含Ce的CuCrZr合金退火前后在氯化钠溶液中的电化学性能

退火作为工业上控制和改变金属材料组织、结构和性能的重要手段,在生产中具有很重要的意义.采用电化学工作站研究了含稀土Ce的CuCrZr合金退火前后在氯化钠溶液中的电化学性能.结果表明,稀土元素Ce的添加有利于提高合金的耐蚀性.对于未退火的研究试样,Ce的添加降低了合金的腐蚀电流;而对于经过退火处理的试样,退火增加了合金在氯化钠溶液中的腐蚀电流,但Ce对耐蚀性的提高作用依旧存在,它的存在可减缓退火对合金耐蚀性的降低作用.同时,试样在1 mol/L NaCl水溶液中的阻抗谱表明:退火提高了试样表面产物膜的致密度,增加了腐蚀反应的难度.     

Manufacturing and High Heat Flux Testing of Brazed Flat-Type W/CuCrZr Plasma Facing Components

Water-cooled flat-type W/Cu Cr Zr plasma facing components with an interlayer of oxygen-free copper(OFC) have been developed by using vacuum brazing route.The OFC layer for the accommodation of thermal stresses was cast onto the surface of W at a temperature range of 1150oC-1200 oC in a vacuum furnace.The W/OFC cast tiles were vacuum brazed to a Cu Cr Zr heat sink at 940 oC using the silver-free filler material Cu Mn Si Cr.The microstructure,bonding strength,and high heat flux properties of the brazed W/Cu Cr Zr joint samples were investigated.The W/Cu joint exhibits an average tensile strength of 134 MPa,which is about the same strength as pure annealed copper.High heat flux tests were performed in the electron beam facility EMS-60.Experimental results indicated that the brazed W/Cu Cr Zr mock-up experienced screening tests of up to 15 MW/m~2 and cyclic tests of 9 MW/m~2 for 1000 cycles without visible damage.     

Achieving High Strength and High Electrical Conductivity in a CuCrZr Alloy Using Equal-Channel Angular Pressing

In the present work, a CuCrZr alloy characterized by ultrafine grains and nanoscale particles was prepared by equalchannel angular pressing(ECAP) at 450 °C. A desired combination of a tensile strength(580 MPa) and an electrical conductivity(81% International Annealed Copper Standard) is simultaneously obtained in the as-ECAP-processed CuCrZr alloy without additional aging treatment. The improved properties can be mainly attributed to the ultrafine grains and nanoscale precipitates. This processing may pave a way to develop the CuCrZr alloys having high strength and high electrical conductivity for engineering applications.     

Be/CuCrZr合金扩散连接的界面行为

在不同表面粗糙度的Be侧镀Ti/Cu中间层,采用热等静压技术将铍与CuCrZr合金进行扩散连接。通过AES、SEM(EDS)、室温剪切试验和XRD等分析其镀层形貌及成分、界面特性与相结构。结果表明:9μmTi、35μmCu镀层带征较为均匀,影响扩散连接强度的元素较少,采用双靶单侧镀复合膜的工艺有利于减少Ti镀层的氧化;界面剪切强度明显提高,最高可达243MPa,Be表面粗糙度的不同对强度影响不明显;Be-Ti连接强度高,剪切断裂均发生在Cu镀层。     

熔铸法制备VC/CuCrZr复合材料及其微观组织与性能

用熔铸法制备了VC颗粒增强CuCrZr基复合材料,并探讨了热处理工艺对材料组织和性能的影响.结果表明,以微量Cr和Zr强化的铜基体,经过适当的时效处理,可同时发挥弥散强化和复合强化两种机制的增强作用,显著提高铜基复合材料的力学性能.     

CuNiCoBe与CuCrZr合金电极的点焊性能比较及其失效分析

文中对比研究了CuNiCoBe合金与CuCrZr合金电极点焊镀锌钢板的性能,并利用超景深显微镜,光谱仪、XRD等分析测试手段研究了电极表面的剥落、端部塑性变形的程度及表面合金层的成分和物相等,分析了电极失效机理.结果表明,在相同的点焊工艺参数下,CuNiCoBe电极点焊寿命达到3 500点,为CuCrZr电极寿命1 500点的2.3倍.CuCrZr电极寿命低于CuNiCoBe电极的原因在于CuCrZr合金强度硬度低,易形成剥落孔洞、塑性变形大,电极端部尺寸增大明显.表面合金层的成分和产物和CuNiCoBe电极的不尽相同.     

Potential and limits of water cooled divertor concepts based on monoblock design as possible candidates for a DEMO reactor

In this paper water-cooled divertor concepts based on tungsten monoblock design identified in previous studies as candidate for fusion power plant have been reviewed to assess their potential and limits as possible candidates for a DEMO concept deliverable in a short to medium term (“conservative baseline design”). The rationale and technology development assumptions that have led to their selection are revisited taking into account present factual information on reactor parameters, materials properties and manufacturing technologies.For that purpose, main parameters impacting the divertor design are identified and their relevance discussed. The state of the art knowledge on materials and relevant manufacturing techniques is reviewed. Particular attention is paid to material properties change after irradiation; phenomenon thresholds (if any) and possible operating ranges are identified (in terms of temperature and damage dose). The suitability of various proposed heat sink/structural and sacrificial layer materials, as proposed in the past, are re-assessed (e.g. with regard to the possibility of reducing peak heat flux and/or neutron radiation damages). As a result, potential and limits of various proposed concepts are highlighted, ranges in which they could operate (if any) defined and possible improvements are proposed.Identified missing point in materials database and/or manufacturing techniques knowledge that should be uppermost investigated in future R&D activities are reported.This work has been carried out in the frame of EFDA PPPT Work Programme activities.     

结构钢电阻焊新材料——铜铬锆稀土电极合金的研究

研究了结构钢电阻焊铜铬锆稀土电极合金的真空熔铸、热冷加工和热处理工艺,研制的合金化学成分稳定,合金的性能HB≥150、σ_b≥495MPa、IACS≥80%、T_c≥580℃。使用结果证明在铜铬锆合金中加入稀土可以显著地提高合金的耐磨性。     

Tribological Properties of Al<Subscript>2</Subscript>O<Subscript>3</Subscript>/CuCrZr Composites

Al₂O₃ particles reinforced Cu–Cr–Zr alloy matrix composite was fabricated through a powder metallurgy plus hot extrusion process by using the water atomization Cu–Cr–Zr powder as raw material. The effect of aging treatment on the tribological behavior of the composite was investigated. Experimental results show that tiny coherent precipitated phases were formed in the matrix after proper aging treatment and therefore good combination properties could be obtained. The wear rates of the Al₂O₃/CuCrZr composite and its matrix alloy were obviously influenced by the aging treatment, wherein the best wear resistance was reached at the aging temperature corresponding to the highest Vickers hardness. The major reason was that the depth of plastic deformation in the subsurface region was dramatically decreased due to the improvement of mechanical properties of the matrix, and therefore adhesion induced surface materials loss could be markedly alleviated. By comparing with the SiC20 vol%/Cu composite, it is indicated that the Al₂O₃/CuCrZr composite exhibited much better wear resistance as well as higher electrical conductivity.     

等径角挤压工艺对固溶状态CuCrZr合金性能的影响

研究了等径角挤压工艺(ECAP)对固溶态CuCrZr合金性能的影响.结果表明,随着挤压道次的增加,合金的硬度迅速上升,导电率略有下降.时效前经ECAP处理可以加速时效初期第二相的析出,使合金的性能以较快的幅度上升.ECAP六道次试样400℃时效1 h,导电率和硬度分别为81.1%IACS和200 HV30.