摘要
采用机械球磨和放电等离子烧结法(SPS)制备了W-0.5%ZrC-(1, 3)%Re(WZC1R,WZC3R)和W-0.5%HfC-(1,3)%Re(WHC1R,WHC3R)(质量分数)4种钨基材料,并对其微结构、力学性能和高温稳定性进行了测试与分析。WZC3R合金在500℃时的极限抗拉强度(UTS)高达728 MPa,600℃时UTS维持653 MPa,比SPS制备的纯W提升近2.1倍。弥散分布的纳米尺寸ZrC颗粒起到钉扎晶界和位错的作用,提升了材料强度,此外抑制晶粒粗化带来细晶强化作用。WHC3R在400℃时,其延伸率为13.9%,韧脆转变温度(ductile-brittle transition temperature, DBTT)介于300℃和400℃,比SPS制备的W-ZrC和纯W分别降低200℃和300℃。固溶元素Re通过增加可动滑移面的数量,降低引发塑性变形所需的临界应力,从而改善钨材料的韧性。SPS制备的4种钨基材料展现出优异的热稳定性,1600℃真空退火1 h后,试样的晶粒尺寸和维氏显微硬度均未显著变化。其原因是Re溶质原子使钨产生晶格畸变,抑制高温下钨原子的扩散,阻碍晶界迁移,减缓钨晶粒粗化的动力学过程,从而提升材料的高温稳定性。
Four kinds of tungsten-based materials,W-0.5wt%ZrC-(1,3)wt%Re(WZC1R,WZC3R)and W-0.5wt%HfC-(1,3)wt%Re(WHC1R,WHC3R)were prepared by mechanical ball milling and spark plasma sintering(SPS).The microstructures,mechanical properties and thermal stability were investigated.The WZC3R alloy exhibits a high ultimate tensile strength(UTS)of 728 MPa at 500°C and an UTS of 653 MPa at 600°C,which are about 2.1 times higher than that of SPSed pure W.The uniformly distributed nano-sized ZrC and HfC particles can pin the grain boundaries and dislocations,thereby increasing the strength and inhibiting grain coarsening.The WHC3R exhibits a total elongation of 13.9%at 400°C,and its DBTT is in the range of 300-400°C,which is about 200 and 300°C lower than that of SPSed W-ZrC and pure W,respectively.The addition of the solid solution element Re improves the toughness of W materials by increasing the number of available slip planes and reducing the critical stress needed to start plastic deformation.In addition,the four alloys show excellent high-temperature stability with no significant change in grain size and Vickers microhardness even after heat treatments at temperatures reach up to 1600°C.The Re element solidly dissolved in W leads to lattice distortion;it can inhibit the diffusion of W atoms at high temperatures,hinder the migration of grain boundary,and slow down the kinetic process of W grain coarsening,thus enhancing the high-temperature stability of the W materials.
作者
王慧
丁晨师
谢卓明
刘瑞
方前锋
王先平
刘长松
吴学邦
Wang Hui;Ding Chenshi;Xie Zhuoming;Liu Rui;Fang Qianfeng;Wang Xianping;Liu Changsong;Wu Xuebang(Institute of Solid State Physics,Hefei Institutes of Physical Science,Chinese Academy of Sciences,Hefei 230031,China;University of Science and Technology of China,Hefei 230026,China)
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2024年第5期1321-1331,共11页
Rare Metal Materials and Engineering
基金
国家基金委基金项目(52325103,12375260)
科技部国家磁约束核聚变能发展研究专项(2019YFE03110200)
中国科学院战略性先导科技专项(XDB0470303)。
关键词
钨合金
固溶强化
弥散强化
力学性能
高温稳定性
tungsten alloys
solution strengthening
dispersion strengthening
mechanical properties
thermal stability
