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They Don't Make 'Em Like They Used To [Manufacturing Engineering]
[September 26, 2014]

They Don't Make 'Em Like They Used To [Manufacturing Engineering]


(Manufacturing Engineering Via Acquire Media NewsEdge) Demand for greater fuel efficiency and lower emissions is changing the face of motorized vehicle manufacturing A new era has dawned in motorized vehicle manufacturing. Until recently the dominant trend has been the implementation of lean manufacturing and continuous improvement processes to make automotive production more efficient.



The new trend also stresses efficiency, but now there is a sharp focus on fuel efficiency driven by government regulation. (Even though production efficiency is being forced to take a back seat, it will still play a part in this new era.) While lightweighting is the term being widely applied to this new era, it is a bit of a misnomer. Lighter materials will certainly play a major role, but key drivers also include what components will be lightweighted, what powertrains will be used to meet fuel-efficiency targets and what assembly techniques will be employed in motorized vehicle manufacturing going forward.

Aluminum, after decades of small but steady growth, is on the verge of the big time, according to The Aluminum Association. Previously used in powertrain components, wheels and suspension parts, aluminum is about to substitute for steel in some mass-market automotive bodies. The 2015 model of the Ford F-150-the top-selling vehicle in North America-is kicking off this change by using an aluminum alloy body atop a high-strength steel frame. This pickup is the first high-volume vehicle to be produced with an aluminum body, said Doug Richman, chairman of the technical committee of the Aluminum Association Transportation Group and Kaiser Aluminum's vice president of engineering and technology.


Weight Savings of up to 700 Pounds The fuel efficiency benefit of the shift to an aluminum body, according to Doug Scott, Ford Truck Group marketing manager, is that it is "going to take up to 700 lb [315 kg] of weight out of the vehicle." According to Ducker Worldwide in the 2015 North American Light Vehicle Aluminum Content Study conducted for the Aluminum Association, per vehicle usage of aluminum grew from 75 lb (34 kg) in 1975 to 350 lb (158 kg) in 2012 and is forecasted to reach 547 lb (248 kg) in 2025. Compared to today's vehicles which have about 10% of their curb weight made up of aluminum, 16% of the weight of vehicles will be made up of aluminum.

"Our findings indicate that by 2025 26% of all the body and closure parts [hoods, doors, tailgates, etc.] for light vehicles In North America will be made of aluminum," said Richman.

Looked at another way, the use of aluminum In the average light vehicle produced in North America grew by 7 lb (3.15 kg) a year from 1975 to 2013. It will grow by 14 lb (6.4 kg) per year every year from 2014 through 2025. In most cases these aluminum alloys will substitute for steel components of a greater weight.

And aluminum is not alone in throwing down the gauntlet. Steel also faces a challenge from composites.

Composites on the Way Until 2014 carbon-based composites had been used almost exclusively for the hoods of the Dodge Viper and the Chevrolet Corvette Stingray as well as certain body panels for highperformance vehicles such as select BMW models. In 2014 BMW introduced the i3, an electric compact car with its body-or Life module, as BMW calls it-made of carbon fiber reinforced composite. The Life module is bonded to an aluminum frame that contains the vehicle's batteries. A front subframe contains the front suspension while a rear subframe holds both the rear suspension and the i3's powertrain.

While the innovative BMW is the most composite-intensive passenger vehicle to be made available for purchase, its sales volumes are likely to be quite small given the time it takes to cure composites and the costs of the high-tech material (for more details, visit http://tinyurl.com/hifiber). Still, it is a pioneering step that could lead to success such as aluminum is enjoying.

The big hurdle for composites to clear, according to Rani Richardson, CATIA Composites Product Specialist at Dassault Systèmes, is lack of experience. Richardson has a wealth of experience working with composites in both the aerospace and the automotive industries, and said she agrees with a poll in Reinforced Plastics Magazine that found readers believe "the biggest challenge in the composites industry today is 'Poor knowledge of composites in end-user industries.'" "One of the things we need to get smarter about," she said "is how to take what we know about aerospace to automotive. Aerospace structures are very rigid, but cars shouldn't be, so we may have to use different materials in auto composites than in aero.

"We also need to know," Richardson said, "about the machine tools out there so we know what can be done on what." Digital Solutions Dassault played a role in creating the composite-bodied BMW i3.

"It is a big effort. I think the entire supply chain knows what a big effort goes into something like the BMW i3," Richardson said. "There is still a lack of knowledge on the part of many people about the software available to manufacture composites for automotive." Stiff as these challenges from emerging materials may be, reports of steel's demise are greatly exaggerated.

While the Aluminum Association's Richman notes that steel's role is diminishing from the commanding position it once held, even the Ducker report admits that steel will tremain as the principal material used in the average light vehicle produced in North America. Part of this is due to the lower cost of steel (at least currently) as well as the massive capital investment that has been made in the material over a couple of centuries.

In addition, steel is not giving up without a fight.

The companies that make up Big Steel, in conjunction with automakers, have been researching and developing new, stronger and, yes, lighter types of steel for decades.

