摘要
第二代高温超导涂层导体由于具有高的不可逆场和在高磁场下的优异导电性能成为目前各国竞相研发的热点。涂层导体制备需要金属材料作为基体,这就要求基体带材有较强立方织构、小的晶界取向差、均匀的晶粒尺寸和较高的表面质量,镍钨合金是目前已知的理想基体材料之一。采用显微硬度实验、EBSD(电子背散射衍射分析)和XRD等技术研究冷轧变形量为98%的Ni-5%W(原子分数)合金基带在不同温度退火后立方织构的变化。EBSD数据结果表明,合金基带在700,900和1200℃退火相同时间后,随着退火温度的升高,晶粒大小分布虽逐渐变均匀,晶粒的形状也更趋向于等轴晶,但平均晶粒尺寸迅速增长,从4.29μm增加到53.80μm。基带的立方织构百分含量从49.7%快速增加到93.8%,小角度晶界的含量也由10.4%增加到79.6%,而Σ3晶界长度百分比却由47.70%下降到9.68%。同时,XRD的ω扫描半高宽(FWHM)结果显示,随着退火温度的升高,半高宽变化程度不大,从5.9增加到6.8后又下降到5.9,这说明在1200℃时立方织构已很尖锐。该研究结果表明较高的退火温度更有利于获得理想取向的立方织构。
The second generation of coated superconductor was paid broad attention worldwide for its high irreversibility field and excellent conductivity in the high magnetic field. As the substrate metal of coated conductor, strong cube texture, small range of grain boundary orientation, uniform grain size and high surface quality were needed. Ni-W alloy was one of the known ideal substrate materials. The formation of cubic texture was studied in Ni-5% W（ atom fraction） alloy substrates after cold rolling and annealing. The cubic texture of cold-rolled samples annealed at various temperature was characterized using EBSD, XRD and other techniques. With the an- nealing temperature increasing, grain size distribution became more uniform and the grains approximately approached equiaxial strueture, while the average grain size grew rapidly, from 4.29 to 53.80 μm. The cubic texture component, which was 49.7% at 700 ℃, was accelerated to 93.8% at 1200 ℃. Length percentage of low angle boundary was 10.4% at 700 ℃, then increased to 79.6% at 1200 ℃ , while the proportion Σ3 boundary showed the opposite trend, dropping from 47.70% to 9.68%. X-ray rocking curves sug- gested the FWHM first increased from 5.9 to 6.8, and then decreased to 5.9. The present results demonstrated that ideal cubic texture could be more easily formed when annealed at high-temperature.
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2012年第6期893-897,共5页
Chinese Journal of Rare Metals
基金
国家自然科学基金资助项目(51171215)
