Additive for Automotive

When will additive manufacturing be ready for high-volume production?

Whether you call it “3D printing,” “additive manufacturing” or any of its many process- or material-based subsets (rapid prototyping, fused deposition modeling, direct metal laser melting, etc.), there is no denying the technologies are coming on strong. Consulting firm IDC says global spending on 3D printers, both desktop and industrial, hit about $11-billion last year and is forecast to reach $27 billion by 2019. Local Motors (localmotors.com), the company that makes extensive use of additive in building cars, quotes another research company (MarketsandMarkets; marketsandmarkets.com) that says 3D printing will experience a 30 percent compound annual growth and reach $30-billion by 2022.

The American National Standards Institute (ANSI) has held a kickoff meeting with America Makes (Youngstown, OH) to start establishing additive manufacturing standards. How and where will all this activity impact automotive manufacturing? Is 3D printing ready for the high-volume primetime?

In its April 2016 study, “3D Printing Comes of Age in U.S. Industrial Manufacturing,” Price Waterhouse Coopers (pwc.com) says the process will go high volume soon. Compared to two years ago, more manufacturers (52 percent this year compared to 38 percent in 2014) expect 3D printing to be used in high-volume production in the next three to five years. And where in the 2014 survey, 47 percent cited quality of the final product as the most commonly cited barrier to adopting 3D printing, that figure dropped to 33 percent in the current survey. Now the most-cited barrier is where to find the talent.

Equipment technology providers are sharing, if not driving, the enthusiasm. Andrew Snow, vice president of Electro Optical Systems (EOS; eos.com), cites an automotive connection in the company’s origins in Germany with BMW’s R&D department, where it worked developing resin-based stereolithography (SLA) equipment in the early 1990s. EOS also pioneered direct metal laser sintering, or 3D metal printing, over the same period.

The emergence of high-output, high-quality fiber lasers led to processing a whole new suite of metal powders, including aluminums, stainless steels, cobalt chromes and titaniums, Snow says. “We began selling equipment for low-volume production parts such as gear shifters and gas pedals in Formula One cars, where lightweighting is paramount,” he says.

“The automotive industry has been using 3D printing since its infancy,” confirms Brandy Badami, business development manager at Roush (roush.com). “Automotive OEMs are truly embracing additive manufacturing more than we think. Although 3D printing is not yet suitable for their high-volume demands, they are constantly pushing the limits of the technology, allowing them to propel on innovation. Using 3D printing, engineers can design, print and test components designed with one of their biggest challenges in mind, weight reduction. This allows for quick-turn creativity that can provide a competitive edge with first-to-market product.”

Typically, 3D-printed polymer components are less expensive and quicker to build than metal components, she continues. “Using FDM, PolyJet, SLA and/or SLS technologies during the design phase provides a more cost-effective option, while still allowing for fit and function uses. Using FDM, you’re open to real thermoplastics like ABS and Ultem. You can 3D print production-quality parts using the actual production-quality material. It’s a huge advantage for lower-volume components. 3D metal printing obviously gives you the most flexibility with providing an end-use part, much like a casting. Brackets, housings and engine components are commonly printed in metal. Metal 3D printing also allows engineers to focus again on light-weighting with hollowing out parts, or creating cooling channels in molds that cannot be machined traditionally.” 

(It is notable that 3D printing can result in more molded, not printed parts. The process allows cooling channels to be produced in molds tailored precisely to the part shape and surface. This means improved thermal management, which means the less temperature difference a part has over its surface during molding, the more it will hold its shape. In addition to reduced warp and eliminating hot and cold spots, more uniform temperature means a much shorter cooling cycle.)

In order to meet the high-volume production demands for automotive, 3D printing machines need to get much bigger and much faster. “Why the technology works so well in aerospace is their volumes are in the hundreds or thousands, where in automotive, we’re talking millions,” says Badami. “The hot targets are going to be the ones that make the most sense either with weight reduction, fuel efficiency or structural design.”

Mythbusting
It’s important to note that 3D printing is not a totally disruptive proposal. While sales brochures may infer otherwise, there is still a significant amount of part post-processing, including grinding, finishing, EDM and even traditional milling and turning. Methods 3D, a newly formed group of Methods Machine Tools (methodsmachine.com), is implementing design strategies to combat these challenges by actively practicing Design for Additive Manufacturing (DFAM) techniques. By combining the best capabilities of both additive and traditional manufacturing, many of these challenges such as powder removal, fixturing and tool holding, surface finishing and finish machining can be alleviated. During concept development, cavities and passageways are incorporated to allow for un-melted powder removal during post-processing. Support structures are tailored that double as transfer fixtures for secondary machining operation such as a 5-axis CNC or lathes. 

Machining center builders also are responding with hybrid machines incorporating laser ablation additive manufacturing capabilities. The Integrex i-400AM Hybrid from Mazak (mazak.com) has dual laser cladding heads stored in the tool magazine to melt metal powders and either grow near-net-shape forms or add new part features in a material harder or lighter than the parent workpiece material. With the Lasertec 4300 3-D from DMG MORI (us.dmgmori.com), up to five laser and metal powder deposition heads can be docked in the tool magazine. Components can be built up in several steps and milling can function in areas that were previously impossible to reach. 

From engineering resins to titaniums, from production parts to circuit boards, 3D printing will be finding its way on board the vehicles of the near future.