制备条件对非晶态Fe_(78)B_(13)Si_9合金的热膨胀各向异性的影响

EFFECT OF PREPARATION CONDITION ON THERMAL EXPANSION ANISOTROPY FOR AMORPHOUS Fe_(78)B_(13)Si_9 ALLOY

本文研究了不同条件下形成的非易态Fe_(78)B_(13)Si_9合金在长轴和短轴方向上的热膨胀。结果表明,在所有条件下均存在热膨胀的各向异性。热膨胀系数随着冷却速度的增加而增加,但其各向异性减小;随着熔体喷铸温度的提高两者均减小。在热循环的作用下,短轴方向的热膨胀系数及其各向异性均减小;而在长轴方向的热膨胀系数却增大。我们认为热膨胀各向异性来源于原子交互作用力的方向性、原子振动频率和短程有序结构或缺陷的方向性。

The thermal expansion anisotropy appears in all specimens prepared under various forming conditions. The expansion along the longitudinal direction is less than that along the transverse direction. The cooling rate, the temperature of melt before jet casting and the cycling temperature affect the thermal expansion coeffi- cients and anisotropy. The anisotropy of thermal expansion originates from the direc- tional atomic interaction force, atomic oscillatory frequency and the directional short range order structure or defects in the alloy