Variation improvement of mechanical properties of Mg-9Al-1Zn alloy with melt conditioned high pressure die casting

Abstract

Melt conditioning treatment via high shearing on Mg-9Al-1Zn melt was employed to disperse the oxide inclusions, and to harness the well-dispersed particles as the effective heterogeneous nucleation sites for primary α-Mg grains during solidification in high pressure die casting. To reveal the mechanism of property improvement, Prefil pressure filtration cleanliness analyser, field-emission scanning electron microscopy with energy dispersive X-ray spectroscopy and high-resolution transmission electron microscopy were employed in present study. The experimental results showed that the application of high shearing not only improved elongation, ultimate tensile strength and yield strength simultaneously, but also reduced the variation of the mechanical properties of Mg-9Al-1Zn alloy. The improvement was ascribed to the refinement of the primary α-Mg grains formed in both shot sleeve and die cavity, and to the reduction of porosity as well as refinement of Mg17Al12 phases.

Improve mechanical properties of high pressure die cast Al9Si3Cu alloy via dislocation enhanced precipitation

“…The molten alloy was poured into a pre-heated crucible at 720±5ºC and then was forced to go through a filter located at the bottom of the crucible under a pressure of 0.8 bar. Due to the blocking effect of the filter disc having very fine pore size on the solid phases in liquid melt, the particles with size above tens nanometer will not be forced through the filter and remain on the top of the filter instead [27][28][29]. After solidification, samples for analysis of the size and morphology of the particles were taken from the top of the filter perpendicular to the filtration direction.…”

Effect of Boron on the Grain Refinement and Mechanical Properties of as-Cast Mg Alloy AM50

“…An effective grain refiner of Al containing Mg alloys is needed. Furthermore, for the Al-bearing Mg alloy, there is still no commercially used grain refining technique, although several methods have been developed [10,11,12]. For instance, Zhang et al refined the grains of AZ91 with melt conditioned high pressure die casting [10], Jiang et al used Al2Y as a grain refiner for Mg–Y–Al alloys [12].…”

Rheological transitions in semi-solid alloys: In-situ imaging and LBM-DEM simulations

“…Examples include high-pressure die casting [1][2][3][4], twin-roll casting [5][6][7], and the soft reduction in the continuous casting of steel [8,9]. However, their use is often limited by semi-solid deformation-induced casting defects such as macrosegregation [6,[10][11][12][13][14][15][16], and shear cracking [11,17]. To optimize these processes and gain better control of these defects, a deeper understanding of semi-solid alloy deformation is required.…”