Aluminium vs. Steel - (2) Automobile Industry needs an Aluminium revolution!

Read our previous post on Aluminium vs. Steel here

Let's move on to the benefits of integrating aluminium into the cars of today. 

A car made out of a maximum aluminium instead of steel will engender a larger positive impact on the environment leading to lesser dangerous emission. 

Although at the raw material and production of the metal cannot be isolated with high energy consumption and Green House Gas emissions, in the Total Lifecycle of the metal, it has far less impact than steel because of its light-weight, corrosion resistance and near 100% recyclability. This makes a strong case for why aluminium should keep replacing steel in the automobiles.

Tesla uses 3 layers of protection in its cars – layers of aluminium and titanium. 

• This combination can literally crush concrete and let the driver manoeuvre the vehicle even when there are steel obstacles on the road. The reason why an aluminium body is superior in safety to a steel one is because when aluminium parts get bent or deformed, the deformation remains localised to the areas of impact while the rest of the body retains the original shape, ensuring safety for the passenger compartment. 

Tesla Model S

Tesla’s Model S has an entirely aluminium body which gives it a superior range than a steel made body.

The argument that the steel producers make to uphold the steel dominance in the automobile industry is that -

• Only 9% of the weight of the car comprises of aluminium compared to 55% for steel. 
• Also, worldwide, around 190 million tonnes of steel products per year are used, compared to the meagre 11 million tonnes of aluminium products (according to 2015 data). 

To this, the aluminium sector has responded by saying that there is a limit to their product development. Beyond a threshold, steel cannot be made thinner and stronger than aluminium. This can be supported by the consistent use of aluminium alloys like the 5 and 6 series which have a high tensile strength, usually four times greater than traditional steel. 

Although these alloys are costlier to produce, the ROI on such a material is far greater when evaluated on the Total Lifecycle Assessment. For example, the 7 series aluminium alloys are engineered to withstand extreme weather conditions and is mostly used in the aerospace industry due to its high cost.

Today, aluminium is mostly found in engine parts, auto hoods and trunk lids. This is soon going to change in the future. 

• It is estimated that by within a decade, 75% of pickup-truck body parts, doors, hoods and lift gates, 22% of SUVs, 24% of large sedans and 18% of minivan body and closure parts will involve the use of aluminium. 
• This might even improve the fuel efficiency of the vehicles to as much as 90% given the drastic weight reduction it can provide thanks to treated aluminium sheets, extrusions and high pressure die castings. 

Find out about aluminium usage in Jaguar – Land Rover cars

Industry fact: 

The aluminium industry is becoming more aggressive in its pursuit of automotive business. In fact, General Motors Corp. recently inked an innovative 10-year, multi-billion dollar agreement to buy aluminium at predictable prices and co-develop new applications with Alcan Aluminum. It also agreed to buy more than $1 billion worth of recycled aluminium over 13 years from another supplier.

However, Aluminium is not without its own set of challenges. 

• Implementing aluminium into production for automotive parts is less of a motivation or mass manufacturers right now. The following are a few reasons which might be a bit of a hindrance for low-cost cars right now:
• Aluminium’s property of forming an oxide layer on its surface complicates many welding and finishing processes. This is unlike steel which can be readily welded to rectify the damage.
• Sheets made from aluminium are especially difficult to form and fasten, compared to sheet steels.
• Low-volume vehicles such as sports cars and heavy trucks are the ones which use a lot of the metal. It is due to the high cost of production of the metal right now.

Aluminium is a fickle metal to bend on the assembly line, and its quirky metallurgy could mean that body shops will have a tough time replacing bashed-in sheet metal. Mostly, it’s a lack of experience with the material which is causing many operational inefficiencies.

So, is there a threat to aluminium before we even embark on replacing it with steel? Far from it! More research on the metal in the finished form and its application in the downstream is needed to maximise the use of the ‘The Metal of the Future’ in the automobile industry. If the high-end sports car manufacturers see a point in manufacturing their engineering pièce de résistance with aluminium, then why can’t it become available for the mid to premium level cars at an economical price? 

With sturdy and inexpensive carbon fibre, nanosteel and other thermoplastics coming into the picture sooner than later, aluminium manufacturers have got to gear up for the next revolution in the automotive industry -  the Aluminium Revolution.