Despite steel producers’ best endeavors, aluminum continues to make inroads into the industry’s previously unassailable position as construction material of choice for the automotive industry.
Stronger and, hence, thinner grades of steel allow automotive body formers to find new applications for steel where aluminum seemed like the obvious choice. However, at best this is slowing the uptake of the light metal, not turning the situation around.
Novelis’ announcement that it is bringing its automotive alloy Advanz 6HF – e/s200 to North America after successful development and uptake in Europe only re-enforces the impression that both steel and aluminum producers are innovating and investing like mad — but aluminum is gradually winning market share.
And it is not hard to see why. Aluminum has lower mechanical properties than steel when compared on samples of the same thickness, but has the far lower weight, 2.7g/cm3, compared to 7.85g/cm3. This means thicker sections or parts can be formed while still achieving substantial weight gains.
Novelis Advanz 6HF – e/s200 is one of a range of alloys the firm has developed broadly based on the 6000 series with careful control of alloying elements and production giving enhanced properties. But in some applications producers have developed 7000 series alloys as used by the aerospace industry in aircraft wings and bodies to achieve even higher properties.
7000 series alloys are harder to form and more expensive but have even higher mechanical properties — circa 600MPa compared to circa 300Mpa for 6000 series — and allow automakers to achieve better weight gains. In an Aleris presentation, the company illustrated how the use of 3.5 millimeter thick 7000 series alloy in the manufacture of B pillars achieved the same safety crash performance as 2 mm boron UHS steel, but resulted in a 40% weight saving.
As if to reinforce Novelis’ announcement, competitor Aleris has just opened its new $400 million auto body sheet production centre in Lewisport, Kentucky, and started delivering product to customers. Like Novelis, the firm uses primarily scrap as its feedstock, boosting its green credentials. Aleris produces a range of proprietary alloy grades with enhanced properties over common 6061 grades specifically tailored for a variety of automotive applications. The 6000 series is the industry’s grade family of choice, as they sit comfortably between cheaper and less strong 5000 series and stronger but more expensive (and often harder to form) 7000 series.
In Europe, manufacturers like Audi are going Body in White — meaning the whole structural body shell, plus closing panels like hood, trunk and doors, as wholly or largely in aluminum.
Not surprisingly, this is more at the premium end of the market, where the pressure to improve fuel economy from larger engines is greatest and where higher margins can more readily absorb the cost of using aluminum.
But you do not need deep research to show the direction — Repair and Drive in a recent article quoted a Ducker Worldwide study that predicted that aluminum doors will have gone from virtually zero use as a material in 2014 to 25% of the North American fleet in 2020.
Underlining how rapid the uptake is underway, the consulting firm also estimated 71% of hoods would be aluminum by 2020, up from 50% in 2015, and bumper beams would grow from 33% aluminum in 2015 to 54% in 2020, the article explained.
The current administration’s adverse reaction to broader climate change policies is not the issue here. Automotive is a global business and U.S. manufacturers need to be at the forefront of design and material use to maintain their global positions. The legislation for ever higher fuel efficiency is going to remain a relentless one-way dynamic, encouraging automotive construction to use ever lighter materials and aluminum producers to continue to innovate with alloys and production processes to meet the industry’s demand.
For now, the focus is on improved 6000 series; in time, more components will justify the use of 7000 series alloys. Either way, the industry has shown it is willing to spend big bucks to stay in what is proving to be a very lucrative race.