From carbon-fiber composites to wide-bandgap semiconductors, producers are shedding kilos with out sacrificing efficiency, security, or sustainability – reworking every little thing from battery enclosures to physique buildings.
Physique buildings
Lightweighting improvements in physique buildings sometimes middle on the usage of a number of supplies. Whereas aluminum can supply weight financial savings, its stiffness in comparison with metal means it must be carried out with the right geometry to present it the mandatory energy.
William Morgan, Buyer Technical Providers Supervisor – Automotive Sector Tata Metal UK says, “We now have seen an enormous change in the direction of superior high-strength steels (AHSS) and totally different metal merchandise from standard ones to help lightweighting.”
There are a number of methods metal could be optimized to cut back weight. Morgan says, “Utilizing thinner gauges of metal in non-critical areas can considerably cut back weight with out compromising energy.”
Changing gentle metal with high-strength metal additionally offers weight saving however maybe one of the important advances on this space is tailor welded laser blanks. “This method can create stronger and extra environment friendly joints in metal buildings using a number of grades and sizes in a single single part, permitting for thinner and lighter elements,” Morgan says. For instance, in a door panel ring panel, the metal grade closest to the hinge could be stronger the place elevated fatigue efficiency is required, than the fabric the place the door closes the place elevated formability is required to match the design of the automobile structure.
Contemplating the potential for bio-based composites and notably their use in motorsports, Peter Quigley, Director at Athena Blue Innovation, says, “One of many benefits of utilizing flax primarily based physique panels in GT4 is round well being and security and crash efficiency.” Not like carbon fiber panels that grow to be brittle and break into shards, Quigley explains flax primarily based composites expertise ductile failures.
Electrical motors
Maybe probably the most elementary side of lightweighting is choosing the appropriate materials or part for the job. For Dr David Moule, Technical Specialist – Electrical Drives, Servo Drives Centre of Competence at ZF, sizing the machine for the applying is the primary method. “After that, it’s the design optimizations that be certain that there isn’t materials that doesn’t must be there.
“Taking an electromagnetic instance, taking a look at a part and seeing if there are bits of a magnetic circuit the place there isn’t a lot flux going by way of. At that time you may probably hole out these components of the magnetic circuit and due to this fact take some weight out.”
Dr Moule suggests one other space of consideration is minimizing inactive mass that’s not contributing to the torque. He suggests higher integration is an efficient lightweighting technique. “Should you convey a circuit board very near a motor you don’t then have plenty of housing across the exterior that’s taking over area and weight.”
By using mathematical algorithms or increasing the protection of 1 sensor, Dr Moule argues sensor elimination inside a product may help to cut back weight and dimension if its operate could be accomplished elsewise.
By way of materials use, Dr Moule says, “If there’s a materials that permits you to take away warmth from part of a machine, then that will allow you to have a machine that runs cooler and that may help you want much less warmth sinking some other place.”
Thermal administration programs
Lowering weight in thermal administration programs depends on appropriately designed cooling channels which serve a number of functions. Thermal properties are the precedence however the elements that make up these programs can even present structural integrity or crash safety.
Providing an instance of how a light-weight thermal administration answer may very well be carried out, Andrew Halonen, President at Mayflower Consulting explains, “Aluminum extrusion may encompass your complete battery pack. What’s vital right here is that it’s made as one steady piece. Voids can be utilized to switch scorching or chilly fluid. That’s the great thing about a steady piece like aluminum extrusion, you get a leak-free path constructed into your structural half, so it brings numerous worth for structural integrity for torsion and stiffness.
“Hollows within the materials are additionally areas that have to crush and soak up power. It’s meant to maintain that crash power out of the delicate battery supplies. So, there’s this total stiffness worth, there’s crush power worth and there’s fluid passageway.
“Aluminum has a excessive conductivity for thermal properties, so it brings numerous worth to battery enclosures, which is why it’s used throughout America, Europe and China. It’s a great materials for batteries and aluminum is light-weight.”
