Aluminium in the aeroplanes? (1 Viewer)

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Elmas

Staff Sergeant
1,433
1,418
Jan 17, 2011
Italy
From
How to build an aeroplane
by
Robert Petit
Traslated from French by T.B Hubbard and H. Ledeboer
New York, Year 1910
The Author does not seem at all to have had a good foresight about the use of aluminium in airplanes.......

Screenshot_2013-09-25-23-05-16.png
 
He seems to be talking about aluminum in its pure form. Subsequently, alloys having vastly improved mechanical characteristics were developed. For example:

"Aluminium alloy 7075 is an aluminium alloy, with zinc as the primary alloying element. It is strong, with a strength comparable to many steels, and has good fatigue strength and average machinability, but has less resistance to corrosion than many other Al alloys. Its relatively high cost limits its use to applications where cheaper alloys are not suitable.

7075 aluminum alloy's composition roughly includes 5.6–6.1% zinc, 2.1–2.5% magnesium, 1.2–1.6% copper, and less than half a percent of silicon, iron, manganese, titanium, chromium, and other metals. It is produced in many tempers, some of which are 7075-0, 7075-T6, 7075-T651." (Wikipedia)

Aside from airframes, aluminum was of critical importance in high powered piston engines, particularly for cylinder heads and blocks. This was not only for reasons of weight, but also thermal conductivity.

Interestingly, I have recollections of publications from the 1930s describing schemes for using beryllium in aircraft structures. This never caught on, presumably because of its cost and toxicity.
 
Pure aluminium has the structural strength of "solidified dirt" according to some engineers of the time. It took alloying and heat treatment to turn it into a material suitable for things other than sauce pans and statues.

The "steel age" was about 70 years old when this article was written and while much more remained to be learned about steel it was much better known than aluminium, which in 1910 had only been available in commercial quantities of around 15-20 years. Before that it was more expensive than silver or gold.
 
Pure aluminium has the structural strength of "solidified dirt" according to some engineers of the time. It took alloying and heat treatment to turn it into a material suitable for things other than sauce pans and statues.

The "steel age" was about 70 years old when this article was written and while much more remained to be learned about steel it was much better known than aluminium, which in 1910 had only been available in commercial quantities of around 15-20 years. Before that it was more expensive than silver or gold.


Confusion obviously since we dont give the aluminium alloys a name. Steel is an alloy of Iron, pure iron doesnt have much going for it either. Early uses of Iron/steel are punctuated with disasters bridge collapses boiler explosions and sinking ships, the Liberty ships being an example.
 
Liberty ships were not made of iron and their problems were not due to the basic material but design/workmanship (bad welding for one).

Plain steel is an 'alloy' of iron and carbon but has a carbon content in-between wrought iron and cast iron. Wrought iron being a bit too soft for many uses and cast iron too brittle. Steel had been known for hundreds of years but was too expensive for most uses until the Bessemer converter. From about 1860 on steel became used in every increasing amounts and alloy steels with Nickel and Chrome were being introduced in the 1880s and 90s. They simply had more time to work with steel than they did with aluminium. And steel alloys still had something to offer even in the 1940s in some applications. Wright changed to forged steel crankcases for their radial engines because the steel crankcase was stronger for less weight than the aluminium one. Some aircraft used steel brackets of joiner plates instead of aluminium because they were lighter for the strength required.
 
New York Times wrote in October 9th, 1903:

"The flying machine which will really fly might be evolved by the combined and continuous efforts of mathematicians and mechanicians in from one million to ten million years."

Orville Wright's diary the same day: "We started assembly today."
 
Post number 3 pretty much nailed it.

Aluminium is one of the most abundant elements on earth but despite this it was difficult to extract. When that article was written commercial processes for its extraction were less than thirty years old. There was much yet to be discovered about the properties of it and its alloys.
Prior to this pure aluminium was more an object of wonderment and also fantastically expensive, not, as today, taken for granted. It was shown at the Exposition Universelle des produits de l'Agriculture, de l'Industrie et des Beaux-Arts de Paris 1855 (Exposition Universelle) precisely as an object of wonder.

Cheers

Steve
 
Liberty ships were not made of iron and their problems were not due to the basic material but design/workmanship (bad welding for one).

