CAJ | 학술논문

利用金相显微镜(OM)、X射线衍射仪(XRD)和扫描电镜(SEM)及能谱分析(EDS)等测试方法研究Nb含量对铸造TiAl-xNb (x=1,3,5,7；原子分数，%)合金组织的影响。结果表明：Nb含量为1%时，TiAl-Nb合金铸锭组织主要为单相的γ组织；随Nb含量升高，合金组织主要为α2/γ层片组织；并在层片组织间存在2种偏析，分别是网状β相和γ相，合金的层片晶团平均尺寸逐渐增加，β相的体积分数逐渐升高；当合金中Nb的含量从1%增加到7%，层片晶团平均尺寸由89μm增加至190μm，β相的体积分数从1.9%增至12.9%；随合金中Nb含量增加，β相中Nb含量增加而Cr含量减少，γ相的偏析区域宽度变窄。
이용금상현미경(OM)、X사선연사의(XRD)화소묘전경(SEM)급능보분석(EDS)등측시방법연구Nb함량대주조TiAl-xNb (x=1,3,5,7；원자분수，%)합금조직적영향。결과표명：Nb함량위1%시，TiAl-Nb합금주정조직주요위단상적γ조직；수Nb함량승고，합금조직주요위α2/γ층편조직；병재층편조직간존재2충편석，분별시망상β상화γ상，합금적층편정단평균척촌축점증가，β상적체적분수축점승고；당합금중Nb적함량종1%증가도7%，층편정단평균척촌유89μm증가지190μm，β상적체적분수종1.9%증지12.9%；수합금중Nb함량증가，β상중Nb함량증가이Cr함량감소，γ상적편석구역관도변착。
The effect of Nb content on the microstructure of as-cast TiAl-xNb (x=1,3,5,7; atom fraction,%) alloy was investigated by means of optical microscopy (OM), X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS). The results show that when the Nb content is 1%, the structure of as-cast TiAl-Nb is mainly singleγphase;with the increase of Nb content, the main structure of alloy isα2/γlamellar;there exist two kinds of segregations in lamellars, indicating to be webβphase andγphase, the average size of lamellar colony and the volume fraction ofβphase increase;with increasing Nb content from 1%to 7%, the average size of lamellar colony decreases from 89μm to 190μm, the area fraction ofβphase increases from 1.9%to 12.9%;with increasing Nb content in as-cast TiAl alloy, the Nb content in β phase increases while the Cr content in β phase decreases, the width of γ segregation decreases.