What is the effect of temperature on Young's modulus?

Young's modulus generally decreases with increasing temperature due to increased thermal vibrations of atoms.

When a material is heated, its atoms vibrate more rapidly, which causes the bonds between them to stretch and weaken. This leads to a decrease in the stiffness of the material and a corresponding decrease in Young's modulus. This effect is more pronounced in materials with weaker interatomic bonds, such as polymers, than in those with stronger bonds, such as metals.

The relationship between Young's modulus and temperature can be described by the coefficient of thermal expansion, which is a measure of how much a material expands or contracts when its temperature changes. As the temperature of a material increases, its coefficient of thermal expansion also increases, which leads to a decrease in Young's modulus.

In some materials, such as metals, the decrease in Young's modulus with temperature can be partially offset by an increase in the number of dislocations, which are defects in the crystal structure that allow atoms to move more easily. This effect can cause the material to become more ductile at higher temperatures, even as its stiffness decreases.

Overall, the effect of temperature on Young's modulus is an important consideration in the design and use of materials, particularly in applications where the material will be exposed to high temperatures.