Mechanical Properties of High Strength Al-Mg-Si Alloy during Solidification

Abstract

Mechanical properties of high strength Al-Mg-Si alloy during solidification have been investigated. Tensile strength and ductility have been measured by using an electromagnetic induction heating tensile machine. The relation between solid fraction and temperature was calculated by the Gulliver-Scheil model applied with the thermodynamic data-base Thermo-Calc for multi-component system, and its validity was confirmed, comparing with the experiment. Zero Strength Temperature (ZST) and Zero Ductility Temperature (ZDT) were evaluated and correlated with the corresponding solid fraction. Furthermore, the capability of the high temperature tensile test to apply to the break-out of direct chill (DC) casting was examined, comparing the breaking section of the tensile test sample with that of DC billet. Main conclusions are as follows: (1) ZST and ZDT were 893 and 883 K at which the corresponding solid fraction were 0.69 and 0.77, respectively. (2) Breaking sections of the tensile testing sample and DC billet had a similar rupture structure where intergranular fracture was observed. Consequently, it was considered that breaking elongation and breaking strength that were obtained by the present tensile test can be used as one of the criteria of Direct-Chill casting crack formation.

Effect of Iron Content on Hot Tearing of High-Strength Al-Mg-Si Alloy

“…Chemical compositions of cast billet are given in Table 1. In comparison with previously reported alloy (HS60), 11,16) Magnesium, silicon and copper contents in this alloy were decreased from 1.12 to 0.83 mass%, from 1.23 to 1.0 mass% and from 0.79 to 0.40 mass%, respectively, to reduce the hot tearing. The samples for microstructure observation were taken from the billet after casting and the crystallized phases were investigated by X-ray diffraction method (XRD) and electron probe micro analysis (EPMA).…”

“…5, the phase formation sequence during solidification comparing the solidification sequence between HS65 (present study) and HS60 (previous study), a small reduction of the content of magnesium, silicon and copper, resulted in the crystallization of (AlFeSi) prior to Mg 2 Si. 16) In order to confirm the calculated results, several temperatures were selected for the quenching test (quenched temperatures as indicated in Fig. 6) and the quenched samples were analyzed by XRD and EPMA.…”

Prediction Method of Crack Sensitivity during DC Casting of Al-Mn and Al-Mg Alloys

“…According to the previous reports, 4,5) the wider solidification temperature range causes higher crack sensitivity of the alloys. However, we found that the solidification temperature range was not sufficient to estimate the crack sensitivity, at least for A3000 and A5000 series aluminum alloys.…”

Phase Diagram of Al-Ca-Mg-Si System and Its Application for the Design of Aluminum Alloys with High Magnesium Content

“…It is advisable to alloy aluminum-magnesium alloys with silicon, which is included in a number of branded alloys (for example, 512) with a content of 1.5-2% [1,[5][6][7]. Silicon (Si) maintains a low density (it forms, with magnesium (Mg), the Mg 2 Si phase, the density of which is only 1.88 g/cm 3 [2]) and high corrosion resistance, while also increasing the hardness and casting properties of the alloy.…”