Classic materials won’t be replaced

Departments - Editor’s Page

June 14, 2021

Robert Schoenberger Editor ||

Throwing together sawdust and other wood byproducts, Desktop Metal startup subsidiary Forust figured out how to make wooden products on 3D printers, complete with aesthetically pleasing grain patterns. Luxury cars and other products could soon feature printed wood inlays or other trim components without the need for artisans to craft such pieces from felled trees.

Most important, though, is the ecological cost. Deforestation is a global issue, so any technology that reduces the need for virgin hardwood is welcome. Forust’s process uses wood waste products, reducing garbage at landfills while creating something of value. Like everything in the additive manufacturing (AM) world, a big focus will be scale. If Desktop Metal and Forust can print materials quickly and affordably, wood inserts may become standard features on dashboards and instrument panels again.

Future automotive designers can program grain patterns into the products, similar to how they use laser etching to create faux leather patterns in dashboard vinyl coverings. Don’t be surprised if a future Porsche features door panel decorative inserts that magically seem to have the company’s logo grown into the wood grain.

Even with new technologies, wood won’t become a primary material in future vehicles. Between safety regulations, manufacturability, cost, and performance, steel will be the go-to material for generations of vehicles to come (see Infographic). Yet high-tech advancements in the world’s original building material show that the oldest dogs in manufacturing can constantly perform new tricks.

The debate on how quickly aluminum and other lightweight materials would replace steel in cars began in the early 1920s and hasn’t let up since. Steel was invented nearly 4,000 years ago while aluminum wasn’t even discovered until 1825 and wasn’t commercially viable until the late 1880s. How could a nearly prehistoric metal compete against this hotshot newcomer with its lower weight? Pretty darned well, it turns out.

Steel producers examined the competition decades ago, and focused on their metal’s strengths: low cost, high formability, easy customization. Sure, aluminum is lighter, but with minor changes to alloy formulae, steel could be made stronger, more ductile, easier to stamp into complex shapes, easier to paint, and resistant to corrosion while maintaining its massive cost advantage.

Steel is heavier, so metallurgists and designers found ways to make steel parts smaller (therefore lighter) without sacrificing crashworthiness or strength. High-strength steel (HSS) and advanced high-strength steel (AHSS) are rapidly replacing mild steel, and those high-tech alloys are keeping aluminum at bay.

As this issue’s Infographic notes, steel continues to hold its own against lighter materials because it continues to adapt to new challenges. Analysts still expect lighter-weight materials to make up larger shares of future vehicles, but they’ve been thinking that for a century, and steel remains king.

As Desktop Metal and Forust are showing, advances in material science aren’t always about polymers or heat-resistant super alloys (HRSAs). Sometimes, it can be about a technology that might lead to a comeback for wood-paneled station wagons.