摘要:
采用分子动力学方法深入研究热效应对纳米焊接界面结构的影响。具体分析了碳管直径和时间的变化对界面结构的影响规律,并详细给出了1530 K下的焊接过程。结果表明,除碳管(5,5)外,碳管(6,6),(7,7),(9,9),(11,11)中纳米线形成的时间分别为13.8, 14.6, 17.5, 19.6 ps。纳米线是由单根或多根Ni原子链组成,碳管(6,6),(7,7),(9,9),(11,11)中Ni原子链数分别为1,3,7和16。界面结构包括内部焊接和外部焊接。内部焊接的临界直径由碳管(6,6)决定,其值为0.814 nm。在同一时刻,大直径的碳管可获得更大的外部接触长度。外部接触长度的增长速率随碳管直径的增加而增大,接触长度的最大增长速率可达0.013 nm/ps。最后确定了界面结构形成临界温度,发现对于相同直径碳管,外部焊接的临界温度高于内部焊接的临界温度,临界温度与碳管直径无关。
Abstract:
Nanowelding configuration under thermal effects is investigated with molecular dynamics method. The influence of single walled carbon nanotube (SWNT) diameter and time on the interface structure is analyzed, and the detailed process is illustrated at 1530 K. Nanowires are observed in SWNT (6,6), (7,7), (9,9) as well as (11,11) at 13.8, 14.6, 17.5 and 19.6 ps respectively except for SWNT (5,5). These nanowires are composed of one or several Ni atom chains. The numbers of Ni atom chains for SWNT (6,6), (7,7), (9,9), (11,11) are 1, 3, 7 and 16 respectively. The interface structures of both inside nanowelding and outside nanowelding are also revealed. The critical diameter of inside nanowelding can be determined by SWNT (6,6) with a diameter of 0.814nm. As for outside nanowelding, a longer outside contact length can be obtained with a larger diameter of SWNT. The growth rate of the outside contact length increases with the diameter of SWNT. The maximal growth rate of the outside contact length is up to 0.013 nm/ps. The critical temperature of the interface structure is provided, which indicates the critical temperature of outside nanowelding is higher than that of inside nanowelding for the same diameter of SWNT, and the critical temperature is irrelevant to the diameter of SWNT.
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