I'd love to see somebody with the $$$ and the foresight develop engine parts with this technology. This little excerpt from a paragraph on Wikipedia outlining the properties of nanotechnology suggests that engine bearings might be a place to start:

"Multiwalled carbon nanotubes, multiple concentric nanotubes precisely nested within one another, exhibit a striking telescoping property whereby an inner nanotube core may slide, almost without friction, within its outer nanotube shell thus creating an atomically perfect linear or rotational bearing. This is one of the first true examples of molecular nanotechnology, the precise positioning of atoms to create useful machines. Already this property has been utilized to create the world's smallest rotational motor and a nanorheostat. Future applications such as a gigahertz mechanical oscillator are envisioned."

What it has to say about tensile strength makes me wonder if pushrods might also be a possibility:

"Carbon nanotubes are one of the strongest materials known to man, both in terms of tensile strength and elastic modulus. This strength results from the covalent sp2 bonds formed between the individual carbon atoms. In 2000, an MWNT was tested to have a tensile strength of 63 GPa [2]. In comparison, high-carbon steel has a tensile strength of approximately 1.2 GPa. CNTs also have very high elastic modulus, in the order of 1 TPa [3]. Since carbon nanotubes have relatively low density, the strength to weight ratio is therefore truly exceptional.

Under excessive tensile strain, the tubes will undergo plastic deformation, which means the deformation is permanent. This deformation begins at strains of approximately 5% [Qian et al, 2002] and can increase the maximum strain the tube undergoes before fracture by releasing strain energy.

CNTs are not nearly as strong under compression. Due to their hollow structure, they tend to undergo buckling when placed under compressive, torsional or bending stress."

I'm curious to know what they consider "excessive tensile strain." Seeing as how there are plans floating around to create a "Space Elevator" with this stuff, the standard must be pretty high, no pun intended. Interesting stuff to say the least.

http://en.wikipedia.org/wiki/Carbon_nanotube

 

If the stuff is anything like carbonfiber pushrods would be unlikely to happen since a failurwe would litter the motor with dust. Yeah metal can break and flake but not as badly.

 

Both substrates having the word "carbon" in their names is pretty much where it ends as far as what they have in common. Here's an excerpt from another article that outlines one of the methods that are being developed to form matrices for these tubes:

"A third type of nanotube composite that might be made would have a metal matrix. Craig Blue of ORNL’s Metals and Ceramics Division and Geohegan have a grant from the Defense Advanced Research Projects Agency to produce SWNTs by chemical-vapor deposition; align the nanotubes into a matte; and infiltrate it with powders of molybdenum, titanium, or tungsten—metals that react with carbon. This material would then be rapidly heated using infrared radiation from the plasma arc lamp at the Infrared Processing Center, a Department of Energy user facility at ORNL. The goal here would be to create a nanotube-metal matrix that might be used to make extremely strong structural materials for aircraft and spacecraft and for long power-transmission lines and suspension bridges."
http://72.14.203.104/search?q=cache:...&ct=clnk&cd=70

Polymer composites, like found in carbon fiber, are being used in other applications with carbon nanotubes but they're finding that the tubes don't bond terribly well with polymers and the tubes have a tendency to fall out of the matrix whenever the substrate is subjected to bending or flexing.

 

It is unlikely that nanotubes will make it into engines for a while. The health effects are unknown, so much so that scientists called a conference to call for regulation and oversight. Scientists whose companies would thrive, and have much to lose (short term) by doing this.
They are also very very expensive. I believe that currently nanotubes are used in theoretical chemistry research. We'd probably be more likely to get some sort of carbon nanotube coated products, than full carbon products. But even then, it would still be year down the road
....or better yet, creat long nano tube structures, and thread pieces with them. Similar to how cells use filaments (biology).
edit: I think that is what the the fella above me is saying.
They are talking about just mixing them in there. I wonder if they've thought about threading it like a grid, similar to the strings on a tennis raquet.

