IMPC 2016: XXVIII International Mineral Processing Congress Proceedings - ISBN:

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1 LIGHT WEIGHTING THE AUTOMOTIVE INDUSTRY THE ROAD TO 2025 CAFE G. S. Cole Director Lightweight Operations Automotive Insight LLC, Troy MI USA ABSTRACT By 2025, the U.S. automotive industry will have to average 54.5 mpg (4.3l/100km) Corporate Average Fuel Economy (CAFÉ). While new/improved powertrain technology (turbocharging, electrification, diesels, transmissions and stop/start) will be critical, it is estimated that 25-40% of the new CAFÉ standards will require significant mass reduction, and lightweight structural materials will be required. This presentation examines vehicle mass reduction based on new developments in manufacturing automotive structures and components using light metals (aluminum and magnesium), conventional heavy metals (iron and steel), polymers, and carbon-fiber reinforced polymer composites. Components that used to be sand cast or pressure die cast provided minimal fatigue strength and ductility. But greater mass reduction uses more light metals in structural applications. They require eliminating porosity and inclusions to improve ductility and fatigue strength. Improved casting processing, with vacuum die casting, counter pressure and squeeze casting, and new forging and extrusion applications are being developed for this purpose. New grades of ultra-high strength steels can be made thinner, and save over 1/3 the mass vs conventional mild steels. But more complex and expensive processing, such as hot stamping and in-mold quenching, is required. Most engine block structures have migrated from grey cast iron to aluminum over the past 40 years. But compacted graphite cast iron has higher strength at high combustion temperatures and pressures so that high powered engines can be smaller and even lighter than aluminum. Assembling a range of lightweight materials into vehicle structures requires specialized assembly techniques, including sophisticated structural adhesives that can mitigate vehicles unique corrosion environment. The presentation will conclude with discussing lightweighting strategies of Asian, American and, European marques and the materials, component designs and assembly techniques used to achieve 2025 CAFÉ. KEYWORDS Automotive industry, fuel efficiency, vehicle mass reduction, manufacturing, high strength steels, aluminum, magnesium, cast iron, carbon fiber reinforced polymers. Page 1 of 16

2 INTRODUCTION Fuel Efficiency and CO 2 Emissions in the United States and Europe The U.S. Energy Information Agency (EIA, July 7, 2015) estimated1 that in 2014 U.S. motor gasoline and diesel fuel consumption for transportation in 2014 resulted in the emission of about 1,075 million metric tons and 444 million metric tons of CO 2, respectively, for a total of 1,519 million metric tons of CO 2. This total was equivalent to 83% of total CO 2 emissions by the U.S. transportation sector and equivalent to 28% of total U.S. energy-related CO 2 emissions. There is growing concern that CO 2 Green House Gas (GHG) emissions are causing changes in the earth s climate. In the U.S, the Department of Transportation s National Highway Traffic Safety Administration (NHTSA) and the U.S. Environmental Protection Agency (EPA) have issued joint rules to improve fuel economy (note that every liter of gasoline produces 2.3 kg CO 2 ) and reduce greenhouse gas emissions for passenger cars and light trucks. NHTSA 2016 standards require a fleet average of 6.6 L/100km (35.5 mpg), with 5.95 L/100 km (39.5 mpg) for automobiles and 7.84 L/100km (30 mpg) for light trucks ( Automakers can receive credits by improving their A/C systems, and producing vehicles that run on E85, natural gas, or are zero emission (electric or hydrogen) vehicles. The U.S. Department of Transportation (DOT), NHTSA and the U.S. Environmental Protection Agency (EPA) have developed tougher Green House Gas (GHG) standards for model years (MY) 2017 through 2025, requiring car fuel efficiency of 4.31 L/100 km (54.5 mpg). EPA and NHTSA also are proposing standards for medium- and heavy-duty vehicles tractors, trailers, and engines that would improve fuel efficiency by 40% for 2025 and cut carbon pollution to reduce the impacts of climate change, while bolstering energy security and spurring manufacturing innovation. U.S. emission standards are well behind Japan and the EU (see Figure 1), but will catch up with the 2025 MPG standards. By 2020, the EU auto industry will be required to reduce CO 2 new car emissions to 95g CO 2 /km, from the current 250. Long-term targets for 2025 will require further emissions reductions possibly to 70g CO 2 /km., see Figure 1 (ICCT 2011).. By 2025 most regions of the globe will be trending to approximately the same emission and fuel efficiency levels. EU penalizes automakers by 95 /g CO 2 for missing CO 2 targets The U.S. fine is $55 for each mpg that is missed, multiplied by number of vehicles sold the annual fine can be in $millions for large European imports. Figure 1 Historical fleet a) CO 2 emissions performance and b) fuel consumption and current or proposed standards. Courtesy The International Council on Clean Transportation (2011 ICC.org). Page 2 of 16

