A copper-zinc alloy has the following properties
|
Grain Diameter (mm)
|
Strength (MPa)
|
|
0.015
|
170 MPa
|
|
0.025
|
158 MPa
|
|
0.035
|
151 MPa
|
|
0.050
|
145 MPa
|
Determine
(a) the constants in the Hall-Petch equation; and
(b) the grain size required to obtain a strength of 200 MPa.