Development of Radiation Resistant Vanadium Alloys with Extra-fine Grains and Dispersed Particles

超细晶弥散颗粒抗辐射钒合金的研制

基本信息

批准号：
11680494
负责人：
KURISHITA Hiroaki
金额：
$ 2.11万
依托单位：
Tohoku University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

项目摘要

In order to improve the resistance to radiation embrittlement that is the major concerns in the use of vanadim and its alloys for fusion structural applications, it is necessary to introduce the microstructure with fine grains and dispersed particles. The microstructure can be introduced by power metallurgy (P/M) method including mechanical alloying (MA) and hot isostatic pressing (HIP). For the P/M methods, however, there is a critical issue that solute oxygen and nitrogen contained in the starting powder and introduced through the fabrication processes cause a serious loss of ductility. In this study, first, a process for microstructural control to solve the issue was proposed and applied to fabricate vanadium alloys of V-(1.6-2.6)wt%Y. Then, the microstructure and mechanical properties of the fabricated alloys were evaluated with emphasis on the effects of vacuum annealing at 1273-1573 K and cold rolling up to 80%. Neutron irradiation was performed in JMTR to 0.7 dpa at 563 to 1073 K. Irradiated specimens were subjected to Vickers microhardness testing and TEM microstructural observation.The essential point of the process is that solute oxygen and nitrogen is consumed to form yttrium compounds as finely dispersed particles (Y_2O_3 and YN). It is shown that the vanadium matrix in the alloys is free from solute oxygen and nitrogen and the alloys exhibited good ductility even at 77K, as measured by impact three-point bending and dynamic tensile testing. The effect of annealing on the microstructure and mechanical properties is significant, but that of cold rolling is insignificant, indicating that the alloys in the annealed conditions show good ductility and strength without plastic working after HIP. The irradiated specimens showed radiation induced <110> twinning and much less radiation hardening than commercially available pure vanadium, indicating that the fabricated alloys have much improved radiation resistance.

为了提高对辐射覆盖的抵抗力，这是瓦尼迪姆及其合金用于融合结构应用的主要问题，有必要用细晶粒和分散颗粒引入微观结构。微观结构可以通过功率冶金（P/M）方法引入，包括机械合金（MA）和热等速度按压（HIP）。然而，对于P/M方法，有一个关键问题是，起始粉末中包含的溶质氧和氮，并通过制造过程引入导致延展性严重丧失。在这项研究中，首先提出了微观结构控制解决该问题的过程，并将其应用于V-（1.6-2.6）wt％y的制造钒合金。然后，评估了制造合金的微观结构和机械性能，重点是真空退火时在1273-1573 K时的影响，冷卷高达80％。 Neutron irradiation was performed in JMTR to 0.7 dpa at 563 to 1073 K. Irradiated specimens were subjected to Vickers microhardness testing and TEM microstructural observation.The essential point of the process is that solute oxygen and nitrogen is consumed to form yttrium compounds as finely dispersed particles (Y_2O_3 and YN).结果表明，合金中的钒基质不含溶质氧和氮，即使在77K处，合金也表现出良好的延展性，如撞击三分弯曲和动态拉伸测试所测量的那样。退火对微观结构和机械性能的影响很明显，但是冷滚动的影响微不足道，表明在退火条件下合金在没有髋关节后没有塑料的情况下显示出良好的延展性和强度。辐照样品显示辐射诱导的<110>孪晶和辐射硬化要比市售的纯钒，这表明制造的合金具有很大改善的辐射抗性。