Or, off topic, I wonder if they can use nanotubes to creat blank spots in the atomic structure, so that the when the metal is added, it isn't consistent all the way through, since its interupted by strands of nano tubes. That way, you could arrange nanotubes in a ciruclar pattern so that when you add the metal, it would mold inside a circular arrangement of the tubes, to create individual strands of metal, surrounded by nanotubes. If that worked, you could arrange these circular arrangements of nanotubes to form a braiding pattern, and make the overall structure of the macro part stronger (tension wise anyways).

 

This technology may not be as far off as we think:


Gregory Rast’s Team Phonak BMC SLC01 in Milano at the start of la Primavera last Saturday

"Carbon Nanotube Bike in the Market"

Sunday, March 05, 2006
"The 2005 Tour de France saw the first carbon nanotube frame bikes used in competition. Now the same technology is available to consumers with the new BMC SLC01 Pro Machine. The bike’s frame weighs in at 1055 grams, or 2.33 pounds, which is less than the weight of 5 cellphones - that is, until they start making cellphones out of carbon nanotubes too.
This carbon work of art is the brainchild of Easton Composites and Swiss bike manufacturer, BMC. The SLC01 will be seen this year under the legs of Phonak Professional Cycling Team, one of the most visible and highly ranked of the UCI Pro Teams.
The SLC01 is the very first frameset in history to utilize 100% carbon nanotechnology throughout. Even the front and rear dropouts are made of carbon! Easton’s proprietary CNT (carbon nanotechnology) deals with the manipulation of carbon fibers on an atomic scale measured in billionths of a meter (nanometers). Since the weakest areas in a traditional carbon-fiber component are the tiny spaces between the fibers that contain only resin, Easton’s scientists developed an innovative Enhanced Resin System using carbon nanotubes (CNT).
Carbon nanotubes are an array of carbon atoms arranged in a pattern of hexagons and pentagons (similar to the pattern found on soccer *****). These structures can be manufactured in tubular shapes one billionth of a meter in diameter, hence the name nanotube. Carbon nanotubes have been called "the strongest fiber that will ever be made." Nanotubes have strength-to-weight ratio orders of magnitude greater than steel.
A result of this hyper-strong carbon technology is an increased strength to weight ratio which translates to a reduction in required construction materials. Hence, the SLC01 is one of the lightest and strongest framesets available, weighing in at just 1055 grams for a size 51 but with tubular strength 400 times greater than steel!"
http://www.e-composites.com/frontend....aspx?sno=3061

I'd be curious to see how something like this would hold up in chassis form...

 

That bike frame weighs less than 2.5 pounds....that's crazy.

 

For this reason, carbon nanotubes would be pretty much useless in any moving part in any car, especially pushrods.

Tensile strength is how strong the material is when you pull the ends apart. That's where CNTs are useful, and I can't think of a single automotive application for a part that needs to be strong for pulling but not for pushing, twisting, or bending.

 

True.

I guess you can lead a horse to water but you can't make him drink.

I hope the bike frame pictured above is never subjected to any pushing, twisting, or bending stress..

Let's keep this in perspective: plastic deformation under compression may occur at 5% load, but you're talking about a substrate that is already 400 times stronger than steel. With that much headroom to play with, if you didn't end up making a part any stronger than it's current metal counterpart, the least you could do is make it lighter. The key is in using the nanotubes as a reinforcement for other materials rather than completely replacing them.

Here's an article outlining plans to produce nanotube reinforced ceramic parts:

"A workable material capable of withstanding intense heat, able to conduct electricity, chemically inert and durable — it’s an engineer’s dream come true. And it’s made possible with ceramics. Ceramics make most people think of pottery and artistic sculptures, but those more familiar with the material know it has several industrial uses such as high-temperature melting pots and auto parts.

A team of researchers at UC Davis has improved industrial ceramics even more by creating a new composite involving ceramic materials and single-wall carbon nanotubes — sheets of carbon one atom thick rolled into a hollow, tubular shape.

