ANNEALING BEHAVIOR OF AMORPHOUS FE80B20 ON CONTINUOUS HEATING
ANNEALING BEHAVIOR OF AMORPHOUS FE80B20 ON CONTINUOUS HEATING
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DOI：
10.1007/bf00540327
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发表时间：
1981-01-01
影响因子：
4.5
通讯作者：
KARNOWSKY, MM
中科院分区：
文献类型：
--
作者：
INAL, OT;ROBINO, CV;KARNOWSKY, MM
Fe 80 B20非晶合金在直接加热过程中的电阻测量表明，相变发生在395，500，720和840° C。加热到这些温度并在中性气氛中保持5分钟的样品表明，硬度最大值出现在395° C的结晶温度下，并且在500° C下退火产生具有相同硬度的材料。在500° C以上，可以看到显微硬度下降到低于非晶合金的显微硬度。饱和磁化强度测量结果显示，在每次退火后，直到720° C的温度，饱和磁化强度稳定增加，并且在720 ° C至840° C的范围内，可以看到增加率下降。X射线衍射研究表明，在395° C退火后，只有一小部分基体晶化，转变相为α-Fe和Fe 3B。在500° C退火后，观察到α-Fe和Fe 3B的比例增加，结晶完全，而在720° C热处理的样品由α-Fe，Fe 23 B6和Fe 2B的三相混合物组成。在840° C下退火可以产生α-Fe和Fe 2B相的平衡相混合物。仅在395° C下退火的样品中看到一部分非晶相持续存在，表明在该温度下5分钟退火不足以诱导完全结晶。这些结构特征通过在液氮温度下纯氖介质中进行的场离子显微镜分析和扫描电子显微镜分析得到证实，并且也与我们早期对Fe 80 B 20合金在780° C下等温退火不同时间的研究一致。
Resistance measurements during direct heating of Fe80B20amorphous alloys indicate phase changes occur at 395, 500, 720 and 840° C. Samples heated to these temperatures, and maintained for five minutes in a neutral atmosphere, show that a hardness maximum occurs at the crystallization temperature of 395° C and that annealing at 500° C produces a material with the same hardness. Above 500° C the microhardness is seen to drop below that of the amorphous alloy. Saturation magnetization measurements show a steady increase following each anneal, up to a temperature of 720° C, and the rate of increase is seen to drop in the range of 720 to 840° C. X-ray diffraction studies show that only a small fraction of the matrix is crystallized following the anneal at 395° C and the transformed phases are α-Fe and Fe3B. Following annealing at 500° C, an increased proportion of α-Fe and Fe3B are observed with complete crystallinity while samples heattreated at 720° C are seen to consist of a three-phase mixture of α-Fe, Fe23B6and Fe2B. Annealing at 840° C is seen to produce an equilibrium phase mixture of α-Fe and Fe2B phases. Only in the sample annealed at 395° C is a fraction of the amorphous phase seen to persist, indicating that a 5 min anneal is not sufficient, at this temperature, to induce complete crystallization. These structural features are corroborated by field ion microscope analyses, made at liquid nitrogen temperature in a medium of pure neon, and scanning electron microscopy, and are also consistent with our earlier study involving the isothermal annealing, for various times, of Fe80B20alloy at 780° C.