Why Does Heated Wire Remain Elongated After Cooling?

AI Thread Summary
The discussion centers on the thermal expansion and potential creep of a 3mm iron-chromium-aluminium wire that has been heated to approximately 1000K and then cooled, resulting in an unexpected permanent elongation of about 8mm. Participants suggest that the wire likely stretched while hot, possibly due to creep, especially since it was fixed under tension. Creep is a common phenomenon in steel at high temperatures, and the cooling method may also influence the wire's final state. Observing the wire's behavior during future heating cycles could provide further insights into its properties. The conversation highlights the importance of temperature and tension in the material's response to thermal changes.
130mikep
Messages
6
Reaction score
0
thermal expansion of wire??

hi I've got this 3mm iron-chromium-aluminium wire fixed at both ends, heated to approx 1000k (max 1200K) and suspended horizontally approx 1metre long.

the wire it would appear has been extended by about 8mm, similar to what would be expected when its hot, only it stays this long when brought back down to room temperature!

so my question is: why?! lol

could it really be creep?

thanks, mike
 
Last edited:
Engineering news on Phys.org


The wire probably stretched while it was hot and sagging down. If the wire stretched then it must also have gotten thinner.
 


Was it fixed under significant tension? If it was, then yes, it could be creep.

Otherwise, it may depend on how it was cooled.
 


Creeping is absolutely normal for steel at 1000K, much more at 1200K. Even over a short time with a moderate load.

Then, if your wire was new, you can have glowed it from some initial metallurgical state, like cold drawn. To decide what effect it was, just observe if the wire creeps further next time.
 

Thread 'How could I make it so ferrofluid drops do not coalesce?'

Hello! I've been brainstorming on how to prevent a lot of ferrofluid droplets that are in the same container. This is for an art idea that I have (I absolutely love it when science and art come together) where I want it to look like a murmuration of starlings. Here's a link of what they look like: How could I make this happen? The only way I can think of to achieve the desired effect is to have varying droplet sizes of ferrofluid suspended in a clear viscous liquid. Im hoping for the...
View full post »

Thread 'How do you fabricate microfluidic chips in your lab?'

Hello everyone! I am curious to learn how laboratories handle in-house chip manufacturing using soft lithography for microfluidics research. In the lab where I worked, only the mask for lithography was made by an external company, whereas the mold and chip fabrication were carried out by us. The process of making PDMS chips required around 30 min–1 h of manual work between prepolymer casting, punching/cutting, and plasma bonding. However, the total time required to make them was around 4...
View full post »

Similar threads

B New Theory Explaining Why Certain Alloys don't change size when heated
Replies
1
Views
2K
Why does the snapped wire create heat?
Replies
11
Views
2K

Hot Threads

Recent Insights

Back
Top