作者机构：
[Zhou, Juan; Xu, Wei; Chen, Yong; Qiu, Changjun] Univ South China, Sch Mech Engn, Hengyang 421001, Peoples R China.
通讯机构：
[Chen, Yong] U;Univ South China, Sch Mech Engn, Hengyang 421001, Peoples R China.
关键词：
Hierarchical structures;Surface area;High gas sensing properties
摘要：
The 3D flower-like WO3 nanoparticles with hierarchical structures were synthesized via a hydrothermal synthesis technique by using NaHSO4 as a capping agent. It demonstrates that surface area of the synthesized WO3 products can be manipulated via adjusting concentration of the capping agent NaHSO4 alone. The contribution of alcohol is to construct hierarchical structures with large specific surface areas, while the effect of SO42- is to inhibit the growth rate in the thickness direction of nanosheets which are self-assembled as well to form hierarchical structures. In addition, the gas-sensing property of sensors fabricated by 3D flower-like hierarchical structured WO3 nanoparticles were carried out by detecting different volatile gases with a lower concentration. All the samples are sensitive to ethanol gas and the WO3 3D flowers synthesized by 12 g NaHSO4 exhibit the excellent gas-sensitive property due to the highest surface area, the sensitivity as high as 96 under the concentration of 35 ppm at the optimal temperature of 350 degrees C, which implies that this 3D hierarchical structured WO3 nanoparticles could be used as a high-efficiency sensor candidate materials for selective detection of ethanol.
摘要：
The hybrid architectures comprising different types of nano-structured WO(3 )particles were prepared via facile surfactant-and template-free hydrothermal synthesis process. We demonstrate that morphology of the fabricated hybrid nanomaterials can be manipulated but the phases of those nanomaterials are still monoclinic and hexagonal hybrid structure via tuning the proportion of the reagents. The synthesis mechanism and the gas-sensing properties of the harvested nanomaterials have also been investigated. The as prepared WO3 nano-particles with hybrid architectures exhibit excellent gas-sensing functions to ethanol gas at the optimal temperature as low as 350 degrees C under the low concentration of 35 ppm, rendering them a promising sensing material for the on-site detection of ethanol. (C) 2019 Elsevier B.V. All rights reserved.
摘要：
The coatings are fabricated using austenitic stainless steel powder with various contents of carbon and boron via laser remanufacturing technique. A new synchronous lateral powder feeding device is adopted to avoid surface oxidation of molten pool. The authors find that the strength can be increased but plasticity is decreased of with the rise of boron content due to the formation of lamellar borides phase structures, which are very brittle and have high hardness. In addition, the authors also find that the tensile strength and hardness are enhanced by increasing the content of carbon, while the plasticity is deteriorated due to the formed carbide in the grain of the austenitic stainless steel coating. The coatings of austenitic stainless steel powder with various contents of carbon and boron are fabricated using laser remanufacturing technique. A new synchronous lateral powder feeding device is adopted to avoid surface oxidation of molten pool. The tensile strength and hardness are enhanced by increasing the content of carbon and boron, while the plasticity is deteriorated.
摘要：
We report a new organics cladding pretreatment technique to fabricate the austenitic steel coating via the laser remanufacturing technology and demonstrate that the organics cladding pretreatment could refine the grains and alleviate defects of the coating remarkably, which consequently enhances significantly the mechanical property. In addition, a new synchronous lateral powder feeding device is employed to prevent the nozzle from being blocked by organics coated powder and also protect the surface of the molten pool from being oxidized. This new organics cladding pretreatment technique may be important for the technological improvement in the mechanical property of coating fabricated via laser remanufacturing method.
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 Co, Yibin 644000, Sichuan, Peoples R China.
关键词：
Accident-tolerant fuel;Adhesion strength;Roughness of substrate;Sputtered TiN coating;Sputtering power
摘要：
TiN coatings have been deposited on Zr-4 substrates using direct current (DC) magnetron sputtering and the effects of roughness of substrate and sputtering power on the microstructure, thickness/deposition rate, adhesion properties and residual stress of coatings have been studied. The microstructures of the coatings were characterized by using scanning electron microscope (SEM) and X-ray diffractometer (XRD). The thicknesses of the coatings were detected by using SEM. The adhesion property was tested by using scratch testing. The residual stress was measured by using the XRD method. The results shown that the microstructure, thickness/deposition rate, adhesion properties and residual stress of coating are significantly influenced by the roughness of substrate and sputtering power. The roughness of substrate has significant influence on the surface micrograph of the coating but not obvious on the thickness/deposition rate. The microstructure, thickness/deposition rate is remarkably affected by the sputtering power. In addition, the adhesion property does not vary monotonically with the roughness of substrate and the sputtering power. The adhesion strength presents a trend of first rises and then declines with the increase of surface roughness of substrate and sputtering power. The residual stresses of the coating were compressive and the residual stress magnitude of the coatings deposited by relatively low sputtering power was higher than that deposited by relatively high sputtering power. (C) 2018 Elsevier B.V. All rights reserved.
作者机构：
[邱长军; 陈勇; 胡良斌; 黄鹤] School of Mechanical Engineering, University of South China, Hengyang, Hunan, 421001, China;[李怀林; 刘艳红] State Power Investment Corporation Central Research Institute, Beijing, 102209, China
摘要：
China low activation martensitic (CLAM) steel is the preferred candidate structural material for the Chinese international thermonuclear experimental reactor test blanket module (ITER TBM). Surface coating technology is often adopted to alter or improve the performance of materials. In CLAM steel, surface treatment plays a key role in rendering them appropriate for application in accelerator driven sub-critical system (ADS). Here, the authors prepare multiphase ceramic coatings on CLAM steel via laser in-situ reaction technology. The prepared multiphase ceramic coatings exhibit optimal corrosion resistance. The liquid lead-bismuth eutectic (LEB) corrosion resistance can be attributed to inferior wettability of interface between the LEB and multiphase ceramic coatings, faint shear force produced by LEB, and stable chemical and physical property of the coatings. Moreover, the irradiated specimens also display excellent corrosion resistance against helium ions irradiation. The CLAM steel is found to suffer significant corrosion in the flowing LEB. Such multiphase ceramic coatings as a protective layer on the ADS candidate structural materials CLAM steel surface exhibit the strongest LEB corrosion resistance, which can be applied to handle nuclear waste under extreme conditions.
