INTERFACE ATOMIC BONDING AND MECHANICAL PROPERTIES OF AI-Li-Sc-Zr ALLOYS
With the rapid development of the aerospace and aviation enterprise,as a new light structural aluminum alloy material,the good performance of the Al-Li alloy is more and more paid attention to.The mechanical properties of Al-Li-Zr-Sc alloys are closely related to their phases and biphase interfaces.In order to control and improve the mechanical properties of Al-Li-Zr-Sc alloys,the relationships between the atomic bonding of biphase interfaces and mechanical properties are investigated.In this letter,the empirical electron theory (EET) of solids and molecules and the improved TFD theory are firstly applied to study the relationships among the valence electron structures of phases,biphase interfaces and mechanical properties.The investigated results are listed as below: 1.The concepts of phase structure factors of nα,σ,F,Eαand interface conjunction factors of ρ、 σ、 σ1、 △ρ、 γ are defined.The physics meaning of phase structure factors and interface conjunction factors are explained and the calculation methods of both are improved. 2.The calculation models for segregation cell in the solid solution system of Al-Li-Sc-Zr alloys are established and the valence electron structures and the phase structure factors are calculated.The relationships between the phase structure factors and mechanical properties are discussed.There are much strong interaction among the Sc,Zr and Al atoms in the solid solution of Al-Li based alloy.The atomic bonding between the Zr,Sc and Al are strongest,and lead to form some finer segregation zones,which play an important role for solid solution strengthening in alloy. 3.The valence electron structure and phase structure factors of major strengthening phase,such as Al3Li phase,Al3Zr phase,Al3Sc phase and the compound phase Al3(ScxZr1-x) are calculated.The results show that AI3Li,Al3Zr,Al3Sc and A13(ScxZr1-x) composite phase can pin dislocation and sub-grain boundary,restrict the boundary movement,so they restrain the grains growing and merging,and become the inhomogeneous nucleation of Al3Li.Large Al3Li phase precipitations can enhance the whole bond intensity of matrix and strengthen alloy,improve the thermo-stability of Al-Li-Sc-Zr alloy.
AI-Li-Zr-Sc alloys Atomic bonding Mechanical property Simulation
Y.J.Gao H. N.Chen J.X.Li Q.F.Mo
School of Physics Science and Engineering,Guangxi University,Nanning 530004,China
国际会议
第二届国际非均质材料力学会议(The Second International Conference on Heterogeneous Material Mechanics)
安徽黄山
英文
367-368
2008-06-03（万方平台首次上网日期，不代表论文的发表时间）