3 Role of Vehicle Mass in Fuel Efficiency and Emissions Reduction There is no controversy about the role of vehicle mass reduction (MR) in improving vehicle mobility, drivability, fuel efficiency and emissions. MR reduces vehicle inertia, reducing the amount of fuel required to move a vehicle, and thus reducing CO 2 emissions. Every kg of MR saves g CO 2 (and is worth $5-$8 in the EU). It is generally agreed that 10% MR produces from 3-7% fuel efficiency gain, depending on vehicle size. Reducing vehicle mass in one portion of a vehicle allows downsizing elsewhere with additional MR via smaller powertrain (engine/transmission), suspension, wheels and brakes. The U.S. government's new CAFE targets have spurred OEM s to launch aggressive mass reduction campaigns; there is a growing consensus that mass must be reduced by 10-15% to achieve the MY L/100 km (54.5 mpg) CAFÉ standard. Cutting weight is more important to CAFE than some touted fuel-saving technologies. All OEM s are following this same trend, but automakers are risk averse, and conversion to lighter materials will occur slowly, step by step, as models are changed for example, Ford gradually will reduce the mass of new models by kg through Toyota is lightweighting its fleet using more aluminum sheet outer panels, high strength steel (HSS) frame parts, and magnesium seat frames, so that its midsize cars will be 10 % lighter; this is expected to improve fuel efficiency by ~ 3 %. With the growing trend for electrification, and, because of their extra battery mass, significant mass reduction is required to increase electric and hybrid vehicle range, and make these vehicle palatable for consumers. The ICCT has collaborated and assisted a variety of light-duty vehicle studies in the U.S., EU, and China. Along with studies conducted by public agencies such as the EPA and NHTSA, there is now a firm foundation for assessing the role of mass and emissions. Links to ICCT mass reduction studies are included in the Appendix. The U.S. DOT aggressively promotes vehicle mass reduction. NHTSA awarded a multi-million dollar contract to Electrocore to determine the maximum mass reduction possible from MY 2017 to 2025, while maintaining the same size, price, and vehicle functionalities (performance, safety, crash rating) vs a baseline (MY 2011 Honda Accord, base mass of 1480 kg). To achieve the same vehicle performance, the engine size was proportionally reduced from 2.4L/177 HP to 1.8L/140HP. The completed design discussed in the References (DOT 2012), achieved a 22 5% (332 kg) reduced mass at an incremental cost increase of only $319 or $0.96 per kg. The report details 520 figures on many aspects of mass reduction. Achieving Vehicle Mass Reduction At the component level, mass reduction depends on the application and design intent. For example since a simple body panel is designed for strength and resistance to plastic deformation, 1 kg of an aluminum panel, can replace a 3 4 kg steel part. But for structural components that are designed for enhanced stiffness, fatigue and ductility, 2 kg of aluminum is required to replace the 4 kg of steel. But note that for every incremental kg of mass removed, a further kg of mass savings are possible by downsizing (redesigning) the powertrain, suspension, brakes and wheels. Mass Reduction and Safety Even though lower mass vehicles can accelerate more quickly, have improved stability and response and have a shorter stopping distance than heavier vehicles, there is an urban legend that low mass vehicles are less safe than the heavier vehicles they replace. The Dynamic Research Institute (dynres.com) examined vehicle size and mass vs crash energy and concluded that structural materials which increase a vehicle's crush zones, even by several cm, can achieve significant safety improvements without increasing mass. For the most part, safety is a product of design, not mass, but it is obvious that a very small car cannot sustain a collision with an 18-wheeled truck. NHTSA expects to build on earlier standards that encouraged manufacturers to reduce mass while discouraging reductions in "footprint," (wheelbase times track width). In its 2010 study NHTSA found that mass reduced pickup trucks, vans and SUVs improve Page 3 of 16

4 safety, because after a collision, there would be fewer deaths among occupants of redesigned lighter vehicles (Kahane 2012). A real problem for OEM s is that vehicle mass has been increasing over the past few years as a result of governmental pressure to increase vehicle safety, see Figure 2. This adds additional pressure for innovating materials weight reduction. Figure 2 New vehicle safety standards that require adding mass to vehicles Cost of Vehicle Mass Reduction The benefits associated with vehicle mass reduction must be at an acceptable cost for its successful implementation. OEMs have been reluctant to pay the cost of adopting new lightweight materials, and developing new manufacturing processes, in part because of the established infrastructure, capital equipment, and knowledge base of historical conventional materials. The very essence of engineered products depends largely on the materials from which they are made. Changing a material is not a decision to be taken lightly. It affects how a product is designed, simulated and tested. It can have a dramatic effect on costs, manufacturing time and techniques, along the supply chain. The decision to move away from tried and true materials to something new could affect every stage of a product s development and lifecycle. Cost estimates for using lightweight automotive materials vary widely from $1.20 to $13.70 per kilogram of mass reduction. This is not surprising, since much depends on the type of lightweight material proposed, the vehicle component, assumptions made on the processing of the materials, and the production volume. The Ducker report (2011) suggests the cost of 10 % mass reduction at $500 per vehicle; the CAR study estimates that a 15 % MR would cost $1,156 per vehicle; the DOT estimates $319 or $0.96/kg (DOT 2012 loc cit). Aluminum MATERIALS FOR AUTOMOTIVE MASS REDUCTION Aluminum provides significant performance advantages compared with steel. Since aluminum alloys are 50 % lighter, vehicle bodies can be designed with higher structural stiffness and still be lighter than steel bodies, while delivering the safety, driving performance and durabilty drivers expect. OEM s have steadily added aluminum components to NA and EU vehicles. Whereas most engine blocks, heads, manifolds, and transmissions are conventional diecastings, new applications will demand increased fatigue and tensile properties. They will need higher dutility and fatigue strength and thus negligible porosity, and Page 4 of 16

