Evaluation of solidification cracking susceptibility of heat-resistant magnesium alloy produced by semi-solid injection molding process

New tentative semi-solid injection molding machine for magnesium alloy which was able to control solid fraction from 0 to 30% was developed. The solidification cracking susceptibility of the heat-resistant magnesium alloy containing 4% Al and 3% Ca fabricated by semi-solid injection molding and die-casting were investigated. The critical strain for solidification cracking of the magnesium alloy was obtained by U-type hot cracking test using in-situ observation method. High temperature ductility curve between liquidus and solidus temperatures were compared with semi-solid injection molding and die-casting. As result, solidification cracking susceptibility of semi-solid injection molding process with solid fraction of 25% was better than that of die-casting.