Evaluation of solidification cracking susceptibilities of heat-resistant magnesium alloys during die-casting using in-situ observation method

Abstract

The purpose of this study is to develop the testing method in order to evaluate the critical strain for solidification cracking of the heat-resistant magnesium alloys during die-casting. The critical strain for solidification cracking was obtained by the U-type hot cracking test using in-situ observation method. Ductility curves at elevated temperature for tentative heat-resisting magnesium alloys and commercial ones such as Mg–Al–Ca–RE, Mg–Al–Ca–Mn, Mg–Al–Ca–Sn, AE44 and AZ91D were obtained. The solidification cracking susceptibilities of these magnesium alloys were evaluated by the critical strain rate for temperature drop (CST) using these ductility curves. According to these results, the solidification cracking susceptibilities these alloys decrease in order of Mg–Al–Ca–Sn, AZ91D, Mg–Al–Ca–Mn, Mg–Al–Ca–RE, and AE44.