An 8,000 Ton Giant Made the Jet Age Possible 307
Hugh Pickens writes "Tim Heffernan writes that when 'The Fifty,' as it's known in company circles, broke down three years ago, there was talk of retiring it for good. Instead, Alcoa decided to overhaul their 50,000-ton, 6-story high forging press, now scheduled to resume service early this year. 'What sets the Fifty apart is its extraordinary scale,' writes Heffernan. 'Its 14 major structural components, cast in ductile iron, weigh as much as 250 tons each; those yard-thick steel bolts are also 78 feet long; all told, the machine weighs 16 million pounds, and when activated its eight main hydraulic cylinders deliver up to 50,000 tons of compressive force.' The Fifty could bench-press the battleship Iowa, with 860 tons to spare, but it's the Fifty's amazing precision — its tolerances are measured in thousandths of an inch—that gives it such far-reaching utility. Every manned US military aircraft now flying uses parts forged by the Fifty, as does every commercial aircraft made by Airbus and Boeing making the Jet Age possible. 'On a plane, a pound of weight saved is a pound of thrust gained—or a pound of lift, or a pound of cargo,' writes Heffernan. 'Without the ultra-strong, ultra-light components that only forging can produce, they'd all be pushing much smaller envelopes.' The now-forgotten Heavy Press Program (PDF), inaugurated in 1950 and completed in 1957, resulted in four presses (including the Fifty) and six extruders — giant toothpaste tubes squeezing out long, complex metal structures such as wing ribs and missile bodies. 'Today, America lacks the ability to make anything like the Heavy Press Program machines,' concludes Heffernan, adding that 'The Fifty' will be supplying bulkheads through 2034 for the Joint Strike Fighter. 'Big machines are the product of big visions, and they make big visions real. How about a Heavy Fusion Program?'"
Actually not every... (Score:5, Informative)
There are Airbus and Boeing planes built using parts made by the lower capacity presses used while this one was unserviceable or down for maintenance...
Re:Additive manufacturing? (Score:5, Informative)
The Chinese have started building an 80,000 ton forge press
http://aciers.free.fr/index.php/2012/02/02/china-has-started-the-building-of-an-80000-ton-press-forge-us/ [aciers.free.fr]
Re:Additive manufacturing? (Score:3, Informative)
Sintered powder metal parts are not only not as strong as forged parts but their failure mode is to snap suddenly instead of bending. In car-land we saw this happen to the 7.3 liter powerstroke in 2001, where Ford went from the forged rods used in the pre-powerstroke International-Navistar 7.3 IDI turbo motor to a new powder metal rod chosen for lower cost. Not only is it not forged (cheaper) but instead of machining caps they are simply cracked off and then they get a cleanup pass, maybe. Unfortunately, they are about 10% more likely to fail and when they do, they are 100% more likely to break utterly rather than simply bending. This is not a solvable problem for steel, because forging creates the grain structure which produces the strongest parts, at least in steel. Ti may be different; don't know.
Re:Additive manufacturing? (Score:5, Informative)
The laser Ti benificiation is the strongest additive manufacturing process available at the moment, and even it is very brittle because of the thermal stresses formed when it is produced. These are because as the laser melts the particles they are much hotter than the parts it is bonded with, and as they cool they shrink causing lots of stresses all throughout the material. That said, being able to make a ball inside of a socket during the manufacturing process is quite useful sometimes... not to speak of woven Ti mesh for grafts and such.
Re:"On a plane, ... (Score:3, Informative)
Relative to the weight of the plane, yes, it would be the same as adding two more pounds of thrust, though you'd gain a slight advantage in maneuverability due to less mass.
Re:The future will be printed, not forged. (Score:5, Informative)
Re:The future will be printed, not forged. (Score:5, Informative)
Composites aren't a magic product that replaces everything that came before it. If they were then why isn't anyone making engine blocks out of them? They have their uses but they have their limits as well.
I present to you the carbon fiber engine block.
http://www.thecarbonfiberjournal.com/?p=770 [thecarbonf...ournal.com]
Re:US Steel "Shield" (Score:5, Informative)
A bit of history provides some useful background. During WWII, the area near Pittsburgh PA produced more steel than the rest of the world combined. (But those mills were mostly built with 19th century technology. They were at the 'prime of life' and would have been obsolete soon even without the war.) Steel mills and other heavy industry throughout the rest of the world also were largely destroyed by bombing from one side or the other - mostly Allied bombing of German and Japanese steel mills. So after the war US industry, and particularly US steel, were the only ones still able to produce products. We then lent money to all parties (the Marshall Plan), with the proviso that they had to spend the money on US goods. The boom of the 1950s was the result of this and some other policies (the GI bill was another). This amounted to a postwar bubble.
