looking for a new candidate materials 2

[2stroketech]

I am involved in an R&D project and am looking for at least 15 new candidate materials in each catagory for use in a small two stroke engine. I thought it might be interesting to post this in here to see what ideas come up that we have not concidered.

The criteria for these materials are: Lighter weight, stronger, harder, better insulating properties, corrosion restant, high thermal shock resistant. Our goal is to improve upon the 2 stoke engine by setting aside cost for performance and durability.

#1 Piston
#2 Conecting rod
#3 Cylinder wall
#4 Crank
#5 Coatings

Have fun with this and think outside the box.

 

[tomwalz]

cermets / ceramics

Don't think anyone will pay much more for a more durable 2 stroke

Thomas J. Walz
Carbide Processors, Inc.

http://www.carbideprocessors.com

 

[arunmrao]

Why don't you try metal matrix composites .Lots of work is being done and processes for manufacturing established. There are many research groups actively pursuing in this area,you can get guidance from them.

Chocolates,men,coffee: are somethings liked better rich!!
(noticed in a coffee shop)

 

[CoryPad]

#1 Piston: I would consider forged Al (a strong 7XXX-T7XXX alloy if the temperature is not too high) and forged magnesium (a strong Mg-Zn T5 of T6 alloy if the temperature is not too high). If the temperature is too high, I would consider forged titanium (Timetal's LCB should be able to handle this).

I suppose metal matrix composites of the alloys above could be considered, but commercial vendors are limited. Plus, composites are more about stiffness-limited designs (in general), and I am not sure how much benefit one would derive.

#2 Connecting rod: I would consider forged titanium for this since it is a fatigue-limited two force member. I would apply deep rolling/roller burnishing to improve fatigue strength.

#3 Cylinder wall: Does this mean cylinder block, or a coating/liner for the block? A lightweight magnesium cylinder block appears feasible (see recent work by BMW, AVL and USAMP), and thermal spray coatings are commercial.

#4 Crankshaft: I don't think you will find anything better than forged steel that has been nitrided and rolled/burnished for this fatigue-limited component. Maybe titanium (titanium MMC for higher stiffness) with a nitrogen diffusion hardening process or DLC coating could be considered.

#5 Coatings: in addition to the ones already listed above, how about CrN, TiN, and WC.

Regards,

Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[jedward]

consider using "vanasil" an aluminum silicon composite
with a low cte, developed for engine parts and is castable

 

[2stroketech]

thanks for your replies. I have actually looked into some of your suggestions since they were posted here. A few are ery interesting and at least one is holding our interest quite well.