Very high temperature flexible material?
Thread Starter
|
Hotshot
Joined: Oct 2002
Posts: 18,488
Likes: 22
From: The Big, Oregon
Very high temperature flexible material?
I am working on a project that requires a reed valve able to withstand 1100-1500f for as long as possible. I have ruled out stainless pretty much completely (most alloys lose their temper at 400-500f). Carbon-carbon looks potentially promising, but in dealing with carbon fiber reeds I have seen less of a lifespan than I want, plus the resin is the temperature limiting factor. I have tried researching titanium, but haven't found a whole lot. I know most of those alloys have a good fatigue life, but I haven't been able to find tempering info on them.
I know there is a quite diverse crowd here, and hopefully someone can provide some real first hand info on this.
I know there is a quite diverse crowd here, and hopefully someone can provide some real first hand info on this.
Mountain Pass
Joined: Jun 2011
Posts: 225
Likes: 2
From: Berryville AR
Titanium would be ok with the heat, it's used for TIG welding tips, but too brittle for a reed. The ti tips snap easily if you try to bend them. It would have to be some kind of alloy, but not a metal engineer so don't know what would work. Good luck.
Cargo Master
Joined: Apr 2003
Posts: 3,476
Likes: 224
From: Frequently frozen MN
Not that I really know anything about the subject, but...
F-16s have something on their exhaust nozzles called "turkey feathers" which do something to the aerodynamics. These appear to be thin and withstand a good deal of heat.
I just looked over at the F-16 forum ( f-16.net)and the thread I checked quated security reasons for not discussing the material. However, one of the posts mentioned that the Pratt and Whitney 229 ( one of the engine options, I believe) had black turkey feathers made from carbon fiber. Maybe or maybe not, but whatever is used might suit your needs -- and some of that info may be available.
I also wondered about the old V-1 buzz bomb. It used a pulsed jet engine that had some kind of a valve. Might not have needed to last too long however.
Good Luck,
hj
F-16s have something on their exhaust nozzles called "turkey feathers" which do something to the aerodynamics. These appear to be thin and withstand a good deal of heat.
I just looked over at the F-16 forum ( f-16.net)and the thread I checked quated security reasons for not discussing the material. However, one of the posts mentioned that the Pratt and Whitney 229 ( one of the engine options, I believe) had black turkey feathers made from carbon fiber. Maybe or maybe not, but whatever is used might suit your needs -- and some of that info may be available.
I also wondered about the old V-1 buzz bomb. It used a pulsed jet engine that had some kind of a valve. Might not have needed to last too long however.
Good Luck,
hj
Thread Starter
|
Hotshot
Joined: Oct 2002
Posts: 18,488
Likes: 22
From: The Big, Oregon
Some good thoughts here- And yes, TIG electrodes are tungsten, not titanium, and that material is very brittle. I hadn't thought of the variable exhaust nozzles. A little bit of research is turning up talk of heat resistant coatings and high failure rates so I'll have to dig a bit more in it.
Buzz bombs and similar pulse jets use a reed valve that is exposed to combustion temperatures, but it's an air inlet so it gets cooled by that. On this, it will see typically 600-800 continuously, with bursts as high as 1500, and occasional sustained highs of 1100-1200 for a few minutes. It will also need to cycle at up to 85 times a second, and sustained rates of around 50 times per second for up to hours at any given time.
I may have to get some titanium of various alloys and see how it behaves under high temperatures.
Buzz bombs and similar pulse jets use a reed valve that is exposed to combustion temperatures, but it's an air inlet so it gets cooled by that. On this, it will see typically 600-800 continuously, with bursts as high as 1500, and occasional sustained highs of 1100-1200 for a few minutes. It will also need to cycle at up to 85 times a second, and sustained rates of around 50 times per second for up to hours at any given time.
I may have to get some titanium of various alloys and see how it behaves under high temperatures.
Fleet Owner
Joined: Aug 2010
Posts: 21,255
Likes: 1,657
From: Reynoldsburg, Ohio
Maybe contact your local big university's engineering department---they might be helpful? Since you already have the parameters it needs to meet they could probably hone right in on something suitable.
Trending Topics
Postmaster
Joined: Apr 2000
Posts: 2,881
Likes: 1
From: North of Tulsa, Oklahoma
Here's some info on spring steel, which may help?... I have this bookmarked as i plan to make my own pulse jet some day.
Just curious, what are you making?
Just curious, what are you making?
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
Top 6 Best Deals Available on New Fords & Lincolns Right Now
Brett Foote
This Hennessey Takes the Expedition Tremor's Off-Roading Capability to the Next Level
Verdad Gallardo
Top 10 Fords at 2026 Carlisle Ford Nationals
Joe Kucinski
3 Best / 3 Worst Parts of Modern Ford Ownership
Brett Foote
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches
Pouria Savadkouei
Every 2026 Ford Engine Explained
Brett Foote
10 Ugly Ford Trucks That We Still Kinda Love
Joe Kucinski
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Thread Starter
|
Hotshot
Joined: Oct 2002
Posts: 18,488
Likes: 22
From: The Big, Oregon
I hadn't thought of Inconel, and I have worked with that stuff. I used to be certified to weld that stuff too. I'll have to do some research.
That pulse jet valve cutting method was pretty slick. Spring steel would work briefly, but once things got over about 600f it wouldn't return properly.
This is an exhaust reed valve in an experimental engine. I'm looking to make a high power density, high efficiency engine for a bike or snowmobile. The valve will have a turbo right after it so if it comes apart it'll get expensive fast.
That pulse jet valve cutting method was pretty slick. Spring steel would work briefly, but once things got over about 600f it wouldn't return properly.
This is an exhaust reed valve in an experimental engine. I'm looking to make a high power density, high efficiency engine for a bike or snowmobile. The valve will have a turbo right after it so if it comes apart it'll get expensive fast.
Thread Starter
|
Hotshot
Joined: Oct 2002
Posts: 18,488
Likes: 22
From: The Big, Oregon
Some digging around shows that Inconel 750 will most likely fit the bill, and it looks like I can use a cutting method similar to that shown in the video cigarxtc posted. This just might work. I'm going to have hours and hours of machining work and more design stuff, but this was one of the major stumbling blocks for this project.
Thread
Thread Starter
Forum
Replies
Last Post
Big_Fords
General NON-Automotive Conversation
10
Dec 21, 2004 07:32 PM
BuiltToughF250
General NON-Automotive Conversation
23
Mar 19, 2003 11:15 PM