摘要
采用热力学计算软件,以Ti-42Al-5Mn合金为基础设计出不含Laves相的新型β凝固Ti-43.5Al-1.5Mn-xCr-yNb(x=0,1,%;y=0,2,%)合金,并系统分析了Cr和Nb对相变路径的影响规律。结果表明:Ti-43.5Al-1.5Mn合金铸态组织由α_(2)/γ片层结构所构成,加入Nb、Cr后铸态组织中γ相含量提高,且开始出现βo相和块状γ相。此外,Nb和Cr可细化合金的片层间距,其中,添加1%Cr和2%Nb后使合金的片层间距从180.26 nm细化到129.72 nm。Ti-43.5Al-1.5Mn和Ti-43.5Al-1.5Mn-2Nb合金的凝固过程中均存在明显的单一的α和β相区;Ti-43.5Al-1.5Mn-1Cr合金的凝固过程中存在明显的βo相区;由于Ti-43.5Al-1.5Mn-1Cr-2Nb合金存在较多的β相稳定元素,导致其凝固过程不存在单一的α相区。Nb提高了α→(α_(2)+γ)转变的活化能,降低α相稳定性,使合金的共析转变温度提高,此外,Nb抑制α相中Ti的扩散导致γ相溶解温度升高;Cr可降低α相和γ相稳定性,使合金的共析转变温度提高和γ相溶解温度降低;在Cr、Nb的共同作用下,Ti-43.5Al-1.5Mn-1Cr-2Nb合金的共析转变温度和γ相溶解温度提高。
Based on Ti-42Al-5Mn alloy,a newβ-solidified Ti-43.5Al-1.5Mn-xCr-yNb(x=0,1,%;y=0,2,%)alloy without Laves phase was designed by thermodynamic calculation software.The effects of Cr and Nb on the phase transformation path were systematically analyzed.The results show that the as-cast microstructure of Ti-43.5Al-1.5Mn alloy is composed ofα_(2)/γlamellar structure.The addition of Nb and Cr induces with increasing content ofγphase in the as-cast microstructure,as well as the appearance ofβo phase and blockyγphase.Furthermore,the lamellar spacing of the alloy is refined from 180.26 nm to 129.72 nm after adding 1%Cr and 2%Nb,which is due to the effect of Nb and Cr on refining the lamellar spacing of the alloy.There are obvious singleαandβphase regions in the solidification process of Ti-43.5Al-1.5Mn and Ti-43.5Al-1.5Mn-2Nb alloys,whereas Ti-43.5Al-1.5Mn-1Cr alloy shows apparentβo phase region.Due to the existence of moreβphase stabilizing elements in Ti-43.5Al-1.5Mn-1Cr-2Nb alloy,there is no singleαphase region in the solidification process.Nb increases the activation energy ofα→(α_(2)+γ)transformation,reduces the stability ofαphase,and increases the eutectoid transformation temperature of the alloy.In addition,Nb inhibits the diffusion of Ti inαphase,resulting in an increase in the dissolution temperature of theγphase.Cr can reduce the stability ofαphase andγphase,increase the eutectoid transformation temperature of the alloy and decrease the dissolution temperature ofγphase.Under the combined action of Cr and Nb,the eutectoid transformation temperature andγphase dissolution temperature of Ti-43.5Al-1.5Mn-1Cr-2Nb alloy increase.
作者
王向杰
张孟祥
薛鹏
郝俊杰
陈波
李小兵
刘奎
WANG Xiangjie;ZHANG Mengxiang;XUE Peng;HAO Junjie;CHEN Bo;LI Xiaobing;LIU Kui(Key Laboratory of Electromagnetic Processing of Materials,Ministry of Education,Northeastern University,Shenyang 110819,China;Research Department of Materials Science and Technology,Jihua Laboratory,Foshan 528200,China)
出处
《中国有色金属学报》
北大核心
2025年第6期2005-2021,共17页
The Chinese Journal of Nonferrous Metals
基金
广东省自然科学基金资助项目(2024A1515030091)
国家自然科学基金资助项目(52271094)
国家重点研发计划资助项目(2023YFB3710401,2022YFB3504401)
清远市科技计划资助项目(2023YFJH003)
中央基础研究基金资助项目(N2309003)
兵团财政科技计划资助项目(2023AA003)
新疆维吾尔自治区重大科技专项(2023A01001)。
