摘要
根据反演法获得的对势和ＥＡＭ多体势计算了纯Ａｌ位错发射的临界应力强度因子ＫＩｅ以及Ｇｒｉｆｆｉｔｈ裂纹解理扩展的临界应力强度因子 ＫＩＧ．结果表明，用对势算出的值和断裂力学计算结果更相近. 因此，用对势来研究吸附的影响是可行的．分子动力学模拟表明，Ｇａ吸附在裂纹表面将使 ＫＩＧ＝０．４２ ＭＰａ·ｍ降至 ＫＩＧ＝０．３２ ＭＰａ·ｍ，这表明吸附使表面能γ降至γ（＝０.８７γ）．Ｇａ吸附使 ＫＩｅ＝０．３１ ＭＰａ·ｍ降至 ＫＩｅ＝０．２４ ＭＰａｍ；Ｇａ吸附使位错运动的临界分切应力从Ｔｃ＝２．０５ＭＰａ降至Ｔｃ＝１．８２ ＭＰａ．这就表明，Ｇａ吸附后能降低Ａｌ的表面能，从而促进位错发射和运动.
The effect of adsorption of liquid metal Ga on dislocation emission and motion, and crack propagation in Griffith condition for aluminium has been investigated using the pair potentials obtained based on the first principle calculation and the Mobius 3D lattice inversion formula. The molecular dynamics simulation in quasi-3D crystal shows that adsorption of Ga decreases the critical stress intensity for crack propagation in Griffith condition from K-IG=0.42 MPa(.)rootm to K-IG*=0.32 MPa(.)rootm and then decreases the surface energy from gamma to gamma*=0.58 gamma. The adsorption of Ga atoms decreases the critical stress intensity for dislocation emission from K-Ie=0 31 MPa. rootm to K-Ie* =0.24 MPa(.)rootm- and reduces the critical shear stress for dislocation motion from tau(c)=2.05 MPa to tau(c)*=1.82 MPa, Adsorption of Ga can enhances dislocation emission and motion.
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
2001年第10期1013-1017,共5页
Acta Metallurgica Sinica
基金
国家重点基础研究规划资助项目G19990650
关键词
分子动力学模拟
位错发射
裂纹解理
位错运动
铅
镓
吸附
molecular dynamic simulation (MDS)
adsorption of Ga
dislocation emission and motion (DSM)
crack propagation
