Previously rejected in favour of cheaper steel, aluminium use in Electric Vehicles (EV) is expected to increase over the next few years as COVID-19 has accelerated the move to a green economic recovery. Despite being three times more expensive than steel, EV makers are increasingly depending on aluminium to make electric car parts. This article will discuss how aluminium castings are increasing in popularity.

Casting is a fundamental technique in the metalworking process and is at the heart of many industries and products throughout the world.  Without castings there would be no cars, aeroplanes, or wind energy turbines. The process involves pouring molten metal (metal that may have been re-processed from scrap into a raw material) into a mould containing a hollow cavity of the desired shape, which is then allowed to solidify.  The solidified part, also known as a casting, is ejected or broken out of the mould to complete the process.

There are many benefits associated with casting parts.  It is possible to transition material thicknesses and add a number of radii that reduce stress giving one of the greatest benefits of aluminium casting over other fabrication methods – its high strength.  Also, once a pattern is approved, each casting produced is the same, where an alternative assembly or fabrication process may introduce variability and dimensional errors.  In the permanent mould process, molten aluminium is poured into a metal mould which cools the metal rapidly.

The automotive industry is the largest market for aluminium castings, with cast products making up more than half of the aluminium used in cars.  The trend of using aluminium to reduce a vehicle’s weight is expected to continue as overall weight becomes even more critical to EV performance and range.  Last year, Tesla developed a new aluminium alloy for die casting of car parts confirming this growing trend.  For the new ‘Model Y’, Tesla CEO Elon Musk has said he will replace 70 components glued and riveted into the car’s rear underbody with a single module made using an aluminium casting machine.

The demand for lightweight structures and weight reduction solutions from Electric Vehicle OEM’s will increase significantly within the next 10 years. Lightweight aluminium cast components are becoming increasingly important as alternatives to steel, and the usage of primary aluminium will be significantly higher than we see in internal combustion engine vehicles today.  Electric vehicles use 25-27% more aluminium than combustion engine cars.

Aluminium castings are lightweight and able to withstand the highest operating temperatures of all die cast alloys.  They are also lighter and more energy efficient to process.

Material type is also crucial when it comes to creating castings for the Military, Defence and Aerospace sectors where vehicles and machinery are often exposed to cold temperatures extremes.  In these industries, Aluminium is well as suited as its strength rises in colder environments without compromising its toughness.

However, whilst much of the aluminium used is mechanically strong, some cast parts are prone to porosity which can make the parts useless especially in fluid or air carrying applications. Sealing porosity in otherwise scrap cast parts has been the focus of Impregnation Services Ltd (based in Greater Manchester) for over 50 years and many manufacturers rely on them for final porosity sealing and quality enhancement in these parts.

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Industry leader Impregnation Services Limited is a casting recovery service provider specialising in impregnation of porous castings and other ferrous and non-ferrous materials.
Talk to us today on 0161 344 1004.