Magnesio y sus aleaciones

VALERI CONSULENZA INDUSTRIALE
d i Gu a l t i e ro A. N. Va l e r i
VALERI INDUSTRIELLE BERATUNG - VALERI C ONSULTATION INDUSTRIELLE VALERI INDUSTRIAL CONSULTING - VALERI ASESORAMIENTO INDUSTRIAL

Via Besso, 59 – P.O. Box 729 - 6903 Lugano (CH)
phone +41/91/960 05 60÷61 - fax +41/91/960 05 62 e-mail: valeri@valericonsulenza.eu Web: www.vale riconsulenza.eu

MAGNESIUM AD ITS ALLOYS: AMATERIAL FOR THE XXI CENTURY ENGINEERING INDUSTRY
Symposium “Magnesium and Motorsport”, Modena, october 14, 2009 Gualtiero A.N. Valeri – Valeri consulenza Industriale, Lugano
President of Montevenda Engineering International Association, Foundation for Development of Ethical Engineering, Lugano

Magnesium is not a new metal: its oxide was recognized from the beginning of the eighteenth century andcalled “bitter earth”, but I notice in the form of sulphate (“English salt”, or “bitter salt”, or “Epsom salt”) from the seventeenth century, obtained from the mineral springs of Epsom, the first, though, that distinguished him sharply from the calcium oxide by the different solubility of its sulfate was the Scottish chemist Joseph Black (Bordeaux 16/4/1728 † Edinburgh 6/12/1799) in 1755. To get itin metallic form, however, it was not until 1808, when the English chemist Sir Humphrey Davy (Penzance 17/12/1778 † Geneva, 29/5/1829) obtained it by electrolysis, but you have to wait up until 1831 because the French chemist Antoine Alexandre Brutus Bussy (Marseilles, 29/5/1794 † Paris 1/2/1882) prepared as the metal mass compact. Then spent two centuries in his first identification asgalenicals to the extraction of pure metal from its salts: this is due to its low electronegativity (for which high reactivity, strong reducing agent for excellence), which makes its salts are very stable and difficult to break. This high reactivity is also the basis of difficulties for its use as a pure metal or alligator, machine building, for which, as we shall see, although its use may begin in theaviation industry since the days of World War I, only now it begins to look like metal material serviceable for the manufacture of items of mass consumption. Still, the magnesium is not a rare metal, constituting as much as 2.3% by weight of the lithosphere, entering the composition of dolomite (double carbonate of calcium and magnesium, with an average content of magnesium by 43%), contained largequantities in salt deposits of Stassfurt, and in the sea water which has an average content of 1.37%. It is therefore the eighth most abundant element in Earth's crust. For its extraction are used primarily to dolomite and seawater; obtained oxide, the metal is obtained either electrowinning (with a rather complex process), or by silicotermica.

Gualtiero A.N. Valeri “Magnesium ad its alloys: amaterial for the XXI century engineering industry”, Modena, 14/10/2009

1/4

Magnesium metal, with its density of 1.74 kg/dm3, is the lightest of metals directly employed in construction, it melts at 650°C and has a boiling point of 1,103°C, crystallizes in hexagonal system compact, and this is the main cause of their differences as mechanical properties compared to aluminum, metal chemicallyvery similar, but which crystallizes in face-centered cubic system. Reviewing briefly the history of the use of magnesium as metal buildings, we found a first patent on an technological alloy of magnesium dating back to 1918, filed by Mr. William R. Veazey of Cleveland (Ohio) of Dow Chemical in Midland (Michigan), who obtained a first magnesium alloy technology alligators copper and manganese fora total of 1%. The lightness and the good behavior of the metal even at higher temperatures aluminum stimulating research, and we had in the years following a series of patents of magnesium alloys also very advanced. Its use in the engineering becomes massive when the planes go by the initial structures of wood, metal ones, especially with the Second World War: in 1943 its production was a well...