Metal Story: Beryllium (Be) – Space Age Metal
“Beryllium is one of the most remarkable elements of tremendous theoretical and practical significance.
“Mastery of the aire and daring flights of aircraft and ballons are impossible without light metals; and we already foresee that beryllium will arrive to help the current aircraft metals, aluminum and magnesium.
“And then our aircraft will fly with a speed of thousands of kilometres per hour.
“The future belongs to beryllium!
“Geochemists, start looking for new beryllium deposits. Chemists, learn to separate this light metal from its companion, aluminum. Technologists, it is for you to make the lightest alloys that will not sink in water, but will be hard as steel, elastic as rubber, strong as platinum, and eternal as a semiprecious stone.
“Perhaps now these words seem like a fairy-tale. But how many fairy-tales have become reality before our eyes, a part of our daily life, and we forget that only 20 years ago our radio and our talking pictures sounded like a fantastic fairy-tale.”
So wrote Academician A.E. Fersman, the outstanding Soviet scientist who was able to see the true value of beryllium as early as several decades back.
Yes, beryllium is a metal of the future. But at the same time there are few elements in the Periodic Table whose history extends as far into the past as that of beryllium.
…More than 2000 years ago slaves were mining lovely crystals of green stone – emeralds – in the famous mines of Queen Cleopatra in the lifeless desert of Nubia. Caravans of camels shipped the emeralds to the shores of the Red Sea from where they found their way to the palaces of the sovereigns of Europe, and Middle and Far East – Byzantine emperors, Persian shahs, Chinese mandarins and Indian rajahs.
Throughout the ages emeralds have fascinated man with their gorgeous lustre, purity of color and beauty of iridescene (from a deep green, almost dark, to a sparkling, blinding green). The Roman Emperor Nero liked to watch gladiator fights through a large crystal of emeralds.
“Emeralds are green, pure, gay and tender like the spring grass”, wrote the well-known Russian writer A. Kuprin.
With the discovery of America a new page was written in the history of the green stone. In the graves and temples of Mexico, Peru, and Colombia the Spaniards discovered great numbers of large dark-green emeralds. This fantastic treasure was plundered within a few years. For a long time though, they had failed to find the place where the magnificent gem had been mined. It was only in the middle of the 16th century that the conquerors of America were able to uncover the secret of the Incas and find the emerald mines of Colombia.
The Colombia emerald of exceeding beatury ruled the jewelry market until the 19th century. In 1831 Maxim Kozhevnikov, a Ural charcoal burner, found the first Russian emerald while gathering windfallen branches along the tiny river Tokovaya. The large bright-green emeralds of the Urals rapidly gained recognition among jewellers throughout the world.
The emerald is one of many beryllium minerals. The bluish-green, seawater-colored aquamarine and the rose-colored vorybyevite, the wine-yellow heliodor and the yellowish-green, snake-colored beryl, phenakite of the color of the purest water and the delicate blue euclase, the transparent green chrysoberyl and its astonishing variety alexandrite which is deep green by day and crimson in artificial light (“green morning and blood-red night”, as the Russian writer N. Leskov described it) – these are only some, but perhaps, the most esteemed members of the family of beryllium gems.
Lately it has been reported in newpapers more and more often that geologists are assisted by … dogs in their search for minerals. The ability of out four-legged friends to find something by smell has been known since long ago, but what about their “geological talent”? What minerals can the shaggy “oreseekers” discover? This is what the initiator of the new trend in geological prospecting G.A. Vasilyev, Doctor of Science (Biology), has to say about it: “We are helped in this question by the collection of the Mineralogical Museum of the USSR Academy of Sciences. Our experiment with beryllium metal was particularly successful. The dog Gilda sniffed this mineral and then was offered a whole collection of minerals among which to look for it. Gilda chose emerald, aquamarine, vorobyevite, phenakite and bertrandite, that is, only the minerals containing beryllium. Then we again placed the beryllium-containing minerals among another specimens and after the dog had been through finding them once more, we again asked her to look. Gilda made a round of the museum then put her paws on the case in which a huge emerald was exhibited and barked.”
Of all the beryllium-containing minerals only beryl is of industrial value. Gigantic crystals of beryl occur naturally. They may weigh tens, hundreds or even thousands of kilograms. One of the biggest crystals known is nearly 9 metres long.
