We were studying stress/strain curves in class when asked what the graph would look like if you stopped the test mid-way, then retested it. My professor was on a tangent about the effects of strain on ladders, and said "I don't know, I don't test my ladders every time I use them", and dodged the question. THIS was the answer I was looking for. Thank you so much for being a competent educator.
This helped a lot. The book I have to study often ignores explaining these mechanics but instead focuses more on the effects only. Thank you for this video.
Strain hardening is one of the most commonly used means of adding strength to an alloy. It is simply the use of permanent deformation to increase the strength of the metal. Other names for strain hardening are cold work and work hardening. No discussion of strain hardening would be complete without mention of the term “temper”. Temper is a description of the amount and type of processing done to a material at the mill, including cold work and thermal treatments.
What if during straining the metal in a tensile tests you took a hardness tests perpendicular to the pull axis - Would the hardness measurement be less, equal or greater than the hardness of the virgin metal?
1. Generally, more the number of slip system more will be ductility.Therefore, HCP is brittle. 2. More the number of slip systems, more will be the interaction between dislocations, more will be Strain hardening. So, HCP will undergoes least strain hardening means it should have high ductility. Points 1 and 2 are contradictory, kindly solve it.
Sir, how the complete stress-strain curve will be i.e. up to fracture point for both the cases. I feel the UTS is not going to change in normal case and strain hardened case. So what about the toughness, Are we going to loose some amount of toughness in strain hardened case? please explain.
Ductility, as measured by strain to fracture, decreases upon strain hardening. Thus the toughness, that is area under the curve, also decreases despite the increase in yield stress.
What I wrote in my 4th sem exam was- when various testing is done on a specimen the strain of the specimen increases and is known as strain hardening Le teacher- 0 marks awarded
Respected sir, I have a query up till now we studied that till uniform elongation the load increases because of strength hardening and the reason being the dislocations so as told by you if a material is loaded and unloaded then strain hardening will occur so will it not occur in case of an undeformed material which is loaded for the first time....
Unloading and reloading is done to highlight the strain hardening. But unloading is not necessary. The very fact that stress needs to be increased beyond yield stress for further increase in strain is itself an indication of strain hardening. A material with no strain hardening (called an ideal plastic material) will continue to to deform with increasing strain at the yield stress itself.
Thanks for your suggestions. many others have also expressed similar view. This was my first attempt at online teaching. If I ever make another series of video I will increase the pace.
@@introductiontomaterialsscience no sir u are perfect, teach asu feel comfort, it is understandable . And who want to high speed can use the you tube tool i.e × 1.25 or ×1.5 speed . Sir please elaborate on change of property with adding carbon ,sulpur , phosphorus in steel and other . Thank you
We were studying stress/strain curves in class when asked what the graph would look like if you stopped the test mid-way, then retested it. My professor was on a tangent about the effects of strain on ladders, and said "I don't know, I don't test my ladders every time I use them", and dodged the question. THIS was the answer I was looking for. Thank you so much for being a competent educator.
This helped a lot. The book I have to study often ignores explaining these mechanics but instead focuses more on the effects only. Thank you for this video.
May be because you are reading a textbook designed for civil / mechanical engineering.
@@k.rajashekarreddy9569 so which Book should I study to get these explanations.
@@youboy9586 Material science
@@k.rajashekarreddy9569 would you refer any book name
@@youboy9586 book name is Calister
You are one of the best Gurus of Materials Science Sir. Thanks a lot. Very clear in explanation
Thank you so much sir. For providing us quality education.
Thank you very much. So well explained, so helpful! I understand the strain hardening process better.
Very well explained.
So perfectly explained! Thank you professor!!!
Lovely explanation Dr.
Eye opener indeed ...thank you so much Dr
Thank you sir, nice explanation on strain hardening
Thank you very much sir this helped me a lot.
I love the way of teaching.
Thank you so much. Excellent explanation which really helps me to figure out the pictures！
Sir, thank you Sir. Very good Sir.
Question: Explain the process of applying Strain Hardening on a metal used for Aircraft structures.
Help me with my essay sir.
Strain hardening is one of the most commonly used means of adding strength to an alloy. It is simply the
use of permanent deformation to increase the strength of the metal. Other names for strain hardening are
cold work and work hardening. No discussion of strain hardening would be complete without mention of
the term “temper”. Temper is a description of the amount and type of processing done to a material at the
mill, including cold work and thermal treatments.
thank you very much sir...
