Table 2.

Chemical compositions of different phases in the oxide zone

Region	Composition
	Ti	Cu	Al	Si	O
1 (at %)	47.82	0.04	0.28	-	51.86
1 (wt %)	73.16	0.08	0.28	-	26.51
2 (at %)	6.10	88.87	4.06	0.20	0.77
2 (wt %)	4.81	93.08	1.81	0.17	0.20
3 (at %)	85.36	2.13	2.38	0.25	9.88
3 (wt %)	91.81	3.04	1.44	0.16	3.55