摘要：
By using vacuum sintering method, the shielding materials made of iron-tungsten-carbon-boron (Fe-W-C-B) alloys with different boron (B) contents were prepared. The influences of different B contents on mechanical properties, shielding performance and microstructures of the alloys were investigated. The research results showed that with increasing B content, the fracture of alloys changed from plastic to brittle fractures and the higher the B content was, the more serious the brittle fracture. Moreover, the content of brittle amorphous phase FeWB increased and therefore the hardness and density of alloys increased at first and then reduced. When the B content was 2.5%, the alloy phase was mainly composed of Fe2B, Fe3(C, B) and alpha-Fe phases, with compact microstructure, shown as continuous network microstructure and tiny, long, round rod-like microstructure. In this case, the density, tensile strength and hardness of alloys were 10.05 g/cm(3), 410 MPa and 468 HV, respectively. The gamma-ray shielding performance of the alloy reduced at first, then increased and finally declined with the increase of B contents. When the B content was 1.5%, the half-value thickness reached to the minimum (about 6.36 mm). The transmittance of neutron shields reduced at first and then increased in a low-energy zone (0-4 MeV). When the B content was 2.5%, the alloys showed the lowest transmittance about 0.10842. (C) 2019 Elsevier B.V. All rights reserved.
作者机构：
[徐守龙; 邹树梁] School of Resource Environment and Safety Engineering, University of South China, Hengyang;Hunan;421001, China;Department of Engineering Physics, Tsinghua University, Beijing;100084, China
通讯机构：
[Xiao, Weiwei] U;[Deng, Hua] C;Univ South China, Sch Mech Engn, Hengyang 421001, Hunan, Peoples R China.;CNNC Jianzhong Nucl Fuel Corp, Yibin 644000, Sichuan, Peoples R China.
关键词：
High temperature oxidation;Mechanical properties;Sputtered TiN coating;Substrate bias
摘要：
This study is aimed to investigate the influence of substrate bias on mechanical properties and high temperature oxidation of sputtered TiN coating which is prepared on the surface of Zr-4 alloy. The microstructures of coatings were characterized by using scanning electron microscope (SEM) and X-ray diffractometer (XRD). The thicknesses of coatings were detected by examining the cross-sectional SEM image. The adhesion property was tested by using scratch testing. The residual stress was measured by using the XRD method. The tensile property was evaluated by standard tensile test. And the high temperature oxidation performance in air condition was also assessed. It was revealed that substrate bias has a significant influence on crystalline structure, surface micromorphology, thickness, adhesion strength, and residual stress. Nevertheless, tensile property and high temperature oxidation performance are affected by substrate bias indistinctively. From the cross-sectional SEM image, it can be found that thicker coating can be obtained in unit time with a lower substrate bias. The adhesion property does not vary monotonically with increasing negative substrate bias and the coating deposited with -100 V possesses highest critical load. The sputtered TiN coatings demonstrate a compressive residual stress and the magnitude of residual stress of coatings prepared with -200 V and -300 V is higher than that of coatings prepared with -50 V and -100 V. The tensile test reveals that there is no obvious difference between tensile properties of TiN-coated specimens prepared with different substrate bias and the Zr-4 alloy specimen. And the weight gains of high temperature oxidation of TiN-coated specimens with different substrate bias are almost the same and are lower than uncoated Zr-4 alloy specimen. The XRD and EDS results show that TiN coating is oxidized and cracked and the internal Zr-4 substrate is also oxidized when the specimen is exposed to high temperature circumstance for a long time. (C) 2019 Elsevier B.V. All rights reserved.
作者机构：
[徐守龙; 邹树梁; 匡雅; 郭赞] School of Environmental and Safety Engineering, University of South China, Hengyang;Hunan;421001, China;[黄有骏] Nuclear Power Institute of China, Chengdu;Sichuan
通讯机构：
[Zou, S.] S;School of Environmental and Safety Engineering, University of South China, Hengyang, Hunan, China
作者机构：
[Xu, Shoulong; Zou, Shuliang] Univ South China, Sch Environm & Safety Engn, Hengyang 421001, Peoples R China.;[Xu, Shoulong] Tsinghua Univ, Dept Engn Phys, Beijing 100084, Peoples R China.;[Han, Yongchao; Qu, Yantao] China Inst Atom Energy, Beijing 102413, Peoples R China.
通讯机构：
[Zou, Shuliang] U;Univ South China, Sch Environm & Safety Engn, Hengyang 421001, Peoples R China.
关键词：
active pixel sensor;video monitor;radiation detector;radiation damage;radiation response;nuclear accident
摘要：
In this paper, we present the availability of an active pixel sensor (APS) with four transistors (4T) as a video monitor and radiation detector. Analyzing radiation damage must be one of the first steps in recovering from nuclear accidents, and the radiation response characteristic is the basis for the use of 4T-APS to detect radiation. The goal of this work is to suggest the use of cameras with 4T-APS in widely distributed irradiation detectors. The total ionizing dose (TID) of radiation damage on 4T-APS provided a threshold. Radiation tolerance was improved with the help of a radiation shielding structure. The radiation response showed integration time dependence and pixel information dependence, and greater radiation response was observed from the pixels with lower grayscale values. Two methods are suggested based on different monitoring scenes. This study can help to greatly improve nuclear accident emergency response and the safety of nuclear facilities.
