A contribution to the ternary phase diagrams of Al with Co, Rh and Ir

No ternary phases were revealed in Al-Ir-Rh. A ternary E-phase (Pbma, a = 2.3555, b = 1.6497, c = 2.0035 nm) was exposed around ∼ Al77Co8Rh15. The same structure was also revealed at ∼ Al77Co10.5-16.0Ir12.5-7.0. In addition, Al-Co-Ir contains ternary phases V, ε, W and D. The Al-Co-Ir V-phase and ε-phase are structurally interrelated with the Al-Rh V-phase and ε-phase, respectively. The former is formed at ∼ Al71Co17.5Ir11.5, the latter at Al76Co7.5-10.5Ir16.5-13.5. The W-phase (Pmn21, a = 2.3736, b = 0.8153, c = 2.0757 nm for Al73Co21Ir6) occupies a region inside ∼ Al73.0-71.5Co19.0-22Ir5.0-9.0 at 1100 °C and decomposes between 1000 and 1100 °C. At 1150 °C the same compositional region belongs to a decagonal D-phase, while at 1100 °C this phase exists at ∼ Al74.5Co17.5-21.0Ir8.0-4.5 and at 900 °C around ∼ Al74.5Co19,5Ir6.0.