Stress Dependence of Hall Coefficient in a Nickel-base Superalloy

The paper presents the development of a non-destructive technique for selective residual stress measurement based on Hall coefficient measurements. The Hall coefficient method is anticipated to be less affected by spurious interference from microstructural changes as compared to other non-destructive techniques [1]. A lock-in measurement method was used to measure the Hall voltage non-destructively on a 1 mm thick Nickel-base superalloy IN100 specimen with adequate precision (0.03% standard deviation) and consistency. Linear stress dependence of the Hall coefficient was observed. It is found that there is an approximately 2% change of the Hall coefficient from stress-free condition to 200MPa tensile stress. The promising experimental results indicate the possibility of exploiting this technique for nondestructive measurement of subsurface residual stresses.