5 will require low pressure, squeeze, semisolid, and vacuum die casting as well as wrought and extruded components. Recognizing the limited engineering capability by OEM s, the aluminum industry is taking a proactive role in growing new automotive applications. With GM, Alcoa managed component design and dimensional objectives related to body assembly quality (fit, function and finish). It supplied highlyengineered body sheet, high-integrity castings, complex BIW chassis extrusions, cast front and rear subframes, and a unique front-end crash energy management module. Alcoa also provided manufacturing expertise including performance-critical welding, self-piercing and blind rivets and adhesive bonding. New forming technology is further expanding aluminum sheet applications in lower cost vehicles to body panels other than hoods. Novelis expects that Global OEM body sheet use will increase from the current 300,000T to 2 mt by 2020 (Novelis 2012). Improvements in aluminum are also driving the change. Three years ago, Alcoa figured out a way to pretreat aluminum so it would be more durable when parts are bonded together. Carmakers can now use three or four rivets to piece together parts that would have needed 10 rivets before. Ducker forecasts that global aluminum use in passenger vehicles is likely to grow 65% from about 8-9 mt in 2009 to mt by 2020 (Ducker 2011). In addition to sheet and casting applications aluminum extrusions can provide significant mass reduction opportunities, see in Figure 3. Figure 3 Aluminum extrusion opportunities in vehicles (Courtesy Al Extrusion Council) Aluminum castings for such structural and safety-critical components as engine front and rear cradles, subframes, and control arms (see Figure 4) require intense product and processing development to eliminate porosity, oxide inclusions, and other fatigue-initiating defects that reduce ductility, and fracture toughness. Corrosion and stress-corrosion cracking resistance are required to cope with the under-hood environment. Special die designs, processing and filling algorithms are required. Structural parts use lower magnesium alloys (5000 series); body panels use 6000 series modified to increase strength and formability with, transition metals, such as Mn and Cr, added to promote grain refinement and improve ductility. Mass reduction using structural aluminum components is impressive. For example, BMW s cast aluminum suspension arms weigh one-third as much as steel. Mercedes-Benz supplier ISE Innomotive Systems Inc., switched from a 20 kg steel front-end module for the Mercedes R-class crossover to using aluminum for its upper structure; the net weight reduction is 1 kg. "Every little bit helps," observes Andreas Hackstedt, manager of ISE's plant in Tuscaloosa, Ala. "When you take some out from this part Page 5 of 16

6 and a little from that part, you help the entire vehicle." In all cases, the OEM message is clear. Consumers will not have to give up size, comfort, or horsepower to achieve the required fuel efficiency. Figure 4 a) 10 kg, mm HPDC Cast BMW engine cradle b) Multi-piece cast and welded subframe for BMW 7 c) 3.7k Low pressure cast steering knuckle for Audi A5 Castings always contain inclusions and porosity and do not always supply the required ductility and yield strength for fatigue resistant situations. As a result, some OEM s are opting for aluminum forgings which can have higher elongation (+55%), yield strengths (+26%), and ultimate tensile strength (+13%). As an example of the potential opportunities, Kobe Steel, a major Japanese steel supplier, invested in a U.S. aluminum forging facility to support its customer-base. Bharat Aluminiumtechnik adapted a horizontal continuously casting process to produce very clean forging stock which produced components having a narrower upper-and-lower property band for its forgings rather than that produced extrusion stock, the common route to a forged shape. Examples of Aluminum-Structured Vehicles Aluminum vehicle applications have made significant technological inroads over the past 15 years, including the Audi, Mercedes S-Class, BMW 7 series, Jaguar and so on Cole (2011). The new Jaguar XJ is 250 kg lighter (at 1,700 kg) than its steel-bodied stablemate the XF, despite being 150 mm longer and is kg lighter than its chief rivals. The lighter aluminum body improves the XJ s performance/handling and economy, while delivering increased strength, refinement and safety. Audi started using a hybrid material structure for the new TT in 2006 using aluminum sheet joined with an aluminum space frame, a high strength aluminum and magnesium structure, and strategically integrated panels. It weighed 210 kg. The reduced mass aluminum body provides enhanced performance and exceptional crash protection. The suspension includes front and rear forged aluminum wishbones that pivot directly on the frame and provide maximum steering precision. It has a power-toweight ratio of 210 Kw/t, a kph time of 4.6 secs, and a top speed of 300 km/hr. The Audi A8 is regarded as a forerunner in the use of automotive aluminum panels. The Dodge Magnum and Chrysler 300 saved 7-9 kg by switching to aluminum panels for the hoods and trunk lids. The standard aluminum frame for the 2014 Corvette is over 41 kg lighter and 60% stiffer than the previous model s steel frame. Key aluminum parts in Mercedes vehicles include structural castings (front and rear cradles), and sheet metal stampings. An aluminum floor pan uses 3 multi-chamber hollow extrusions joined by friction stir welding (FSW); part height is minimized and mass is reduced by 0.6 kg. The 2013 Range Rover Sport uses 561 kg of both conventional and high strength AAxxx alloys allowing sheet intensive body-and- structural applications such as control arms, steering knuckles, subframes, and instrument panels. It is 420 kg lighter and 111% stiffer than the older model. Such mass reduction increases fuel economy by an estimated 15 %, from L/100 km (19-22 mpg). The most novel aluminum intensive vehicle is the MY 2015 Ford F-150 pickup truck, shown in Figure 5. It is approximately 318 kg lighter than its predecessor, with 300 kg of aluminum body panels, magnesium parts, and a steel frame which has high proportion of HSS (77%) vs current (23%). Alcoa introduced aluminum improvements, inventing surface pretreatments that increased the durability of the Page 6 of 16