A crystal one and a half metres long is on display at the Leningrad Mining Museum. During the 1942 blockade a shell went through the museum roof and exploded in the main hall. The crystal was damaged severely by the splinters and it could hardly be expected that it would ever be on display again. But a few years ago it was restored through painstaking efforts of the restorers. At present two rusty shell splinters imbedded in the thick plastic glass plate on which the crystal rests and a note telling about its history are the only things that remind us of the “surgery” which the crystal had to go through.
It is not surprising that the beautiful beryllium gems have always attracted not only lovers of precious stones but also chemists.
In the 18th century, when the element which is now placed in the Periodic Table under the number 4 was still unknown to science, many scientists attempted to analyze beryl, however no one could detect the new metal contained in it. It looked like the element was hiding behind the back of aluminum and its compounds – its properties were strikingly similar to those of aluminum. But there were also differences. And the first who was able to note them was the French chemist Nicolas Louis Vauquelin. On the 26th of Pluviose of the fourth year of the French revolutionary calendar (i.e. 15 February, 1789) at a conference of the French Academy, Vauquelin gave a sensational report that beryl and emerald contained a new “earth” different in its properties from alumina or aluminum oxide. Vauquelin proposed to name the discovered element “glucinium” owing to the sweetish taste of its salts (in Greek “glykys” means sweet). Now this name is retained only in France, while in other countries the name “beryllium” proposed by the well-known chemists M. Klaproth and A. Ekeberg is used.
The similarity of beryllium and aluminum caused quite a bit of trouble to the author of the periodic law Dmitry Mendeleyev. The fact is that precisely because of this similarity, in the middle of the 19th century beryllium was considered to be a trivalent metal with an atomic weight of 13.5 and, consequently, should have occupied in the table a place between carbon and nirtogen. This introduced obvious confusion in the regular change of properties of elements and brought under doubt the correctness of the periodic law. Medeleyev, convinced that he was right, asserted that the atomic weight of beryllium had been incorrectly determined, that the element was not trivalent but divalent and possessed the properties of magnesium. On the basis of this he places beryllium in the secound group, having corrected its atomic weight to 9. Soon the Swedish chemists L. Nilson and O. Pertersson who had been convinced of the trivalency of beryllium, had to confirm Mendeleyev’s view: their careful investigations showed that the atomic weight of beryllium was 9.1. Thus one of the fundamental chemical laws triumphed owing to beryllium, “violator of the peace” in the Periodic Table.
The fate of beryllium in many respects is similar to the face of its fellow metals. It was isolated in the free form in 1928 by F. Wohler and A. Bussy, but only seven decades later was the French scientist P. Lebeau albe to obtain pure metallic beryllium by electrolysis of fused salts. It is no wonder that even at the beginning of this century chemical handbooks categorically accused beryllium of being a “sponger”, asserting that “it has no practical use”.
The rapid development of science and technology which has marked the 20th century compelled chemists to reexamine this obviously unwarranted “verdict”. A study of pure beryllium has demonstrated that is possesses many valuable properties.
Being one of the lightest metals, beryllium at the same time is remarkably strong, stronger than structural steels. Moreover, it has an appreciably higher melting point than magnesium and aluminum. This furtunate combination of properties makes beryllium one of the basic aircraft materials today. Aircraft parts made of beryllium are one and a half times lighter than those made of aluminum.
Excellent thermal conductivity, high heat capacity, and heat resistance make it possible to use beryllium and its compounds in space engineering as a heat-protective material. According to American press reports, the nose cone and floor of the cabin of the Friendship-7 spacecraft, on which John Glenn made his orbital flight, were manufactured from beryllium.
Parts made from beryllium are capable of maintaining high precision and stability of dimensions and are used in gyroscopes, instruments of the orientation and stabilization systems installed on rockets, spacecraft and artificial earth satellites.
There is yet another property of beryllium which makes it promising in space engineering: while burning it releases colossal amounts of heat – 15000 kcal per kilogram. Thus, it may well be used in highly efficient propellants for flights to the Moon and other celestial bodies.
Alloys of beryllium with copper – beryllium bronzes – are widely used in aviation for the manufacture of many elements requiring high strength, good resistance to fatigue and corrosion, retention of elasticity in a wide temperature range and high electrical and thermal conductivities. It has been calculated that in a modern heavy aeroplane more than 1000 parts are made of these alloys. Thanks to its elastic properties, beryllium bronze serves as an excellent spring material. Springs made from it are practically unaffected by fatigue, being capable of withstanding up to 20 000 000 load cycles.
