运用固体经验电子理论(EET),对Al-Li合金时效初期的若干偏聚晶胞的价电子结构进行了计算.计算结果表明:不包含空位的偏聚晶胞的键络最强键为Al-Al键,其中Al原子的共价半径较Li原子的共价半径要大;而含空位的偏聚晶胞的最强键为Al-Li键,Al原子的共价半径要比Li原子的共价半径要小;在空位存在的情况下,由于Al原子与Li原子的电负性相差明显,促使Al和Li原子结合,倾向形成Al-Li短程序结构偏聚区,这种含空位的短程序结构很可能就是δ′(Al3Li)亚稳相的前兆结构和生长胚胎;由于Al-Li-空位有序偏聚晶胞的Al-Li键络比基体键络要强许多,因此,淬火过程中合金生成的Al-Li-空位偏聚晶胞对合金过饱和固溶体起主要强化作用;后续析出的δ′(Al3Li)亚稳相键络各项异性显著,键络强度明显提高;由于Al3Li与基体共格,其大量均匀弥散析出起到提升基体整体键络强度,同样对合金产生强化作用.
参考文献
| [1] | Lavernia E J;Srivatsan T S .Review of strength and fracture behavior and ductility of Al-Li alloys[J].Journal of Materials Science,1990,25:1137-1158. |
| [2] | Noble B;Harris S J;Dinsdale K .The elastic modulus of Al-Li alloys[J].Journal of Materials Science,1982,17:461-468. |
| [3] | Enrique J;Nicholas J .Review aluminum-lithium alloys[J].Journal of Materials Science,1987,22:1521-1529. |
| [4] | Kassab T;Menand A;Chambreland S .The early stage of decomposition of Al-Li alloys[J].Surface Science,1992,266:333-336. |
| [5] | Wei Y H;Wang S T .Experiment evidence for spinodal decomposition in Al-12. 7% Li alloys[J].Materials Letters,1996,28:123-127. |
| [6] | Noble B .Evidence for pre β′ precipitation events in an Al-Li alloys[J].Scripta Metallurgica et Materialia,1995,33:33-37. |
| [7] | MENG F L;Chai Z G;Li J X .Small-angle X-ray scattering study of the β′ phase in Al-Li alloys[J].Materials Characterization,2001,47:43-46. |
| [8] | Noble B;Bray S E .The interfacial energy of β′ precipitation in Al-Li alloy[J].Materials Science and Engineering A,1999,266:80-85. |
| [9] | Perez J I;Madariaga G .Quantitative analysis of β′precipitation kinetics in Al-Li alloys[J].Acta Materialia,2000,48(04):1283-1296. |
| [10] | Boukos N;Papastaikoudis C .The influence of β′ precipitates on the electrical resistivity and low-field Hall coefficient of Al-Li alloys[J].PHILOSOPHICAL MAGAZINE B-PHYSICS OF CONDENSED MATTER STATISTICAL MECHANIC,1994,70:67-75. |
| [11] | Ceresara S;Giarda A;Sanchez A .Annealing of vacancies and ageing in Al-Li alloys[J].Philosophical Magazine,1977,35(01):97-110. |
| [12] | Gregson P J;Flower H M .Role of vacancies in coprecipitation of δ′- and S-phase in Al-Li-Cu-Mg alloys[J].Materials Science and Technology,1986,2:349-353. |
| [13] | Gaber A;Afify N .Characterization of the precipitates in Al-Li alloy using thermal measurements and TEM[J].Physical Review B,2002,315:1-6. |
| [14] | Sato T;Tanhka N;Takahashi T .High resolution lattice images of ordered structure in Al-Li alloy[J].Transactions of the JIM,1988,29(01):17-25. |
| [15] | Noble B;Bray S E .On the Al3Li metastable solvus in Al-Li alloy[J].Acta Materialia,1998,46(17):6163-6171. |
| [16] | Poduri R .Computer simulation of morphological evolution and coarsening kinetics of δ′ (Al3Li) precipitation in Al-Li alloys[J].Acta Materialia,1998,46(11):3915-3920. |
| [17] | Guo X Q;Podloucky R;Xu J H .Cohesive and structural properties of Al3Li[J].PHYSICAL REVIEW B,1990,46(18):12432-12440. |
| [18] | Pauling L.The Nature of the Chemical Bond[M].San Simeon:Corrnell University Press,1960:300-400. |
| [19] | 张瑞林.固体与分子经验电子理论[M].长春:吉林科学技术出版社,1993:1-90. |
| [20] | 刘志林.合金价电子结构与成分分析[M].长春:吉林科学技术出版社,1990:1-300. |
| [21] | Li Z L;Ma C X;Liu Z L .Valence electron structure of high property steel and its composition design[J].Acta Metallurgica Sinica(English Letters),1999,12(04):408-416. |
| [22] | Mondolfo L F.Structure and Propertys of Aluminum Alloys[M].London:Butterworths Press,1976:200-400. |
| [23] | 高英俊,韩永剑,赵妙,吴伟明.Al-Zn固溶体价电子结构与Spinodal分解反应[J].中国有色金属学报,2004(05):730-734. |
| [24] | 高英俊,班冬梅,韩永剑,钟夏平,刘慧.Atomic bonding and mechanical properties of Al-Mg-Zr-Sc alloy[J].中国有色金属学会会刊（英文版）,2004(05):922-927. |
| [25] | GAO Ying-jun;HAN Yong-jian .Electron structure and interface energy of GP zone in Al-Zn alloy[J].Materials Science Forum,2005,475-479:3131-3135. |
| [26] | 高英俊,钟夏平,刘慧,班冬梅.Al-Cu合金亚稳相的价电子结构分析[J].稀有金属,2003(06):845-848. |
上一张
下一张
上一张
下一张
计量
- 下载量()
- 访问量()
文章评分
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%