Believe it or not, ceramics, as a class of materials, are stronger than metals, in addition to being able to withstand extreme temperatures, resist corrosion, and be easily molded into arbitrary shapes. But as we all know, ceramics are very brittle. But the geniuses at DARPA think that this problem can be solved and have put out a contract (https://www.darpa.mil/research/programs/intact-intrinsically-tough) for it. Their interest in it is for "airframes, turbine disks, ground vehicle chassis, or submarine hulls.". But the civilian uses would have an impact rivalling that of DARPA's most famous invention; the internet.
DARPA would be better off pursuing artificial diamond materials. Hardest material known to man, its manufacture is already longstanding & the carbon use would help the ecology.
Quote from: Road Hog on February 14, 2025, 09:02:47 PMDARPA would be better off pursuing artificial diamond materials. Hardest material known to man, its manufacture is already longstanding & the carbon use would help the ecology.
Diamonds would need to be cut in cost by several orders of magnitude before they could be used to build submarines.
Ceramics otoh are already very cheap.
Quote from: kernals12 on February 14, 2025, 09:07:51 PMQuote from: Road Hog on February 14, 2025, 09:02:47 PMDARPA would be better off pursuing artificial diamond materials. Hardest material known to man, its manufacture is already longstanding & the carbon use would help the ecology.
Diamonds would need to be cut in cost by several orders of magnitude before they could be used to build submarines.
Ceramics otoh are already very cheap.
Economy of scale.
Quote from: Road Hog on February 14, 2025, 09:17:17 PMQuote from: kernals12 on February 14, 2025, 09:07:51 PMQuote from: Road Hog on February 14, 2025, 09:02:47 PMDARPA would be better off pursuing artificial diamond materials. Hardest material known to man, its manufacture is already longstanding & the carbon use would help the ecology.
Diamonds would need to be cut in cost by several orders of magnitude before they could be used to build submarines.
Ceramics otoh are already very cheap.
Economy of scale.
Artificial diamonds are already mass produced. It takes 2 weeks under extremely high pressure under current processes, which is expensive. And even if that wasn't an issue, diamonds are very difficult to work with and they are quite fragile. Not very desirable for making a submarine hull.
You only need 24 diamonds for a full suit of armor.
What is wrong with HY-80? It's weldable. Are ceramics? What is the strength to weight ratio of ceramics anyway?
Quote from: 02 Park Ave on February 15, 2025, 02:22:50 PMWhat is wrong with HY-80? It's weldable. Are ceramics? What is the strength to weight ratio of ceramics anyway?
Very, very high
(https://i.imgur.com/kIr01VW.png)
http://www-materials.eng.cam.ac.uk/mpsite/interactive_charts/spec-spec/NS6Chart.html
Quote from: hotdogPi on February 15, 2025, 01:07:20 PMYou only need 24 diamonds for a full suit of armor.
I assume this is a video game joke?
Quote from: kernals12 on February 15, 2025, 02:52:06 PMQuote from: hotdogPi on February 15, 2025, 01:07:20 PMYou only need 24 diamonds for a full suit of armor.
I assume this is a video game joke?
Apparently a Minecraft reference:
https://stealthygaming.com/diamonds-for-full-armor-tools/
I'm pretty sure that webpage is AI-generated. Some of the numbers are wrong (as well as the claim that boots aren't part of a full suit).
Quote from: hotdogPi on February 15, 2025, 03:03:11 PMI'm pretty sure that webpage is AI-generated. Some of the numbers are wrong (as well as the claim that boots aren't part of a full suit).
I wouldn't know given I've never played Minecraft. I just took your quote and got that result in a search engine.
It's really too bad they couldn't have succeeded in this 20 years ago. If they had, we'd all be driving turbine powered cars by now.
What correlation is there between ceramic hulls and automotive turbine engine development? It isn't as though the turbine didn't get the old college try by auto manufacturers.
