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 ascastrnmicrostructure of ingots and homogenization practice. It has been investigated phaserncomposition, volume percent of excessive soluble hardening phases and insolublernimpurity-containing phases and possible local eutectic melting in the experimental andrncommercial ingots of high-alloying V96Zr-3pch (7449-type) and V95pch (7175-type) alloyrnwith optical microscopy, X-ray diffraction (XRD), electron probe microanalysis andrndifferential scanning calorimetry (DSC). Hot workability was observed by hot compessionrntests and by hot tensile tests. It has been examined cast structure after preliminaryrnhomogenization annealing at 350-460 ℃. It has been shown that the particles ofrnS(Al2CuMg) phase and phases, containing Fe and Si – natural impurities (Al23CuFe4 a.o.)rnmay be in the ingots at certain conditions.