Al Si. Atomic bondings and properties of U1 andu2 phases of Al-Mg-Si alloy. GAO Ying-jun, CHEN Hua-ning, WEI Na, WEN Chun-li, HUANG Chuang-gao

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1 Vol.20 No.7 The Chinese Journal of Nonferrous Metals July (2010) U1 U2 ( ) EET TFD -- U1 U2 U1 U2 U2 U1 (001) //(110) U1 (001) // (010) U2 ( ) -- U1 U2 TG111.1 A Atomic bondings and properties of U1 andu2 phases of -- alloy GAO Ying-jun, CHEN Hua-ning, WEI Na, WEN Chun-li, HUANG Chuang-gao (College of Physics Science and Engineering, Guangxi University, Nanning , China) Abstract: Atomic bondings of U1 and U2 phases in -- alloy during aging were calculated by using the EET theory and the improved TFD theory. The results show that the strongest bonding and the second strong bonding in two phases are both bonds, which are stronger than those in matrix. The firm network structures of bonds are formed in U1 and U2 phases to enhance the bond network and strengthen alloy, while the bonding networks of in U1 phase are not only stronger than those in U2 phase, but also with greater combining energy, therefore the structure of U1 is more stable. The calculation results also show that the electron density on the interface (001) //(110) U1 between U1 and matrix of is continuous with lower strain energy so that the interface (0001) //(110) U1 is more stable, while that on the interface (001) //(010) U2 is not continuous with a greater stored energy, poor atom-matching and higher stored energy, which will lead to precipitate a new phase or form a creak to break the alloy. Key Word: -- alloy; U1 and U2 phases; atomic bonding; mechanical property -- [1 2] Cu GP β β β [2] [3 5] l-- U1 U2 [5] SSSS (, ) GPZ β (β +B +U1+U2) β( 2 ) U1 U2 l-- 200~300 [4] U1 U2 [5 8] U1 U2 ( , ); ( , , ) ; : ; gaoyj@gxu.edu.cn

2 [9 10] [11] (EET) [12] TFD [13], EET TFD -- U1 U2 4 ( 4 ) U2 β" U1 U2 β β 100 U2 (Co 2 ) [4, 14] Pnma a= nm b= nm c=0.794 nm U2 2 ( U2 [ 310] //[100] U2, [5] 001) //(010), [001] U2 [130] // U1 U1 [4] ( 2 Ca 2 La 2 O 3 [14] ) 50~500 nm 50 nm a=b= nm c= nm w()/w()=0.66 P3 m1(no.164) U1 1 [7 8] (001) A1 //(110) U1 [310] A1 //[001] U1 [ 130] // [ 120] U1 (001) A1 //(110) U1 [100] A1 // [0001] U1 1 10] // [ 120] U1 [ 2 U2 Fig.2 Microstructure of U2 cell: (a) Bond network structure in U2 cell; (b) Bond network structure along [010] 2 1 U1 Fig.1 Microstructure of U1 cell 1.2 U2 U2 [5] EET EET [12 13] s ( n a ) D uv ( nα ) = Ru + Rv β lg (1) D uv R u R v β

3 U1 U β [11 12] u v u v u v u v k1 nc + k2nc = I α (2) α k 1 k 2 u v n u c n v c u v I α [15] [4 5] (BLD) [12] n A [15 18] (1) (2), BLD ε 1 4 n c ρ α E A 1 U1 Table 1 Atomic bonding of metastable phase U1 Bond I D /nm α D /nm /nm nc nd ne nf ng ρ α /nm 1 E A /(kj mol 1 ) D D D D D D D D n H D n I D nj U1 phase: a=0.405 nm, b=0.405 nm, c=0.674 nm; atom state: ε=4, R 1 = nm, n c = ; atom state: ε=3, R 1 = nm, n c = ; atom state: ε=4, R 1 = nm, n c = U2 Table 2 Atomic bonding of metastable phase U2 Bond I α D /nm ρ α /nm 1 E A /(kj mol 1 ) nc nd ne nf ng nh ni nj nk nl nm D D D D D D D D D D D D D D n N n O np D D U2 phase: a=0.675 nm, b=0.405 nm, c=0.794 nm; atom state: ε=4, R 1 = nm, n c = ; atom state: ε=3, R 1 = nm, n c = ; atom state: ε=4, R 1 = nm, n c =3.664

