For the majority of us the word “metallurgy” is associated with the image of a smoky workshop where rough men, wearing heavy overalls and black safety glasses, make steel in open-hearth furnaces. However it is a thing of the past of metallurgy. It has made a giant leap over the last fifty years and has undoubtedly become one of the pillars of modern scientific and technical progress. We will tell you how closely our life and future are linked with the successes of metallurgy.
It is often hard for us to imagine how densely we are surrounded by devices based upon the cutting-edge achievements of metallurgical science. We are used to household appliances, handy equipment, without giving a thought to what makes them operate.
However, no computers, automobiles, household equipment could exist without the achievements of metallurgists who learnt not only to obtain necessary metals from ore, but to make alloys with the desired properties out of them. They are universally used today. For instance, let us take the modern symbols of progress – a tablet and a smartphone. They would not exist without progress made in metallurgy which made it possible to manufacture electronics with the use of such rare metals as indium and gallium.
Electronics requires very clean metals; the same indium is present in minerals in rather small quantities – only fractions of a percent. To clean metal of any impurities of the so-called refinement, we presently use such methods which were unfamiliar to the fathers of modern metallurgist, for instance, zone melting. With this method metal is melted partially, not completely, is a special melting pot which resembles an Indian pirogue. The melting zone is shifted along the pot, so are the impurity metals with it. It is not surprising that the global production of such precious metal is rather limited – approximately 700 tons per year. Metallurgists have a vast field of activity related to the production of metals and alloys for the needs of the automobile industry. Not only are modern cars packed full of electronics, but their engines and bodies are also associated with the successes of metallurgy.
For instance, the body of a car made out of an ordinary iron sheet. It is inevitably apt to corrosion, i.e. a process of connecting iron atoms with atmospheric oxygen atoms. We can naturally produce steel which will not rust, but the price of such a car will increase by far. The body of a car is therefore protected with a layer of zinc. This way metal rusts slower, and the car can be used for a longer period of time.
Any car has an electric generator and electric engines which means that copper, which is called “the pillar of electrical engineering”, is used there. Copper is a great conduit of current; it is slightly inferior to silver, but superior to gold. Copper wires are therefore the best solution for electrical wiring, electrical coils of generators and electric engines. As the popularity of electric cars grows, so does the global consumption of copper (pure copper moreover)
There is another metal which is closely tied with the world of electricity – aluminum. Its electrical conductivity is approximately 60% of the electrical conductivity of copper which is not bad since the electrical conductivity of pure iron is only 1/6 of that of copper. Aluminum is also often used as a material for wires, but apart from that it is a perfect construction material, including as part of alloys for a great many of devices.
Alloys are solid mixtures of chemical elements, principally metals. Modern metallurgy has created more than 5 thousand different alloys, and this list is constantly expanding.
Bronze is one of the oldest alloys in the history of mankind. Initially the alloy of copper and tin was called bronze. However nowadays one speaks about “bronzes”, i.e. a whole family of copper alloys with aluminum, lead, beryllium, silicon and other elements. Bronze is a beautiful alloy which is adored by sculptors and designers.
By the way, it can be found in your clock, home barometer and wearing pieces of a car. But bronze is more commonly used in large industrial machinery, which we will discuss later.
There is another famous copper alloy – latten, an alloy of copper with zinc, which is a classic material for the production of high-quality water fittings.
Aluminum alloys with copper, zinc, magnesium, manganese and other elements compose the parts of engines in our cars, frames of household applications, bodies of electric engines and many other useful things. They barely differ in appearance, but there is a difference in the way they are used.
When we take the bodies of good photo cameras, lens, other optics, we see magnesium alloys. When we drive our cars at high speed, the lightness of our riding is ensured by special alloys out of which bearings are made. A press iron and an electric kettle are heated with the help of a coil made of the alloy of nickel and chrome; there is a tungsten piece of wire that shines in filament lamps, while semiconductors, which are based upon the compounds of the same indium, gallium, aluminum and zinc, glow in ultramodern LED lamps.