Explanation
A bar of aluminium caused a real stir at the 1855 World Exhibition in Paris. This 'malleable silver' was admired like a priceless rarity. We now know that, after oxygen and silicon, aluminium is the third most common element in the Earth’s crust. It comes from a red sedimentary rock first discovered at Les Baux in France and thenceforth known as bauxite ore.

When aluminium is first extracted, it has to be said that rather a lot of energy is consumed. But this is more than made up for by the way the material performs when it is worked, used and, above all, recycled. Almost 95 per cent less energy is used at the reprocessing stage than during the initial extraction process.

And the wonder of aluminium is that it can be reprocessed over and over again without any of it being lost. This lightweight amongst metals is pleasant to the touch, primarily because it is particularly good at adapting to environmental temperatures.

In the mid-1990s, we at FSB launched the 'Hard Aluminium' project. We were intent on giving the material we had been using at our company for over 50 years a boost. Whilst aluminium had become steadily more popular in some manufacturing sectors – e.g. the motor-car, furniture and luminaire industries – in the architectural hardware trade it had been increasingly losing out to stainless steel.

We started by asking ourselves what might lie at the root of this trend. We concluded that users were unhappy with the way the material tends to reveal traces of use. Evidently, there was no wish to allow door handles to age gracefully, getting 'wrinkles' and all. We decided to remedy this alleged drawback in such a wonderful material by dabbling in a spot of rejuvenation.

Our research work extended over several years and took a very exciting course. Ultimately, we found ourselves on the trail of nothing less than the secret of the elements that go to make up aluminium, this means magnesium, iron, copper, zinc, titanium, manganese, nickel and silicon.

In keeping with standard practice in the industry, in the past we had used primary aluminium with a relatively high share of magnesium. And, by substituting magnesium with another material, this is precisely where we determined to take action. But which material was it to be?

After much testing we opted for the significantly harder silicon. The outcome vindicated our decision, since the surface of the new alloy had the radiant grey colouring of quartz. We were so taken with it that we changed the project’s title from 'Hard Aluminium' to 'AluGrey'.

Those amongst our friends in business who are of a scientific inclination may be curious to know how swapping an alloy’s constituents can lead to it becoming 50 % harder (giving it a Brinell hardness of approx. 75-80). If so, please note the comparative analysis of silicon and magnesium set out below.

      Silicon (from the Latin silex = pebble) is a chemical element belonging to the fourth
        principal group in the periodic fable under which metal elements are grouped, whereas
        magnesium belongs to the second principal group, referred to as the alkaline earth group.

      Silicon is extracted from quartz and accounts for more than 20 per cent of the constitution         of our planet. Magnesium, by contrast, is extracted from anhydrous magnesium chloride
        using a complex technique known as igneous electrolysis and makes up less than two
        per cent of the Earth’s crust.

      Silicon crystallises into a dark grey diamond structure that is hard and brittle. Magnesium,
        by contrast, is a lightweight silvery metal that is very reactive and ductile.

      Silicon only melts at above 1,400° Centigrade, unlike magnesium, which only requires
        upwards of 500° Centigrade.

Pictures often speak louder than words, as they say. Which is why you will find below a microscopic sectional image of the sturdy structural make-up of AluGrey.

It can be clearly seen that the bright aluminium base and the grey silicon matter both occupy about 50 per cent of the overall area. As the two constituents solidify, the silicon claws its way into the aluminium in an allpervasive branching action.

Those in the know speak of eutectic mixtures and dendritic formations here. We at FSB are convinced that our probings have revived the traditional material of aluminium and given it the necessary hardness for its new lease of life.

The lively grey, crystalline texture of the surface is full of subtle fluctuations, making every piece virtually a one-off design. The silvery grey colour achieved through the anodisation process imbues fittings with a very distinctive character whilst the material’s enhanced hardness significantly improves their use value. The metal’s deeper texturing is externalised in the form of mottling and 'pigmentation' effects. The silvery grey of the hardware creates a charming contrast to the face of the door.

Roses and accessories are identical in colour to the main castings. The anodised coating is at least 20 µm thick. And so the final verdict is that a new, harder alloy has rendered our handsome hand tools for operating doors and windows even better suited to their purpose.