Quote from: Max Rockatansky on February 15, 2025, 08:32:03 PMWhat correlation is there between ceramic hulls and automotive turbine engine development? It isn't as though the turbine didn't get the old college try by auto manufacturers.
probably the idea that technologies, including advanced materials, tend to trickle down from most demanding applications to more mundane.
composites may be a good example, which is still making its way into the general car market
Quote from: Max Rockatansky on February 15, 2025, 08:32:03 PMWhat correlation is there between ceramic hulls and automotive turbine engine development? It isn't as though the turbine didn't get the old college try by auto manufacturers.
It's actually very interesting. Kerosene burns at about 3500 degrees fahrenheit, gasoline slightly more. Such heat will easily melt all but the most exotic metals. That's not a problem for piston engines because combustion is intermittent and it's easy to provide external cooling. Turbine engines don't have the same luxury, as combustion is continuous and the turbine blades are always going to be exposed to the heat. Engineers can only fix that problem by running the engines with lots of excess air. That keeps the engine from being destroyed, but it also hurts fuel economy because you need a bigger compressor to get the same amount of output.
Beginning in the late 60s, engineers looked at ceramics for the solution. They can handle much higher temperatures than metals (and they're also cheaper and lighter). If they could just get over ceramics' brittleness, they could make turbine engine more efficient than a diesel. But that never happened.
Quote from: kernals12 on February 15, 2025, 08:46:34 PMQuote from: Max Rockatansky on February 15, 2025, 08:32:03 PMWhat correlation is there between ceramic hulls and automotive turbine engine development? It isn't as though the turbine didn't get the old college try by auto manufacturers.
It's actually very interesting. Kerosene burns at about 3500 degrees fahrenheit, gasoline slightly more. Such heat will easily melt all but the most exotic metals. That's not a problem for piston engines because combustion is intermittent and it's easy to provide external cooling. Turbine engines don't have the same luxury, as combustion is continuous and the turbine blades are always going to be exposed to the heat. Engineers can only fix that problem by running the engines with lots of excess air. That keeps the engine from being destroyed, but it also hurts fuel economy because you need a bigger compressor to get the same amount of output.
Beginning in the late 60s, engineers looked at ceramics for the solution. They can handle much higher temperatures than metals (and they're also cheaper and lighter). If they could just get over ceramics' brittleness, they could make turbine engine more efficient than a diesel. But that never happened.
Still have to exhaust that heat somewhere. That was a major issue with the turbine car concepts, stepping behind the exhaust could lead to a bad time.
Quote from: kalvado on February 15, 2025, 08:45:32 PMQuote from: Max Rockatansky on February 15, 2025, 08:32:03 PMWhat correlation is there between ceramic hulls and automotive turbine engine development? It isn't as though the turbine didn't get the old college try by auto manufacturers.
probably the idea that technologies, including advanced materials, tend to trickle down from most demanding applications to more mundane.
composites may be a good example, which is still making its way into the general car market
Fair enough, but composite materials don't necessarily solve the issues of packaging a powertrain (as noted in the above comment). Even the early nuclear car concepts never really got off the drawing board because there was no way to solve the exhaust issues.
Quote from: Max Rockatansky on February 15, 2025, 08:57:34 PMQuote from: kernals12 on February 15, 2025, 08:46:34 PMQuote from: Max Rockatansky on February 15, 2025, 08:32:03 PMWhat correlation is there between ceramic hulls and automotive turbine engine development? It isn't as though the turbine didn't get the old college try by auto manufacturers.
It's actually very interesting. Kerosene burns at about 3500 degrees fahrenheit, gasoline slightly more. Such heat will easily melt all but the most exotic metals. That's not a problem for piston engines because combustion is intermittent and it's easy to provide external cooling. Turbine engines don't have the same luxury, as combustion is continuous and the turbine blades are always going to be exposed to the heat. Engineers can only fix that problem by running the engines with lots of excess air. That keeps the engine from being destroyed, but it also hurts fuel economy because you need a bigger compressor to get the same amount of output.
