Measurement of stress factors and residual stress of a film by in situ X-ray diffraction during four-point bending

A method is proposed for the simultaneous measurement of the stress factors and residual stress state of a film by in-situ X-ray diffraction during four-point bending. The externally applied load acts as an additional degree of freedom in the stress-strain relation, which allows the problem to be solved for both residual stress and elastic moduli without assuming any grain interaction model. The procedure was tested on a galvanic nickel deposit and the predictions of existing grain interaction models were compared with the experimental results.