When you design a new vehicle from scratch, it’s easy to think big – push the limits of performance and fuel efficiency, explore radical designs that will excite and challenge buyers, integrate every electronic bell and whistle you can imagine.

However, when you’re working on vehicles with decades of history, loyal fans, and billions of dollars invested in manufacturing capacity, things get much tougher. On one hand, staying competitive means changing as much as possible. On the other, change too much, and you risk customer loyalty and corporate profits.

That’s been the challenge for Fiat Chrysler Automobiles’ (FCA’s) most important vehicles. In the past 18 months, the automaker has massively reimagined its iconic Jeep Wrangler, a vehicle with more than 75 years of heritage, and its Ram 1500 pickup, the best-selling model for the entire company. The new vehicles are lighter and more efficient than the models they replace, yet they retain the elements needed to keep buyers, corporate cost managers, and regulators happy.

“We are the stewards of a brand that owes everything to the enthusiasm of the Jeep community,” says Mike Manley, FCA’s recently named CEO and the former head of the Jeep and Ram brands. “Our job is to listen and deliver on what they so clearly want.”

Both vehicles show what manufacturing technology is enabling in modern production. Better machining techniques support higher performance engines, better understandings of materials allow the combination of aluminum and steel to lower weights, and better simulation and visualization software have provided designers more freedom to imagine the future of transportation. That’s why GIE Media chose FCA’s two most iconic vehicles to showcase at IMTS 2018 in Booth #236900.

2018 Jeep Wrangler

Making a pickup or off-road vehicle that gets 30mpg is deceptively easy. Throw in a 66hp, 1.3L, 4-cylinder engine; replace heavy-duty frame components with less-capable ones; and avoid four-wheel drive systems and their heavy transfer cases. That was the thinking behind the 1986 Suzuki Samurai, a vehicle that looked a lot like the Jeep CJ7 on sale more than 30 years ago.

But it wasn’t a Jeep.

It couldn’t splash through steams, power up hills, or ignore major obstacles in its path. Every component that makes a Jeep Wrangler heavy is what makes it the most dominant off-road vehicle in U.S. history. So, when FCA officials tasked the Wrangler design team with lowering weight and improving fuel efficiency for the 2018 Wrangler, the simple, easy options were off the table.

“The all-new Wrangler is instantly recognizable as a Jeep, staying true to the original, yet it is better in every way – delivering even more rugged capability, more ride comfort, more fuel efficiency courtesy of several advanced powertrain options, more interior comfort, more safety, and more technology,” Manley says.

Designers working on the 2018 model knew they couldn’t lower power, remove rugged-but-heavy suspension components, or eliminate four-wheel drive systems. The new Wrangler would need a stiff, rugged, steel frame under its body.

Some clever engine technologies (a turbocharged 4-cylinder option or a V-6 with start-stop technology that shuts off the engine at stop lights to conserve gas) and a more-efficient transmission would help, but those improvements wouldn’t offer the efficiencies needed to comply with future fuel-economy regulations or help the vehicle’s popularity grow in countries with high fuel costs.

Jeff Gale, Jeep’s chief exterior designer, says designers opted to replace steel doors, liftgates, fenders, and hoods with aluminum, shaving about 200 lb from each vehicle. The goal was better fuel economy, but other benefits flowed from lightweighting – mainly better handling on roads and easier operation for drivers.

“With the lighter panels, we only need one bolt per hinge on the doors and liftgate,” Gale says. “So, it’s much easier to remove those for off-roading. We only needed four bolts to lower the windscreen from the safety frame.”

2019 Ram 1500

While pickup drivers don’t want to waste gasoline, fuel economy tends to be a secondary concern to performance. So, improved efficiency for FCA’s best-selling vehicle couldn’t come at the expense of power, towing capacity, or seating space. As with the Jeep, strategic use of advanced materials lowered weight by 225 lb compared to the outgoing model.

The Ram’s chassis is 120 lb lighter than the outgoing model – 100 lb from the frame, 20 lb from the suspension. Nearly all the frame’s material (98%) is high-strength steel. Automakers increase their use of stronger, stiffer steel each year to cut weight by replacing thicker components with hard-to-cut, and hard-to-form, thin-walled replacements.

Ram 1500 hoods have been aluminum for several years, but for the 2019 model, the company also used the lightweight metal for the tailgate, engine mounts, front-axle center section, front-suspension crossmember, transmission crossmember, and steering system gear.