Battery enclosures
When designing battery enclosures that use composite supplies, the composite should be rigorously chosen to make sure it has the appropriate hearth retardancy traits. The examine titled, ‘A evaluate of developments in synthesis, manufacturing and properties of atmosphere pleasant biobased Polyfurfuryl Alcohol Resin and its Composites,’ argues the seek for environmentally pleasant and sustainable supplies in fibre-reinforced composite materials manufacturing has led to the usage of biobased supplies.
“Biomass-derived chemical compounds, their derivatives, and their purposes have grow to be more and more prevalent in numerous industries and processes, vastly contributing to the objective of ecological sustainability,” the examine states. “The biobased Polyfurfuryl Alcohol (PFA) resin is one in all such polymeric supplies that’s gaining consideration for composite purposes because of its endearing Hearth Smoke and Toxicity properties.”
SGL Carbon claims a battery case which makes use of carbon fiber-reinforced plastic could be as much as 40% lighter in comparison with aluminum or metal alternate options. The development of composites means the fiber design inside the fabric may also be optimized to create the energy wanted in sure areas of the part, saving materials within the course of. This may be considered a hybrid materials inside the composite itself to tailor the part to its use case.
Inside elements
No materials choices are made in a vacuum, and there are a variety of further elements to think about within the pursuit of lighter inside elements together with price, sustainability, recyclability, texture and look. From a weight perspective alone, Halonen says, “So far as taking weight out of plastic, it’s actually onerous [because] it’s already tremendous mild.”
Quigley says, “I feel with interiors, one of many greatest drivers is styrene emissions. One other is utilizing the appropriate materials in the appropriate place. One of many greatest challenges, particularly in plastics, is we use hundreds of various grades of plastics.” Having a lot of various kinds of supplies impacts the automobile’s recyclability.
Comparatively, bio primarily based composites can supply sustainability and advertising advantages. Whereas bio primarily based composites may not have the equal energy and efficiency of non-bio primarily based composites, Quigley argues inside use is right for these supplies.
In dashboard and trim purposes, these composites visibly reveal the feel of the biomaterials and permits the upper worth materials to be on show, as carbon fiber sometimes is in sports activities automobiles, for instance.
For elements like seats, overmolding can be utilized to mix the advantages of composites and conventional injection molded thermoplastics. Quigley provides, “What that offers you is the energy, stiffness and type of the composite. However the injection molding permits you to get extra intricate options, like stiffening ribs, so localized reinforcement may very well be mounting options for meeting.”
Energy electronics
“If you consider the general electrical drive, one of many areas the place there was new supplies used is the wide-bandgap (WBG) semiconductors and the alternatives they provide,” Dr Moule says, “Wanting on the controller the place the WBG semiconductors can swap rather a lot sooner, that then permits you to cut back the scale of passive elements: the inductors, the capacitors which you will have within the system for native power storage or for filtering, sometimes these elements could be comparatively giant.
“Should you push up the switching frequencies with silicon carbides (SiC) and gallium nitride (GaN), the WBG semiconductors, the sizes then come down. If the sizes come down it reduces the inactive mass, and the packaging round additionally reduces, which is nice.”
The paper ‘Functions of extensive bandgap semiconductors in electrical traction drives:
Present developments and future views’ concludes “By leveraging the superior electrical properties, extensive bandgap-based traction drives can obtain excessive switching frequencies, higher thermal administration, and decreased energy dissipation.”
The researchers clarify, “The literature evaluate persistently identifies SiC semiconductors as probably the most most popular WBG machine throughout numerous inverter configurations, notably because of their maturity and better breakdown voltage ranges. In distinction, GaN is very favored in purposes involving multi-level inverters.”
Chassis elements
Discussing totally different entrance higher management arm examples, Halonen says, “The Ford F150’s is 2 components welded metal. That is the primary means on the planet to make this half, it’s the bottom price, just a little bit heavier, it’s had trillions of miles of success, it’s extraordinarily dependable. The lightest technique to do it might be an aluminum forging. That is the bottom weight however greater price.”
One other means of making the identical part is to make use of metal stamped elements with glass stuffed nylon insert molding for structural rigidity. This technique has been seen in Ram pickup vehicles and Tesla automobiles. Halonen explains this combines the low price of metal with the low weight and energy of the composite.