Beginning in the late 60s, engineers looked at ceramics for the solution. They can handle much higher temperatures than metals (and they're also cheaper and lighter). If they could just get over ceramics' brittleness, they could make turbine engine more efficient than a diesel. But that never happened.
Still have to exhaust that heat somewhere. That was a major issue with the turbine car concepts, stepping behind the exhaust could lead to a bad time.
That is exactly the opposite of the truth. Thanks to the use of a regenerator, Chrysler was able to get exhaust temperatures *lower* than that of a piston engine.
Quote from: Max Rockatansky on February 15, 2025, 09:00:51 PMQuote from: kalvado on February 15, 2025, 08:45:32 PMQuote from: Max Rockatansky on February 15, 2025, 08:32:03 PMWhat correlation is there between ceramic hulls and automotive turbine engine development? It isn't as though the turbine didn't get the old college try by auto manufacturers.
probably the idea that technologies, including advanced materials, tend to trickle down from most demanding applications to more mundane.
composites may be a good example, which is still making its way into the general car market
Fair enough, but composite materials don't necessarily solve the issues of packaging a powertrain (as noted in the above comment). Even the early nuclear car concepts never really got off the drawing board because there was no way to solve the exhaust issues.
Nuclear car concepts? Is that a typo?
Quote from: kernals12 on February 15, 2025, 09:02:03 PMQuote from: Max Rockatansky on February 15, 2025, 09:00:51 PMQuote from: kalvado on February 15, 2025, 08:45:32 PMQuote from: Max Rockatansky on February 15, 2025, 08:32:03 PMWhat correlation is there between ceramic hulls and automotive turbine engine development? It isn't as though the turbine didn't get the old college try by auto manufacturers.
probably the idea that technologies, including advanced materials, tend to trickle down from most demanding applications to more mundane.
composites may be a good example, which is still making its way into the general car market
Fair enough, but composite materials don't necessarily solve the issues of packaging a powertrain (as noted in the above comment). Even the early nuclear car concepts never really got off the drawing board because there was no way to solve the exhaust issues.
Nuclear car concepts? Is that a typo?
No, this was a thing Ford did some work on. The concept was called the Nucleon and never was more than something that existed on paper.
With this program, DARPA could send us into the stone age.
There is a series of sci-fi military adventure books about a near future war between the US, UK and others and a German/South African alliance. The main players in these books are a US submarine with ceramic hull (50kt top speed, dive to 5,000 feet shooting all sorts of high power conventual and nuclear torpedoes. The other side also has a couple of these. See:
https://www.goodreads.com/series/85465-jeffrey-fuller
I'm imagining ceramic bridges. They could be made from panels fabricated off-site, trucked in, and then bolted together using far less material and labor than ones made from reinforced concrete. They'd also be largely immune to corrosion and thermal expansion.
Quote from: kernals12 on February 15, 2025, 09:01:25 PMChrysler was able
What Chrysler vehicle used a turbine? A vehicle that was older than most members on this board. In a half-century since, there hasn't been improvements that could cause such a thing to become viable. Chrysler stopped development because of emissions and poor fuel economy. So what would a turbine contribute today?
Quote from: GaryV on February 16, 2025, 08:36:57 AMQuote from: kernals12 on February 15, 2025, 09:01:25 PMChrysler was able
What Chrysler vehicle used a turbine? A vehicle that was older than most members on this board. In a half-century since, there hasn't been improvements that could cause such a thing to become viable. Chrysler stopped development because of emissions and poor fuel economy. So what would a turbine contribute today?
Well a ceramic material that's ductile not brittle makes that possible, or at least it would if not for the imminent dominance of the electric vehicle.
