Research and development of gas induced semi-solid process for industrial applications

Several rheocasting processes are developed or applied worldwide in the metal forming industry. One of the new rheocasting processes is the gas induced semi-solid (GISS) process. The GISS process utilizes the principle of rapid heat extraction and vigorous local extraction using the injection of fine gas bubbles through a graphite diffuser. Several forming processes such as die casting, squeeze casting, gravity casting, and rheo-extrusion of the semi-solid slurries prepared by the GISS process have also been conducted. The GISS process is capable of processing various alloys including cast aluminum alloys, die casting aluminum alloys, wrought aluminum alloys, and zinc alloys. The GISS process is currently developed to be used commercially in the industry with the focus on forming semi-solid slurries containing low fractions solid (< 0.25) into parts. The research and development activities of the GISS process were discussed and the status of the industrial developments of this process was reported.