What if during straining the metal in a tensile tests you took a hardness tests perpendicular to the pull axis - Would the hardness measurement be less, equal or greater than the hardness of the virgin metal?
how about the final failure strength? is it different in comparison with one time loaded sample?
Thank you sir
Thanks! easy to understand!
Freehand diagrams, very comforting. Even family like.
Excellent 😊 explained
awesome...nice explanation.
Hello sir! what will be the effect on Sigma UTS in strain hardening?
UTS also increases due to strain hardening.
Thanks for this Video
You are great sir 🙏
What about proportional limit and elastic limit during reloading.
Does the UTS also affected due to work hardening/strain hardening???
Teaching method is awesome
Thanks for the video
sir, what is "compliance of UTM machine"???
Respected Sir,
What is strain hardening coefficient?
The stress and strain can be related by true stress=constant*(true strain)^n. In this case n is called the strain hardening exponent.
it is the slope of line when we draw a graph between log(true stress) to log(true strain)
1. Generally, more the number of slip system more will be ductility.Therefore, HCP is brittle.
2. More the number of slip systems, more will be the interaction between dislocations, more will be Strain hardening. So, HCP will undergoes least strain hardening means it should have high ductility.
Points 1 and 2 are contradictory, kindly solve it.
Active slip planes in hcp is lesser
Shouldn't it be called "strain strengthening"... instead of "hardening"??
I agree with you. Strengthening appears to be more appropriate. But hardening has become quite common in actual usage.
what is the area of cross-section taken after deforming curve (second curve), like initial area or area after deformation in stress calculation
For true stress you take the instantaneous area but for engineering stress you take the initial area.
Sir, how the complete stress-strain curve will be i.e. up to fracture point for both the cases. I feel the UTS is not going to change in normal case and strain hardened case. So what about the toughness, Are we going to loose some amount of toughness in strain hardened case? please explain.
Ductility, as measured by strain to fracture, decreases upon strain hardening. Thus the toughness, that is area under the curve, also decreases despite the increase in yield stress.
Sir, What’s Strain Aging?
Where do we see practical application of strain hardening, ex in automobiles
Car body is an example. Thin steel sheets, if not strain hardened, will be too weak for the purpose.
@@introductiontomaterialsscience Thanks
What I wrote in my 4th sem exam was- when various testing is done on a specimen the strain of the specimen increases and is known as strain hardening
Le teacher- 0 marks awarded
Respected sir,
I have a query up till now we studied that till uniform elongation the load increases because of strength hardening and the reason being the dislocations so as told by you if a material is loaded and unloaded then strain hardening will occur so will it not occur in case of an undeformed material which is loaded for the first time....
good job
Unloading and reloading is done to highlight the strain hardening. But unloading is not necessary. The very fact that stress needs to be increased beyond yield stress for further increase in strain is itself an indication of strain hardening. A material with no strain hardening (called an ideal plastic material) will continue to to deform with increasing strain at the yield stress itself.
thanks
Nice lecture
I couldn't understand any thing because of accent , Indian ACCENT Is really hard and completely a new Language.
You are god 🙏
With all due respect Sir, you are good but you must increase speed otherwise people will be bored.
Thanks for your suggestions. many others have also expressed similar view. This was my first attempt at online teaching. If I ever make another series of video I will increase the pace.
@@introductiontomaterialsscience Dear Sir,
I have some doubts in mechanics how can I ask them.
@@savagedeuterium374 Why don't you look at some mechanics course. I am not knowledgeable in mechanics.
@@introductiontomaterialsscience no sir u are perfect, teach asu feel comfort, it is understandable .
And who want to high speed can use the you tube tool i.e × 1.25 or ×1.5 speed .
Sir please elaborate on change of property with adding carbon ,sulpur , phosphorus in steel and other .
Thank you
genius
kral
Does not talk about stages involved in work hardening
So skip this video if that's what u r looking for
Sir if u might speak in bilingual english nd hindi...more students will get advantage of ur knowledge....and thanks to you
One of worst GATE question paper given by iit-Delhi
Sorry, but I was not involved in setting it!
Thanks for this Video
Thank you sir
Thank you sir