低抖动Marx型触发源系统设计与实验

设计了一套具有低输出抖动的小型Marx型触发源系统。将充电、触发电源等进行了整体集成,结合高储能密度的四端型薄膜电容器设计,实现了系统的紧凑化,体积仅0.20 m3。将场畸变气体开关电极设计为环形轨道状,采用平面触发方式,以利于开关的低抖动输出和稳定工作。该系统输出电压、工作频率分别在10~90 kV,1~30 Hz范围内独立可调。以30 Hz重复频率工作300次,输出抖动的最大偏差(极差)仅为13.0 ns。相比30 Hz、30次结果,工作时间延长了9倍,输出抖动极差仅增加了38%,表现出极低的输出抖动和高的稳定性,是一种理想的高压触发源系统。     

304LN不锈钢表面激光熔覆钴基合金组织和性能

为了提高304LN不锈钢的耐磨性,延长控制棒导向筒组件使用寿命,采用激光熔覆技术在304LN不锈钢表面制备了Stellite 6钴基熔覆层.利用光学显微镜(OM)、能谱仪(EDS)、显微硬度计、摩擦磨损试验机、腐蚀试验装置等多种试验测试设备,分析了熔覆层组织形貌、成分、显微硬度、摩擦磨损性能及腐蚀行为,确定了多道多层钴基熔覆层的工艺参数.结果表明,熔覆层与基体之间形成了冶金结合,显微组织主要由平面晶区、胞状和柱状晶区、树枝晶区和等轴晶区组成.熔覆层硬度为500 ~ 550 HV,摩擦磨损系数为0.30 ~ 0.35,熔覆层均匀腐蚀速率和缝隙腐蚀速率分别为0.153 和0.143 mg/(dm2·d). 激光熔覆钴基合金可以有效提高304LN不锈钢表面的硬度、耐磨性能和耐腐蚀性能.     

超高温下核级316H不锈钢材料基础特性研究

第四代反应堆的一个基础特征是设计运行温度大多数在500~800℃,而传统压水堆材料体系和数据均在350℃以下得到,无法满足需求。本文通过广泛论证分析,筛选出了适用于大多数反应堆、最接近工程应用的316H不锈钢材料作为研究对象。开展800℃超高温下力学性能、比热容、平均线膨胀系数、晶间腐蚀特性、低周疲劳等试验研究,结果表明,316H不锈钢实测数据结果大幅高于规范标准值,长期应用温度限值建议不超过700℃,短时瞬态运行温度限值建议不超过800℃。该研究为第四代反应堆结构材料筛选和评价提供了依据。      

激光增材制造技术在堆内构件中的应用研究

针对钴基合金手工钨级氩弧焊（TIG）堆焊出现的质量问题,开展了钴基合金增材制造工艺研究,尤其是激光增材制造工艺参数的优化研究,然后对钴基合金增材制造层进行一系列的硬度、耐磨性能、耐腐蚀性能等试验研究,并与手工TIG堆焊层性能进行对比。对比结果表明,激光增材制造层的组织更加细化,硬度更加均匀,耐磨性与耐腐蚀性能均优于手工TIG堆焊层。      

Development and experimental study of large size composite plasma immersion ion implantation device

Plasma immersion ion implantation(PⅢ) overcomes the direct exposure limit of traditional beamline ion implantation, and is suitable for the treatment of complex work-piece with large size. PⅢ technology is often used for surface modification of metal, plastics and ceramics. Based on the requirement of surface modification of large size insulating material, a composite full-directional PⅢ device based on RF plasma source and metal plasma source is developed in this paper. This device can not only realize gas ion implantation, but also can realize metal ion implantation, and can also realize gas ion mixing with metal ions injection. This device has two metal plasma sources and each metal source contains three cathodes. Under the condition of keeping the vacuum unchanged, the cathode can be switched freely. The volume of the vacuum chamber is about 0.94 m~3, and maximum vacuum degree is about 5?×?10~(-4) Pa. The density of RF plasma in homogeneous region is about 10~9 cm~(-3), and plasma density in the ion implantation region is about 10~(10) cm~(-3). This device can be used for large-size sample material PⅢ treatment, the maximum size of the sample diameter up to 400 mm. The experimental results show that the plasma discharge in the device is stable and can run for a long time. It is suitable for surface treatment of insulating materials.