Mixing metals lowers weight, but the process requires upgraded paint pre-treatment systems, investments in joining systems, and higher material costs. Joe Dehner, head of Ram and Mopar design at FCA, says those changes were needed to meet the company’s “no sacrifices” goal for the truck.

“Cutting weight and boosting efficiency are easy if you’re willing to ask your customers to accept less or pay more. It’s a lot harder when you don’t want them to have to deal with the tradeoffs,” Dehner says.

To further cut weight, engineers replaced steel upper front suspension control arms (integrated with a steel structure) and air-dam structures with composite versions.

One issue designers ran into during the redesign, he says, was increased noise in the truck’s cabin when equipped with the company’s popular 5.7L Hemi V-8 engine. Adding insulation or thicker materials deadens noise but adds weight. Instead, the team added electronically controlled, side-frame-mounted, active tuned-mass modules (ATMM) that work with an interior active noise cancellation (ANC) system Hemi-equipped models. The system reduces ambient sounds down to a low 67.1dB, making the new model the quietest Ram 1500 ever.

About the author: Robert Schoenberger is the editor of TMV and can be reached at 216.393.0271 or rschoenberger@gie.net.

Advanced steel alloys continue to gain favor in the auto industry, allowing original equipment manufacturers (OEMs) to reduce metal volumes and weights without sacrificing crashworthiness or performance. However, replacing bulky, mild steel components with thin, high-strength steel alternatives creates a new engineering challenge.

With less mass, corrosion protection becomes crucial. With a 50mm mild steel suspension component, for example, losing 5mm to rust throughout a 10-year lifespan is often acceptable because the remaining 45mm of material is still enough to structurally support the vehicle. With a 10mm high-strength steel replacement part, losing 5mm of mass to rust in 10 years would mean losing half of the component.

“Trends toward high-strength steel will lead to [OEMs] increasing their corrosion standards,” says Sean McKeon, vice president for BASF’s North American OEM Coatings business. “There’s less thickness to the steel, so they have to increase their corrosion standards to meet that.”

BASF and Swiss zinc coating specialist Thermission have introduced Zinc Thermal Diffusion (ZTD), a heat-treat coating process that deposits thin layers of zinc onto steel substrates, creating an intermetallic protective layer that could extend service lives of existing steel components and support further decreases in component masses.

Physical process

Virtually every component on modern vehicles goes through electrocoating (e-coat), in which entire vehicle bodies are submerged in zinc-phosphate tanks to impart ultra-thin layers of that crystalline coating on the metal. Thermission USA CEO Andreas Hackstedt says e-coat is sufficient for sheet metal or 10-year lifespans for thicker steel structural parts, but it doesn’t provide the protection needed for the new generation of lightweight components.

“Zinc diffusion is completely independent of e-coating. With ZTD, we apply a metal layer of zinc onto the substrate between 8µm and 10µm thick, and the OEM will still e-coat that with 10µm to 15µm of zinc phosphate,” Hackstedt says. “Then, you have a superior layer that meets the higher corrosion standards that automakers are mandating.”

The ZTD process uses a thermal chamber that heats the component to about 700°F, along with aluminum and zinc powdered metals. As the temperature rises, the powdered metals vaporize, and the chamber rotates, infusing the metallic powders onto the steel component. Though hot enough to vaporize the powders, the treatment process is cool enough to not change the metallic structure of the underlying steel.

“This is a strategic process, something to apply to the most sensitive parts,” Hackstedt says. “Our target is underbody components. They get hammered by impingements – stone and gravel bombardments that can destroy the coatings on top of it. And those are some of the most safety critical components on the vehicle. The intermetallic zinc-iron structure created by the process protects the crucial interface between the e-coating and the base steel.”

BASF and Thermission are in the process of setting up ZTD demonstration systems in North America. Several OEMs have discussed using the process, but so far, the technology has not been used in finished vehicles. McKeon says he believes the process will be part of the toolbox in supplier plants that provide structural components to OEMs. He adds that it will not be as widespread as e-coat systems that exist in every assembly plant.

“Top tier suppliers will be the early adopters, especially the ones working on body structures,” McKeon says. “Preventing corrosion on these parts is a safety concern – the frame, control arms, suspension components – you don’t want those breaking, or you’re going to lose control.”

Corrosion challenges

Protecting components with thin wall gauges is the primary target for ZTD technology, but there are other corrosion issues that it addresses. Most underbody assemblies are multi-part components made of various stamped parts that have been welded together. As part walls get thinner, those weld points connect less metal. In addition, the heat from the welding process can alter the microstructure of the steel. These conditions can create potential weak points that corrosion could exacerbate.

