Aluminium

Aluminium

Aluminium is the specialty of BURAK. Let's introduce the aluminium metal.

A young metal 

There are three main groups of materials. These are metals, ceramics and polymers. In the group of metals, the aluminium is the most abundant metal in the Earth's crust and it is also the third most abundant element. 

As it is not available in pure form and there are difficulties of energy and production to obtain it in pure form, aluminium is a very young metal in spite of being abundant. 

Increased demand for aluminium

  • Energy saving
  • Lightness
  • Easy fabrication
  • Recycling and re-evaluation


Production stage 

After alumina is obtained from the bauxite ore by the process of Bayer, the aluminium is produced by electrolysis of the alumina in the second stage. Cost of the production consisting of these two stages originates from the high energy costs and difficulty of the processes. However, there is another point; aluminium is recyclable.

Let's Give An Example…

Energy required to produce 1 ton of Aluminium from ore is 17000 kwh. However, the energy required to produce aluminium in the same amount from the recycle scrap is only 250 kwh. 

Energy saving 

There is a concept of energy balance equation.

  •     E1: Energy required to produce the material
  •     E2: Energy saving obtained by use of the material


Aluminium is a light metal and ensures fuel (energy) saving on vehicles such as cars. When aluminium alloy is used in producing vehicles, there is a high energy cost in using this alloy. 

Let's get to the better side of the point …

When we purchase a vehicle having an aluminium body, the energy saving we make while using it is higher than the energy spent while producing it. 

E2>E1

We should not neglect it for correct use of the energy resources…

Recycling 

What we call as scrap for the aluminium is not anything other than a loss of production originating from the process conditions or the beverage cans we throw away after consuming the contents of them. Aluminium is a hundred percent recyclable material and it is therefore limitless in terms of resource. In the recycling process, the optimization of the casting parameters and the control of the composition is sufficient for first quality production.

Be assured that aluminium is aluminium all the time … Its scrap contains high value.

30% of the aluminium used is obtained from recycling of the scraps. 70% of the aluminium used in the sectors of electricity, construction and automotive is recycled over and over again. 


A detail …

Recycling of the aluminium beverage cans is 37% in Europe and 66.5% in America. Recycling of the beverage cans is a fast and easy cycle due to their consumption rate; however,  the service life of an aluminium facade system is 50 years in average in parallel with the life of the building on which it is applied and you should wait for long years for recycling of the facade profile.

Considering its contribution to the environment and energy economy, we should encourage recycling of the aluminium beverage cans…

Let's have a look at the general characteristics of the pure aluminium in details…

  • It is the third most abundant element in the Earth's crust.
  • The metal bauxite is its raw material.
  • It is the newest, but most widely used non-ferrous metal.
  • Minerals containing aluminium are quite stable.
  • Physical and chemical characteristics depend on its purity.
  • Terminology by the purity grade:
    • 99%: Low purity
    • 9-99.9%: Commercial purity
    • 99.9-99.95%: Super purity
  • Low density
  • High electrical and thermal conductivity
  • High reflection
  • Excellent corrosion resistance
  • High resistance by alloying
  • Adaptable to the methods of manufacture (casting, plastic forming, welding, machining, surface treatment)
  • Basic impurities in the aluminium of commercial purity are Fe and Si.


Mechanical Characteristics

  • Impurities in the pure aluminium improve tensile strength of the material.
  • Alloying results in obtaining strength equal to high strength steel.

Physical characteristics 

  • Fusion temperature: 660.50
  • Evaporation temperature: 24940
  • Solid density: 2699 kg/m3
  • 7000 density: 2357 kg/m3
  • Expansion factor at 200: 23x10-6/K
  • Thermal conductivity at 250: 237 W/cmK
  • Fusion heat: 397J/g
  • Evaporation heat: 10.8 kJ/g
  • Heat capacity: 0.90 J/gK
  • Atomic and crystal structure Atomic number: 13
  • Atomic weight: 26.98
  • It has different isotopes. Its crystal cage structure is face centered cubic structure.
  • Coordination number is 12.
  • Atomic diameter 2.86x10-6.


Now we are going to explain technically the mechanism which makes us to attain the strength value that we obtain in the alloy 6063 Al-Mg-Si. 

Precipitation mechanism is a three-stage mechanism which effectively functions for the alloy 6063 to attain strength.

  • Solution treatment
  • Rapid cooling
  • Ageing (Thermal)


The first two stages are defined as press thermal process and the foundation of the improved strength is laid at these stages. The ageing stage is defined as thermic in the industry and the final strength is attained at the end of this thermal process.

Mikroyapıda bir örneği halka içerisine alınan siyah partiküller alaşımın kompozisyonu ve gördüğü termomekaniksel işlemler gereği oluşan Mg2Si intermetalik fazıdır. The resulting phase restricts movement of the dislocations charged at times of tension against the plastic deformation and causes formation of new dislocations, leading to the dislocation locking. As a result of interaction of these micro-sized particles with the dislocations at time of charging, we can, by this mechanism, reach the desired strength values in 6063 aluminium alloy.