From carbon-fiber composites to wide-bandgap semiconductors, producers are shedding kilos with out sacrificing efficiency, security, or sustainability – reworking every part 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 proper geometry to provide it the required energy.
William Morgan, Buyer Technical Companies Supervisor – Automotive Sector Tata Metal UK says, “We’ve seen an enormous change in the direction of superior high-strength steels (AHSS) and completely different metal merchandise from typical ones to assist lightweighting.”
There are a number of methods metal could be optimized to scale 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 gives weight saving however maybe one of the crucial 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 parts,” 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 based mostly physique panels in GT4 is round well being and security and crash efficiency.” In contrast to carbon fiber panels that develop into brittle and break into shards, Quigley explains flax based mostly composites expertise ductile failures.
Electrical motors
Maybe essentially the most basic facet of lightweighting is deciding on the precise 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 ensure that there isn’t materials that doesn’t have to be there.
“Taking an electromagnetic instance, a part and seeing if there are bits of a magnetic circuit the place there isn’t a lot flux going by. At that time you can doubtlessly hole out these elements of the magnetic circuit and subsequently 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 effective lightweighting technique. “For those who carry a circuit board very near a motor you don’t then have a number of housing across the outdoors 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 scale back weight and dimension if its perform could be accomplished elsewise.
When it comes to materials use, Dr Moule says, “If there’s a materials that lets you take away warmth from part of a machine, then that will allow you to have a machine that runs cooler and which may permit you to want much less warmth sinking elsewhere.”
Thermal administration methods
Lowering weight in thermal administration methods depends on appropriately designed cooling channels which serve a number of functions. Thermal properties are the precedence however the parts that make up these methods may also present structural integrity or crash safety.
Providing an instance of how a light-weight thermal administration resolution might be carried out, Andrew Halonen, President at Mayflower Consulting explains, “Aluminum extrusion might encompass your complete battery pack. What’s essential 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 take up power. It’s supposed 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 superb materials for batteries and aluminum is light-weight.”
Battery enclosures
When designing battery enclosures that use composite supplies, the composite have to be fastidiously chosen to make sure it has the precise hearth retardancy traits. The research titled, ‘A evaluation of developments in synthesis, manufacturing and properties of setting 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 develop into more and more prevalent in numerous industries and processes, tremendously contributing to the objective of ecological sustainability,” the research states. “The biobased Polyfurfuryl Alcohol (PFA) resin is certainly one of such polymeric supplies that’s gaining consideration for composite purposes attributable to its endearing Fireplace 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 options. The development of composites means the fiber design inside the fabric can be optimized to create the energy wanted in sure areas of the part, saving materials within the course of. This may be regarded as a hybrid materials throughout the composite itself to tailor the part to its use case.
Inside parts
No materials selections are made in a vacuum, and there are a variety of extra components to contemplate within the pursuit of lighter inside parts together with value, sustainability, recyclability, texture and look. From a weight perspective alone, Halonen says, “So far as taking weight out of plastic, it’s actually exhausting [because] it’s already tremendous gentle.”
Quigley says, “I believe with interiors, one of many largest drivers is styrene emissions. One other is utilizing the precise materials in the precise place. One of many largest 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 based mostly composites can supply sustainability and advertising advantages. Whereas bio based mostly composites won’t have the equal energy and efficiency of non-bio based mostly composites, Quigley argues inside use is good for these supplies.
In dashboard and trim purposes, these composites visibly display 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 parts like seats, overmolding can be utilized to mix the advantages of composites and conventional injection molded thermoplastics. Quigley provides, “What that provides you is the energy, stiffness and type of the composite. However the injection molding lets you get extra intricate options, like stiffening ribs, so localized reinforcement might be mounting options for meeting.”
Energy electronics
“Whenever 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 loads sooner, that then lets you cut back the scale of passive parts: the inductors, the capacitors which you have got within the system for native power storage or for filtering, sometimes these parts could be comparatively massive.
“For those who 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 vast bandgap semiconductors in electrical traction drives:
Present developments and future views’ concludes “By leveraging the superior electrical properties, vast bandgap-based traction drives can obtain excessive switching frequencies, higher thermal administration, and lowered energy dissipation.”
The researchers clarify, “The literature evaluation constantly identifies SiC semiconductors as essentially the most most popular WBG system throughout numerous inverter configurations, notably attributable to their maturity and better breakdown voltage ranges. In distinction, GaN is very favored in purposes involving multi-level inverters.”
Chassis parts
Discussing completely different entrance higher management arm examples, Halonen says, “The Ford F150’s is 2 elements welded metal. That is the primary means on the earth to make this half, it’s the bottom value, somewhat bit heavier, it’s had trillions of miles of success, it’s extraordinarily dependable. The lightest technique to do it could be an aluminum forging. That is the bottom weight however greater value.”
One other means of making the identical part is to make use of metal stamped parts with glass stuffed nylon insert molding for structural rigidity. This technique has been seen in Ram pickup vans and Tesla automobiles. Halonen explains this combines the low value 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 value, 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 can be used to construct a strong provide chain inside nations or areas by sourcing and recycling end-of-life wind power gear 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 doubtlessly an enormous discount in unsprung mass, the price of carbon fiber means the wheels will more than likely solely be utilized in motorsport or on high-end automobiles.
“If it appears to be like good, do you care as a client whether or not it’s a metal or aluminium wheel?” says Halonen. “It depends upon how a lot they cost on the markup. I believe metal and aluminum are going to dominate that area in mainstream automobiles perpetually.”
Improvements in wheel development will possible unlock the lightest and least expensive options utilizing aluminum alloys. Volkswagen, for instance, launched elective cast 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 other manufacturing strategies.
“The bold weight goal posed a serious 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 precise stability 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 needs to be bigger. Since wiring is already confined to small areas, further diameter can current packaging challenges. If a producer was seeking 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 value 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 choice. The steel itself although doesn’t remedy 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 could solely have a small affect on the automobile’s complete weight, choosing the lighter and cheaper resolution might 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 choice for all purposes. At present, polycarbonate home windows see essentially 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 resolution.
Nevertheless, for fastened aspect home windows, rear windscreens, sunroofs and panoramic roofs, which are much less more likely to be scratched, the load financial savings might be large. Once more, the precise coatings have to be utilized to make sure the fabric’s UV resistance over time to forestall degradation.
Corning’s Gorilla Glass is maybe essentially the most sensible different to conventional automotive home windows. Its windshields are manufactured 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 typical 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.
