The development of the dislocation evaluation method by high-intensity, high-resolution pulsed neutron

2015 Fiscal Year Final Research Report

• Project/Area Number: 26600146
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Quantum beam science
• Research Institution: Japan Atomic Energy Agency
• Principal Investigator: HARJO Stefanus 国立研究開発法人日本原子力研究開発機構, 原子力科学研究部門 J-PARCセンター, 研究主幹 (40391263)
• Co-Investigator(Renkei-kenkyūsha): KAWASAKI Takuro 国立研究開発法人日本原子力研究開発機構, 原子力科学研究部門 J-PARCセンター, 研究員 (20626361)
• Project Period (FY): 2014-04-01 – 2016-03-31
• Keywords: 中性子回折 / 飛行時間法 / 転位密度 / 転位配列 / 強度 / その場測定

Outline of Final Research Achievements

We challenged to establish a dislocation evaluation technique for the time-of-flight neutron diffraction with high-intensity-resolution, which was needed to elucidate the microstructure effects on deformation mechanisms of metallic materials. In this study, we focused on a lath martensitic steel because it showed large changes in width and shape of diffraction profiles during deformation, and carried out dislocation evaluations using two kinds of methods. The evaluation using the profile separation method based on the peak width gave possibly un-correct results because of ignoring the profile tails. The evaluation using the convolution method of whole profile gave reliable dislocation density results and also information of dislocation arrangement which was related to the large work hardening at the beginning of deformation. The establishment of dislocation evaluation technique led also to the elucidation of microstructure changes associated with deformation of other materials.

Free Research Field

量子ビーム科学