Method for producing investment castings

Abstract

A method for producing investment castings, preferably in ceramic moulds, from alloys based on Al, Mg, Cu, Zn and Fe, characterised in that the ceramic mould is baked at temperatures of 800-1000° C. for 2-4 hours, then the mould is cooled to a temperature of 20-950° C. and is held at this temperature for 10-40 minutes, then it is poured with liquid alloy overheated by from 50 to 200° C. above the initial melting point and after a lapse of 10-100 seconds, the mould is immersed at a fixed or variable speed in a liquid cooling medium, which is a 1-99 volume percent aqueous solution of liquid polymer at a temperature of 15-85° C. The liquid polymer is a polymer of the PAG or PVP, or ACR, or PEO type. The ceramic moulds made of aluminosilicate, or high alumina refractory materials, especially based on synthetic sand, for example Molochite, are used.

1 . A method for producing investment castings, in ceramic moulds, from alloys based on Al, Mg, Cu, Zn and Fe, comprising:
 baking a ceramic mould at a temperature of 800-1000° C. for 2-4 hours;   cooling said mould to a temperature of 20-950° C., and holding said mould at this temperature for 10-40 minutes;   pouring into said mould a liquid alloy overheated by from 50 to 200° C. above the initial melting point and after a lapse of 10-100 seconds; and   immersing said mould at a fixed or variable speed in a liquid cooling medium, the said liquid cooling medium being a 1-99 volume percent aqueous solution of liquid polymer at a temperature of 15-80° C.   
     
     
         2 . A method for producing investment castings according to  claim 1 , characterised in that the liquid polymer is a polymer of the PAG, or PVP, or ACR, or PEO type. 
     
     
         3 . A method for producing investment castings according to  claim 1 , characterised in that the ceramic moulds made of aluminosilicate or high alumina refractories, especially based on synthetic sand, for example Molochite, are used. 
     
     
         4 . The method according to  claim 1 , further comprising:
 pouring an aluminum alloy into said mould.   
     
     
         5 . The method according to  claim 1 , further comprising:
 pouring a magnesium alloy into said mould.   
     
     
         6 . The method according to  claim 1 , further comprising:
 pouring a copper alloy into said mould.   
     
     
         7 . The method according to  claim 1 , further comprising:
 pouring an iron alloy into said mould.