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刘伟, 熊华平, 唐思熠. Si元素含量对激光快速成形制备Nb-Si二元合金显微组织演变的影响[J]. 焊接学报, 2017, 38(3): 53-56,61.
引用本文: 刘伟, 熊华平, 唐思熠. Si元素含量对激光快速成形制备Nb-Si二元合金显微组织演变的影响[J]. 焊接学报, 2017, 38(3): 53-56,61.
LIU Wei, XIONG Huaping, TANG Siyi. Effect of Si content on microstructural evolution of Nb-Si binary alloys fabricated by laser rapid forming[J]. TRANSACTIONS OF THE CHINA WELDING INSTITUTION, 2017, 38(3): 53-56,61.
Citation: LIU Wei, XIONG Huaping, TANG Siyi. Effect of Si content on microstructural evolution of Nb-Si binary alloys fabricated by laser rapid forming[J]. TRANSACTIONS OF THE CHINA WELDING INSTITUTION, 2017, 38(3): 53-56,61.

Si元素含量对激光快速成形制备Nb-Si二元合金显微组织演变的影响

Effect of Si content on microstructural evolution of Nb-Si binary alloys fabricated by laser rapid forming

  • 摘要: 以铌粉和硅粉为原料,采用双通道同轴送粉制备了四种不同Si元素含量的Nb-Si二元合金,通过扫描电镜(SEM)、能谱仪(EDS)及X射线衍射仪(XRD)等分析了合金的显微组织演变及维氏硬度.结果表明,硅含量由7%增加至25%,合金的显微组织由NbSS+Nb3Si转变为初生NbSS+(NbSS/Nb3Si)共晶,硅含量为18%时,呈NbSS/Nb3Si全共晶组织,硅含量提高至25%,合金中出现初生β-Nb5Si3相,并仍存在NbSS/Nb3Si共晶组织.铌和硅粉末在激光作用下原位反应并快速凝固,显著细化了Nb-Si合金的显微组织.随硅含量增加,硅化物含量逐渐增加,合金显微硬度由746 HV增至1 342 HV.

     

    Abstract: The high purity Nb powder and Si powder were used as raw powder and four kinds of Nb-Si binary alloys with different Si content were fabricated by laser rapid forming with double coaxial powder feeding. The microstructural evolution and the micro-hardness of these alloys were investigated by scanning electron microscope (SEM), X-ray energy dispersive spectroscopy (EDS) and X-ray diffraction spectrometer (XRD). The results showed that with the content of Si increasing from 7% to 25%, the microstructure of Nb-Si binary alloys was changed from NbSS+Nb3Si to primary NbSS+ (NbSS/Nb3Si) eutectic structure. When the content of Si was 18%, the fabricated alloy is almost 100% NbSS/Nb3Si eutectic structure. With the Si content reaching 25%, the primary β-Nb5Si3 phase appears and the NbSS/Nb3Si eutectic structure still existed. Moreover, under the high energy of laser beam, the in situ reaction between Nb and Si powder would occur and the microstructure of Nb-Si alloys could be refined significantly. With the content of Si increasing, the volume fraction of silicide increased gradually and the micro-hardness of the alloys increased from 746 HV to 1 342 HV.

     

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