Microstructure, Mechanical Properties and Die-Filling Behavior of High-Performance Die-Cast Al–Mg–Si–Mn Alloy

Abstract

This work aims to reveal the relationships between the microstructure, mechanical properties and flow behavior of die-casting AlMg 5 Si 2 Mn alloy. Results indicated that the microstructure of the die-cast AlMg 5 Si 2 Mn consists of a 1-Al grains, fine-size a 2-Al grains and (Al ? Mg 2 Si) eutectic. The surface layer observed has the thickness in a range of 120-135 lm, while an ellipse-like surface layer edge is observed in the corner of the plate-like sample. Tensile strength and elongation (d) of the specimens are slightly decreased along the die-filling direction due to the backflow of melt. Pure (Al ? Mg 2 Si) eutectic layer and ultra-fine-size a 2-Al grains observed are around the overflow channels. Mass feeding is predominantly responsible for the superior mechanical properties of the round bars as compared to those of plate-like samples.

Research and Evaluation of the Influence of the Construction of the Gate and the Influence of the Piston Velocity on the Distribution of Gases into the Volume of the Casting

“…At velocity reaching the value of v P5 = 4.78 m·s −1 the crust gets torn off and has the character of random spattering, which results in larger free surface of the melt coming into the contact with gasses in the mold cavity ( Figure 5 and Figure 6 ). It creates conditions supporting the melt oxidation and gas entrapment in its volume [ 3 , 4 , 34 ].…”

“…Apart from the aforementioned difficulties, air entrapment leads to reactions of oxygen with chemical components in the melt during mold filling, where it forms oxide inclusions that can be distributed to the cast volume. Regarding aluminum casts, the metal is transferred through free surface turbulences and primarily oxidized skin comes into contact with the melt and other oxides and can form double oxide films—Bifilms—which eventually manifest themselves as channels and reduce resistance of casts against mechanical stress [ 3 , 4 , 5 , 6 ].…”

Effect of Zn Addition on the Microstructural Heterogeneity and Mechanical Properties of Vacuum‐Assisted High‐Pressure Die Casting Al–Si–Mg–Cu alloys

“…To predict the thickness of the surface layer, the die temperature during a brief moment of pressure intensification was designated as T M‐S , and the temperature was between T I and T F . The thickness of the surface layer can be calculated using Equation () [ 33,34 ] where S is the solidified thickness, h is the heat‐transfer coefficient, ρ is the density of the alloy, H is the latent heat of solidification, and t is the solidification time.…”

“…To predict the thickness of the surface layer, the die temperature during a brief moment of pressure intensification was designated as T M-S , and the temperature was between T I and T F . The thickness of the surface layer can be calculated using Equation (4) [33,34] S ¼ h…”