THE EFFECTS OF AGING ON THE PROPERTIES OF A RAPIDLY SOLIDIFIED AL-LI-MG-ZR ALLOY

The microstructures and tensile properties of rapidly solidified Al-Li-Mg-Zr alloys at various aging temperatures and times have been studied. delta' was the strengthening phase during aging. When Al-3.42Li-0.82Mg-0.12Zr alloy was solution treated at 533-degrees-C and naturally aged, its strength was relatively low and elongation was relatively high. The delta' phase was identified, but it was difficult to distinguish as its size was very small. When the alloy was aged at 110-degrees-C for 16 h, the strength increased but the elongation decreased as the result of much more delta' particles. When the alloy was aged at 150-190-degrees-C for 16 h, the strength was relatively high, the elongation was relatively low, delta' began to grow. When aged at 230-degrees-C for 16 h, the alloy was softened, delta' was reversely resolved. The Al-3.35Li-0.8Mg-0.12Zr alloy reached its highest strength after aged at 190-degrees-C for 8 h, when aged for 50 h, the strength decreased and the ductility increased as the result of delta' coarsening.