摘要
Based on the Almen method, the authors have modified this test method so that the results of the simple test can be correlated to the absolute values of residual stress measured by conventional methods such as X-ray diffraction, or mechanical techniques. The technique utilizes changes in the strain of standardized test substrates, which is measured by BHP-700℃ temperature-compensated resistance strain gauges, as an indication of the level of residual stress in the sprayed coatings. Based on the concept that the sprayed coating on the surface of substrate with residual stresses acts a force (N) and bending moment (M) on the test piece, the calculating equation of residual stress in the coatings has been proposed. The results of the test method showed that the technique is potentially reliable and accurate, although deficiencies and many controversies are still exist.
Based on the Almen method, the authors have modified this test method so that the results of the simple test can be correlated to the absolute values of residual stress measured by conventional methods such as X-ray diffraction, or mechanical techniques. The technique utilizes changes in the strain of standardized test substrates, which is measured by BHP-700℃ temperature-compensated resistance strain gauges, as an indication of the level of residual stress in the sprayed coatings. Based on the concept that the sprayed coating on the surface of substrate with residual stresses acts a force (N) and bending moment (M) on the test piece, the calculating equation of residual stress in the coatings has been proposed. The results of the test method showed that the technique is potentially reliable and accurate, although deficiencies and many controversies are still exist.