Ceramic Engine Parts - Does this look gimmicky?
Ceramic Engine Parts - Does this look gimmicky?
(OP)
https://www.3printr.com/first-entirely-ceramic-pis...
I don't have much knowledge of ceramics. This article popped up on my news feed, I can understand complex computer modelling can lead to unexpected optimisations of shape. The part that gets me is the wild beam geometry yet my Caterpillar diesel engines have more interesting optimizations of the big end of the rod.
Also, any guesses on the ceramic? I didn't think they had very good tensile strength. I see 69ksi listed for alumina. Maybe that's equal to what is normally used in connecting rods?
I don't have much knowledge of ceramics. This article popped up on my news feed, I can understand complex computer modelling can lead to unexpected optimisations of shape. The part that gets me is the wild beam geometry yet my Caterpillar diesel engines have more interesting optimizations of the big end of the rod.
Also, any guesses on the ceramic? I didn't think they had very good tensile strength. I see 69ksi listed for alumina. Maybe that's equal to what is normally used in connecting rods?
RE: Ceramic Engine Parts - Does this look gimmicky?
RE: Ceramic Engine Parts - Does this look gimmicky?
That con rod is something though. I have seen where different optimization strategies yield remarkably similar results, so I accept that such forms are not aberrations. Typical manufacturing methods drive shapes - con rods could be hollow, but those are tougher to make. With direct deposit additive manufacturing the shapes are less constrained.
I wonder if that thick strand is the oil line to lube the wrist pin.
RE: Ceramic Engine Parts - Does this look gimmicky?
RE: Ceramic Engine Parts - Does this look gimmicky?
RE: Ceramic Engine Parts - Does this look gimmicky?
RE: Ceramic Engine Parts - Does this look gimmicky?
je suis charlie
RE: Ceramic Engine Parts - Does this look gimmicky?
The joint doesn't need lube, it just needs to stay below some critical temp.
In fact if they made the pin from a different ceramic it might work fine dry.
The compression strength of these materials is fantastic.
Fracture toughness is about zero though, it does get better at high temp.
One issue with these 'geometry optimized' designs is how much redundancy is built in.
Ones that I have seen work used 4x or 5x load path designs.
Less than that and minor build flaws can doom you.
But my beef with AM is still there.
They can't tell you before they make the parts what the microstructure or properties will be at any specific location in any specific direction.
That isn't a process for making parts with low redundancy.
It works in many aerospace parts because they are replacing a heavy part that is 50x overbuilt with AM that is only 25x overbuilt.
Or an assembly of 32 parts with a single AM one in order to get special geometries and load isn't a design criteria (fuel nozzles).
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P.E. Metallurgy, consulting work welcomed
RE: Ceramic Engine Parts - Does this look gimmicky?
je suis charlie
RE: Ceramic Engine Parts - Does this look gimmicky?
Most Al alloys start with RT yield strength of 25-40ksi, and at 500F they are <1/4 of that.
Fairly low bar to clear.
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P.E. Metallurgy, consulting work welcomed
RE: Ceramic Engine Parts - Does this look gimmicky?
RE: Ceramic Engine Parts - Does this look gimmicky?
RE: Ceramic Engine Parts - Does this look gimmicky?
RE: Ceramic Engine Parts - Does this look gimmicky?
je suis charlie
RE: Ceramic Engine Parts - Does this look gimmicky?
At that temp a ceramic skirt will withstand some serious loads and impact.
I am not suggesting that this particular design is good, just that the concept of ceramic engine parts is very valid and actually fairly well understood. Remember the Army Adiabatic Deisel program? There is decades of data from that and other work.
The strength and toughness of ceramics when hot is truly impressive.
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P.E. Metallurgy, consulting work welcomed
RE: Ceramic Engine Parts - Does this look gimmicky?
je suis charlie
RE: Ceramic Engine Parts - Does this look gimmicky?
RE: Ceramic Engine Parts - Does this look gimmicky?
je suis charlie
RE: Ceramic Engine Parts - Does this look gimmicky?