Study on refine and morphology change of AlFeSi phase in A380 alloy by K addition

Aluminum-Silicon (Al-Si) alloys are one of the most widely used aluminum alloys. But iron can severely deteriorate the mechanical property of Al-Si diecasting alloy because its presence leads to the precipitation of different AlFeSi intermetallic phases which damage the ductility of alloys. Thus controlling the fraction and morphology of AlFeSi phase, especially the β-AlFeSi phase is important way to refine the ductility of Al-Si die casting alloys. In this article, K element was added into A380 alloys to study the effect of K on the morphology change of AlFeSi phase. The results show that a certain level of K addition 0.05-0.1 wt% will refine β-AlFeSi and transform β-AlFeSi phase to α-AlFeSi. In addition, K addition can better refine AlFeSi at high ccoling rates. The mechanism of refinement of K on AlFeSi phase is analyzed.

Considerations on the Reliability of Advanced Squeeze Casting Process

This paper presents an analysis of an advanced squeeze casting process suitable for the manufacturing of high performance industrial components more quickly and cheaply. After a short description of the process, some produced components are considered. The components, in A380 alloys, have been T6 heat treated and their soundness has been certified by non destructive tests. All considered components have been designed for advanced application in the automotive field, in particular for quite important sport cars. Standard samples for tensile and impact tests have been machined directly from the previous components. After the execution of the tests the fracture surface of samples has been observed by SEM in order to analyze details and to evaluate the influence of the process and of the alloy on the fracture behavior. On polished transverse sections of samples the microstructure of the alloy has been observed, highlighting a mainly globular shaped microstructure as expression of the attained semi-solid conditions during the processes. A critical analysis has been developed to evaluate the real potential and to present some criticism of the process.