7 adhesive bonding. This allowed the amount of rivets to be reduced by less than half from normal assembly. The aircraft quality aluminum alloy is stronger than conventional aluminum, and costs about twice as much as the steel used on the current F-150. However Ford makes up the premium by reducing its recycling costs via a sophisticated process of collecting stampings, and reshipping alloy back to Alcoa for reprocessing. Conventional steel components are replaced in the cargo box, hood, tailgate, chassis and suspension. This equates to a 12-13% mass reduction from MY 2014, producing 8-20% improved fuel efficiency achieving about 7.84 km/l (28 mpg) in highway driving. The importance of this decision by Ford cannot be overstated. At ~770,000 units pa, the F150 is the number one vehicle sold globally. a) Ford F-150 b) Al body on HSS frame construction Figure 5 MY2015 Ford F-150 Aluminum Light Truck The new F150 illustrates how mass reduction can provide equal or better performance especially when paired with downsized engines: it can tow and haul more, accelerate and stop more quickly and allow a downsized engine (from 3.7L V6 to 3.5L). Aluminum alloys are more resistant to dents and dings and rust, and will only be marginally more expensive to insure. As well, since the new sheet must be annealed, it can be stamped into the differing auto body shapes required by the designers. Repair is a major concern for a vehicle that is supposed to last 200,000 km for more than 10 years. If the current steel truck is damaged, the entire floor structure has to be replaced; with the aluminum vehicle, only individual sections need be removed. Repairing aluminum structures requires a more complex and expensive process since damaged castings have to be T6 heat treated to recover original as-formed properties. Body shops have to handle rivet guns, metal inert gas welders, vacuums and tools. Even a heavy duty rubberized curtain is needed to seal off repair areas, since if aluminum dust comes into contact with steel parts in adjacent bays those parts could corrode. The aluminum truck is possible because of a new era in vehicle design and manufacturing. Twenty years ago, it took nine months to develop two possible frame designs. Now, 100 different models can be created in the same time using CAE tools. Digital experimentation and optimization can be performed with different lightweight materials, producing a many different component designs having a variety of stiffness and strength requirements. Steel Steel is still the primary material for automotive construction. But as a result of aluminum s penetration, there has been decrease in the use of mild steel. The steel industry has been accelerating its development of new stronger alloys, and new rolling, stamping, and forming capabilities that can produce thinner and lighter structures. It claims that its products are only slightly heavier than their aluminum counterparts and can provide almost the same mass reductions at less cost. ( 2014). The WorldAutoSteel partnership comprises 17 major global steel producers working together to develop light weight steel solutions that can compete with light metal and plastics competition. Key projects include: UltraLight Steel Auto Body, UltraLight Steel Auto Closures, UltraLight Steel Auto Suspensions, and the UltraLight Steel Auto Body. The interested reader is referred to the worldautosteel.com website for further information. As OEM s began to shed mass to meet emissions standards, the industry developed 45 new high strength steels (HSS) and advanced high strength steels Page 7 of 16

8 (AHSS) as shown in Figure 6, along with 19 new manufacturing techniques, such as roll forming and tailor-rolled blanks. Figure 6 New HSS and AHSS steel materials and applications (autosteelpartnership.com) Many EU OEM s, have opted to reduce mass using new grades of thin wall HSS rather than aluminum. For example, VW s latest Golf s thin HSS is up to six times as strong as conventional mild steel to help reduce 100kg. "It is a very cost-effective way of reducing mass," said Armin Plath, VW's head of materials research and manufacturing. Cutting one kg of car mass with AHSS costs $1; with aluminum it would cost 4x more. VW said that this approach confounds forecasts that aluminum would be the metal of choice for reducing mass. Even though aluminum is almost 1/3 the mass of steel it costs 3X as much. Ford used HSS for more than half of the Fiesta's body structure. Nissan plans to deploy a new AHSS across its entire lineup, thereby eliminating at least 15 kg from each vehicle. Because of the increased mass-reduction potential, Ducker (2011) predicted that NA AHSS use, after nearly doubling to 68 kg from , will more than double to 166 kg by Automotive steel is becoming thinner with body sheet approaching the 0.6 mm range. Higher tensile strength allows significant vehicle lightweighting so that a typical C-class vehicle can achieve a total mass reduction of approximately 19% (74 kg). ArcelorMittal, the world's largest steel maker, is reacting to mass reduction through its new third-generation UHSS grades which have a tensile strength up to 1200 MPa. Such steel can reduce the mass of a baseline compact car door from 18.3 to 13.3kg, while reducing cost by 27 %. More than half of the steel used in automotive bodies includes some form of AHSS. A-pillars are becoming so big, due to higher roof crush standard s that they partially block the view of side traffic or pedestrians; but with AHSS, they can be made thinner with no sacrifice to structure or safety. But since AHSS cannot easily be cold stamped, more expensive hot stamping is required. There are additional mass savings using structural adhesive technology, which obviates having to use additional brackets, gussets or panels to strengthen structure. In addition, the steel industry claims that if the Life Cycle Analysis (LCA) for a steel-structured vehicle were taken into account, steel components would have lower emissions and cost even less than aluminum. According to the steel industry, since virgin aluminum is highly energy-intensive, aluminum parts produce 5-20 times greater GHG emissions than steel during manufacturing, except where the energy is generated by hydro-electricity and until there are enough aluminum body panels for commercial recycling. The steel industry wants vehicle emission regulations to consider total LCA-related emissions, instead of only tailpipe emissions. However the aluminum industry says its material is comparable in LCA emissions if end-of-life recycling is taken into account. Plastics and Polymer Composites Plastics currently make up about 8% of a vehicle by mass but 50% by volume, according to the American Chemistry Council. The most common plastics are configured as composites; they include glass fiber reinforced thermoplastic polypropylenes in rear hatches, roofs, door inner structures, door surrounds, Page 8 of 16

