非晶Fe_(73.5)Cu_1Nb_3Si_(13.5)B_9合金激光纳米化的超精细结构研究

Hyperfine stucture during nanocrystallization of amorphous Fe_(73.5)Cu_1Nb_3Si_(13.5)B_9 alloy irradiated by laser

在CO2激光功率为50—300W、扫描速度为20mms、激光散光斑为20mm照射条件下,诱导非晶Fe73.5Cu1Nb3Si13.5B9带中发生结构重组,产生定量纳米αFe(Si)晶相形成双相组织结构材料.利用穆斯堡尔谱研究了非晶Fe73.5Cu1Nb3Si13.5B9合金激光纳米化的超精细结构.实验结果表明,激光诱导非晶Fe73.5Cu1Nb3Si13.5B9纳米化后,其超精细磁场的分布随着激光功率变化由单峰向双峰变化,在高功率辐照时,出现了双峰分布,并且峰位向高场移动.高激光功率辐照非晶Fe73.5Cu1Nb3Si13.5B9合金纳米晶化相有四种超精细结构,即2个超精细磁场较小的初晶相和2个超精细磁场较大的纳米晶化相.其中超精细磁场较大(17—25MAm)的αFe(Si)相为DO3结构.

The material composed of a definite amount of nanocrystalline phase α-Fe（Si） with a double-phase structure was produced by laser irradiation on the amorphous Fe73.5Cu1Nb3Si13.5B9 alloy with a laser power ranging from 50 to 300W, scanning speed 20mm/s, laser beam spot 20mm. Hyperfine structures of the nanocrystallized samples were analyzed by Moessbauer spectra. Experimental result shows that after the CO2 laser irradiated on the amorphous alloy Fe73.5Cu1Nb3Si13.5B9 , its hyperfine magnetic field distribution transformed from a single peak to double peaks with the change of laser power. When irradiated at a high laser power, it formed a double-peak structure and the peaks moved to a high field position. Nanocrystallization of amorphous Fe73.5Cu1Nb3Si13.5B9 irradiated by a higher laser power produces four hyperfine structures, i.e. two primary crystal phases with relatively small hyperfine magnetic field and two nanocrystalline phases with a relatively large hyperfine magnetic field. The major crystal phase is the α-Fe（Si） phase of DO3 whose hyperfine magnetic field is comparatively larger （17-25MA/m）.