One of the things that those other countries did was build new steel plants, using the latest technology. By the end of the 1950s these new plants were coming online, able to make steel for much lower prices. At that point the US steel industry, still based on late-19th century mill technology, became completely obsolete. The US steel companies, still competing with each other as well as the rest of the world, could not justify spending $zillions to essentially compete against themselves, while it was well worth while for other countries to develop their own industries, as they were starting from a zero base. This is a classic problem that results in constant turnover in many/most/all industries - it rarely seems like a good idea to build your own competition looking at the short term - all it does is spend money to reduce profits- but it's often a good idea to come in from outside and build the competition to the entrenched, inefficient market leader..
Since the 1970s there have been quite a few new, smaller mills built here using the latest (IIRC NUCOR was one of the first examples) but they still have to work hard to compete with the lower costs elsewhere - lower wages, lower land prices, etc. So it's an uphill battle, and that kind of dominance after WWII was a one-time deal.
One of the side-effects of the loss of those two-mile-long mills in the Pittsburgh area is that the side has become clean. When I lived there (early 1990s) the Carnegie Library and Museum was being scrubbed. The building had been black for 80 years or so. After scrubbing it turned out to be blond! I saw pictures from the 1950s where it was too dark and smoky to see across the street in downtown Pittsburgh. And those big mill areas along the rivers are now available to be turned into parks, housing, light industry, clean industry, whatever. But of course, there aren't many jobs. The population of Pittsburgh now is about 1/3 what it was in 1965. Houses are (or at least were) cheap.
Re: carbon fiber engine block (Score:5, Informative)
http://blog.caranddriver.com/is-this-the-engine-of-the-future-in-depth-with-matti-holtzberg-and-his-composite-engine-block/ [caranddriver.com]
This article goes into a little more depth. The block is actually a combination of aluminum and carbon. The parts that see the highest stress and highest temperature still have to be metal.
Also, this engine was announced a year ago, and I haven't been able to find any links to people actually driving one.
Re:The future will be printed, not forged. (Score:5, Informative)
Modern planes, and other transport/engineering structures, are moving to composites. Which are layered, printed, sometimes pressure baked and squeezed into form. But no longer forged on this scale.
While these machines are awesome, I've wandered along a car body stamping line and watched plates go from a flat sheet to a car door in 100meters, they are becoming less necessary to us. They will still be needed, of course, for some jobs where only such a monster can help, but I think the US should look on these as potential future museum pieces, with nostalgia for a bygone age of megaengineering, rather than a source of future industrial dominance.
Even a rudimentary knowledge of chemistry would help you understand how you're wrong. There are fundamental differences at the atomic level between things that are cast, forged, and "printed" in the manner that modern metal-based 3D printing works. The Venn diagram of things forged metal is good for and composites are good for has some overlap, but not a lot.
Thankfully, the engineers who are actually building things know the difference.
"At the atomic level" is incorrect (Score:5, Informative)
Re:Airbus? (Score:5, Informative)
Then you know nothing about aviation manufacturers - a modern Airbus aircraft can be over 50% American by weight if chosen with GE or P&W engines, and 40% with RR engines. Airbus has major US suppliers.
It all depends (Score:5, Informative)
The author of this paper is obviously biased MPIF 2005 paper [mpif.org] but it shows how active research is in this field, with the forging companies and powder metal companies constantly overtaking one another. The paper referenced actually demonstrates the superior fatigue strength of the powder technology used.
Forging involves the distortion of the metal grains, and as such there are always treatment issues with locked-in strain and the effects of any inclusions in the metal. Powder metallurgy has different problems. Neither is a perfect process. But the people who up-moderated drinkypoos comment certainly weren't metallurgists.
Re:Summary contains entire article... plus some? (Score:5, Informative)
The summary is a summary of the article on BoingBoing, here:
http://boingboing.net/2012/02/13/machines.html
which mentions all of those things. (Specifically, the company that built the press went bankrupt some decades ago and the machines used to cast the parts of that size have been sold for scrap). The link is to a similar article in The Atlantic, for whatever reason.
Re:The future will be printed, not forged. (Score:5, Informative)
There are laser-sintering machines that can "print" parts out of powdered metals. Titanium, Aluminum, Bronze can all be used in these machines. While most 3d printers use low temp plastics, like ABS, there is one sintering machine in the Midwest that uses PEEK plastic.
Laser-Sintering machines start at about $500k now. Significantly cheaper than they were 10 years ago
Re:The future will be printed, not forged. (Score:3, Informative)
Seems to me that it would be a simple matter to use 3D printing to build a model for traditional metal casting methods. But as mentioned, none of that gives you the strength of forged metal. So is there a way to combine 3D printing with casting and some sort of "generic" forging process?
3D printing is compatible with both casting and forging. 3D printing is a good way to make the initial master model for a casting mold. It can also be used to create the model from which the forging dies will be created.
As far as 3D printing replacing forging, that's a different story. The forging process itself affects the material being forged, essentially aligning the "grains" of the metal along the contours of the piece. This is what gives forged parts increased strength. At this point I don't believe we can replicate that with any known 3D printing technique.