Plain steel is an 'alloy' of iron and carbon but has a carbon content in-between wrought iron and cast iron. Wrought iron being a bit too soft for many uses and cast iron too brittle. Steel had been known for hundreds of years but was too expensive for most uses until the Bessemer converter. From about 1860 on steel became used in every increasing amounts and alloy steels with Nickel and Chrome were being introduced in the 1880s and 90s. They simply had more time to work with steel than they did with aluminium. And steel alloys still had something to offer even in the 1940s in some applications. Wright changed to forged steel crankcases for their radial engines because the steel crankcase was stronger for less weight than the aluminium one. Some aircraft used steel brackets of joiner plates instead of aluminium because they were lighter for the strength required.



Plain steel is an 'alloy' of iron and carbon but has a carbon content in-between wrought iron and cast iron. Wrought iron being a bit too soft for many uses and cast iron too brittle. Steel had been known for hundreds of years but was too expensive for most uses until the Bessemer converter. From about 1860 on steel became used in every increasing amounts and alloy steels with Nickel and Chrome were being introduced in the 1880s and 90s. They simply had more time to work with steel than they did with aluminium. And steel alloys still had something to offer even in the 1940s in some applications. Wright changed to forged steel crankcases for their radial engines because the steel crankcase was stronger for less weight than the aluminium one. Some aircraft used steel brackets of joiner plates instead of aluminium because they were lighter for the strength required.[/QUOTE]

Iron and steel are such old products it gets confusing Steel is an alloy of Iron and Carbon (and a lot of other elements) but wrought Iron has more carbon than steel, Pig Iron even more.

After the problems with Liberty ships a little known test called the Charpy test became common, and in America the Battelle Drop weight tear test was developed. It tests the impact strength or resiliance of the material. The point I was making is that steel had ( and still has) problems. Part of the problem with Liberty ships was design, comically the basic same design problem as beset the De havilland Comet square holes in a structure under stress. But also it was steel quality. Now it is a matter of routine that Oil projects are qualified with Charpy transition curves (tests at ever reducing temperature) and for plates Battelle tests. The use of the word Battelle is now obsolete it in now a Drop Weight Tear Test. Not scoring points here Steve, the point I am making was that at the start of the industrial revolution many problems were faced and overcome with Iron and steel, I am surprised in the original post that someone who obviously knows about steel didnt think the same was possible with aluminium.

Cheers Peter
 
from shortround
Plain steel is an 'alloy' of iron and carbon but has a carbon content in-between wrought iron and cast iron. Wrought iron being a bit too soft for many uses and cast iron too brittle. Steel had been known for hundreds of years but was too expensive for most uses until the Bessemer converter. From about 1860 on steel became used in every increasing amounts and alloy steels with Nickel and Chrome were being introduced in the 1880s and 90s. They simply had more time to work with steel than they did with aluminium. And steel alloys still had something to offer even in the 1940s in some applications. Wright changed to forged steel crankcases for their radial engines because the steel crankcase was stronger for less weight than the aluminium one. Some aircraft used steel brackets of joiner plates instead of aluminium because they were lighter for the strength required.

Iron and steel are such old products that the names are not descriptive Steel is an alloy of Iron Carbon and a lot of other elements but Cast Iron and Pig Iron have more carbon in them than steel has.

After the problems with Liberty ships a little known test called the Charpy test became common, and in America the Battelle Drop weight tear test was developed. It tests the impact strength or resiliance of the material. The point I was making is that steel had ( and still has) problems. Part of the problem with Liberty ships was design, comically the basic same design problem as beset the De havilland Comet square holes in a structure under stress. But also it was steel quality. Now it is a matter of routine that Oil projects are qualified with Charpy transition curves (tests at ever reducing temperature) and for plates Battelle tests. The use of the word Battelle is now Obsolete it in now a Drop Weight Tear Test. Not scoring point here Steve, the point I am making was that at the start of the industrial revolution many problems were faced and overcome with Iron and steel, I am surprised in the original post that someone who obviously knows about steel didnt think the same was possible with aluminium.

Cheers Peter
 
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I am surprised in the original post that someone who obviously knows about steel didnt think the same was possible with aluminium.

Cheers Peter
At the turn of the 20th century, alloy-metallurgy was still a wild frontier of the Industrial age. The best examples of early steel alloy formulas can be found in the works of ancient swords (Iberian, Damascus and the Orient) but the learning curve was a long-slow process and really became advanced during the 20th century. The knowledge of Aluminum has been around since the Roman Empire, but advanced alloy formulas were just coming into being by the time WWI broke out.
 
Maybe the guy who wrote the article still thought the word was flat, too.

In fact, we still use the wondderful composite material they did back then ... wood.
 
