Microstructural Evolution as a Function of Increasing Aluminum Content in Novel Lightweight Cast Irons

Microstructural characterization and kinetics modelization of vermicular cast irons

Several experimental techniques are used for phase identification and microstructure characterization of austempered vermicular cast irons (XRD, SEM, TEM and Mössbauer spectroscopy). Acicular structures were found to be composed by ferrite and austenite with average sizes compatible with those reported for bainitic ferrite in steels. An assessment of the free energy change involved in the auste...

Microstructural evolution in a spray-cast aluminum alloy during equal-channel angular pressing

A spray-cast Al-7034 alloy was processed by equal-channel angular pressing (ECAP) to a total of 8 passes at 473 K and the pressed samples were examined using transmission electron microscopy, differential scanning calorimetry and electron back-scatter diffraction. It is shown that the grain size of the alloy is reduced to ~0.3 μm by ECAP and the high pressures associated with ECAP lead to a fra...

Investigation of Ca in the Microstructural Evolution and Porosity Analysis of ZK60 Alloy in As-Cast and Extruded Conditions

This research work has been carried out to study the effect of different Ca contents (0.5, 1.0, 1.5, 2.0 and 3.0) on the microstructure and porosity content of ZK60 alloys. The samples were examined by using optical and scanning electron microscopy (SEM) to evaluate the modification efficiency of the alloy with different Ca concentrations. The cast specimens were modified, homogenized and extru...

The Microsegregation Pattern of Aluminum and Silicon in the Matrix Microstructure of the Nodular Cast Irons

The Microsegregation Pattern of Aluminum and Silicon in the Matrix Microstructure of the Nodular Cast Irons