Summary of Our Manufacturing Process

Iskenderler Aluminum Inc. operates the whole aluminum manufacturing processes from cradle (aluminum ingots) to the end operations (delivery and customer service).

The aluminum manufacturing process can be simply described as follows:

The process begins by melting ingots of 100% pure aluminum in a natural gas furnace. It takes 3 to 8 hours to melt 15 tons of aluminum in our free melting furnace operated at 750 degrees Celsius. The fusion temperature of aluminum is 660 degrees Celsius and it can grew up to 671 degrees Celsius by depending on the alloy.

A sample is analyzed in the laboratory using a spectrometer to check the ratio of the ingredients (e.g. silisium) in the mixture, before the casting process. Depending on the laboratory outputs, the ingredients of the molten aluminum alloy is modified. After that, the ingredient ratios are brought to the desired levels in a good agreement. Later, the molten mixture is degassed using nitrogen gas. After the degassing, the slag is removed from the surface of the molten metal. The mixture is now ready to be casted.

Before initiating the casting process, the beds, which carry the molten metals into the permanent molds, are heated up in order to avoid rapid cooling. For the final filtering, a ceramic foam is also used to eliminate impurities.

Döküm esnasında eriyik alüminyum mütemadiyen titanyum diborür ile beslenir. Kalıplarda donmaya başlayan alüminyum asansör sistemi ile bir kuyuya döküm hızında indirilir. Bu aşamada kalıplar ve kütük su ile soğutularak donma süreci hızlandırılır.

Titanium diboride is continuously fed to the molten metal mixture during the casting. The aluminum is carried to four molds simultaneously. When the aluminum reaches to the molds, an elevator continuously descends the molds in a well. During this descending, the molds and the slab are cooled by using water to accelerate the solidification process.

Ingots are unmolded, cut into four pieces and now ready for the milling stage.

The crust removing machine removes the defects and impurities to achieve the perfect smooth finishing. All the traces of the liquid, which are used to cool the decrusting knives, are eliminated. After achieving the perfect surface, slabs are reheated in an oven for homogenizing and annealing purposes as illustrated in the figure below.

After this stage, the thinning process of the ingots begins.
After the hot-rolling process, the cold rolling begins to achieve final thickness. In the subsequent step, the discs are obtained with a blanking press as shown below.

The aluminum is crushed by the hot mill rollers. Angular speed of the mills, the thinning of the ingot, and the temperature of the mills are actively controlled and adjusted by the automated system. Nevertheless, the sensor data and the pressure on the ingot are continually verified by technicians, operators, and quality engineers. The ingot becomes increasingly thinner and longer with each pass through.

The final thickness is varied with respect to the customer demands. After the hot-rolling process, the cold rolling begins to achieve final thickness. In the subsequent step, the discs are obtained with a blanking press as shown below.

When the discs are obtained, they are heated up in an oven and annealed to remove the effects of prior cold working process. Microscopic grain structure comparison of before and after final annealing is also illustrated below.
Grain structure after rolling (left) and annealing (right)
The final products are visually inspected and packaged for shipment.