Metallurgical World

Aviation accounts for 2% of man made CO2 emissions and the manufacture of the aircraft we use to travel around the world is exceedingly wasteful, but when it comes to sustainability, the industry does not have its head in the clouds.

Manufacturers are tackling this problem through the use of advanced jet engines and lightweight materials to reduce emissions, and also 3D printing (or additive manufacturing, as some like to call it) to reduce waste.

A European project called Merlin, which wrapped up in December, brought together some of the biggest players in the industry, such as Rolls Royce, TWI and Fraunhofer, to look into the potential of additive manufacturing in making jet engine parts, particularly a type called laser-metal disposition manufacturing (LMD).

The video above is of an engine casing being made by LMD out of a powdered form of the metal Inconel 718. You can read the case study here.

From the Merlin website, you can see why new manufacturing methods are needed for some aerospace components:

-       To create a 7 tonne high-thrust aeroplane engine, 28 tonnes of high specification, high environmental impact material needs to be processed.

-       Much of the waste material is toxic and carcinogenic

-       A bladed disk, weighing just 90kg, could need 800kg of billet to manufacture. 

It is expected that over the next 20 years, 24,300 new passenger and freight aircraft will be delivered, requiring 60,750 engine deliveries. This means a staggering 1.28 million tonnes of waste will be created.

The materials involved have an estimated average value of £7,480 per tonne giving an overall cost of about £9.57bln worth of waste material, much of which can’t be recycled.

These are truly enormous amounts of waste and underline why new techniques are needed. Enter 3D printing.

According to Merlin, additive manufacturing techniques have the potential to approach zero waste through close to 100% use of the material and the use of recycling within the processes. But the technology still has a long way to go, because as you can imagine, the quality needed for parts in a jet engine is extremely high.