players can feel is mojo being lost, thinking that the way that brought us here maybe will not bring us there. This era will need companies to develop an open and trustworthy mindset when implementing changes and visualize changes as an opportunity for growth.
Safety first… but with zero emissions?
Although the transition to electric vehicles will drastically reduce the traffic-related emissions and greatly improve air quality, it would be mistaken to talk about emission-free driving. Tyres and brakes are parts of the vehicles designed to be evenly worn with use and produce the so-called local emissions. With the gradual reduction of fuel-origin emissions, local emissions will be dominating.
Moreover, considering that tyre particles are usually big enough to fall to the ground, brake dust will be of greater immediate concern as they are increasing their role in the overall emissions mix and particles created are mostly airborne [2],[3]. A possible aid would go through designing PAD materials to emit bigger particles in order to ease their deposition in the ground, instead of volatilise. On the other hand, the use of anti-corrosion additives in PAD material, zinc coatings or the use of slow corroding disc materials, can reduce also the amount of material released from the interface due to their oxidation [4].
Besides the promise of cleaner brake formulations, electrification is in the horizon and so on, Furthermore, it is possible also to create systems to capture wear on the vehicle [5].
Regenerative braking will reduce the mechanical brake usage, and so the brake system wear. But there are several safety related reasons (ABS, ESC, ADAS, etc) why the mechanical brakes will remain on board of the electric vehicles for years. However, it is fair to say that regenerative braking will greatly reduce the need of brakes in urban areas, where speeds and brake efforts are lower and software can control dust emissions [6], but this will introduce new challenges to friction pair, like corrosion, different temperature profile, etc [4].
The more that brake regeneration becomes an auto industry standard, the easier to think in new ways to solve those problems and also to reduce the dead weight and costs associated with legacy friction brake systems. Maybe will see in the future lighter rotors than the ones made in grey cast iron, maybe will see a renaissance of the drum brakes, maybe brakes system will look closer to the one we see today in the motorcycles [7], [8], [9], [10]…The storyline is getting more and more convoluted as the plot advance…But we ain’t over!
New industry “drivers”
Cost, safety and environmental concern have been traditional friction industry drivers. But the “driver” itself has been also one of the key performers when defining many of the technical rules related to comfort, like pedal feel and NVH. Differences in requirements for OE and Aftermarket companies where clear.
Autonomous driving will make all those concepts to evolve. The “new driver” will feel in a different way, bringing new requirements in terms of NVH and performance. And projections show big numbers. Probable scenarios in Europe and China show the future of mobility with a reduction in total number of vehicles, an increase in the yearly mileage by vehicle and an increase in vehicle sales, due to the accelerated renovation of fleets [1].
Autonomous driving will most probably optimize brake efforts in terms of timing, speed and force needed, so probably wear will be reduced even more, and lifetime of brake PADS increased. But then the responsibility of the car maintenance will be transferred from a private individual to a fleet company in many cases. There will safety, regulatory and operational factors that will drive this fact.
No one knows except that the panorama is so open that we can expect changes in the aftermarket and OEM companies in the friction industry. There are different players on stage, slowly transforming the industry in the sake of the environment and rentability, of course. In this scenario there’s a need for friction suppliers and manufacturers to work closely together and evolve with the ever-changing needs of the automotive industry. In RIMSA we are ready for the challenge and we think is exciting to be right here, right now. Innovation has been one of the RIMSA drivers since their creation in 1985. And we keep working extensively with scientific and technological partners and customers to keep learning the basics to contribute to the development for the industry, for now and for the future.
Sources consulted
[1] Five trends transforming the Automotive Industry. Felix Kuhnert Partner, Global Automotive
Industry Leader. Christoph Stürmer Global Lead Analyst, PwC Autofacts
[2] T. Grigoratos, G. Martini, Environ Sci Pollut Res. (2015) 22, 2491–2504
[3] B. D. Garg, S. H. Cadle, P. A. Mulawa, P. J. Groblicki, C. Laroo, G. A. Parr, Environ. Sci. Technol. (2000), 34, 4463-4469.
[4] Dr. Ralf Leiter (Conference at IQPC Intelligent Braking-2018) “Future requirements for Future Brake Systems in Pass Cars – Consequences for Design and Development”
[5] David Kiley (The Brake Report, 2019) “Brake Pad Waste Collection Systems: Innovating Greener Brakes”
[6] Deaglán Ó Meachair (The Brake Report, 2019) “Clean Air and Dirty Brakes”
[7] W. Krenkel, F. Brendt, Materials Science and Engineering A (2005), 412, 177-181.
[8] T. Zeuner, P. Stojanov, P. R. Sahm, H. Ruppert et A. Engels, Materials Science and Technology (1998), 14, 857-864.
[9] N.Natarajan, S.Vijayarangan, I.Rajendran, Wear (2006), 261, 812-822
[10] R.K.Uyyuru, M.K.Surappa, S.Brusethaug, Tribology International (2007), 40, 365-373
