【摘要】 研究了电弧熔炼过程中LaFe13-xSix合金的凝固行为。应用XRD和扫描电镜分析了合金组织相组成和结构。结果表明:电弧熔炼铸锭随温度梯度出现分层;La(Fe,Si)13(简称:1∶13)相是包晶反应生成的,冷速和硅含量变化对合金的凝固行为有很大的影响,当Si含量x≤1.0时合金显微组织由α-(Fe,Si)相和共晶相La Fe Si(简称:1∶1∶1)相组成,α-(Fe,Si)(简称:α-Fe)相为主要相,随硅含量增加1∶1∶1相增多;x≥1.5时由α-Fe相、1∶13相和1∶1∶1相组成;随x增加1∶13相为主要相,1∶1∶1相减少;当x≥2.0时显微组织中1∶13相作为初生相析出,且随温度梯度和硅含量变化1∶13相的形貌不同。更多还原

【Abstract】 Solidification behavior of La Fe13-xSixalloys was investigated using arc melting. Phase formation and structure in arc melting La Fe13-xSixalloys were investigated by power X-ray diffraction analysis( XRD) and scanning electron microscopy( SEM). The results showed that the arc melting ingot is stratified with the temperature gradient. The phase of La( Fe,Si)13( 1∶ 13) is generated by the peritectic reaction. The cooling rate and the change of silicon content have a great influence on the solidification behavior of the alloy. When x≤1 the microstructure is made of α-( Fe,Si) phase and eutectic La Fe Si( 1∶ 1∶ 1) phase,the composition of α-( Fe,Si)( referred to as: α-Fe) phase is the main phase and the 1∶ 1∶ 1 phase increases with the increase of silicon content with; When x≥1. 5 the microstructure include α-Fe phase,1∶ 13 phase and 1∶ 1∶ 1 phase; the 1 ∶ 13 phase is the main phase and the1∶ 1∶ 1 phase decreases with the increase of x. When x = 2 the 1∶ 13 phase as a primary phase is precipitated in the microstructure,and the morphology changes with temperature gradient and silicon content.更多还原