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From Ancient Oaks to Turbine Blades – it’s a Material World

About 20 years ago I was on the phone to Ken Harris of Cannon Muskegon, who was at that time Vice President, Director of Technology, at this well-known U.S. super-alloy maker. Ken was the materials scientist behind countless alloy patents that revolutionised the world of modern aircraft engines but my aim that day was just to sell rhenium.

The night before, though, there had been a great storm in Michigan and the centuries old oak in Ken’s garden had come crashing down, split in half by the wind. Ken wanted to talk about the tree not rhenium, and used the event to remark upon how rare it was for the wind to be of sufficient force to break an oak.

Oak, he explained to me (the non-materials scientist), has one of the highest tensile strengths of all natural forms. It was one of the reasons the ancient woods of Britain were felled to build ships for the British Navy and supply beams for castles, palaces, churches, barns and homes.

What he was telling me was that here was one of nature’s masterpieces; a broken oak, in a sense mocked by comparison with man’s ingenuity to create a man-made form so many times stronger  – the single crystal turbine blade – the object of Ken’s life’s work.

The usurper, that Ken had done so much to commercialise, is one crystal, selected and grown through a ceramic core into its desired shape; once formed, able to withstand pressures several thousand times greater than the oak, its strength under pressure maintained because of its absence of grain boundaries; with no points of weakness between crystals, and the right mix of elements, an object able to keep its shape at temperatures of 1600°C over many hours. Without those alloys, (containing rhenium!) there would be no engines of equivalent power and thrust to fire up the A380, the Boeing 787 Dreamliner, the F35 or any modern plane.

Perhaps I was guilty of taking both the oak and single crystal for granted? At my school (a school from which 656 of its young sons served and died in the First World War) a propeller blade of oak from an early Royal Flying Corps bi-plane (perhaps a Sopwith Camel) had hung casually from a corridor wall in our boarding house, used for kicking footballs just below it. Today, I would rather wonder at how that particular use of wood held aloft the lives of young airmen.

High pressure turbine blade, grown from a single crystal alloy including they key ingredient of rhenium

So here is an example of the history of materials science – man’s mastery of materials, and materials’ mastery over man – the core reason for our trade, without which we merchants might be rather redundant.

Why, you might ask, should the websites, such as Lord Copper be occupied with such matters? What have algorithmic trades in copper and aluminium to do with people who actually use stuff? Perhaps the only answer to this question is “Precisely”. To be a good metal merchant or broker you really do not need to know too much about the microstructure of metals and their applications. However, if you happen to have an interest, finding out where in the chain our metals contribute to the service of man is illuminating – it has certainly been a hobby of mine for many years and helps to while away the hours or minutes between trades.

If you happen to share this yen, there are lots of ways in which you can pursue this too. One pleasant means is via the host of popular science books on the subject of elements, metals, and materials where wide knowledge is lightly displayed. Books such as ‘The Disappearing Spoon’ (Publ Doubleday 2010), by Sam Kean and subtitled ‘And other True Tales of Madness, Love, and the History of the World from the Periodic Table of Elements’. Another is ‘Seven Elements that have changed the world’(Publ Orion Books 2013) by John Browne (Lord Browne of Maddingly, formerly of BP) or ‘Nature’s Building Blocks’ by John Emsley (Publ Oxford 2001) or Stuff Matters by Mark Miodownik (Publ 2013 and also available in Penguin).

These publications plough a furrow that illuminates the world of materials and metals in a popular way, but, above all, provide an alternative lens through which to see the world –  namely, the lens of science rather than the lens of money.

Today, materials science schools at various universities reach out for this cross-fertilization. This writer could have been knocked down by a feather (a natural material that can flex and twist like carbon fibre) had his younger English Literature self been told 40 years ago he would be invited to give a short talk at the Dept of Materials at Oxford on the subject of rhenium. In a positive example of cross-fertilization, students of the Camborne School of Mines, the training ground for some of the most talented UK geologists, have found their way to our office to learn how and where the minor elements found in their ores are refined, marketed and sold. All this tells me that cross-fertilization between business and science is something to be cherished.

Today, the minor metal trade has been at the epicentre of an explosion of new uses of minor metals which created an imperative, as never before, to reach out between our world of supply and those with the wit to exploit elements. One of the hotbeds of that interface here in London is a marvellous place called The Institute of Making( on Malet Street, part of the University of London. Here you will see cabinets of elements and materials displayed like the back-lit waxwork heads at Madame Tussauds. Students and members of the public, by invitation, are encouraged to touch, see, manipulate and use elements and materials. The founder of the 4-year old institute, Mark Miodownik, teaches that the world we live in is informed from the micro to the macro, that we need to understand the structure of things to see why and how they work, and also, sometimes, why things go wrong.

The IoM puts on talks too. On Friday Feb 24th 2017, the subject was ‘Good Riddance to Bad Rubbish’ – an atom size examination of why and how we waste. Showing a video clip of something called The Scrap Club, where Londoners pay to put on overalls and use a mallet to hammer computer screens to smithereens, we were encouraged by Miodownik to wonder at our destructiveness and to what perdition we are being drawn when objects as complex as iPhones or computer screens are treated as objects demanding  of as little care as a bottle-top. Talking of which, we also learned the reason why your local recycling company asks you not to put the bottle-top in the blue bin, only the empty plain milk bottle. The answer is as banal as it is shocking. Indeed the plastic of lid and bottle are the same, but the super markets demand the colour-coding  so the consumer can grab the pint of semi or skimmed without thinking. But the coloured tops contaminate the recycling process. Instead of finding another means to assist the consumer  to determine the difference of the milks – such as a clearer self-adhesive paper label – recyclability of the plastic is reduced by 10-fold.

It’s a mad, mad, world and it’s a material world too. Not in Madonna’s sense of the word but one in which material, and the way man manipulates material, lies at the heart of everything – including, possibly, our future.

Published April 5th 2017 on


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