原子与分子物理学报
原子與分子物理學報
원자여분자물이학보
CHINESE JOURNAL OF ATOMIC AND MOLECULAR PHYSICS
2010年
3期
551-559
,共9页
Q-SC多体势%分子动力学模拟%非晶态合金%基本团簇%原子合金效应%微观结构转变
Q-SC多體勢%分子動力學模擬%非晶態閤金%基本糰簇%原子閤金效應%微觀結構轉變
Q-SC다체세%분자동역학모의%비정태합금%기본단족%원자합금효응%미관결구전변
QSC many-body potential%molecular dynamics simulation%amorphous alloys%basic cluster%atomic alloying effects%microstructure transition
本文根据量子Sutton-Chen多体势,采用分子动力学方法对含有50000个原子大系统液态二元合金CuxPd1-x(CuPd的原子半径比为1.14)在快速凝固过程中的微观结构转变特性进行模拟研究.运用Honeycutt-Andersen(HA)键型指数法和原子成团类型指数法(CTIM)分析了液态和固态的微观结构特性.研究结果发现:在7.73×1013 K/S冷却速率下,CuxPd1-x合金形成以1551、1541和1431三种键型为主的非晶态结构;系统以1551键型和由1551键型构成的(12 0 12 0)二十面体团族在所有的键型和团簇中占主导地位,并且在液态合金CuxPd1-x微观结构转变中起着关键性作用.通过分析键型、团簇和平均原子体积,我们发现液态合金CuxPd1-x的玻璃转变温度是573K.同时还发现,原子的平均配位教的变化与1551,1441,1661键型的变化趋势相当接近,这反映出体系对称性结构的变化规律与配住数的变化有关.
本文根據量子Sutton-Chen多體勢,採用分子動力學方法對含有50000箇原子大繫統液態二元閤金CuxPd1-x(CuPd的原子半徑比為1.14)在快速凝固過程中的微觀結構轉變特性進行模擬研究.運用Honeycutt-Andersen(HA)鍵型指數法和原子成糰類型指數法(CTIM)分析瞭液態和固態的微觀結構特性.研究結果髮現:在7.73×1013 K/S冷卻速率下,CuxPd1-x閤金形成以1551、1541和1431三種鍵型為主的非晶態結構;繫統以1551鍵型和由1551鍵型構成的(12 0 12 0)二十麵體糰族在所有的鍵型和糰簇中佔主導地位,併且在液態閤金CuxPd1-x微觀結構轉變中起著關鍵性作用.通過分析鍵型、糰簇和平均原子體積,我們髮現液態閤金CuxPd1-x的玻璃轉變溫度是573K.同時還髮現,原子的平均配位教的變化與1551,1441,1661鍵型的變化趨勢相噹接近,這反映齣體繫對稱性結構的變化規律與配住數的變化有關.
본문근거양자Sutton-Chen다체세,채용분자동역학방법대함유50000개원자대계통액태이원합금CuxPd1-x(CuPd적원자반경비위1.14)재쾌속응고과정중적미관결구전변특성진행모의연구.운용Honeycutt-Andersen(HA)건형지수법화원자성단류형지수법(CTIM)분석료액태화고태적미관결구특성.연구결과발현:재7.73×1013 K/S냉각속솔하,CuxPd1-x합금형성이1551、1541화1431삼충건형위주적비정태결구;계통이1551건형화유1551건형구성적(12 0 12 0)이십면체단족재소유적건형화단족중점주도지위,병차재액태합금CuxPd1-x미관결구전변중기착관건성작용.통과분석건형、단족화평균원자체적,아문발현액태합금CuxPd1-x적파리전변온도시573K.동시환발현,원자적평균배위교적변화여1551,1441,1661건형적변화추세상당접근,저반영출체계대칭성결구적변화규률여배주수적변화유관.
Based on the quantum Sutton-Chen many-body potentials,a molecular dynamics simulation study has been adopted to investigate the features of microstructural transition of binary liquid alloys CuxPd1-x(the atomic radius ratio of the CuPd being 1.14)for a large-scale system consisting of 50000 atoms during the rapid cooling processes.To describe the complex microstructural properties in the liquid and solid states,the index method of Honeycutt-Andersen(HA)and the cluster-type index method(CTIM)have been used.It has been found that in the cooling rate of 7.73×1013 K/S,CuxPd1-x alloy finally forms amorphous structures with the three bond-types of 1551、1541 and 1431 as the main body in the system.It is demonstrated that both the 1551 bond-type and the icosahedral cluster(12 0 12 0)constructed by 1551 bond-types are dominant among all the bond-types and cluster-types,and they play a critical and leading role in the microstructure transitions of liquid alloys CuxPd1-x.By analyzing the bond-types,clusters and average atomic volume,we find that the glass transition temperature Tg for liquid alloys CuxPd1-x is 573K.At the same time,it is still found that the variation of the mean coordination nunlber of atoms is rather close to that of 1551,1441,1661 bond-types,this reflects that the varying rule of the symmetric configurations in system is related to the variation of the coordination Rumber.
