Residual stress analysis of plasma sprayed coatings through the weak magnetic field testing method

A proposed technique for swiftly evaluating coating stress variations involves utilizing weak magnetic detection under geomagnetic field conditions. This method examines the surface magnetic induction strength on uncoated test specimens, analyzing the magnetic induction change pre- and post-spraying. Employing the Almen test method, the assessment of specimen deflection and residual stress magnitude affirms the viability of weak magnetic detection for assessing coating residual stress. The experimental findings establish a direct link between the rate of magnetic induction intensity change and residual stress magnitude through polynomial fitting, suggesting that weak magnetic detection can preliminarily analyze coating stress variation.