Maybe he worked for a steel company :)

The thing is that in 1910 they had a pretty good idea what they could do with various types of Iron and with various types of steel. They had had hundreds of years ( or thousands ?) of practice with iron (cast iron cannon, not as good as Bronze ones for several hundred years for example but much cheaper). They had about 70 years worth of experience with cheap steel, not knife,sword or spring steel which had been known for hundreds or thousands of years.They really had no idea what to do with aluminium because pure aluminum was pretty poor stuff from a structural stand point and had only existed in commercial form ( not decorations like the cap on the Washington monument) for around 20 years. Since pure Aluminium is pretty useless you can't really start with it and then try to modify it. ( cast iron too brittle? what can you do to make it less brittle? wrought iron too soft? what can you do to harden it?) You have to modify the Aluminium before you can do much of anything with it, like figure out what you can do with the new alloy(s).
Engine makers continued to use 'iron' pistons in heavy duty engines (or cheap ones) for years because iron slides on iron (with a bit of oil) better than aluminium does. Aluminium tends to 'grab' and gall. Pure ( or nearly so) aluminum also has a low melting point.
It's strength to weight ratio is pretty poor in pure form so it actually wasn't going to save much, if any weight.

Metallurgy (even Iron) was still in it's infancy form a scientific point of view even in WW I. Proper heat treatment of steel rifle receivers was 'gauged' by an experienced 'eye' bring the steel to the proper color before quenching (don't shoot pre-1917 Springfield rifles) . Metal fatigue was just being worked on, it was often called 'crystallization' at the time and while they it was going on they didn't understand why. They needed better test instruments, better micro-scopes and better research studies. As better 'tools' became available to metallurgists they could be applied to ALL metals and aluminum made very rapid progress.
Just a few years could make a big difference in the use of some materials.
 
Yeah. Today we mostly use 2024-T3 or -T6 Alclad for aircraft, though we used 7075 for the canopy windscreen bow in the YP-59A to replace a piece of bent sheet metal that wasn't very strong.

We might give the author of the article a break.

Back in the early 1950's they weren't sure if the transistor would turn out to be useful either ... and look where it is today! Without it we have no cell phones, no digital computers, no magic TV, no satellites, and certainly no super avionics in aircraft.

Perhps we will someday find an article by the same guy 15 years later admitting his error.
 
Guy dint mention titanium or carbon fibre either.

Reminds me of a story when Honda built a racecar out of magnesium. It caught fire and how!
 
I have a vintage electrical engineer's reference book, printed in 1901, that stated alternating current was nothing more than a novelty and would be remembered in 50 year's time as a technological dead-end.

The technical innovations involving metallurgy within the past century alone are phenomenal and would have been thought to be science fiction when that French article was written.
 
That's pretty interesting, Graugeist. My "Van Nostrand's Sccientific Encyclopedia" from 1938 notes that most circuit at that time were AC, though DC was a formidable competitor in the early days.

So things turned completely around in about 37 years.

Sometimes we forget how many scientific advancements happened in the early 1900's. I recall a lecture from 1968 college days when a math professor told us that more new mathmatics had been discovered or invented from 1900 to 1950 than from the beginning of the wolrd up to 1900. That certainly got our attention at the time. Of course, the calculus we were learning was as old as the 1600's.
 
The war between DC and AC was really heating up about the mid 1890's.

You had Edison and General Electric as the champions of DC versus Tesla and Westinghouse who were the driving force behind AC. While Alternating Current proved itself to be superior to Direct Current around the turn of the century, Edison's salesmanship and the fact that DC was in use first made it difficult to sell people on the AC theory and it would be well into the 50's before the transition was complete (even later in some places around the world...India still uses DC on their suspended-supply electromotive trains). Even some American products, like drill-motors and kitchen appliances had an AC/DC switch on them somewhere.

As with any new (emerging) technology, you have the old-school that balks at it, going so far to vilify it. We saw this in the late 30's where the RLM looked at anything without propellers with great suspicion because those in charge were "good ol' boys" from the great war and were entrenched in the old school of thought.
 
DC is making a comeback. A few years back DC was going to be consigned to cheap battery powered toys everything was going to be AC. Now Brushless DC motors are appearing everywhere and Hign Voltage DC power transmission is starting to be the long distance power line of choice.

Every time someone says a technology has gone it annoyingly pops back up, even the humble thermionic valve (Tube for you colonials :lol: ) at the nano scale could be what powers your electronics in the future.
 

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