Process for producing a thin die-cast molded article of an aluminum material

Abstract

A process for producing a thin die-cast molded article of an aluminum material having a portion having a thickness in the range of 0.4 to 1.2 mm using a mold having a gate having an opening of 0.2 mm or greater and the same as or smaller than the thickness of the portion of the molded article separated from a gate portion, members constituting the gate having been treated by nitrogenation at the surface. The thin die-cast molded article of an aluminum material can be produced efficiently with excellent flow of the melted metal of the aluminum material through the gate portion.

1. A process for producing a thin die-cast molded article of an aluminum alloy for casting comprising filling a cavity of a mold with a melted metal of the aluminum alloy for casting under pressure and producing a die-cast molded article of the aluminum alloy for casting having a portion having a thickness in a range of 0.4 to 1.2 mm, wherein the  said mold has a gate having an opening of 0.2 mm or greater and a same as or smaller than a thickness of a  an edge portion of the  said die-cast molded article separated from a  adjacent to said gate portion  and members  wherein a member constituting the  said gate have been treated by nitrogenation at a surface  has a nitrogenation layer for providing improved fluidity for the melted metal of the aluminum alloy at said gate when introduced into said cavity. 
     
     
       2. A process according to  claim 1 , wherein members which have been treated by nitrogenation at a surface are used for constituting the cavity of the mold. 
     
     
       3. A process according to  claim 1 , wherein one or more porous iron members which do not allow the melted metal of the aluminum alloy for casting to pass but allow gases to pass and are connected to a passage of gases open to an outside are disposed in portions of members surrounding the cavity of the mold. 
     
     
       4. A process according to  claim 3 , wherein members which have been treated by nitrogenation at a surface are used for constituting the cavity of the mold. 
     
     
       5. A process according to  claim 1 , wherein the aluminum alloy for casting is one selected from Al—Cu alloys, Al—Si alloys, Al—Mg alloys, Al—Si—Cu alloys, Al—Si—Mg alloys, Al—Co—Cu alloys, Al—Mn—Mg alloys, Al—Mn—Fe alloys, and Al—Mn—Zn—Fe—Mg alloys. 
     
     
       6. A process for producing a thin die- cast molded article of an aluminum material for casting comprising filling a cavity of a mold with a melted metal of the aluminum material for casting under pressure and producing a die - cast molded article of the aluminum material for casting having a portion having a thickness in a range of  0 . 4  to  1 . 2  mm, wherein said mold has a gate having an opening of  0 . 2  mm or greater and a same as or smaller than a thickness of an edge portion of said die - cast molded article adjacent to said gate and wherein a member constituting said gate has a nitrogenation layer for providing improved fluidity for the melted metal of the aluminum material at said gate when introduced into said cavity.    
     
     
       7. A process according to  claim 6 , wherein members which have been treated by nitrogenation at a surface are used for constituting the cavity of the mold.  
     
     
       8. A process according to  claim 6 , wherein one or more porous iron members which do not allow the melted metal of the aluminum material for casting to pass but allow gases to pass and are connected to a passage of gases open to an outside are disposed in portions of members surrounding the cavity of the mold.  
     
     
       9. A process according to  claim 8 , wherein members which have been treated by nitrogenation at a surface are used for constituting the cavity of the mold.  
     
     
       10. A process according to  claim 6 , wherein the aluminum material for casting comprises a material selected from a group consisting of Al—Cu alloys, Al—Si alloys, Al—Mg, alloys, Al—Si—Cu alloys, Al—Si—Mg alloys, Al—Co—Cu alloys, Al—Mn—Mg alloys, Al—Mn—Fe alloys, and Al—Mn—Zn—Fe—Mg alloys.  
     
     
       11. A process according to  claim 6 , wherein the gate of the mold has an opening of  0 . 6  mm or smaller.