The new material is a combination of traditional ceramics, single-wall carbon nanotubes and the metal niobium. It exhibits high temperature endurance, controllable heat conductivity, chemical inertness, electrical conductivity, and increased fracture strength; all of these are desirable in a variety of applications and make it a better choice than metals for many applications.

”The material can endure greater temperatures than metals,” said Amiya Mukherjee, a professor of applied science at UCD. “But is not susceptible to melting.”

The material is able to withstand temperatures up to and perhaps above 1,000 degrees Celsius and may be used in space vehicles, factories, or high-power conventional engine parts where traditional ceramics would be too susceptible to breakage.

”We may be able to conduct heat one way,” said Dr. Goudong Zhan, UCD postdoctoral researcher involved in creating the composite.

Depending on the alignment of the carbon nanotubes inside the composite, the material can be made to conduct or not conduct heat. For computer heat sinks, the material would be mixed to conduct heat out, whereas a thermos could be designed to keep heat in, and the same material could be used for both.

Unlike basic alumina ceramics — which insulate — the nanotube composite can conduct electricity as either a semi or full conductor. The conductivity of many materials changes when temperatures shift, which is problematic for computers which create a lot of heat. With very little change in the composites conductivity from -200 to 100 C, the composite may be a potential silicon substitute.

Another significant improvement of carbon nanotube ceramics over conventional alumina ceramics is that the tubes are able to reinforce the material. The result is that the composite can support five times the weight of traditional ceramics without suffering damage. This allows the material to be used in heavy lifting jobs traditionally reserved for metals.

With a material this strong, it is important that the material be shapeable. Fortunately, the composite has the attribute known as superplasticity.

”Superplasticity means we can shape this material with pressurized air,” said Mukherjee. “If it did not have this feature you would spend forever shaping it.”

Perhaps one of the composite’s most important attributes is that it is chemically inert, meaning it should not undergo chemical reactions with its surroundings. This feature makes it a good material for organ replacement and implants and the team has already received inquiries from at least one company regarding this facet.

”They should have much better wear properties than traditional implants because of their increased strength,” said graduate student Joshua Kuntz.

Each of these attributes may seem useful alone, but that they are all combined into a single material is remarkable.

The study to create the composite was prompted by the U.S. military’s interest in carbon nanotube and ceramic composite applications. For example, military vehicles may wind up receiving a coating of nanotube ceramics to help protect them from chemical attacks.

Despite all the positive results, development and production of the material has several hurdles to overcome.

The largest sample the team has been able to produce so far is only 19 millimeters (in diameter? in length?) –rh), an amount smaller than a quarter — not enough to be of commercial use. Larger samples are more difficult to properly mix. If the alumina and carbon nanotubes are not properly combined and prepared, the heat and electrical conductivity properties of composite are lost.

Even with smaller samples, cost is still an issue. “One gram of carbon nanotubes costs $500 to $750,” Dr. Zhan said.

Prices of the tubes are coming down slowly, so at least that difficulty will become less important in coming years. Already firms are gearing up to produce thousands of kilograms of carbon nanotubes. Dr. Zhan anticipates it will take a large drop in the price before the composite becomes truly marketable.

Also on the development team was graduate student Javier Garay; despite the challenges ahead, the team has high hopes for their new creation, and already they have four patents pending on the material.?

 

I wonder about that myself. While I'm not very familiar with the actual physics of bicycling, I think it is safe to assume that a bicycle is never subjected to loads with magnitude anywhere close to the loads seen in automotive applications, especially engine internals.

The way I read the article, plastic deformation occurs if the tensile loads exceed 5% of the maximum, but they did not specify a percentage at which the buckling under compressive loads begins to occur. I assumed, therefore, that it was likely to occur under any compressive load.

Maybe I'm wrong, and it'd be awesome if I am. If it's feasible, I'd love to see this sort of technology used in cars.