Help with material selection - Car Piston

[chuffy]

Hi guys,
1st year mech engineering student looking to get some input on a recent project for my Material Selection class

I have to select an alternative material that could be used to make a car piston
For simplicity I'll only be forcusing on the piston itself, not the con rods or anything like piston rings

I have done some research and most car engines for public use are made from silicone aluminum alloy. The properties are light weight, easy to machine, available material and can be forged to increse strength

I've thought about suggesting a Titanium piston. Advantage would be less thermal expansion than aluminium, higher melting point ... Disadvantage would be cost to procure and it's harder to machine than aluminum.

As long as I pick a material of similar properties as what is currently used I'll be fine.

Does anyone have more innovative ideas? I think most of my class will be choosing titanium. as long as I state the positive and negative sides to the selected material, the answer is acceptable.

thanks for reading.

 

[Q_Goest]

Hi chuffy. welcome to the board. How about carbon pistons and ceramic coated or even solid ceramic pistons.

 

[chuffy]

cheers like the sound of ceramic just need to research it now
would they just be ceramic coated or the whole part made from ceramic (plus what kind of ceramic?)

 

[Q_Goest]

When I was in college 25 years ago, ceramic pistons were a big research area but it seems like it's tapered off since then. I don't do any work in that area so I can't tell you much. Take a look through the literature and see what you come up with. If you find anything you'd like to discuss, go ahead and respond here. I'd be curious to see what the state of the art is today for ceramic pistons.

I've read some of the research regarding carbon pistons and it sounds pretty interesting. There's a lot of information out there on them and may even be more heavily researched than ceramic. Don't know.

 

[chuffy]

Not sure if I should go with carbon-carbon or silicon carbide

 

[Q_Goest]

I might suggest going with carbon pistons, only because there seems to be lots of reference material out there that addresses the questions you need to address for your class (ie: advantages/disadvantages).
http://www.anl.gov/PCS/acsfuel/preprint%20archive/Files/36_3_NEW%20YORK_08-91_1088.pdf
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19940031440_1994031440.pdf