Quote from: Max Rockatansky on February 15, 2025, 09:00:51 PMQuote from: kalvado on February 15, 2025, 08:45:32 PMQuote from: Max Rockatansky on February 15, 2025, 08:32:03 PMWhat correlation is there between ceramic hulls and automotive turbine engine development? It isn't as though the turbine didn't get the old college try by auto manufacturers.
probably the idea that technologies, including advanced materials, tend to trickle down from most demanding applications to more mundane.
composites may be a good example, which is still making its way into the general car market
Fair enough, but composite materials don't necessarily solve the issues of packaging a powertrain (as noted in the above comment). Even the early nuclear car concepts never really got off the drawing board because there was no way to solve the exhaust issues.
It's not about power train, it's an example of advanced material.
Composite bodies for race cars seem to be a thing. Lighter, stronger, hard to repair, more expensive (at least for now). Composite planes are a thing right now.
Quote from: Max Rockatansky on February 15, 2025, 08:57:34 PMQuote from: kernals12 on February 15, 2025, 08:46:34 PMQuote from: Max Rockatansky on February 15, 2025, 08:32:03 PMWhat correlation is there between ceramic hulls and automotive turbine engine development? It isn't as though the turbine didn't get the old college try by auto manufacturers.
It's actually very interesting. Kerosene burns at about 3500 degrees fahrenheit, gasoline slightly more. Such heat will easily melt all but the most exotic metals. That's not a problem for piston engines because combustion is intermittent and it's easy to provide external cooling. Turbine engines don't have the same luxury, as combustion is continuous and the turbine blades are always going to be exposed to the heat. Engineers can only fix that problem by running the engines with lots of excess air. That keeps the engine from being destroyed, but it also hurts fuel economy because you need a bigger compressor to get the same amount of output.
Beginning in the late 60s, engineers looked at ceramics for the solution. They can handle much higher temperatures than metals (and they're also cheaper and lighter). If they could just get over ceramics' brittleness, they could make turbine engine more efficient than a diesel. But that never happened.
Still have to exhaust that heat somewhere. That was a major issue with the turbine car concepts, stepping behind the exhaust could lead to a bad time.
Heat in exhaust is lost energy. Noise, high fuel burn..
As far as I understand, small turbines are difficult due to more strict tip seal requirements. And that is a fast seal, unlike slower piston ring.
I believe there are turbine tanks, but not even heavy military support vehicles....
Parnelli Jones drove a turbine powered car for Andy Granatell (STP) in the 1967 Indy 500.
He led most of the race but failed to finish when he experienced a transmission failure eight miles from the checkered flag.
I'm looking forward to ceramic cars and houses.
Quote from: kernals12 on February 16, 2025, 12:47:59 PMI'm looking forward to ceramic cars and houses.
Bricks are a flavor of ceramic. Jus'saying.
Quote from: kalvado on February 16, 2025, 12:55:08 PMQuote from: kernals12 on February 16, 2025, 12:47:59 PMI'm looking forward to ceramic cars and houses.
Bricks are a flavor of ceramic. Jus'saying.
Hence what I said about DARPA sending us back to the stone age
Quote from: kernals12 on February 15, 2025, 01:05:35 PMArtificial diamonds are already mass produced. It takes 2 weeks under extremely high pressure under current processes, which is expensive. And even if that wasn't an issue, diamonds are very difficult to work with and they are quite fragile. Not very desirable for making a submarine hull.
They could always try using spades or clubs instead. (Not hearts, they're easily broken.)
The great thing about ceramics is they are made from unbelievably abundant substances. 28% of the earth's crust is silicon (silicon nitride and silicon carbide). In the future, our cities may be made of the very dirt that was excavated to build them.
Quote from: kernals12 on February 22, 2025, 01:40:06 PMThe great thing about ceramics is they are made from unbelievably abundant substances. 28% of the earth's crust is silicon (silicon nitride and silicon carbide). In the future, our cities may be made of the very dirt that was excavated to build them.
Lol... Wait until you see rare earth ceramics.