杨磊
,
何国球
,
严彪
,
陈成澍
材料科学与工程学报
doi:10.3969/j.issn.1673-2812.2005.02.015
本文研究了用元素W部分替代典型FINEMET合金中Nb和Fe的新型合金Fe73.3Cu1Nb1.5W1.7Si13.5B9,在淬火态和不同退火温度及保温时间下,结合不同载荷大小和加载时间测试合金带芯部的显微硬度.随着纳米晶化的进行,自由体积缺陷含量和纳米晶晶界比例的变化会显著影响Fe73.3Cu1Nb1.5W1.7Si13.5B9合金的显微硬度;合金在非晶态下有一定的压痕尺寸效应,而经过450℃和600℃退火1h,压痕尺寸效应消失;在550℃退火温度下,在0.1kgf～0.2kgf之间压痕尺寸效应不明显;合金的显微硬度变化趋势不符合超塑性波动公式.
关键词:
FINEMET
,
纳米晶
,
显微硬度
,
压痕尺寸效应
Chengdong LI
,
Xuelei TIAN
,
Xichen CHEN
,
A.G.Ilinsky
,
Likai SHI
材料科学技术（英文）
The crystallization kinetics of amorphous Fe¬¬68.5Si¬13.5B¬9Cu¬1Nb¬3C¬5 (at. pct) melt-spun ribbons were studied by the DSC method in the mode of continuous heating. The apparent activation energy Ep1 and Ep2 (373.07±7.92 and 518.75±21.35 kJ/mol, respectively) derived from the Kissinger plots were calculated by the peak temperatures Tp1, Tp2, which display a strong dependence on the heating rates. The crystallization behavior during isothermal annealing at 823 K for 1, 5, 10 h and 973 K for 5 h were investigated using XRD and TEM. The results show that crystallization behavior becomes completely different from that of FINEMET. It is not bcc α-Fe (Si) but metastable fcc γ-Fe (Si) that participates in the first crystallization step combining the appearance of Fe23B6 and Nb2B. Therefore, the addition of C promotes the combination of Fe and B. Fe3.5B is participated in the second step together with the disappearing of Fe23B6, which indicates that transition Fe23B6→Fe3.5B+Fe2B presumably happens. γ-Fe (Si) with peculiar stability cannot transform into nano-sized α-Fe (Si) crystals until the amorphous ribbons were annealed for 5 h at 973 K.
关键词:
Amorphous
,
null
,
null
,
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