【摘要】 本文采用多种实验手段对Fe₆₅Cr₁₈Mo₂Si₁B₁₄和 Fe₆₂Cr₁8)Mo₂Si₁B₁₇单辊快淬带的结构和性能进行了综合的考察。XRD、TEM和DTA检测结果表明快淬带完全为非晶态,但由TEM还观察到非晶基体中分布着几十纳米大小,衬度较深,呈颗粒状的非晶第二相,第二相的数量随硼含量的增加而增加。相应的磁矩测试、磁滞迴线和Mssbauer谱显示非晶态由磁性能不同的相所组成,在室温下,少量铁磁相分散在呈顺磁性的基体中,并表现出单畴颗粒的高矫顽力。铁磁相的数量也随硼含量的增加而增加。快淬带未经退火即已脆化,增加硼含量既提高非晶形成能力及非晶态总体无序程度和稳定性又明显加剧脆性。分析表明,快淬过程中早期过冷液体硼的偏聚导致非晶第二相的形成。相分离对淬火带的磁学和力学性能都有重要影响。更多还原

【Abstract】 A comprehensive examination was made by using various experimental methods on the structure and properties of Fe65Cr18Mo2Si1B14 and Fe62Cr18Mo2Si1B17 single - roll quenched ribbons. Although XRD, JEM and DIA indicated that the ribbons were perfectly amorphous, TEM revealed particle- like amorphous second phase with sizes of tens of nanometer distributed in amorphous matrix, which increased with boron content. Correspondingly, magnetic moment analysis, bystresses loop and Mossbaure spectrum indicated that die ribbons were coraosed of phases with different magnetic properties. A small amount of magnetic phase, which similarly increased with boron content, was detected to be dispersed in paramagnetic matrix and show high coercive force as single - domain particle. The quenched ribbons were brittle before annealing. Increase of boron content did not simply enhance amorphous formation ability, stability and disorder degree, but seriously promoted the britteness of quenched ribbons. A conclusion can be drawn from analysis of these results that boron segregation in early undercooled liquid during quenching results in the formation of amorphous second phase, and the phase separation significantly in fluences magnetic and mechanical properties of quenched ribbons.更多还原