Microstructure Properties of Rapidly Solidified Al-Zn-Mg-Cu Alloys

Table 2

The calculated weight percent (wt.%), lattice constants 𝑎_𝛼Al (in Å), and atomic coordinates of Al_0.71Zn_0.29, 𝜃 (Al₂Cu), and 𝑆 (Al₂CuMg) precipitations in melt spun Al-8Zn-4Mg-𝑥Cu, 𝑥=4, 8, and 10 (in wt.%), by Rietveld refinement.

Phase	Sample	wt.%	Lattice constant and volume; (𝑉) of unit cell in Å^3 (published)	Lattice constant and volume of unit cell in Å^3 (calculated)	(Wyckoff); Atom	Atomic coordinates
						𝑥	𝑦	𝑧
Al0.71Zn0.29; Space group: R-3M (no.166); Pearson symbol; hR3	4Cu; 8Cu; 10Cu	1.1; 2.0; 1.0	𝑎=2.852; 𝑐=6.785; V =  47.80	𝑎=2.887416; 𝑐=6.790545; V  =  49.03; 𝑎=2.916072; 𝑐=6.760643; V  =  49.79; 𝑎=2.896012; 𝑐=6.756977; V  =  49.08	Al(4𝑎); Cu(4𝑎)	0; 0	0; 0	0; 0
𝜃; Space group: 14/mcm (no.140); Pearson symbol; 𝑡/12	8Cu; 10Cu	1.2; 3.2	𝑎=6.067; 𝑐=4.877; V  =  179.51	𝑎=6.073108; 𝑐=4.862606; V  =  179.35	Al(8ℎ); Cu(4𝑎)	0.113; 0	0.676; 0	0; 0.25
				𝑎=6.093951; 𝑐=4.884749; V  =  181.40	Al1(8ℎ); Cu1(4𝑎)	0.178; 0	0.638; 0	0; 0.25
𝑆; Space group: Cmcm (no.63); Pearson symbol; oC16	4Cu; 8Cu; 10Cu	0.6; 3.8; 0.8	𝑎=4.000; 𝑏=9.230; 𝑐=7.140; V  =  263.61	𝑎=4.004232; 𝑏=9.212124; 𝑐=7.110884; V  =  262.30	Al(8f); Cu(4c); Mg(4c)	0; 0; 0	0.196; 0.694; 0.493	0.122; 0.25; 0.25
				𝑎=3.928803; 𝑏=9.176976; 𝑐=7.089059; V  =  255.59	Al(8f); Cu(4c); Mg(4c)	0; 0; 0	0.168; 0.679; 0.295	0.119; 0.25; 0.25
				𝑎=4.012201; 𝑏=9.256917; 𝑐=7.102004; V  =  263.77	Al(8f); Cu(4c); Mg(4c)	0; 0; 0	0.205; 0.709; 0.488	0.135; 0.25; 0.25