4 (001) // (110) U1 Table 3 Atomic bonding of (001) // (110) U1 interphase boundary Bond I α Cell D /nm ρ α /nm 1 E A /(kj mol 1 ) D D Bond nc nd ne nf ng I α U1 Cell D /nm ρ α /nm 1 E A /(kj mol 1 ) D D D D D D D D n H D n I D nj In matrix, atom state: ε=5, R 1 = nm, n c = In U1 phase, atom sate: ε=4, R 1 = nm, n c = ; atom state: ε=3, R 1 = nm, n c = ; atom state: ε=4, R 1 = nm, n c = Interface combination state: (001) face: S= nm 2, n c = , ρ= nm 2, σ N =2, ρ min = %, σ =68; (110) U1 face: S= nm 2, n c = , ρ= nm 2, σ N =79, ρ = nm 2 ρ ρ S σ σ 2.2 TFD [13] ρ (hkl) ρ (uvw) ρ σ( ρ 10% ρ 10% ρ 10% ) ρ (hkl) (uvw) ρ (hkl) ρ (uvw) ρ TFD [13] uvw c n nc ρ ( uvw) =, ρ ( hkl) = (3) S S ( uvw) hkl ( hkl) ρ( uvw) ρ( hkl) ρ = 100% (4) 1 ( ρ( uvw) + ρ( hkl) ) 2 nc n A I A +n B I B +n C I C + S (uvw) S (hkl) (uvw) (hkl) U1 U2 U1 U2 D uv (n a ) nm BLD [12, 16] (ε 6, ε 4, ε 6) [16] 3 4 5

5 U1 U (001) // (010) U2 Table 4 Atomic bonding of (001) // (010) U2 interphase boundary Bond I α Cell D /nm ρ α /nm 1 E A /(kj/mol) D D Bond nc nd ne nf ng nh ni nj nk nl nm I α U2 Cell D /nm ρ α /nm 1 E A /(kj/mol) D D D D D D D D D D D D D D n N n O np D D In matrix, atom state: ε=4, R 1 = nm, n c = In U2 phase, atom state: ε=6, R 1 = , n c =3; atom state: ε= 4, R 1 = nm, n c =2; atom state: ε=5, R 1 = nm, n c = Interface combination state: (001) face: S= nm 2, n c = , ρ= nm 2, σ N =2, ρ min =47.856%, σ =80; (010) U2 face: S= nm 2, n c = , ρ= nm 2, σ N =40, ρ = nm [19] [14] [19] U1 U2 10 (U1 E U kj/mol [9, 20] E U1 = kj/mol U2 E U2 = kj/mol [9, 20] E U2 = kj/mol) [9] 15% U1 U2 [13] D uv (n a )

6 ( ρ A n A /D A ) n A E A E = (5) A BAFA /DA B A A b u b v F A /D B A [12] F A 1 4 U1 3 U1 (100) Fig.3 Bonding structure of plane (100) in U1 cell 4 U2 (010) Fig.4 Bonding structure of plane (100) in U2 cell nm ρ (001) // (110) U1 (001) // (010) U U1 U2 EET [13] σ N n A ρ A E A σ N σ N n A ( σ N n A ) n A n A n A ρ A U2 [16] ( 6 ) U1 U2 n A n B ρ A ρ B E A E B ( n A ()= ρ α = nm 1 E A = kj/mol) 2~3 U2 U1 U2 1 2 EET U1 n A = ρ A = nm 1 E A = kj/mol U2 n A = ρ A = nm 1 E A = kj/mol U1 U2 U1 U2 E A (U1)= kj/mol E A (U2) kj/mol(e A (U1) E A (U2)) U1 [9] U1 U2 U1 U2 5 E U1 = kj/mol E U2 = kj/mol U2 U1 3.2 U1 U2 EET [13]

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3. What would you predict for the intensity and binding energy for the 3p orbital for that of sulfur?

3. What would you predict for the intensity and binding energy for the 3p orbital for that of sulfur? PSI AP Chemistry Periodic Trends MC Review Name Periodic Law and the Quantum Model Use the PES spectrum of Phosphorus below to answer questions 1-3. 1. Which peak corresponds to the 1s orbital? (A) 1.06