THE METALLURGY OF ALUMINIUM

Unalloyed metals generally have only few applications while they exhibit very particular properties, these properties are often limited to a very narrow field of application. 

The art of the metallurgist is to create alloys from a given base metal, be it copper, iron or aluminium, etc. by adding controlled amounts of other metals (or metalloids) in order to improve or modify certain properties such as mechanical properties, formability, weldability, etc. This is how, more than 5000 years ago, the most ancient metallurgists discovered that by adding tin to copper, they produced an alloy that was easy to mould and that offered an outstanding resistance to marine corrosion. 

Sainte-Claire DevUle prepared an aluminium alloy containing 10% silicon. The silversmith Charles Cristofle used an alloy containing 2% copper, thus harder and easier to chisel, for the objects that he manufactured in aluminium during the Second Empire. Immediately after the development of electrolysis of molten salts by Heroult in France and Hall in the United States in 1866, metallurgists tried to improve the properties of aluminium such as mechanical resistance, resistance at high temperatures, machinability, corrosion resistance, etc. 

Research and development work carried out for over 100 years on the composition of 

---

Borisoglebsky Y, Galevsky G, Kulagin N. The metallurgy of aluminium (in Russian). Novosibirsk Nauka 1999. 437 p. 

The reader will find the basic principles of the metallurgy of aluminium in this chapter and should refer to specific technical books or catalogues such as Pechiney Rhenalu s catalogue of semi-products, which has been a source of inspiration for Chapters 3 and 4 of Part A of this book. 

France, as is shown in the accompanying map (Fig. 3), is favourably situated for the production of aluminium. The close proximity of the bauxite beds, the alumina works, and the water power necessary for the electro-metallurgy, forms a unique combination, and, in addition, carbon can bo easily conveyed to the works. 

It is worthy of note that the metallurgy of the element titanium is in the same state of development at the present time that aluminium was forty years ago. 

With an annual world consumption of 25 million tons, aluminium is the leader in the metallurgy of non-ferrous metals. The production of aluminium has been increasing steadily since 1950 (see Figure Al). 

With eight series or families, aluminium alloys are very numerous and offer a wide range of compositions, properties and uses. The continuing progress in the metallurgy of... 

The metallurgy of industrial aluminium alloys is, therefore, based on six systems ... 

Strictly speaking, all metals and alloys can be strain hardened. However, in the field of aluminium metallurgy, this designation is used only for alloys of those series that cannot be age-hardened. 

The 8-hydroxyquinoline method was applied for determination of aluminium in plant materials [15,76,77], soil extracts [76], silicate rocks and minerals [2], cast iron and steel [1,8,9,14], nickel- and copper alloys [1], chromium [78], beryllium [79], metallurgy products [80], titanium concentrates [7], and phosphates [81]. 

Metallurgy. — The metals of most of the cerium group elements have been prepared, three general methods having been used t (1) fusion of the anhydrous halides with sodium, potassium, calcium, or aluminium (2) electrolysis of the fused chlorides or of a solution of the oxide in the molten fluoride (3) heating the oxides with magnesium, calcium, or silicon. Reduction with aluminium has also been tried, but it is not satisfactory except possibly for cerium itself. Electrolysis has been the most successful, the other methods usually giving at best an alloy. 

Metallurgy produces gaseous as well as solid exhalates depending on the type of the production and technology used. Fluorine exhalates from aluminium works are very harmful, as also are tars and arsenic compounds. Iron and steel works produce fly ash, its main components being similar to those in the fly ash from coal, only with different abundances (a high... 

---