Exotic metals for engines?

bpost

The internal combustion engine uses about 30% of the gas burned to power the vehicle. Most of the heat produced is wasted. To operate more efficiently more of the heat must be used; to do that will take exotic materials able to operate at the elevated temperatures captured for additional power.

What ever happened to ceramic engine blocks and exotic glass pistons and rods? I thought the engineering was close to making it work on a commercial scale and that was 10 years or so ago?

Anybody have the skinny on engine improvements?

txfeller

It's my understanding that it's the epa.

Fracture technology has drastically reduced the machining costs that accompanied the exotic metals. But while higher compression ratio engines require less fuel to deliver more horsepower (and heat), as the compression is increased, the amount of Nox increases.

shoff14

The main problem with exotic metals and ceramic is machineability.

Ceramic is still around on the diesel engine side of things. Mostly for pistol sleeves and various other non impact stress type applications. Ceramic is not impossible to machine, but is extremely difficult. The advantage of ceramic is that it can be made to tight tolerances without the need for other processes, depending on the application.

Exotic metals, lets define exotic. I call all high temp alloys exoctic, these include Inconel (in its various alloys), Hastelloy, Titanium Aluminide (alpha and gamma). All of these materials come in various forms.

Inconel is used quite extensively in turbos, it is easily investment cast and holds tolerances quite easily. It is a bear to machine. Depending on the alloy, it is about impossible to drill. I have seen it in other applications. Inconel has it down sides, it is somewhat brittle and rather expensive.

I am not aware of any engine uses for Hastelloy.

Titanium Aluminide is used for various engine components. Jet engines are using it for compressor blades. It can be cast using investment casting but tough to manage casting size changes. It is much more difficult to machine then Inconel. It is very brittle. Very light with a density of 4.0 g/cm^3 according to wiki.

yoshmyster

If there is 70% wasted fuel after the initial combustion. It would make sense to have a secondary engine behind (like a jet). Sure all compact cars would be a size of a rig but if one can get 70% usage out of the fuel it'll be worth it [:D].

select-fire

Cost. Way too expensive to make such an item.

pwillie

Solyndra! To make an engine more efficient.Like less moving parts,thst was the hope of the Wankel[;)]

jonk

Fuel cells. Rather than burn the gas, seperate out the hydrogen and use it to power an electric motor. The only byproducts are carbon and water and a little nitrogen. While getting hydrogen from water is a pipe dream (pardon the pun) getting it from petrochemicals or natural gas is quite doable.

bpost

quote:Originally posted by pwillie
Solyndra! To make an engine more efficient.Like less moving parts,thst was the hope of the Wankel[;)]


The Wankel is a fantastic smooth power producing engine with great power for size and free spinning high RPM's that would grenade most other reciprocating engines. The life expectancy is greater than a piston engine too. The issue that killed the Wankel in the USA is emission standards from the EPA.

asphalt cowboy

Yamaha uses a ceramic composite cylinder liner in their Star line of motorcycles.

grumpygy

In the 90's they were testing Military truck with ceramics. From what I saw it was going very good. They could even run the engines without any antifreeze. This testing was going on on a army base north of Detroit.

Little base, I had to go there for a school on a new vehical for the Marines our classs was in the same building as these trucks. They were testing the M1 tank at the same time.

Mr. Perfect

ceramics stress crack.

Wankel is the best route, IMO.