Direct Observations of Cracks and Voids in Structural Materials by X-ray Imaging Using Ultra-bright Synchrotron Radiation
Direct Observations of Cracks and Voids in Structural Materials by X-ray Imaging Using Ultra-bright Synchrotron Radiation
复制标题
使用超亮同步加速器辐射通过 X 射线成像直接观察结构材料中的裂纹和空隙
DOI：
10.2355/isijinternational.43.589
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发表时间：
2003
影响因子：
1.8
通讯作者：
J. Matsui
中科院分区：
文献类型：
--
作者：
T. Nakayama;Fumio Yuse;Y. Tsubokawa;J. Matsui
利用SPring-8的BL 24 XU超亮同步辐射X射线束，对带有人工圆柱孔的丙烯酸树脂、A7075铝合金、A6063铝铸件、含裂纹或孔洞的低碳钢和含夹杂物的低合金钢进行了折射衬度X射线成像实验。常规的吸收衬度X射线成像实验也进行了比较。X射线束由硅双晶控制为单色，并由狭缝准直。样品和探测器之间的距离从0到3 m变化，X射线能量为15到25 keV。通过X射线胶片和/或X射线CCD相机拍摄照片。结果表明，折射成像法比吸收成像法对丙烯酸树脂中的人工圆柱孔成像清晰得多。在铝合金和低碳钢中也观察到明显的疲劳裂纹。X射线成像显示低合金钢中存在MnS非金属夹杂物。通过成像可以清楚地检测到铝铸件中的空隙缺陷。此外，还成功地利用高分辨率X射线CCD摄像系统对铝合金拉伸断裂进行了原位观察。利用非对称反射技术进行的X射线成像实验也取得了较好的观测效果。由此可见，超亮同步辐射X射线成像技术在材料断裂研究中具有重要的应用价值。
Refraction contrast X-ray imaging experiments were conducted on acrylic resin with an artificial cylindrical hole, A7075 aluminum alloy, A6063 aluminum castings, mild steel with cracks or voids, and low alloy steel with inclusions, using a ultra-bright synchrotron radiation X-ray beam in BL24XU hutch C of SPring-8. Conventional absorption contrast X-ray imaging experiments were also done for the comparison. The X-ray beam was controlled to be monochromatic by Si double-crystals and collimated by a slit. The distance between the sample and the detector was changed from 0 to 3 m, and the X-ray energy was 15 to 25 keV. Photographs were taken by X-ray film and/or X-ray CCD camera. As a result, the refraction imaging method gave a much more distinct image of the artificial cylindrical hole in acrylic resin as compared with the absorption method. The fatigue cracks in aluminum alloy and mild steel were also distinctly observed. The X-ray imaging revealed the presence of MnS nonmetallic inclusions in low alloy steel. Void defects in aluminum castings were clearly detected by the imaging. In addition, in-situ observation of tensile fracture of aluminum alloys using a high resolution X-ray CCD camera system was successfully conducted. The observations by use of asymmetric reflection technique for X-ray imaging experiment were also well performed. From above, the X-ray imaging method using ultra-bright synchrotron radiation is concluded to be very useful for fracture research of materials.