CAJ | 학술논문

用电化学双喷、凹坑法和离子减薄制备了4组Zr52.5Cu17.9Al10Ti5金属玻璃的透射电子显微镜样品.透射电镜观测表明,电子透明区域的微结构随采用的离子减薄条件变化敏感.通过对比选区电子衍射花样和相同成分样品等温退火的X衍射花样发现,在一些严重依赖于离子减薄制备的电镜样品中存在显著的加热效应,导致在离子减薄区域形成了不同的有序结构.在那些特意使用长时间减薄的样品中,可达到约780 K的局域峰值温度,远远超过了该成分的玻璃转变温度.这个结果表明,在用离子减薄获得非晶合金的电镜样品时,必须注意减薄过程所诱导的潜在的微结构变化,以避免得到错误的判断.
용전화학쌍분、요갱법화리자감박제비료4조Zr52.5Cu17.9Al10Ti5금속파리적투사전자현미경양품.투사전경관측표명,전자투명구역적미결구수채용적리자감박조건변화민감.통과대비선구전자연사화양화상동성분양품등온퇴화적X연사화양발현,재일사엄중의뢰우리자감박제비적전경양품중존재현저적가열효응,도치재리자감박구역형성료불동적유서결구.재나사특의사용장시간감박적양품중,가체도약780 K적국역봉치온도,원원초과료해성분적파리전변온도.저개결과표명,재용리자감박획득비정합금적전경양품시,필수주의감박과정소유도적잠재적미결구변화,이피면득도착오적판단.
Four groups of transmission electron microscopy (TEM) specimens of Zr52.5Cu17.9Ni14.6Al10Ti5 metallic glass were prepared by double-jet electropolishing, dimpling and ion milling. TEM observations indicate that the microstructures in electron-transparent areas change sensitively with ion milling conditions. Detailed comparisons between the selected area electron diffraction patterns of TEM specimens and the X-ray diffraction patterns of thermally annealed samples of the same composition show that significant heating effects exist in some severe milling processes, resulting in the formation of various ordered structures in thin areas. In TEM specimens prepared by intentionally long time ion milling, the peak temperature locally reached is estimated as high as 780 K, far above the glass transition temperature of this metallic glass. The results suggest that precautions must be taken to prepare TEM specimens of amorphous alloys by ion milling, particularly when the induced microstructure changes may lead to invalid judgments.