The automotive industry is evolving. The trend toward more electromobility is also changing the way cars are being manufactured. In some cases, this has a serious impact, not only on automakers themselves, but also on suppliers. Jürgen Hechler, global application engineering leader at 3M, is nevertheless confident: "We expect the demand for high-precision abrasives to continue to grow, despite the discussion about electromobility." Among other things, 3M supplies the automotive industry with abrasives for machining gears and shafts.

More and more electric

The share of electromobility is increasing. Between 2016 and 2020, the number of registered electric cars rose from 2.15 million to almost eleven million vehicles (source: Center for Solar Energy and Hydrogen Research Baden-Württemberg (ZSW)). By 2030, experts believe that the share of newly registered hybrid and fully electric vehicles worldwide will exceed the 50 percent mark.

Fewer components

"Generally, transmissions and the entire powertrain of purely electric vehicles are simpler than in cars with internal combustion engines. The elimination of the combustion engine and a significant reduction in the size of the transmission mean that fewer components are required. But the quality standards for the individual components increase substantially. Transmissions for electric vehicles have particularly high standards for quality, especially in terms of profile accuracy and surface quality for gears," says Hechler. “In order to increase the efficiency in driving comfort, noise development and driving range in electric vehicles, automotive manufacturers place the very highest demands on ground surfaces in gear manufacturing. The aim is to transmit high torque with low noise at the smallest possible proportions, which in turn increases the demands on the geometry and quality of the components." For this reason, highest profile and flank line accuracies and flawless surfaces are required. For an abrasives manufacturer like 3M, which supplies the automotive industry with grinding wheels for machining these components, this means adapting to the market.

Higher demands

"In the future, demands for abrasives will increase significantly," Hechler explains. This means that in addition to more expertise in application technology, new solutions will be required to meet the increased demands of automotive manufacturers — solutions that 3M is currently developing. One such result is the newly developed ceramic grinding wheels of the 3M Nano 2.0 and 3M Nano+ series with the innovative bond series V450 & V470, which achieve higher performance in profile flank line and surface quality.

Less bonding

Bonding does not grind. Bonding is the unloved ingredient holding together the individual components of the grinding wheel to produce a solid homogeneous structure. However, the bond also creates pressure and friction, which can subsequently cause thermal damage to the component. The new 3M V450 & V470 bonds allow a significant reduction in the amount of bond required in the grinding wheel while increasing the amount of abrasive grit and maintaining the same grit retention force. "By reducing the amount of bond in the grinding wheel, you prevent these thermal stresses. At the same time, you create more space for the abrasive grains to achieve improved performance of the wheel throughout its entire life cycle," says Hechler. The result is grinding wheels that produce finer profiles and surfaces with increased metal removal rates, longer tool life and reduced thermal stress. "3M Cubitron II grinding wheels are the benchmark for us when it comes to grinding performance. If, in the case of smaller modules, particular importance is placed on surface quality with increased requirements for contact ratio and profile accuracies well below ffα 2.0 µm, 3M Nano 2.0 and 3M Nano+ grinding wheels are the better choice," says Hechler. Nano 2.0 grinding wheels offer good performance in virtually all applications and on all common machine types at an attractive price-performance ratio. Nano 2.0 fine grinding wheels in grit size 150 mesh are the right choice for surface finishing applications with required Rz values below 2 µm and dimensional accuracy. Nano+ wheels with Precision Shaped Grain (PSG) are particularly high-performance and offer the highest dimensional accuracies and process stability for demanding geometries at the tooth tip and root in the module range 0.6 to 4.0. Nano 2.0 Duowheel grinding wheels for use in fine grinding or polishing of gears complete the range. "We are therefore ideally equipped to meet the increased demands of manufacturers," says Jürgen Hechler.

The grinding wheels are manufactured at the 3M plant in Villach, which was rebuilt and extensively modernized only a few years ago after a major fire. "We always have the right product for every requirement in stock and can deliver quickly, and for all common machine types," says Hechler. In the meantime, 3M Nano products are being used successfully by a large number of major automotive manufacturers and suppliers. However, according to Hechler, 3M is already thinking ahead: "The demands on abrasives will continue to increase. And the geometries of the components will also become more complex. In addition, manufacturers are placing ever greater value on long service lives for the abrasives used." According to Hechler, the next step and next challenge is "superfinishing" with vitrified bonded abrasives — in other words, polishing for even greater dimensional accuracy and even finer surfaces, cost-effectively and with process reliability.

At IMTS 2022 in Chicago from September 12 - 17, visitors can see the benefits of the new 3M Nano grinding wheels for themselves at 3M's booth (East Building, Level 2, Booth 121321).

Furthermore, for the first time, customers from the gear cutting industry will have the opportunity to participate in the two-day technical event "US Grinding Days" at 3M's U.S. headquarters on May 4-5, 2022, organized in close cooperation with machine manufacturer Liebherr. There, the topic of e-mobility and grinding will be a central theme. You can register at:

https://go.3M.com/grindingdays