Incidentally, a curious episode from the history of the Second Wolrd War is connected with springs. Germany’s industry was cut off from the main source of beryllium raw material. The world extraction of this valuable strategic metal was almost wholly in the hands of the USA. The Germans resorted tu cunning. They decided to use neutral Switzerland to smuggle beryllium bronze: an order was sent to American companies from Swiss “watchmakers” fur such a quantity of beryllium bronze that it would be sufficient to supply the entire world with watch springs for 500 years to come. True, the ruse was discovered, but nevertheless springs made of beryllium bronze appeared from time to time in the latest models of rapid-firing aircraft machine guns delivered to Hitler’s army.
Fatigue is one of the “occupational diseases” of many metals and alloys which gradually disintegrate, unable to steel of even a small quantity of beryllium makes this disease vanish as if by a wave of a wand. While automobile springs break after 800-850000 impacts, they can withstand 14 million impacts without a sign of fatigue after “vitamin Be” has been introduced to the steel from which they are made.
Unlike steel, beryllium bronze does not spark when hit on stone or metal. That is why it is indispensable for making tools used in explosion-hazard work in mines, at powder factories and oil dumps.
Beryllium strongly affects the properties of magnesium. The addition of only 0.01% of beryllium prevents magnesium alloys from igniting during casting (i.e. at a temperature of something like 700 degree Celcius). It also drastically reduces the corrosive properties of alloys both in the air and in water.
Alloys of beryllium with lithium are evidently to play an important role in the future. It is very likely that the union of these two lightest metals will result in the creation of alloys that will not sink in water.
Beryllium is also an excellent steel deoxidizer, although it is, unfortunately, still too expensive. Metallurgists have found yet another important use for beryllium. Saturation of the surface of steel parts with this metal (beryllization) substanitally increase their hardness, strength and wear resistance.
X-ray technicians are also favourably disposed to beryllium, since it transmits X-ray better than any other metal stable in the air. Now the “windows” for X-ray tubes are made from it throughout the world. The transperancy of such “windows” is by a factor of 17 higher than that of aluminum previously used for this purpose.
Beryllium has played a remarkable role in the development of the atomic structure theory. While bombarding beryllium with alpha-particles, the German physicists V. Bothe and G. Becker discovered the so-called “beryllium radiation”, which was very weak but possessed a very appreciable penetrating alibity: it went throught a layer of lead several centimetres thick. In 1932 the British scientist Sir James Chadwick established the nature of this radiation as being a flux of electrically neutral particles, each with a mass approximately that of the proton. The new articles were given the name “neutrons”.
The absence of an electric charge enables the neutrons easily to become imbedded in the nuclei of other elements. Owing to this property, the neutron has become a most effective “shell” of the atomic artillery. Today neutron guns are extensively used to trigger off nuclear reactions.
The study of the atomic structure of beryllium has shown that it is characterized by a small neutron-capture coss-section and a large scattering factor. Beryllium scatters neutrons, changes their direction and slows down their speed to values where chain reactions proceed more effectively. Beryllium is considered to be the best of all hard materials in showing down the neutrons. It is also an excellent neutron reflector returning neutrons to the active zone of the reactor and preventing their leakage. It likewise possesses a high radiation resistance, a property it retains even at very high temperatures. All these remarkable properties make beryllium an essential element in atomic engineering.
The “sound transmitting” ability of beryllium is doubtlessly of internest to science. The velocity of sound is 330 metres per second in the air and 145 metres per second in water. In beryllium it is the record-breaking 12500 metres per second.
Beryllium oxide too has many valuable properties. The high refractoriness (melting point 2570 degree Celcius), appreciable chemical resistance and high thermal conductivity explain the use of this material to line induction furnaces and to manufacture crucibles for melting metals and alloys. Thus, crucibles of beryllium oxide are used in a vacuum for melting beryllium, which absolutely does not react with them. This oxide is tha basic material for fuel-element jackets of atomic reactors.
The heat-insulating properties of beryllium will probably be used in the study of the deep-lying layers of our planets. A project has been initiated to take a mantle sounding at a depth of 32 kilometres by means of the so-called “atomic needle” which is a miniature atomic reactor in a beryllium oxide casing.
The prophetic words of the remarkable scientist and dreamer A.E. Fersman have come true. Beryllium has needed quite little time to justify the hopes places on it. From a little-known rare element it has become one of the most important metals of the 20th century.
Source: Tales About Metals, S. Venetsky