Development of fatigue damage evaluation technique by synchrtron radiation diffraction contrast tomography

2015 Fiscal Year Final Research Report

• Project/Area Number: 25420017
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Materials/Mechanics of materials
• Research Institution: Kobe University
• Principal Investigator: Shiozawa Daiki 神戸大学, 工学(系)研究科(研究院), 准教授 (60379336)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 非破壊評価 / 疲労 / 材料強度学 / 放射光

Outline of Final Research Achievements

A three dimensional grain mapping technique for polycrystalline materials, called X-ray diffraction contrast tomography (DCT), was developed at SPring-8. The shape and location of grains could be determined by DCT using the apparatus in a bending beam line of SPring-8. To evaluate the dislocation structure in fatigue tests, the rotation angle spread of individual grains was measured. The rotation angle spread is caused by mosaicity, which is related to the dislocation structure in a grain. The total misorientation in a grain is calculated from the rotation angle spread. The total misorientation in a grain was found to increase with increasing the number of loading in the low cycles fatigue test and high cycles fatigue test. The biggest change of the total misorientation obtained by DCT is observed at the diffraction plane with the largest schmid factor. Fatigue damage could also be evaluated from the total misorientation obtained by DCT measurement.

Free Research Field

非破壊検査，材料強度学