Aluminum-Lithium Alloys: Chapter 3. Phase Diagrams and Phase Reactions in Al–Li AlloysElsevier Inc. Chapters, 20.09.2013 - 608 Seiten The formation of metastable and equilibrium phases in binary Al–Li, ternary Al–Li–Mg and Al–Li–Cu, and quaternary Al–Cu–Li–Mg alloys has been studied by using a variety of experimental techniques including differential scanning calorimetry, electrical resistivity, X-ray diffraction, conventional and high-resolution electron microscopy and 3D atom probe measurements. Al3Li (δ′) is the strengthening phase in binary Al–Li and ternary Al–Li–Mg alloys. Mg reduces the solubility of Li in Al and also substitutes for Li in δ′. The characteristics of θ′ (and θ) and T1 phases in Al–Li–Cu alloys and the composition limits where these phases are formed are well understood. For low Li contents (1.4–1.5%). Formation of T1 is promoted by small additions of Ag and Mg and by cold work prior to artificial aging. Zr forms the metastable β′ (Al3Zr) phase, which has an appreciable effect on retarding recrystallization besides providing nucleation sites for composite δ′ particles. Sc and Yb additions behave in a similar way; the added advantage is improved creep strength. The available information from phase equilibria studies of Al–Li–Cu–Mg alloys is somewhat limited, but sufficient to give an indication of the desirable solution treatment and aging temperatures and the phases formed at these temperatures. 3D atom probe studies suggest the involvement of Mg atoms in the formation of clusters which lead to the formation of the T1 phase, during artificial ageing of aging of quenched Al–Cu–Mg–Ag alloys. All these aspects are covered in detail, with specific reference to different commercial and semi-commercial Al–Li alloys, wherever possible. |
Häufige Begriffe und Wortgruppen
3DAP aging temperatures Al–Cu Al–Cu–Mg Al–Li alloys Al–Li–Cu alloys Al–Li–Cu–Mg alloys Al–Li–Mg System Al–Ti–B Al2CuMg Al3Li Al3Zr alloying elements alloys containing Alrich end Aluminium–Lithium Alloys aluminum artificial aging atom probe binary Al–Li coarsening commercial alloy composition Conference on Aluminium–Lithium congruent ordering cubic dislocations dispersoids Drits ductility ductility and fracture effect electrical resistivity equilibrium phases Eswara Prasad formation fracture toughness GP zones grain boundaries Grain Boundary Precipitation grain refinement Gregson PJ Harris SJ highangle boundaries HREM interface International Conference L12 structure lattice parameter lithium master alloys matrix planes mechanical properties metastable Mg atoms Mg content Minor Alloying Additions nucleation orientation relationship orthorhombic particles Peel CJ PFZs phase diagram phase equilibria phase forms Precipitate Phases quenched quenched disordered recrystallization Sanders TH secondgeneration alloys small additions solid solution solidus solidus temperature solubility solution treatment spinodal decomposition Starke strength strengthening phase studies T1 phase ternary system thirdgeneration alloys