f the ASTM Grain size number of one piece of metal is 2 and

f the ASTM Grain size number of one piece of metal is 2 and the ASTM Grain size number of another piece of metal is 8, in which piece would you expect grain boundary diffusion to be most significant? a. They will both be the same b. The one with an ASTM Grain size of 2. Oc. The one with an ASTM Grain size of 8.

Solution

Option c is the correct answer

Grain boundary diffusion is most significantly the one with astm of grain size of 8

If grain are realtively bigger there will be high expect grain boundary diffusion.

Grain boundary diffusion is directly propotional to grain size