Method of producing semi-solid metal slurries

Abstract

By determining an amount of a metal to be prepared into a slurry in its liquid state, thereafter applying a motion to the melted metal via a mechanical or physical means when at least a part of the melted metal reaches a temperature below the liquidus temperature and cooling the melted metal in a slurry preparing container to prepare the melted metal into a metal slurry in a semi-solid state, and by concurrently making the semi-solid metal slurry in the slurry preparing container with a shape to be kept almost unchanged, and feeding the semi-solid metal slurry in a state wherein the shape is nearly kept as it is into the shot sleeve/prechamber of the part making machine, a semi-solid metal slurry with the non-dendritic (spherical) primary crystal particles being fine and almost uniform can be fed into the part making machine, with no need of any specifically complex process but with a simple system and plain equipment. Thus, a shaped part with high quality can be produced.

What is claimed is:  
     
         1 . A semi-solid metal slurry making method, comprising determining an amount of a metal to be prepared into a slurry in its liquid state, thereafter cooling the melted metal to a semi-solid state, concurrently making the semi-solid metal slurry in a slurry preparing container with a shape to be kept almost unchanged during being transferred, and feeding the semi-solid metal slurry into the shot sleeve/prechamber of a part making machine.  
     
     
         2 . A semi-solid metal slurry making method according to  claim 1 , comprising applying a motion to the melted metal in the course of cooling when at least a part of the melted metal is at a temperature below the liquidus temperature, thereafter cooling the melted metal into the semi-solid state.  
     
     
         3 . A semi-solid metal slurry making method according to  claim 2 , wherein the motion applied to the melted metal is through a mechanical or physical means.  
     
     
         4 . A semi-solid metal slurry making method according to  claim 2 , comprising letting the melted metal flow down on the slope face of a cooling device, thereby applying a motion to the melted metal while at least a part of the melted metal is at a temperature below the liquidus temperature of the metal.  
     
     
         5 . A semi-solid metal slurry making method according to  claim 2 , wherein the motion applied to the melted metal is (derived from) the pouring procedure of the melted metal into a slurry preparing container.  
     
     
         6 . A semi-solid metal slurry making method according to  claim 1 , wherein the cooling rate of the melted metal in the slurry preparing container is 3° C./sec or less.  
     
     
         7 . A semi-solid metal slurry making method according to  claim 1 , wherein the semi-solid metal slurry is fed into the shot sleeve/prechamber from the divided face of a mold (parting surface) of a part making machine of a crosswise injection type.  
     
     
         8 . A semi-solid metal slurry making method according to  claim 1 , wherein the slurry preparing container has a tube shape with bottom close and top open or a pipe shape, comprising a thin metal plate.  
     
     
         9 . A semi-solid metal slurry making method according to  claim 1 , comprising feeding plural slurry preparing containers serially into the shot sleeve/prechamber of a part making machine, so that each slurry preparing container might reach the shot sleeve/prechamber of the part making machine just in time when the semi-solid metal slurry prepared in the slurry preparing container attains a given fraction solid.