9 and instrument panel brackets. Glass mat reinforced thermoplastics use sheet molding compounds made with thermoset polyesters, bulk molding compounds or thermoset vinyl esters. Carbon fiber reinforced polymer (CFRP) composites are more expensive but offer significant strength and weight-saving benefit, as discussed later. Plastics are as much as 50 % lighter vs comparable steel parts in fenders and other exterior applications, and are poised for a comeback as OEM s intensify their search for mass reduction ideas. An FCA study group is reviewing its deciding whether a switch to such composites might deliver % mass savings compared with traditional steels. But slow growth is expected due to lengthy production cycle times and the cost of fibers. Several plastic applications include a sheet molding compound (SMC) inner structure and a thermoplastic lower outer panel on the new Range Rover Evoque; the resulting hybrid plastic tailgate provides a 30 % mass reduction vs steel, while providing rigidity properties that meet mechanical specifications. ZF opened a new composite technology center to develop designs and production processes with mass reduced FRP s. They showed that a plastic suspension strut and knuckle module was 16% lighter than the current steel version and a Porsche FRP plastic brake pedal was 50% lighter than steel. But to make these parts cost-effective, cycle times need to be shorter. In addition, better control over fiber orientation is required since the material has acceptable impact in the fiber direction, but is more fragile in other directions. Additional research is needed to develop pedal structures that can compete with steel s uniform directional crash resistance. Vehicle Dynamics International (2015) analyzed composites in chassis applications to reduce vehicle weight. The article reports that composite springs have been used in the auto industry since the Chevrolet Corvette s first use of a composite leaf spring in the early 1950 s. IFC has been mass-producing glass-reinforced epoxy-based leaf springs since 2005, supplying more than 1.3 million for light-duty trucks, including Daimler s Sprinter cargo van. It claims to have a 0% rejection rate and no customer complaints to date. Plant manager Rüdiger Trojahn said that the Sprinter leaf spring is 20 kg lighter that its steel predecessor, an 80% weight reduction. Volvo s 2015 XC90 uses a transverse composite leaf spring in its rear integral axle; that is a 65% weight reduction vs a traditional steel leaf spring. Sogefi Group has introduced the world s first mass-produced glass fiber reinforced polymer coil spring on the Audi A6 Ultra achieving a weight saving of 4.4 kg weight saving. Carbon Fiber Reinforced Plastics (CFRP) BMW believes that there is no way around making cars lighter, and states that steel has reached its limit. Its electric i3 car requires a very light structure because its heavy battery has to power the car 100 km. An ultra-light weight carbon-fiber frame was selected as a solution. But C-fiber is prohibitively expensive, at~$20/kg. As an example of the importance of this technology to BMW, a joint venture was formed with SGL Carbon SE to build a $100m C-fiber factory in Moses Lake Washington. Here, local utilities charge about 3 cents/kwh using hydro-electric power to run the furnaces, or less than 1/5th the German cost. BMW s goal is to produce C-fiber in Washington, and manufacture an electric vehicle in Germany that has a reduced carbon foot-print. This will allow BMW to future-proof its entire portfolio, such as the forthcoming i7, and 8. The company has set a goal to reduce the frame cost to that of aluminum in 5 years. Other CFRP auto parts are being initiated throughout the industry. Dow has demonstrated a lightweight seat base using a resin transfer molding process with its commercial Voraforce 5300 epoxy + 60% C-fiber. The material's low viscosity, low moisture absorption, and cycle time of less than 90 seconds make structural C-composite parts more price-competitive with several joined steel subassemblies when large, complex parts are made quickly and in high volumes. Thorough wetting and filling is the key for large structural OEM parts and for consolidating several parts into one large one. There are important roadblocks to widespread implementation of CFRP in vehicle construction. First and foremost is the cost and availability of fiber, currently at $35/kg. According to the Rocky Page 9 of 16

10 Mountain Institute (2011), if carbon fiber costs could be reduced to <$5/kg (for large-tow, standardmodulus, automotive-grade creel fiber), a carbon-fiber-based auto would become cost-competitive with a steel-based auto. The second problem is manufacturing. For the high volume throughput of 1 vehicle per minute, polymer viscosities are too high and curing times too long for CFRP assemblies to keep up with the current steel and aluminum assembly lines. Lastly, are the legacy constraints associated with replacing the existing manufacturing infrastructure with something very different. Magnesium The magnesium industry has serious problems competing in the automotive materials world, since its industrial infrastructure is small and there are few financial resources to support applications research. Magnesium s annual global production is only about 1 mt, vs aluminum (> 30mT), and steel (>1,000m). There are few Tier One suppliers that have magnesium processing know-how, and neither the Chinese, who produce 90% of the world s supply, nor the one U.S. producer, support automotive product development. This is unlike the aluminum, steel and plastics industries which have sophisticated global OEM-centric research and marketing activities. Without supplier involvement, there is little OEM desire or ability to expand automotive applications. During the past 40 years, over 100 different magnesium products (all high pressure die castings) have been developed and approved for vehicle use. These are summarized by Cole ( ) and Cole and Quinn (2006). Since 1990, component applications have grown by 10-15% pa, reaching 180,000 T, by But the 2009 global recession ended much of the NA developments, with OEM financial difficulties compounded by closures of many die casters. The largest magnesium die casting, the Lincoln MKT liftgate, produced by Meridian Light Metals (in Ontario), is shown in Figure 7. It is mated to a stamped aluminum outer panel using a hemming/adhesive bonding process. Compared to the original steel design, which had 6 assembled and welded components, this single part saves 9.6 kg, increases passenger headroom and exceeds stiffness targets. The lighter liftgate also allows reduced steel in the roof and smaller/lighter struts. Along with other mass saving measures, the MKT is rated as having the best fuel economy in its class. Figure 7 a) Lincoln MKT liftgate, and b) HPDC magnesium mated to a stamped aluminum outer There has been recent interest in stamped magnesium sheet for potential body and interior application. POSCO, the South Korean steelmaker, and Magnesium Flachprodukte (GmbH), a subsidiary of ThyssenKrupp Steel Europe AG, began producing twin roll cast 1,500-2,000 mm wide, 1-2 mm gauge coils for auto industry use. TRC has the potential to significantly reduce magnesium sheet costs vs conventional ingot processing, since fewer steps are needed to achieve the desired gauge thickness. Glass Ford has been looking into weight efficiency for all its products. Hau Thai-Tang, group vice president of global purchasing at Ford told reporters that about 35 kg. of the Ford Focus weight is its glass, and on a larger car, such as a Ford Explorer, glass comprises about 45 kg. of the overall weight. Ford is partnering with Corning Inc. to put on this vehicle a Gorilla Glass hybrid windshield and rear engine cover that is about 30 percent lighter than traditional glass. The laminate in the Gorilla Glass hybrid window is also about percent thinner, but its strength is at least equal that of traditional laminate. Page 10 of 16