“The Thermission ZTD process will induce the zinc into the body of the part and into the welds. Weld corrosion and edge corrosion [corrosion that forms on the edges of components instead of the main walls] are the main challenges with e-coating today with standard zinc phosphate,” McKeon explains.

Another problem that has gotten more extreme as vehicles get lighter is galvanic corrosion – metal corrosion that occurs when different materials meet.

“If you look at the Ford F-150, they’re using a lot of aluminum in the body panels, but the frame is high-strength steel,” Hackstedt says. “Somewhere on the vehicle, you have a connection between steel and aluminum. If you don’t protect that connection, you create galvanic corrosion, like a battery effect.”

Typically, only one metal corrodes at the connection point, so OEMs could coat the steel component with zinc to eliminate the issue, he adds.

Supporting the trend

Even with the increases in high-strength steel and lightweight aluminum in recent years, e-coating is still sufficient to protect most vehicles. However, Lepkowski says, industry trends call for cars to be even lighter in the coming years, and there are few ways to do that without targeting vehicle underbodies.

“You’re getting to the end of what zinc phosphate e-coat can do,” he adds. “If you want to get past 10 years with steel or mixed metal, or if you’re going to cut component gauge thickness even more, you’re going to have to look for something different.”

Hackstedt is blunter in his assessment.

“There is no other choice,” he states. “When you get past the combustion-engine cars and look at the move to hybrids and electric vehicles, the goal is for those vehicles to have long travel ranges on a single charge. So, OEMs are going to have to take more weight out, and they can’t do that without addressing corrosion.”

BASF SE
www.basf.com

Thermission AG
www.thermission.com

About the author: Robert Schoenberger is the editor of TMV and can be reached at 216.393.0271 or rschoenberger@gie.net.

Aerospace

ONE Aviation’s Eclipse 550 Very Light Jet boasts best-in-class performance, economics, and safety. Flying at up to 41,000ft at a max. cruise of 430mph, all while consuming only 59 gallons of fuel per hour, the Eclipse 550 is the most efficient twin-engine jet available today.

Planes are assembled using friction stir-welding, a green manufacturing process that uses a spinning tool to push two sheets of metal into each other, stirring the metals together without melting either base metal plate. ONE Aviation officials call the process faster and more rigid than heat-based welding.

The IMTS exhibit shows the aircraft’s delivery paint scheme on its left side and a revealing “X-ray view” of systems below the skin on the right. Visitors may sit in the aircraft’s cockpit and experience the cabin found on production models of this 5-passenger, twin-engine personal jet. www.oneaviation.aero

Medical

Pushing the medical industry toward growth, to support an aging population, are the latest medical tools and devices. Today’s Technical Center will display the industry’s most advanced precision instruments that underpin technology innovation in this sector. Explore the materials and tools used to optimally manufacture these medical devices and learn what elements are shifting in the medical industry to adapt to a world of connected devices. Knee, hip, and shoulder implants will be featured in addition to stents, pacemakers, defibrillators, bone screws, plates, and other durable equipment.

Miles 4 Manufacturing

Returning to IMTS for its third time is GIE Media’s Miles for Manufacturing (M4M) 5K Run/Walk, taking place on Wed., Sept. 12, 2018 at 6:30 a.m. M4M, which debuted at IMTS 2014, is an excellent opportunity to get moving while benefiting manufacturing education! The recipient schools prepare young men and women for success in life-long learning and work by providing customized programs in selected career pathways based on their interests, offering programs in CNC machining, CAD, and welding, along with courses in automotive repair and computer design.

Motor Vehicle

Fiat Chrysler Automobiles (FCA) is radically reshaping two of its best-selling vehicles to meet new lightweight standards. The 2018 Jeep Wrangler updates the iconic SUV, using ultra-high-strength steel alloys for the frame and aluminum doors, rear gates, and hoods – improving fuel economy without sacrificing the Wrangler’s off-road dominance.

The 2019 Ram 1500 pickup goes down the same path – heavy use of the toughest-to-process steel on the market, coupled with some aluminum exterior components. The truck can tow and haul more while improving fuel economy. The vehicle also integrates safety systems into its design, hiding camera, Lidar, laser, and other systems, keeping sensors safe from road conditions. www.jeep.com; www.ramtrucks.com