Question

A specimen of commercially pure copper has a strength of 240 MPa. Estimate its average grain diameter using the Hall-Petch equation.

Answer 1

3.115×
`10^(-3)` meter

Step-by-step explanation:

hall-petch constant for copper is given by

`S_0`=25 MPa

k=0.12 for copper

now according to hall-petch equation

`S_Y`=
`S_0` +
`(K)/(√(D))`

240=25+
`(0.12)/(√(D))`

D=3.115×
`10^(-3)` meter

so the grain diameter using the hall-petch equation=3.115×
`10^(-3)` meter