11 Multi-Material Construction Aluminum and HSS, along with improved CAD designs, can lighten automotive components. Aluminum lower and upper cross members, and a steel reinforcing cross beam and side members allows Johnson Controls Industries to reduce seat mass by 34% or 5 kg per seat. Additionally the steel back panel thickness was reduced from 0.6 to 0.4 mm, reducing seat weight by a further 4%. Hyundai s new hydrogen-fueled Intrado uses a new construction method that brings together lightweight steels and strong, rigid CFRP frames for the doors, roof and the power source support. A USCAR-sponsored project (MFERD) is examining a magnesium-intensive front-end. The Chinese, American and Canadian team members demonstrated a 45% mass reduced unibody car structure, a 24 % mass reduced body-on-frame truck construction and a 59% reduced part count through integrating magnesium castings and aluminum extrusions that met all vehicle specifications of stiffness, fatigue and crashworthiness. Magna International Inc. and Ford Motor Company unveiled a multi-material lightweight Fusion vehicle (MMLV) concept that uses advanced material solutions, to achieve a nearly 25% weight reduction compared to the current production vehicle. The Magna-led R&D activity, in cooperation with Ford included an engineering prototype vehicle build, and selected validation testing associated with a new aluminum-intensive passenger vehicle design architecture. An extensive use of advanced lightweight and high-strength materials, with carbon fiber, magnesium and titanium, resulted in reducing a conventional Fusion s weight by 25 %, increasing its fuel economy by 6 to 8 %. (SAE, 2015). The new materials for a vehicle structure included 19-inch CFRP wheels, ( mass 42%), composite coil springs, 57%, stainless steel-coated aluminum rotors, 39 %, CFRP seats, chemically toughened laminate windows, 35%, and a compacted graphite 40% engine block. There was 69 kg of AHSS and 290 kg of conventional steel. An LCA study predicted that the cradle-to-grave total net savings of the MMLV (in percentage basis), relative to the cradle-to-grave LCA of the 2013 Fusion, resulted in significant environmental benefits of 16% improvement in global warming potential and 16% improvement in total primary energy (fuel usage plus the energy needed to produce and recycle materials). Joining/Assembling Multi-Material Structures Extensive engineering design is needed with lighter materials, which often require new manufacturing technology to join and assemble these different materials into economically viable vehicles that address vehicle performance, durability and cost. The strength, fatigue and corrosion durability of multi-material joints depends on the processing and materials being joined. Any welding process that melts ferrous and non-ferrous metals will produce intermetallic layers that develop weak and brittle joints. Any process that uses a salt flux (e.g. laser welding), can cause corrosion. Brazing a steel/aluminum joint uses a filler material which wets the two metals and creates a thin, strong intermetallic layer. Mechanical joining includes rivets/self-piercing rivets, bolts/nuts/washers and clinches. Corrosion is always a concern unless there is substantial materials engineering to eliminate corrosion couples, Cole (2013). Assembling hybrid structures is better served by unique joining/bonding, and corrosion-inhibiting techniques that depend on novel, structural adhesives. Adhesive bonding offers the most promise for multi-material automotive assembly/joining by preventing metal-to-metal contact and the associated galvanic corrosion. The extensive subject matter requires a considerable knowledge-base: surface preparation (primers); adhesion properties with the bonding materials (epoxies, phenolics, acrylics, hot melts and pressure sensitive adhesives); chemical reactions among the various metals and non-metals; time for cure. The environment (temperature, humidity, fatigue, corrosion) has a significant effect on joint mechanical behavior and durability. Traditional joining methods cannot bond aluminum to steel. However, Johnson Controls Industries engineers developed an adhesive technology with its new rear seat frame technology, which was a suitable substitute for welding. Adhesives can be used to join flat panels, eliminating the risk of damaging the substrate by drilling holes. Adhesives can replace rivets and weld lines and enable lightweight and cost-efficient designs. Page 11 of 16

12 Cast Iron Engine blocks used to be fabricated from grey cast iron (GCI). In the 1970 s, lighter aluminum block engines were developed in Europe responding to higher fuel prices. As power densities increase to above 100 HP/L, and as vehicle structures get smaller, space under the hood is becoming more limited. A stronger, (but still machinable) compacted graphite cast iron, developed in Sweden by Sintercast, allows thinner walls and a smaller block. Typical CGI structure is shown in Figure 8. Controlled CGI structure is based on controlling graphite morphology (which is a function of the alloy s sulphur content predicted from cooling curve measurements and thermodynamic models) by inserting the required magnesium desulphurization via a controlled length of steel/mg wire inserted into the molten alloy. Audi engineers, developed their next generation 3.0 L V-6 diesel engine, after benchmarking the aluminum-block Mercedes Benz 3.0LV-6 for horsepower, torque, mass and size; they chose a CGI block for its castability, strength, stiffness and recyclability. The Audi CGI V-6 matched torque and horsepower but was 15 kg lighter and 125 mm shorter than its aluminum counterpart.. Ford s MY2015 aluminum F-150 truck has the lightest and smallest 2.7L V-6 engine in its class, about 45 cm from front to rear. The two-piece cylinder block has a CGI upper section/main bulkhead (where strength is needed) and an HPDC aluminum lower half, see Figure 8. CGI is also used on the F- 150 s PowerStroke 6.7-liter diesel engine. CGI Upper HPDC Al Lower (a) GCI flake (b) CGI (c) SGI Molded Plastic Oil Pan (not shown) Figure 8 Ford F-150 s 2.7-liter V-6 CGI/ Engine Block (Courtesy of Sintercast) GLOBAL OEM LIGHTWEIGHTING EXPERIENCE Japan's automakers, long at the forefront of small-car design, insist that shedding weight doesn t compromise safety as their OEM s race to slash mass and boost fuel efficiency. It is more difficult to maintain safety by reducing mass" said a Suzuki Motor Corp representative, but by employing new materials, designs and technologies, we can deliver cars that are small, lightweight and still safe. Koichi Kamiji, senior chief engineer for automobile safety at Honda R&D, said that the new premium on shedding mass employs new engineering and design architectures, advanced cabin safety technologies, new lightweight materials such as HSS, and shaving grams from any component not related to safety. For example, Honda has developed a new frame structure which uses thinner and lighter frame rails to absorb crash energy. He pointed out that today's minicars are safer than previous vehicles, despite being smaller. Mazda has made mass reduction the centerpiece of product planning and environmental performance. By 2015, Mazda plans to boost average fleet fuel economy by 30 % above 2005 levels, allowing a 5 % fuel economy increase for each new car, by trimming 110 kg from the next generation of each model. Mazda made its CX-5 crossover as much as 261 kg lighter than its similar-sized predecessor, Page 12 of 16

