摘要
采用非自耗电弧熔炼方法经3次重熔制备了Ti45Al-6Nb-x Co合金(x=0,0.5,1,2,4,at%),研究了不同Co含量合金的组织结构和高温抗氧化性能。结果表明,增加合金中的Co含量能够细化α2+γ片层组织,促进合金中形成γ和B2相,并抑制α2相形成;合金中Co含量超过2at%会导致富Co相析出和组织粗化。1000℃空气中的恒温氧化结果表明,适量的Co合金化能够显著改善TiAl-Nb合金的高温抗氧化性能;Ti45Al-6Nb-1Co合金的氧化的抛物线速率常数约为1.36×10^-2 mg^2/cm^4h,较Ti45Al-Nb合金低约1个数量级;但Co含量超过2at%后,随Co含量增加,合金的氧化速率呈增加趋势。
Ti45Al-6Nb-xCo(x=0,0.5,1,2,4,at%)alloys were prepared using non-consumable arc melting method by three times of remelts.The microstructure and high temperature oxidation resistance of the alloys with different Co contents were investigated.The results show that increase of Co content in the alloy can significantly refine theα2+γlamellaer,promote the formation ofγand B2 phases while inhibit the formation ofα2 phase.Co-rich phase precipitates and microstructure coarsening are observed when the content of Co is higher than 2 at%in the alloy.The static oxidation results at 1000℃in air show that the oxidation resistance of TiAl-Nb alloy has been remarkably improved by appropriate Co alloying.The oxidation parabolic rate constant of the Ti45 Al-6 Nb-1 Co alloy is about 1.36×10^-2 mg^2/cm^4 h,lower than that of the Ti45 Al-Nb alloy by about one order of magnitude.However,once the content of Co exceeds 2 at%,increase of Co content in the alloy leads to an increase of the oxidation rate of the alloy.
作者
田进
张聪惠
田伟
李轩
Tian Jin;Zhang Conghui;Tian Wei;Li Xuan(Xi’an University of Architecture and Technology,Xi’an 710055,China;China United Northwest Institute for Engineering Design and Research Corporation,Xi’an 710077,China;Sichuan University of Science and Engineering,Zigong 643000,China;College of Metallurgical Engineering,Xi’an University of Architecture and Technology,Xi’an 710055,China)
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2020年第10期3597-3603,共7页
Rare Metal Materials and Engineering
基金
国家自然科学基金(51961003)
陕西省重点研发计划(2018GY-112)
陕西省重点产业创新链(群)(2019ZDLGY05-03)。