Yet, it may be Little Steel that rides to the rescue. Really, really little steel. NanoSteel, in fact.

Advancing the Science of Steel NanoSteel Company Inc. (Providence, Rl), designs proprietary nano-structured steel material. The company has researched, developed and commercialized surface coatings and foils since its founding in 2002. These products have been used in the oil & gas, mining cement/concrete and power industries. Now NanoSteel's Advanced High Strength Steel sheet is on the verge of being used in automotive bodies in white (BIW). NanoSteel has developed a new class of nanostructured advanced high strength steel (AHSS) which delivers high strength and high ductility in a cold-formable steel.

"It will allow automakers to use thinner gauges of steel to lightweight vehicles without compromising safety," said Craig Parsons, NanoSteel president. "This material provides the unique combination of high tensile strength and high ductility properties resulting in performance beyond the boundaries of existing AHSS sheet materials." Furthermore, he said, it can be used cost effectively in the existing automotive parts manufacturing infrastructure. "Our new material can take advantage of the steel industry's current capacity," Parsons said. "Aluminum requires new investment to reconfigure parts stamping equipment and add new processes such as extrusion lines. There is not enough aluminum sheet production or capacity in the world to fully supply the entire automotive industry if steel were to suddenly disappear." The upshot is that going forward the world of motorized vehicles will be even more of a multimaterial world than it is now and that the majority of those materials by weight will be metals. A large reason for the reliance on metal is, as mentioned, an infrastructure already exists and well-known construction techniques abound in the auto industry even though there may be some hurdles to clear in the joining of dissimilar metals (see article on page 93).

Dissimilar Materials There is one surprising instance in which dissimilar materials are being joined, and that is in the new 2.7-1 V6 that will be available in the aluminum-bodied 2015 Ford F-150.

Using a structure similar to one that was common more than a decade ago, the turbocharged engine uses an engine block containing iron. (The majority of modern engines use aluminum for both block and head.) Where the twin-turbo 2.7-1 differs from its predecessors is that the upper section of its block is of compacted graphite iron (CGI) and the lower section is made of aluminum.

The upper section is composed of an iron casting, which includes the cylinders, and the main bearing caps. The lower part is a ladder frame design of die-cast aluminum that bolts onto the iron upper block.

While diesel engines commonly use CGI blocks, this is the first time the material has been used for the block of a gasoline engine. CGI provides the strength of normal cast iron, but with reduced weight.

"Previous engine block design choices were high strength or compact or lightweight," said Ed Waszczenko, engine systems supervisor. "We wanted to go further with the 2.7-1 EcoBoost and design an engine with compact structure and high strength and light weight." The weight part of the equation is obvious. The strength part is due to the fact that Ford will use high levels of "boost" or pressure produced by the engine's two turbochargers to deliver the torque levels that pickup drivers expect. The 2015 small-displacement V6 is rated at 375 Ib-ft, virtually the same output generated by the nearly twice as large 2014 5.0-1 V8 (380 Ib-ft).

Tooling up for Turbos The use of turbochargers is another accelerating trend in motorized vehicle manufacturing. The forced induction they provide allows small displacement engines to be used in applications once reserved for larger displacement engines with more cylinders. In theory the turbocharger acts as on off/on switch. A four-cylinder engine thus can deliver small-engine fuel economy when the turbo is "off" and deliver big-engine power (but greater fuel consumption) when the turbo is engaged. An added advantage is that big-engine power is available at small-engine weight, another fuel efficiency consideration.

An example of this swap of a little engine for a big one occurred when the 2011 Hyundai Sonata midsize sedan debuted with a 2.0-1 turbocharged fourcylinder in place of the 3.3-1 normally aspirated V6 that had been offered previously. Ford followed a similar path with its Fusion midsize sedan for the 2013 model year when it substituted a turbo four for a V6.

Another sign of the small-engine surge are turbocharged three-cylinder engines being offered by General Motors (only in Europe for now), BMW's Mini brand and Ford. Toyota also has announced that it will soon offer a turbo three-cylinder engine. Displacement of these engines is in the 1.0-1.5-1 range.

An increase in the use of turbocharging will quite naturally lead to more demand for turbochargers, which require precise machining for not only the turbocharger impeller but the impeller housing as well. The same can be said for superchargers, another device that boosts induction in internal combustion engines. The market for superchargers is also growing. Eaton Corp. expects the global market for boosted engines of both types will grow from 4 million to 17.5 million in 2017 (for more details visit http://tinyurl.com/forcedair).

Other powertrain trends will impact manufacturing. The growing number of gears being used in automatic transmissions to help achieve fuel efficiency is a move that has been afoot for a few years (for more details visit http://tinyurl.com/gearmaking).

Are EVs Dead? While internal combustion engines are not fading away as quickly as once was thought, pure electric vehicles are not capturing market share as quickly as some predicted in the wake of President Barack Obama's call in his 2011 State of the Union address to have a million electric vehicles on US roads by 2015. Between December 2010, when 19 battery electric vehicles (BEVs) were sold, and July 1, 2014, only 82,817 of these vehicles were purchased in the US, according to the Electric Drive Transportation Association.

