Semi-solid metal casting

They transferred their 1987 patent in 1990 to Thixomat Inc. Japan Steel Works Ltd. and Husky Injection Molding Systems Ltd. licensed the technology.

[7] Thixocasting utilizes a pre-cast billet with a non-dendritic microstructure that is normally produced by vigorously stirring the melt as the bar is being cast.

Thixocasting can produce high quality components due to the product consistency that results from using pre-cast billets manufactured under the same ideal continuous processing conditions that are employed to make forging or rolling stock.

[8] The main disadvantage is that it is expensive due to the specialized billets, although facilities with in house magnetohydrodynamic continuous casting capabilities can recycle 100% of in-house returns.

Other disadvantages include support for a limited number of alloys, and in-house magnetohydrodynamic casting capability to directly reuse scrap.

[9] Rheocasting develops the semi-solid slurry from the molten metal produced in a typical die casting furnace.

In a single step process, room temperature magnesium alloy chips are fed into the back end of a heated barrel through a volumetric feeder.

A screw conveyor located inside the barrel feeds the magnesium chips forward as they are heated into the semi-solid temperature range.

The screw rotation provides the necessary shearing force to generate the globular structure needed for semi-solid casting.