Optimizing the Magnesium Die Casting Process to Achieve Reliability in Automotive Applications

Microstructure Formation in AlSi4MgMn and AlMg5Si2Mn High-Pressure Die Castings

“…Past research has shown that the large grains form in the shot sleeve and are injected into the die cavity during die filling. [17,[29][30][31] These large grains are therefore commonly termed ESCs. Figures 6(a) and (b) show that ESCs with both branched-dendritic and globular-rosette morphology are present in the samples.…”

“…The slight tendency for ESCs to be concentrated toward the cross-sectional center in Figures 8(a) and (b) can be explained by the hydrodynamic effects proposed in Reference 35, although this effect is less marked here than in previous research. [29,31,35] The difference between the volume fraction of ESCs in the AlSi4MgMn and AlMg5Si2Mn in Figures 8(a) and (b) is due to the variation that occurs from casting to casting. This is possibly caused by difficulties in the control of the process parameters, i.e., from shot to shot there is a small variation in the actual values of the temperature of the shot sleeve and plunger tip, etc.…”

“…The primary a-Al commonly nucleates and grows in the thermally undercooled regions adjacent to the shot sleeve walls and plunger tip. [17] The ESCs in this study are large relative to the in-cavity solidified grains (Figures 6(a) and (b)), due to the relatively low cooling rates in the shot sleeve (shot sleeve cooling rates are typically 10 Ks -1 [31] ). The ESCs are distinct from cold flakes, another feature that can form due to shot sleeve solidification.…”

“…Microstructure formation begins when the liquid alloy is poured into the shot sleeve. [17,[29][30][31] In this study, a liquid alloy with ã 80°C superheat came into contact with shot sleeve walls and a plunger tip that were at a temperature of~300°C and~250°C, respectively. The primary a-Al commonly nucleates and grows in the thermally undercooled regions adjacent to the shot sleeve walls and plunger tip.…”

Using quality mapping to predict spatial variation in local properties and component performance in Mg alloy thin-walled high-pressure die castings: an ICME approach and case study

“…There has been some effort to correlate Mg alloy mechanical properties directly to variations in HPDC processing parameters [26,[35][36][37]. Sannes et al [26], for example, demonstrated that changing the gating configuration of a tensile bar die produced as-cast tensile specimens that had statistically significant differences in ductility.…”