Sales of BEVs are so low that Morgan Stanley Research issued a market study recently titled, EVs Are Dead, Long Live Tesla. Elon Musk's luxury sedan was singled out for praise, wrote Morgan Stanley researcher Adam Jonas, because, "Tesla's true success is making compelling performance vehicles that just happen to be EVs." The majority of auto industry observers praise the Tesla Model S as an exceptional car regardless of the powertrain.

Perhaps more tellingly, Toyota, which has sold more than a million HEVs in the US over the course of nearly 20 years, has turned its back on BEVs. The Japanese auto giant has withdrawn from an agreement to procure components for a RAV4 EV from Tesla.

Automotive News quoted Jim Lentz, CEO of Toyota's North American region, as saying the company believes BEVs are beneficial only in "a select way, in short-range vehicles that take you that extra mile, from the office to the train, or home to the train, as well as being used on large (corporate] campuses. But for long-range travel primary vehicles, we feel there are better alternatives, such as hybrids and plug-in hybrids, and tomorrow with fuel cells," Hybrid Market Share Seems Static Hybrid electric vehicles (HEVs) have done much better than BEVs, with 592,232 HEVs, plug-in hybrids (PHEVs) and extended-range electric vehicles like the Chevrolet Volt being sold in 2013 alone.

The growth of the hybrid segment may be in the past, however.

A study by IHS/Polk released in May 2014 found that "the number of hybrid models in U.S. showrooms has increased every year from 2009 through this year, but their market share has not kept pace. Hybrid share actually declined from 2009 to 2010 and again from 2013 to 2014, despite an increase in model count during both these time periods." Toyota will not turn its back on HEVs anytime soon, but it is turning toward EVs that rely on fuel cells.

In April 2015 it will began sales of a fuel cell sedan in Japan. The fuel cell will convert hydrogen to electricity. It will have an estimated price of about $70,000. Later that year sales will begin in the US and Europe. Pricing in these markets has not been hinted at.

More Fuel Cells are Coming When Toyota's fuel cell vehicle (FCV) goes on sale in the US next summer, it will be a year behind Hyundai in marketing such a powertrain in America. The Korean carmaker leased the first Tucson Fuel Cell crossover in the US to a California family in June. The FCV began mass production for the US market in April 2014 at Hyundai's Ulsan, Korea, assembly plant that also manufactures the Tucson gasoline-powered CUV. The company claims that is "world's only mass-produced fuel cell vehicle." And-at least for now-it is.

Nissan plans to introduce its first FCV in 2017. Honda expects to be producing FCVs by 2020 and is collaborating with GM on the technology. Ford, Daimler, BMW and other automakers are known to have FCV programs as well.

As a consequence of this search for high fuel efficiency and low exhaust emissions vehicles will become even more complex than they are now. In many cases that greater complexity will have to fit in a smaller envelope. And of course, it will all have to weigh less.

Software will play a big role in achieving this, both for metal and composites. CAD/CAM and metal have worked hand in hand for years, but now topology-the shapes and voids in a component-is becoming an even bigger part of the process in order for components to have the necessary strength and functionality at the lightest weight.

As noted above, Dassault software played a large role in creating the composite-bodied BMW i3. Siemens PLM Software also has expertise in software for the design and layup of composite structures. It has worked on a number of automotive projects and has years of experience in the use of composite bodies in Formula One Racing.

On the Factory Floor As vehicles and the technology in them become more complicated and complex, digital solutions have become more important. It is now common for manufacturing facilities to be laser scanned. The data acquired is then used by digital manufacturing software from Autodesk as well as Siemens and Dassault to lay out the most efficient theoretical factory floor plan and then prove out the layout through simulation.

More efficient manufacturing hardware is coming into play as well. An example of this was shown at the 2014 Detroit Auto Show as part of the display used to introduce the aluminum-bodied 2015 Ford F-150.

Called ComauFlex, it is a flexible BIW manufacturing strategy from Comau Inc., part of the Comau Group. According to Martin Kinsella, Comau Inc.'s director of Advanced Materials and Process Technology, rather than being "on a traditional manufacturing footprint, ComauFlex moves to an engineered footprint based on flexible manufacturing management, flexible logistics, flexible conveyance and flexible tooling." The flexibility can allow cars, SUVs, light trucks and minivans to be built in the same facility, he said. "It can allow a random build sequence with up to four different vehicle types moving through the system one after the other or it can handle batch builds," he noted. In addition it can accommodate scalable production rates, diverse materials and diverse joining methods.

"Furthermore," Kinsella said, "it does not require truss supports or equipment in pits." "The system could be placed in a warehouse," he said,"because it is ground based with little or no roof-based fitments. All components are designed to be transported on standard trucks with no need for a 'wide-load' escort. And as a rule of thumb it results in a reduction of 20 to 40% over a traditional manufacturing footprint. '' More information on ComauFlex may be found at http:// tinyurl.com/comauflex. ME James D. Sawyer Executive Editor (c) 2014 Society of Manufacturing Engineers (publishers)

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