Emphasizing – which focuses on Enhancing Materials Properties of Recycled Glass Fibers By way of Sizing – is engaged on recycling composite supplies from the wind power sector to automotive. The consortium, led by Longworth, goals to introduce reclaimed fibers into automotive manufacturing in a low price, top quality and excessive yield means.
Longworth’s Deecom technique permits resins and fibers from composites to be recovered and used once more as virgin supplies. Whereas this will increase the lifecycles and circularity of composite supplies, it may also be used to construct a strong provide chain inside nations or areas by sourcing and recycling end-of-life wind power tools and different used composites.
Wheels
Carbon Revolution claims its carbon fiber wheels are 40% to 50% lighter than comparable aluminium wheels whereas providing the identical energy. Though that is probably an enormous discount in unsprung mass, the price of carbon fiber means the wheels will probably solely be utilized in motorsport or on high-end automobiles.
“If it appears good, do you care as a client whether or not it’s a metal or aluminium wheel?” says Halonen. “It will depend on how a lot they cost on the markup. I feel metal and aluminum are going to dominate that area in mainstream automobiles without end.”
Improvements in wheel development will possible unlock the lightest and least expensive options utilizing aluminum alloys. Volkswagen, for instance, launched elective solid wheels weighing simply 8kg on the brand new Golf R mannequin. In comparison with equal alloy wheels, the cast rims are 20% lighter, demonstrating the potential of different manufacturing strategies.
“The formidable weight goal posed a significant problem for us, because the structural stability of the wheel rim is paramount,” says Volkswagen designer, Ranbir Kalha. “It took months and lots of iterations and simulations to seek out the appropriate steadiness between energy and weight.”
Wiring harnesses
“Everyone knows aluminum is lighter than copper, however it comes again to particular conductivity, which is the place copper wins,” Halonen says. To match the identical conductivity make-up as copper, aluminum wire must be bigger. Since wiring is already confined to small areas, additional diameter can current packaging challenges. If a producer was trying to change wiring from copper to aluminum, Halonen advises planning early within the design course of to account for the bigger dimension.
Sumitomo Electrics argues the decrease price of aluminum alone is an incentive for OEMs to make the swap to aluminum wire. Regardless of the bigger gauge required, aluminum continues to be a lighter possibility. The steel itself although doesn’t clear up the issue because it has a decrease energy, develops oxide layers and suffers from galvanic corrosion.
To deal with the problems with aluminum on this utility, Sumitomo Electrics has developed an aluminum alloy for the conductor. At terminals, the corporate’s system options distinctive serrations and anti-corrosion know-how to make sure the longevity and robustness of the aluminum alloy.
Whereas lowering wiring harness weight might solely have a small impression on the automobile’s complete weight, choosing the lighter and cheaper answer may have important monetary implications for mass manufacturing.
Glazing
Polycarbonate home windows are roughly half the load of glass, however they don’t supply a fast lightweighting possibility for all purposes. At the moment, polycarbonate home windows see probably the most use in motorsports the place each potential optimization is explored to chop lap occasions.
Whereas polycarbonate begins out crystal clear, except it’s handled appropriately with superior coatings, it has poor scratch resistance over time. As a windscreen on a road-going automobile, the longevity and danger of scratches from common use of wipers makes polycarbonate an unsuitable answer.
Nevertheless, for mounted aspect home windows, rear windscreens, sunroofs and panoramic roofs, which are much less prone to be scratched, the load financial savings may very well be large. Once more, the appropriate coatings must be utilized to make sure the fabric’s UV resistance over time to stop degradation.
Corning’s Gorilla Glass is probably probably the most sensible different to conventional automotive home windows. Its windshields are fabricated from three layers, a soda-lime glass, polyvinyl butyral and Gorilla Glass. To be used in windscreens, panoramic roofs and aspect home windows, the answer is as much as 30% lighter than standard glass and as much as 50% extra sturdy towards sharp and blunt impacts. Gorilla Glass has been used on the Ford GT, Porsche 911 GT2 and GT3 RS, Jeep Gladiator and McLaren 720S.
