铸造技术2024，Vol.45Issue(2)：126-133,8.DOI:10.16410/j.issn1000-8365.2024.3275
NbC纤维增强共晶镍基合金的超高梯度定向凝固组织研究
Study on the Microstructures of NbC Fiber Reinforced Eutectic Nickel-based Alloy under Super-high Thermal Gradient Directional Solidification
摘要
Abstract
NbC fiber reinforced high-temperature eutectic nickel-based alloys were prepared using liquid metal cooling(LMC)directional solidification process.By using methods such as SEM,XRD,EDS,and EPMA,the microstructures and formation mechanisms of eutectic nickel-based alloys in different regions were analysed.The effects of various process parameters,including the pulling rates(v=2、7 and 12 μm/s)and melt temperatures(T=1 550、1 580 and 1 600℃),on the microstructures were studied.According to the differences in microstructural types and morphologies,directionally solidified eutectic nickel-based alloys can be divided into two regions,i.e.the start zone and the composite zone.The start zone is mainly composed of Nb-rich and W-rich block carbides,while the composite zone above the start zone is mainly composed of distributed NbC fibers arranged in a directional manner.The growth of NbC fibers during directional solidification can be divided into three stagess,namely,the initial stage,competitive stage,and stabilizing stage,based on the changes in morphology and special distribution of the NbC phase.As the pulling rate increases,the volume fraction of the NbC fiber increases,and the mass fractions of C,Nb,and W in the NbC fibers decreases,with a more significant decrease in the Nb content.As the melt temperature increases,the volume fraction,cross-sectional area,and spacing of the NbC fibers all increase,and the mass fractions of C,Nb,and W in the NbC fibers also increase,with a more significant increase in the W content.关键词
共晶镍基合金/碳化物纤维/凝固组织/熔体温度/抽拉速率Key words
eutectic nickel-based alloy/carbide fiber/solidified structure/melt temperature/pulling rate分类
矿业与冶金引用本文复制引用
裴家纬,杨敏,杨东伟,崔婷婷,杨帆,郭敏,杨文超,张军..NbC纤维增强共晶镍基合金的超高梯度定向凝固组织研究[J].铸造技术,2024,45(2):126-133,8.基金项目
国家自然科学基金(52031012,52301171) （52031012,52301171）
凝固技术国家重点实验室自主研究课题(2022-TZ-01) （2022-TZ-01）
国家科技重大专项(J2019-Ⅵ-20-135) （J2019-Ⅵ-20-135）
陕西省科技创新团队计划(2021TD-17) （2021TD-17）
