Nitriding of ferritic Fe-Cr-Al alloys
Nitriding of ferritic Fe-Cr-Al alloys
复制标题
铁素体 Fe-Cr-Al 合金的氮化
DOI：
10.1016/j.surfcoat.2009.08.031
复制
发表时间：
2010
影响因子：
5.4
通讯作者：
E. Mittemeijer
中科院分区：
文献类型：
--
作者：
K. S. Jung;R. Schacherl;E. Bischoff;E. Mittemeijer
铁素体铁基 Fe-Cr-Al 合金（含 0.25-1.25at.% Cr 和 Al）氮化后，会形成一层非常坚硬的表面层，其中含有合金元素氮化物的纳米沉淀物。通过 X 射线衍射 (XRD) 和透射电子显微镜 (TEM) 研究渗氮区的微观结构。 TEM 揭示了纳米氮化物与铁素体基体的相干性，特别是对于富铬合金，与 X 射线衍射图中不存在单独的氮化物反射相一致；大的相干失配应变会导致衍射线极端且特定形状的展宽。衍射线展宽的 h k l 依赖性表明氮化物纳米沉淀物和铁素体基体的特定取向关系，如通过 TEM 测定的。随着Cr/Al原子比的增加，显微硬度和衍射线展宽增加，而过量氮的量减少。
Upon nitriding ferritic iron-based Fe–Cr–Al alloys (containing 0.25–1.25at.% Cr and Al) a very hard surface layer develops containing nano-precipitates of alloying element nitrides. The microstructure of the nitrided zone was investigated by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Coherency of the nano-nitrides with the ferrite matrix, as revealed by TEM, especially for the chromium-rich alloys, is compatible with the absence of separate nitride reflections in the X-ray diffractograms; the large coherency misfit strains induce extreme and particularly shaped broadening of the diffraction lines. The h k l dependence of the diffraction-line broadening is indicative of the specific orientation relationship of the nitride nano-precipitates and the ferrite matrix, as determined by TEM. For increasing Cr/Al atomic ratio, the microhardness and the diffraction-line broadening increase, whereas the amount of excess nitrogen decreases.