13 the CX-7, by designing the frame so that less steel is needed to provide the necessary strength. Even 8 gram lighter bolts are used. At Nissan, achieving 7.6L/100k city and 5.9L/100k highway required a 120 kg mass reduction. Significant aerodynamic redesigns added 1% fuel efficiency improvement. A 1.6L engine (vs 1.8L) produces less HP, but with the reduced mass, and with a new continuously variable transmission, the performance was approximately the same. The Citroen Picasso wheelbase is the longest in its category at 2,840mm, or 110mm longer than the current model. It is 100kg lighter and combines aluminum and steel alongside a composite rear floor, which reduces weight by 60 kg. The aluminum hood, composite tailgate, and 70mm lower stance also save an additional 40kg. With a 1.6L diesel engine, fuel use has been reduced by an average of 1L/100km and CO 2 emissions by 30g/km to 98 g/km. The MY 2011 Porsche Cayenne Hybrid vehicle achieved 10% mass reduction (220 kg) using an aluminum hood, tailgate, doors, fenders and chassis components, as well as HSS throughout the body. Lightweighting conferences abound to inform engineers and managers about the issues and techniques to reduce vehicle mass. Appendix 2 lists a short summary so some of the current activities. CONCLUSION The United States, Canada and 90 other countries have instituted increasingly aggressive emission standards to address the global warming, greenhouse gas targets of the 2015 Paris Agreements. GHG emissions from vehicles is an important element contributing to global warming. Since mass reduction is a key enabler for reducing some 25% of automotive emissions, automotive OEM s are critically examining each gram throughout their vehicles construction. Mass reduction is no longer an option but a necessity to sell vehicles. Electric, hybrid-electric and fuel cell vehicles are ramping up production. Mass reduction is essential to extend the range of vehicles containing the large battery/energy cells required to achieve the 300 km range demanded by consumers. A host of materials and manufacturing processes will have to be employed to optimize lightweighting, and meet vehicle performance, safety, and cost considerations: high strength steels, high temperature polymers, carbon fiber reinforced polymer composites, and the light metals, aluminum and magnesium in sheet and new cast forms. The need to reduce substantial mass is balanced with cost implications, crashworthiness and vehicle durability. This requires robust materials processing and joining methods. Governments demand fuel efficiency and emissions reduction. They spend millions of $, and, sponsoring research and technology development that support auto industries manufacturing, engineering and scientific infrastructure to achieve the long term goals of < 70 gm CO 2 /km required if the Paris Agreements are to be fulfilled. REFERENCES An Assessment of Mass Reduction Opportunities for a Model Year Vehicle Program (2010), Lotus/ICCT Auken and Zellner, Updated Analysis of the Effects of Passenger Vehicle Size and Weight on Safety: Summary of the Results for 2002 to 2008 Calendar Year Data for 2000 to 2007 Model Year Light Passenger Vehicles Vs Induced-exposure Data and Vehicle Size Variables (2013) DRI/ICCT Bharat Forge Aluminiumtechnik, North American Automotive Lightweight Procurement Symposium, Detroit (November 2015) CAR, Center for automotive Research, U.S. Automotive Market and Industry in 2025, June (2011) Cole, G.S., A Strategic Vision for Light Weighting the Automotive Industry, Guthrie Symposium, McGill University, (2011). Page 13 of 16

14 Cole, G.S. Magnesium Vision 2020: A North American Automotive Strategic Vision for Magnesium, United States Materials Partnership, United States Council for Automotive Research, (Nov 2006). Cole, G.S. & Quinn, J. F., Expanding the Application of Magnesium Components in the Automotive Industry: A Strategic Vision, SAE Transactions, Paper No (2007) Cole, G., S., Magnesium Corrosion Protection Techniques in the Automotive Industry, Corrosion Prevention of Magnesium Alloys, Song, G., L., Editor, Woodhead Publishing, p (2013) Vehicle Dynamics International.com, p (May/June 2015) CompositesWorld, February 2, (2015) Ducker Worlwide, December 8, (2011) Evaluating the Structure and Crashworthiness of a 2020 Model-Year, Mass-Reduced Crossover Vehicle Using FEA Modeling (2012), Lotus/CARB Future Steel Vehicle: Phase 2 Report (2011), EDAG/WorldAutoSteel Investigation of Opportunities for Lightweight Vehicles Using Advanced Plastics and Composites (2012) LBL/DOE, NHTSA German, J., & Lutsey, N., Size or Mass? The Technical Rationale for Selecting Size as an Attribute ICCT, International Council on Clean Transportation, Global Comparison of Light-Duty Vehicle Fuel Economy/GHG Emissions Standards, August (2011) ICCT, The International Council on Clean Transportation Design of Fuel Economy Greenhouse Gas (GHG) Standards Learning from international experiences, theicct.org (2012) ICCT, The International Council on Clean Transportation, Light-Duty Vehicle Mass Reduction and Cost Analysis: Midsize Crossover Utility Vehicle (2012) EPA- 420-R , FEV/EPA Mass Reduction for Light-Duty Vehicles for Model Years (Report No. DOT HS ). DOT Contract DTNH22-11-C Contract Prime: Electricore, Inc., August (2012) Mock, Evaluation of Parameter-based Vehicle Emissions Targets in the EU (2011), ICCT Rocky Mountain Institute (2011) Singh, Mass Reduction for Light-Duty Vehicles for Model Years (2012) National Highway Traffic Safety Administration Report No. DOT HS , EDAG/Electricore/NHTSA Wagner, D., Zalucek M., Conklin, J., Skszelk, T. Light Weight Concept 2013 Fusion, with Multi-material Mixed Materials, ASM Advanced Materials & Processes, March ( 2015) Wenzel, Analysis of the Relationship Between Vehicle Weight/Size and Safety, and Implications for Federal Fuel Economy Regulation (2010) LBL DOE Wenzel, Assessment of NHTSA s Report Relationships Between Fatality Risk, Mass, and Footprint in Model Year Passenger Cars and LTVs (2012) LBL/DOE Page 14 of 16

