Aluminium Billet, nexAL

Aluminium billet is a semi-finished product, serving as the raw material for the extrusion process. It is manufactured through Direct Chill Casting, a semi-continuous process. In this method, liquid metal enters a cooled mould, initiating solidification from the surface and progressing towards the inner parts of the billet. Once the shell region is formed, the aluminium surface is subsequently cooled through direct water contact. Thus, the entire cross-section of the billet is cooled through a heat transfer mechanism facilitated by water application.

This process continues until the desired length of the billet is achieved. Following this, the billets are transferred to a horizontal line. Initially, a sufficient amount of engineering scrap is cut from both edges of the billet, and an ultrasonic test is conducted to check for any cracks or porosity within the billet. If the results are acceptable, the billets are taken into the homogenisation furnace, a necessary treatment to achieve a homogeneous macro and microstructure. Within the homogenisation furnace, the billets are exposed to high temperatures for a specific duration. Subsequently, they are rapidly cooled to room temperature to attain the required microstructure for the extrusion process.

This life cycle assessment study is conducted for ASAŞ aluminium billet, branded as nexAL. NexAL aluminium billets include a higher portion of post-consumer scrap than usual production and low-carbon primer ingot input. Materials used in the production of the investigated product are shown in the table below. Since all the produced billets are fed to the extrusion lines, no packaging material is considered for the product.