New technique could make nickel as strong as titanium
A new technique that allows metals to mimic the internal structure of wood could make nickel, and other metals, far far strong.
Led by James Pikul, Assistant Professor in the Department of Mechanical Engineering and Applied Mechanics at Penn Engineering, the new study looked at new ways to take metal and give it the porous structure that gives wood its strength. In the past, this has been done by finding ways to turn molten metal into foam, or using 3D printing with hundred-nanometer precision to build up wood-like metal bit by bit. The problem is that metal foam is crude by modern engineering standards, while the 3D printing process is slow and very hard to scale up from lab-bench scales.
“The reason we call it metallic wood is not just its density, which is about that of wood, but its cellular nature,” Pikul says. “Cellular materials are porous; if you look at wood grain, that’s what you’re seeing – parts that are thick and dense and made to hold the structure, and parts that are porous and made to support biological functions, like transport to and from cells. Our structure is similar. We have areas that are thick and dense with strong metal struts, and areas that are porous with air gaps. We’re just operating at the length scales where the strength of struts approaches the theoretical maximum.”
According to the researchers, the key was to go to much smaller scales to produce much greater increases in strength. They manage this by suspending plastic spheres a few hundred nanometers wide in water, which is allowed to evaporate. As the water disappears, the spheres drop into a neat geometrical, crystalline pattern. This is then electroplated with a thin layer of chrome and the spaces between the spheres are filled with nickel. The plastic is then dissolved, and what’s left behind is an open network of metallic struts with 70 percent empty space – making it light enough to float in water.
The process is however very expensive, and so far has only produced some very small samples.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
A new technique that allows metals to mimic the internal structure of wood could make nickel, and other metals, far far strong.
Led by James Pikul, Assistant Professor in the Department of Mechanical Engineering and Applied Mechanics at Penn Engineering, the new study looked at new ways to take metal and give it the porous structure that gives wood its strength. In the past, this has been done by finding ways to turn molten metal into foam, or using 3D printing with hundred-nanometer precision to build up wood-like metal bit by bit. The problem is that metal foam is crude by modern engineering standards, while the 3D printing process is slow and very hard to scale up from lab-bench scales.
“The reason we call it metallic wood is not just its density, which is about that of wood, but its cellular nature,” Pikul says. “Cellular materials are porous; if you look at wood grain, that’s what you’re seeing – parts that are thick and dense and made to hold the structure, and parts that are porous and made to support biological functions, like transport to and from cells. Our structure is similar. We have areas that are thick and dense with strong metal struts, and areas that are porous with air gaps. We’re just operating at the length scales where the strength of struts approaches the theoretical maximum.”
According to the researchers, the key was to go to much smaller scales to produce much greater increases in strength. They manage this by suspending plastic spheres a few hundred nanometers wide in water, which is allowed to evaporate. As the water disappears, the spheres drop into a neat geometrical, crystalline pattern. This is then electroplated with a thin layer of chrome and the spaces between the spheres are filled with nickel. The plastic is then dissolved, and what’s left behind is an open network of metallic struts with 70 percent empty space – making it light enough to float in water.
The process is however very expensive, and so far has only produced some very small samples.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
tangentially:
processing titanium-
The Armstrong Method
Oak Ridge National Lab
https://youtu.be/73HLzYuIfx0
1:37
The Kroll Method
Oak Ridge National Lab
https://youtu.be/oWyrzZh3We0
4:58
and…..
Dr. Roger Penrose
Forbidden crystal symmetry in mathematics and architecture
Royal Institution lecture 2014
https://youtu.be/th3YMEamzmw
58:13
“Dr. Roger Penrose provides a unique insight into the “forbidden symmetry” of his famous penrose tiles and the use of non-repeating patterns in design and architecture.
It is a rigorous mathematical theorem that the only crystallographic symmetries are 2-fold, 3-fold, 4-fold, and 6-fold symmetries.
Yet, since the 1970s 5-fold, 8-fold, 10-fold and 12-fold “almost” symmetric patterns have been exhibited, showing that such crystallographic “forbidden symmetries” are mathematically possible and deviate from exact symmetry by an arbitrarily small amount.”
We get closer to Star Trek’s transparent aluminum.
Phill O
Excellent obscure cultural reference!
I can’t resist….
Star Trek IV The Voyage Home
“Transparent Aluminum”
https://youtu.be/xaVgRj2e5_s
4:44
What is additionally fascinating about all this– we have no idea what magical substances we could engineer in low or zero G.
Nice technology! The weight penalty would still exist. Equal volumes and structures of Nickel would still weigh more when compared to Titanium. It’s great progress though!
I wonder about strength improvements using similar structures, but with Titanium as the metal?