Table 3.
Invariant reactions in the system Al–Cu–Si and the estimated composition of the reactants.
| Reaction | T/°C | Phase | Composition/at.% |
||
|---|---|---|---|---|---|
| Al | Cu | Si | |||
| Max: L = γ0,1 + Si | 778 | L | 27.0 | 57.0 | 16.0 |
| γ0,1 | 26.0 | 72.0. | 2.0 | ||
| Si | 0 | 0 | 100 | ||
| U1: L + γ0,1 = ɛ1,2 + Si | 747 | L | 37.0 | 50.0 | 13.0 |
| γ0,1 | 36.0 | 62.5 | 1.5 | ||
| ɛ1,2 | 40.0 | 59.5 | 0.5 | ||
| Si | 0 | 0 | 100 | ||
| U2: L + γ0,1 = δ + Si | 740 | L | 13.5 | 66.0 | 20.5 |
| γ0,1 | 21.0 | 72.5 | 6.5 | ||
| δ | 15.5 | 73.5 | 11.0 | ||
| Si | 0 | 0 | 100 | ||
| E1: L = δ + η + Si | 730 | L | 11.0 | 68.0 | 21.0 |
| δ | 15.0 | 72.0 | 13.0 | ||
| η | 2.0 | 75.0 | 23.0 | ||
| Si | 0 | 0 | 100 | ||
| U3: δ + Si = γ0,1 + η | 579 < T < 730 | δ | 14.0 | 75.0 | 11.0 |
| Si | 0 | 0 | 100 | ||
| γ0,1 | 21.5 | 71.5 | 7.0 | ||
| η | 2.0 | 76.0 | 22.0 | ||
| U4: ɛ1,2 + γ0,1 = δ + Si | 679 | ɛ1,2 | 40.0 | 59.5 | 0.5 |
| γ0,1 | 36.0 | 62.5 | 1.5 | ||
| δ | 38.5 | 61.0 | 0.5 | ||
| Si | 0 | 0 | 100 | ||
| U5: γ + τ = ɛ + κ | 500 < T < 700 | γ | 5.0 | 80.0 | 15.0 |
| τ | 6.0 | 79.0 | 15.0 | ||
| ɛ | 2.0 | 78.0 | 20.0 | ||
| κ | 8.0 | 81.0 | 11.0 | ||
| U6: L + ɛ1,2 = η1 + Si | 603 | L | 60.0 | 32.0 | 8.0 |
| ɛ1,2 | 42.5 | 57.0 | 0.5 | ||
| η1 | 48.5 | 51.0 | 0.5 | ||
| Si | 0 | 0 | 100 | ||
| U7: ɛ1,2 + η1 = Si + ζ2 | 599 | ɛ1,2 | 42.0 | 57.5 | 0.5 |
| η1 | 47.5 | 52.0 | 0.5 | ||
| Si | 0 | 0 | 100 | ||
| ζ2 | 44.5 | 55.0 | 0.5 | ||
| U8: ɛ + η = γ0,1 + η′ | 583 | ɛ | 2.0 | 78.0 | 20.0 |
| η | 2.0 | 75.5 | 22.5 | ||
| γ0,1 | 24.5 | 70.0 | 5.5 | ||
| η′ | 1.5 | 76.0 | 22.5 | ||
| U9: η1 + ζ2 = η2 + Si | 579 | η1 | 47.5 | 52.0 | 0.5 |
| ζ2 | 45.0 | 54.5 | 0.5 | ||
| η2 | 46.0 | 53.5 | 0.5 | ||
| Si | 0 | 0 | 100 | ||
| U10: L + η1 = Si + θ | 573 | L | 67.0 | 26.5 | 6.5 |
| η1 | 48.5 | 51.0 | 0.5 | ||
| Si | 0 | 0 | 100 | ||
| θ | 67.0 | 32.0 | 1.0 | ||
| E2: τ = ɛ + γ0,1 + κ | 500 < T < 700 | τ | 10.5 | 77.0 | 12.5 |
| ɛ | 2.5 | 77.5 | 20.0 | ||
| γ0,1 | 18.0 | 74.0 | 8.0 | ||
| κ | 11.0 | 80.0 | 9.0 | ||
| E4: η1 = Si + η2 + θ | 500 < T < 573 | η1 | 48.0 | 51.5 | 0.5 |
| Si | 0 | 0 | 100 | ||
| η2 | 48.5 | 50.5 | 1.0 | ||
| θ | 66.5 | 32.5 | 1.0 | ||
| U11: η + γ0,1 = η′ + Si | 579 | η | 2.0 | 75.0 | 23.0 |
| γ0,1 | 24.0 | 70.0 | 6.0 | ||
| η′ | 2.5 | 75.0 | 22.5 | ||
| Si | 0 | 0 | 100 | ||
| P1: ɛ + η′ + γ0,1 = η″ | 570 < T < 583 | ɛ | 2.0 | 78.0 | 20.0 |
| η′ | 1.5 | 76.0 | 22.5 | ||
| γ0,1 | 25.0 | 69.0 | 6.0 | ||
| η″ | 2.0 | 75.5 | 22.5 | ||
| E3: ɛ1,2 = δ + Si + ζ2 | 570 | ɛ1,2 | 42.0 | 57.5 | 0.5 |
| δ | 40.0 | 59.5 | 0.5 | ||
| Si | 0 | 0 | 100 | ||
| ζ2 | 44.0 | 55.5 | 0.5 | ||
| U12: δ + ζ2 = Si + ζ1 | 557 | δ | 40.0 | 59.5 | 0.5 |
| ζ2 | 44.0 | 55.5 | 0.5 | ||
| Si | 0 | 0 | 100 | ||
| ζ1 | 43.0 | 56.5 | 0.5 | ||
| U13: η′ + γ0,1 = η″ + Si | 550 | η′ | 1.5 | 76.0 | 22.5 |
| γ0,1 | 24.5 | 69.0 | 6.5 | ||
| η″ | 2.0 | 76.0 | 22.0 | ||
| Si | 0 | 0 | 100 | ||
| U14: Si + ζ2 = η2 + ζ1 | 500 < T < 558 | Si | 0 | 0 | 100 |
| ζ2 | 44.5 | 55.0 | 0.5 | ||
| η2 | 45.0 | 54.0 | 1.0 | ||
| ζ1 | 43.0 | 56.5 | 0.5 | ||
| U15: ɛ + γ0,1 = η″ + κ | 400 < T < 500 | ɛ | 2.0 | 78.0 | 20.0 |
| γ0,1 | 18.0 | 72.5 | 9.5 | ||
| η″ | 2.5 | 76.0 | 21.5 | ||
| κ | 14.0 | 78.0 | 8.0 | ||
| E4: L = Al + Si + θ | 522 | L | 80.5 | 13.5 | 6.0 |
| Al | 96.0 | 2.5 | 1.5 | ||
| Si | 0 | 0 | 100 | ||
| θ | 68.0 | 31.0 | 1.0 | ||