Structural Parameters of Partially Homogenized Ingots of High-Strength Al-Zn-Mg-Cu System Alloys

摘要

The microstructure of wrought products and, consequently its properties, depend on ascast microstructure of ingots and homogenization practice. It has been investigated phase composition, volume percent of excessive soluble hardening phases and insoluble impurity-containing phases and possible local eutectic melting in the experimental and commercial ingots of high-alloying V96Zr-3pch (7449-type) and V95pch (7175-type) alloy with optical microscopy, X-ray diffraction (XRD), electron probe microanalysis and differential scanning calorimetry (DSC). Hot workability was observed by hot compession tests and by hot tensile tests. It has been examined cast structure after preliminary homogenization annealing at 350-460 °C. It has been shown that the particles of S(Al2CuMg) phase and phases, containing Fe and Si – natural impurities (Al23CuFe4 a.o.) may be in the ingots at certain conditions.