Single Tilt Method for Residual Stress Evaluation with 2D Detectors

摘要

When X-ray diffraction is used for residual stress measurement, high 29 peaks are typically used for enhanced 29 shift and better tolerance to the sample height error. But for thin films, coatings, or polymer materials, high 29 peaks may not be available or appropriate for stress measurement. As a result of large angular coverage with a 2D detector, residual stress can be measured with a single tilt angle. The diffraction vector coverage from low 29 angle diffraction ring can satisfy the stress or stress tensor measurement at a single tilt angle. The single tilt method can avoid the sample height error caused by changing the tilt angle, which is especially critical when measuring stress with a low 29 peak. Another advantage is the consistent depth of penetration due to a constant incident angle, which is especially suitable for residual stress measurement on coatings, thin films or samples with steep stress gradient. This paper introduces the single tilt method for stress evaluation with two-dimensional detectors, including experimental examples on coatings and polymers.