15 APPENDIX 1 ACRONYMS AND ABREVIATIONS AHSS Advanced High Strength Steel (YS > 550 MPa, TS >700 MPa) BIW Body in White (body with fixed sheet metal components) CAFÉ U.S. Corporate Average Fuel Economy CAR Center for Automotive Research (at the University of Michigan) CFRP Carbon Fiber Reinforced Plastics CGI Compacted Graphite Iron, formerly called vermicular iron CPH Close Packed Hexagonal crystal structure CUV Crossover Utility Vehicle DOT U.S. Department of Transportation EPA U.S. Environmental Protection Agency EU/EC European economic zone, Economic Commission for Europe FRP Fiber Reinforced Plastic FSW Friction Stir Welding rotating tool passes through contacting materials to cold bond a joint GCI Grey Cast Iron, iron with flake graphite GHG Greenhouse Gases HPDC High Pressure Die Casting HSS High Strength Steel (YS from MPa and TS from MPa) ICCT The International Council on Clean Transportation IHS Institute of Highway Safety LCA Life Cycle Assessment, total product or process emissions from mining to end-of-life MIGW Metal Inert Gas Welding MR Mass Reduction NA North America, Canada + United States + Mexico, NHTSA National Highway Traffic Safety Administration, a unit of DOT OEM Original Equipment Manufacturer (manufacturer/producer of cars and light duty trucks) SGI Spheroidal Graphite Iron, ductile iron with graphite in a spherical (nodular) shape SUV Sports Utility Vehicle TRB Tailor Rolled Blanks TRC Twin Roll Cast, 6-10 µm thick sheet as-cast between two rolls UHSS Ultra High Strength Steel (TS > 700 MPa) Page 15 of 16

16 APPENDIX 2 SOME ANNUAL CONFERENCES AND SYMPOSIA ON WEIGHT REDUCTION Automotive Lightweight Interiors: Cost Effective Material Application & Design 27th - 28th January, 2016, Munich, Germany. Explores the opportunities for lightweighting by adopting material and design strategies within interior components. Electronic air conditioning, interior lightweighting strategies face the challenge of meeting customer expectations, safety standards whilst being financially viable. Lightweight Vehicle Manufacturing: Joining & Forming February 24-25, 2016 Detroit, Michigan, USA Global Lightweight Vehicle Manufacturing 2016 will focus specifically on reducing the costs and shortening production cycles of manufacturing processes with an emphasis on multi material joining, forming and quality assurance for next generation lightweight vehicles. Lightweight Materials: Modeling, Simulation and Crash Safety Congress January 26 - January Detroit Presentations and panels will work towards improved methodologies, cost and time efficiency in crash simulation with the ultimate goal of bringing about a leap forward in lightweight material design & material modeling. There will be a focus on automotive industry best practices & new trends on cost effective modeling & simulation methodologies to enhance predictive capabilities & crash performance of lightweight materials. The 4th annual Global Automotive Lightweight Materials Congress 2015, London 29th-30th April. Industry leaders from OEMs, Tier 1 component providers and material suppliers assessed cost-effective weight reduction of automotive body, chassis and interiors for global markets.. Design strategies for composites, aluminum and steel, for multi-material joining and recycling. How will automotive companies maintain a competitive edge in the race to achieve the 54.5mpg fuel economy standard set by the NHTSA & EPA for 2025? 7 th Annual Advancements in Automotive Light-Weighting Summit May 18-20, 2015 in Detroit, MI Subject areas included advancement of automotive light weighting in structural and non-structural components, and the ability to effectively integrate them into cutting-edge multi-material vehicle constructs. Advancing practices in sourcing, modeling/design, manufacturing, joining and maximization of existing infrastructure to support the cost-effective and efficient implementation of these escalating objectives Lightweight Chassis and Body Design to present the latest innovations in terms of lightweight chassis and component applications. The best material combinations to manufacture multi-material lightweight chassis. New concepts for lightweight brakes to optimize thermal stresses. Optimal design for developing lightweight transmissions for trucks and buses. Innovative steel forming technologies for developing lightweight chassis. Applying corrosion solutions for maximum protection. Leveraging joining methods compatible with diverse material combinations to reduce the number of tools and costs of multi-material joining. Leading the way in reducing costs and cycle times to allow widespread composite adoption. How to adopt new materials such as composites and new forming and joining tools into an assembly process with minimum disruption to production. Comparing methods to cost-effectively create parts from high strength steel, aluminum and magnesium Inaugural Lightweight Vehicle Manufacturing: Joining, Forming & Assembly Summit 2015 came to Birmingham on 18-19th November Latest joining tools, reviewing the latest adhesives, mechanical, and welding techniques to cost- and time-sensitively join multi-material architectures. Manufacturing cost reduction: from automation and simulation. AluMag North American Automotive Lightweight Procurement Symposium, Detroit,MI November 9-11, 2015 Page 16 of 16