What is the effect of temperature on young's modulus above melting point?
Answers
Explanation:
If I get your question correctly, you're asking for a trend in the change of the Young's modulus of substances with changes in temperature. Kindly do correct me if I'm wrong here.
The answer is… you cannot have a fixed, unchanging trend. It all depends. The other guy who answered said that Young's modulus will decrease with decrease in temperature for most substances. I think he probably wanted to say that the Young's modulus would increase with the decrease in temperature for metallic bonded solids, because decrement in temperature should decrease the space between the constituent particles, thus increasing the interaction energy and also making the substance stiffer than it was previously.
Consider the case of a thermosetting plastic. You heat it up the first time, it gets stiff because of development of cross linkages. Now you cool it down to the same temperature it was at initially, it's still a lot stiffer than earlier because you can't get rid of the cross linkages.
Heat up a wet brick in a kiln and then cool it down again. Silicates cross link to make a very hard structure. It's still hard.
There goes the very idea of a trend in the change in Young's modulus.
I would say that your question could've been a better one had you specifically asked for a certain kind of substance, such as metals, maybe? Anyhow… not for me to judge.
If you meant metals, though, I believe you've got your answer.
If you wanted to know about the relationship between the Young's modulus and the coefficient of thermal expansion, (that's a VERY good question by the way), I suggest you make a thermodynamical analysis of a simple situation(which I trust you can do quite easily). You should end up with an inverse relationship in case of a simple metallic solid.
Answer:
When we increase the temperature of a material, up to the temperature of 400K, Young’s modulus decreases appreciably. When the temperature rises above the 400K, it decreases with a lower rate and at a very high temperature it is almost constant.
Explanation: